Why do people dyno their car with higher octane? [Archive]

16g-95gsx

12-07-2002, 12:34 PM

Just curious, as Josh's post reminded me. It seems to me that all the cars that use a dyno always add higher octane fuel to their car and THEN tune it. Is it just me or does this make no sense at all? Yes adding the higher octane will resist knock, but if you are tuning to the threshold anyway like I would hope you are doing, then it wouldnt make any difference whether it was on 100 or 93 octane, since you were teetering on the borderline anyway. I just find it funny that all these people always dyno their car with slightly higher octane and tune it that way, because the moment they get off that dyno and get regular gas in their car, they will begin to knock like a bitch and power will decrease significantly. Anyone here have any thoughts? Sorry this wasnt an attack against you josh, I dont want to make it out to be like that. This thought was actually brought about by my friend with his supra going to tune it on the dyno, but the owners of the shop that were going to tune it said for him to put some 100octane in the tank for the dyno day, and I argued with my friend saying hell no dont do it. Your comment just reminded me thats all.

If you are going to make power claims for a daily driver, then tune and dyno on just plain 93oct. That's my thought for the day.

GreyGT-C

12-07-2002, 12:44 PM

it's so they can get that extra few hp to brag about.....they don't realize they are gonna break their shit later......

Rguy

12-07-2002, 12:49 PM

Yup, the shops just want to get the best numbers they can so they make the owner happy and he can go brag. They really dont care about much else.

marshall

12-07-2002, 02:53 PM

or maybe they use higher octane because it's an extra safety measure while rough tuning.

HighPSI TSi Guy

12-07-2002, 02:56 PM

because they are gay..

actually the other guy was right when he said so they can get extra hp to brag about.. race gas makes pussy cars look like monsters.. i will never put race gas in my car for a serious matter. my car will be built and tuned for the pump, and everyday drivable power.

GreyGT-C

12-07-2002, 03:39 PM

i tune mine using pump gas....... and run pump gas on the street. When i'm on the track however, i run 14 gallons of 93oct and about 6 gallons of 110 oct. (it gets hot during 30 minute run @ 16-17 psi) This will be changing soon with the new fuel system allowing me to run hard w/ low amount of fuel in the tank.

Goofynick6

12-07-2002, 04:48 PM

Originally posted by GreyGT-C
i tune mine using pump gas....... and run pump gas on the street. When i'm on the track however, i run 14 gallons of 93oct and about 6 gallons of 110 oct. (it gets hot during 30 minute run @ 16-17 psi) This will be changing soon with the new fuel system allowing me to run hard w/ low amount of fuel in the tank.

You run at the track w/20 gallons of gas? That's some serious weight. I'd stick with normal octane, because the higher the octane, the harder it is to burn, and it is also cooler, thus cooling your exhuast, making spool times a little slower..etc. If you tuned it on the dyno with 93 oct, then run 93 oct...that's when it will run best ;)

Nick :dunno:

GreyGT-C

12-07-2002, 04:59 PM

i'm talking about roadcourses..not drag racing. and yeah, i run between 15 anfd 20 gallons in the car and finish a session w/ about 10-15 gallons left. Next session is 10-15 gallons ending w/ 5-10 gallons.I NEVER run below 10 gallons at the start of a session because of possible fuel starvation in the curves .I do this because i run pre-mix and it's a pain to leave, haul ass to the gas station and come back, just in time for your next session. Running the car for 11-12 seconds is one thing to do when you tune for it. Run your car wide open for 30 minutes and your intake temps are gonna be high, especially in a turbo car.

PS. i drive a rotary, one ping of detonation means its rebuild time.:mad: But with the new surge tank.....this will no longer be a concern :beer:

16g-95gsx

12-07-2002, 05:01 PM

Originally posted by marshall
or maybe they use higher octane because it's an extra safety measure while rough tuning.

If a shop ever rough tuned my car marshall I'd seriously beat their ass for wasting my money, but then again I wouldnt have someone else tune it in the first place. I would want my car to go all out or not at all.

About the 20 gallons of gas, seriously why do you do that? A gallon of gas weighs at least 3lbs if not more, times that by 20 and you have 60-100lbs of extra weight. May not sound like much, by why even run that much extra?

About the higher octane not burning as hot etc, all youd have to do is turn that boost controller up just a HAIR and it would far outshadow any downside from your original tuning. From my experience with race gas (115oct) I felt a noticable difference throughout the entire RPM range. My car was nicely tuned at that point as well, without any timing dips or plateaus, and maxing around 18*. So although at this point I dont have any hard proof to show you since I cant remember everything I have read, I would have to say that higher octane gas would most likely not hurt you even on 93octane-like tuning.

GreyGT-C

12-07-2002, 05:03 PM

16G...see above post

Jeff Taylor

12-07-2002, 08:02 PM

Yeah, you bring up a good point...tuning with pump-grade octane is probably a good idea... I wouldn't want to have to re-tune for 93 when I get back on the street.

However, running "race gas" or higher octane at the track is definitely not a bad idea. When racing without an automatic data-logger, you usually can't pay attention to your gauges, and therefore don't always know when you're pushing your car past its limit or not. I'd rather have the higher octane in the tank as a fail-safe method to prevent expensive engine damage.

Higher octane will usually not hurt your performance, nor should it improve your performance if the engine is properly tuned (so that it doesn't knock and pull ign timing). So why not run it at the track?

Jeff

bill strong

12-08-2002, 12:19 AM

I run 110 Sunoco Leaded in mine all the time now. I don't consider mine a pussy car either. There is a huge difference in power on pump gas, it will only rev to 7500 on 93 pump, but with 110 it goes right to 9600 where my max power is.

Is it expensive? I buy it by the drum, so I save a ton.
I really think you guys with air filter and big mufflers and OBD / ODBII wont have to worry about adding the max gas.

JS4KIKZ

12-08-2002, 12:35 AM

Detonation is a BITCH! Usually use 93 octane on the dyno, but on occasions, I'll do a mix. Its called PREVENTIVE MAINTINANCE

HighPSI TSi Guy

12-08-2002, 01:14 AM

Originally posted by bill strong
I run 110 Sunoco Leaded in mine all the time now. I don't consider mine a pussy car either. There is a huge difference in power on pump gas, it will only rev to 7500 on 93 pump, but with 110 it goes right to 9600 where my max power is.

Is it expensive? I buy it by the drum, so I save a ton.
I really think you guys with air filter and big mufflers and OBD / ODBII wont have to worry about adding the max gas.

man where in c-ville do you find sunoco?

bill strong

12-08-2002, 08:05 AM

$5.25 a gallon, bring your own cans...
There is a motorcycle shop on 10th street and West Main St. about a block east from the Corner.

IT IS LEADED FUEL.

HighPSI TSi Guy

12-08-2002, 01:17 PM

ah ok.. i didn't realize it was the leaded stuff.. i was thinking it was the pump stuff they have at sunoco stations that you can get for like $2 a gallon

Rguy

12-08-2002, 01:59 PM

"I'd stick with normal octane, because the higher the octane, the harder it is to burn, and it is also cooler, thus cooling your exhuast, making spool times a little slower..etc."

Have any proof of this? The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites.The compression ratio (remember, boost affects compression too) of your engine determines the octane rating of the gas you should use. The higher your compression or boost levels, the more and more you must use higher octane fuel to resist pinging or knocking. No "cooling" or anything happens at all. Tuning your car on race gas or mixed gas is BAD, when you go back to normal pump gas octane ratings your effectively putting yourself closer and closer to a pinging situation.

marshall

12-08-2002, 02:38 PM

i think doing an initial tune (ie 'rough tuning') on high octane is a good idea. especially in certain cases that are out of the ordinary. for instance if someone were to build a saturn motor for high boost, there is really no baseline for that sort of thing. so i would start out with some C16 on the dyno because you never know what you're gonna get. one mistake at 20 psi on 93 octane and you could lose some rather expensive parts.

if i were tuning my car on a dyno i would be interested in tuning on 110+ because that is what i put in the car when i race it. i'm rather uninterested in getting the perfect 93 octane tune because i don't race on the street when i would be running 93...

marshall

Rguy

12-08-2002, 03:03 PM

"if i were tuning my car on a dyno i would be interested in tuning on 110+ because that is what i put in the car when i race it. i'm rather uninterested in getting the perfect 93 octane tune because i don't race on the street when i would be running 93..."

But see, thats a mistake a lot of these stunnas just trying to make high HP numbers do. If you tune that way and just get up and leave without putting some safety measures in (retard timing, back off on boost, etc) your gonna get fucked when you refill with 93. Ping city. I know no one on this board would leave without the safety measures though ;)

JS4KIKZ

12-08-2002, 03:16 PM

:stupid:
but im not calling you stupid, Im just agreeing

16g-95gsx

12-08-2002, 08:11 PM

Originally posted by JS4KIKZ
Detonation is a BITCH! Usually use 93 octane on the dyno, but on occasions, I'll do a mix. Its called PREVENTIVE MAINTINANCE

Think about what you just said. I dont know you, nor do I know your knowledge, but seriously sit down and look hard at this post I am about to make:

If you run 110oct or whatever on the dyno, and tune your car, IF YOU ARE TUNING ON THE EDGE, meaning not just rough tuning so your car runs pretty well without any knock, but truly pulling all the power you can out of the engine (IE Higher EGT's, more timing, less knock) then when you drop the 110 you will GET DETONATION. What you just posted makes absolutely no sense whatsoever. You say that high octane suppresses detonation, right, but you totally ignored the fact that you are TUNING YOUR CAR. Therefore if you are truly tuning your car then you are tuning it for the octane that is IN THE GAS TANK AT THAT TIME! If you remove this gas, and then go back to 93octane you WILL DETONATE. There is no preventive maintenance about that. I could seriously scream at people who say that stupid ass comment but im holding back. What you say just makes no sense whatsoever, and I seriously feel you need to think long and hard about the idea of what tuning does.

Turn the boost down, tune on lower boost to resist blowing headgaskets, etc. THEN slowly raise the boost a tad, and repeat until you have hit your max. THAT is how tuning should be, and CAN BE done on 93octane without any problems whatsoever. Screw the whole "im going to protect my motor by adding 100octane in while im tuning" cause that is just BS, and you are only going to seriously screw up your tuning figures.

16g-95gsx

12-08-2002, 08:17 PM

Originally posted by marshall

if i were tuning my car on a dyno i would be interested in tuning on 110+ because that is what i put in the car when i race it. i'm rather uninterested in getting the perfect 93 octane tune because i don't race on the street when i would be running 93...

marshall

That obviously would be fine, just obviously you would want some sort of readouts so you knew where to set settings for 93octane when you are done. Having 2 fuel maps is definately a good thing. In fact I would recommend when you tune your car, getting the humidity, elevation, and the ambient air temp at that current time and keeping it in some form of log. I have begun doing this myself. It makes future tuning much easier, especially if you travel between the elevation of blacksburg and back to the 80ft asl elevation of fredericksburg

XxX

12-08-2002, 09:58 PM

Thanks god:rolleyes:

JS4KIKZ

12-08-2002, 10:08 PM

Let me clear up what I mean to say. I 99% of the time run 93 octane on the dyno. Probably twice have I put higher octane while on the dyno because I was having trouble with my boost controller and I would only boost up to 15-17. So, I would turn it up a bit. Now, if by chance my boost would creep above 22psi, I would be more than happy to have something better than 93 in my car. Now, I appreciate the information you've given me but it almost seemed like you were coming off as an asshole by saying Think about what you just said. I dont know you, nor do I know your knowledge, but seriously sit down and look hard at this post I am about to make Like I said, thanks for the info, its just the way you posted it, didnt sound like "constructive critisism".

Twelvz

12-08-2002, 11:44 PM

I made 25 more hp on higher octane
I can switch my map over to the high octane setting for the track
1 map for street 93
1 map for race race gas

*edit*
btw...for you boosted guys...if you think you can put C16 in and turn up the boost to make more power your wrong. You need to be tuned for it else your gonna loose power

Rguy

12-09-2002, 12:10 AM

thanks for that info.

16g-95gsx

12-09-2002, 12:31 AM

Originally posted by Twelvz

*edit*
btw...for you boosted guys...if you think you can put C16 in and turn up the boost to make more power your wrong. You need to be tuned for it else your gonna loose power

Very unlikely, most likely the fuel map for the 93oct will closely resemble the fuel map for the higher octane, just it will allow for less knock, and hence higher boost.

Now for JS4KIKZ, why were you only boosting 15-17? A car with your mods should easily be able to hit 18psi on the street, if you were having problems hitting that with your boost controller, then you really should run an intake leak test, etc to figure out what the problem is and fix it BEFORE tuning the car. Don't just simply bump the boost up, as if it's a leak you are just going to be blowing hotter air into the engine and running slightly richer, both of which arent good. About the boost creep issue, if you are able to hit 15psi like you said and hold it without creep, then by no means would you creep at 17+psi, as the higher the boost you run initially, the less likely creep is to occur. Try to run very very low boost and that is where creep will be experienced. With your setup though, I would think that creep would be very unlikely. And assuming you did have creep there is no reason you should be on a dyno trying to tune the car, as that is just too dangerous. At that point procedures for a better wastegate would be needed, whether that is messing with the factory wastegate or going aftermarket. Although I cant say I know any Supra guy who just simply messed with the stock internal gate.

My words came across harsh, because I meant them to. I dont mean to bite your head off but I did mean to make your comment look very stupid. There were multiple posts about how you should tune with higher octane, and by you calling it preventive maintenance and totally ignoring everything that I had said, pissed me off thats all. I know that what you said is very much more apt to damage your car than it is to help it.

16g-95gsx

12-09-2002, 12:33 AM

Originally posted by 16g-95gsx
Very unlikely, most likely the fuel map for the 93oct will closely resemble the fuel map for the higher octane, just it will allow for less knock, and hence higher boost.

I do want to point out that I am not doubting you that more tuning is needed when better fuel is used, I just wanted to say the fact that you very much can gain quite alot of power by having your car tuned for 93oct and dumping in higher octane and raising the boost accordingly.

Jeff Taylor

12-09-2002, 01:29 AM

wow... a lot of tuning experts and a lot of true assholes around here aren't there?

Rguy

12-09-2002, 02:15 AM

i consider myself a little of both.:p

JS4KIKZ

12-09-2002, 06:35 AM

Its wierd, when I run on the street, I never have a problem with hitting 20psi which is what I try to tune by, but after a few pulls on the dyno, it ends up not going past 17? I'll keep working on it

bill strong

12-09-2002, 07:30 AM

Maybe you are not having enough air flow across the intercooler, your engine is detonating, and your ecu is retarding timing or not allowing boost to get top 20.

Not knowing your setup I am just throwing ideas.

16g-95gsx

12-09-2002, 09:04 AM

Originally posted by bill strong
Maybe you are not having enough air flow across the intercooler, your engine is detonating, and your ecu is retarding timing or not allowing boost to get top 20.

Not knowing your setup I am just throwing ideas.

Something is wrong. that's for sure. If you live here in the blacksburg area I have an intake leak tester you can use for your car. It'd be the simplest way to find out. I also have a datalogger for OBD2, I dont know if your car is OBD2 as only a few 1995 car models were, but if you know you are you can use that too. The datalogger will tell if you're knocking, and the intake leak tester will allow you to quickly find any leaks you have.

I agree with Brian, I am a little of both when certain situations arise

V8BRICK

12-09-2002, 09:58 AM

Originally posted by 16g-95gsx
Just curious, as Josh's post reminded me. It seems to me that all the cars that use a dyno always add higher octane fuel to their car and THEN tune it. Is it just me or does this make no sense at all? Yes adding the higher octane will resist knock, but if you are tuning to the threshold anyway like I would hope you are doing, then it wouldnt make any difference whether it was on 100 or 93 octane, since you were teetering on the borderline anyway. I just find it funny that all these people always dyno their car with slightly higher octane and tune it that way, because the moment they get off that dyno and get regular gas in their car, they will begin to knock like a bitch and power will decrease significantly. Anyone here have any thoughts? Sorry this wasnt an attack against you josh, I dont want to make it out to be like that. This thought was actually brought about by my friend with his supra going to tune it on the dyno, but the owners of the shop that were going to tune it said for him to put some 100octane in the tank for the dyno day, and I argued with my friend saying hell no dont do it. Your comment just reminded me thats all.

If you are going to make power claims for a daily driver, then tune and dyno on just plain 93oct. That's my thought for the day.

I'll chime in with my awesome knowledge in general grand wizardry and common sense. The reason I would run higher octane in a forced induction car (with intercooler) is because you're tuning on a dyno with no real world AIRFLOW across your damn intercooler. Most dyno pulls are done in 3rd or 4th gear right? So that would mean at speeds greater than say 40mph as a low figure. Why would I want 110 race fuel in there??? Because it would be incredibly hard for some crappy walmart fans to simulate 40mph+ airflow across an intercooler. Higher octane fuel is a SAFETY precaution against detonation because you are not getting sufficient airflow across your intercooler on a 3rd or 4th gear dyno pull!! On a forced induction car with intercooler you're only rough tuning on a dyno anyway unless you can push the respective airflow across the intercooler that it would see in reality.

So yes, on a dyno:
hotter air + 93 octane = less boost and more detonation.
hotter air + 110 octane = little more boost and less detonation

Originally posted by 16g-95gsx
Very unlikely, most likely the fuel map for the 93oct will closely resemble the fuel map for the higher octane, just it will allow for less knock, and hence higher boost.

If the fuel maps are so close between the two octanes, you shouldn't have a problem running 93 octane on the street with it tuned for raced fuel on the dyno BECAUSE you now have colder air moving across the intercooler. The only exception would be on hot days, which any owner would know to watch the boost and EGT temps for signs of detonation. Now I'm sure you could get technical (enter engineers) and figure out the relationship between non moving air across an intercooler as it relates to octane ratings and figure out exactly how far you could push your street tune in relation to your dyno tune, but if you're really this serious about pushing your car to the outermost limits, it should have been brought to the dyno on a trailer.

So in conclusion, put a dyno in a wind tunnel and do all the tuning your heart desires, and lower your drag coefficient too.

Or get an air to water intercooler.

bill strong

12-09-2002, 10:08 AM

Originally posted by V8BRICK

Or get an air to water intercooler.

I have never understood why guys spend thousands on engine internals and then skimp on a non-efficiant intercooler like an air to air. Yes they look really cool sitting down low in your spoiler, but they are really not that good. Air to water is the best. But at over $1000 for a good setup it is a bit pricey, but then these are the guys that put 20 pound wheels on cars too... so that is why I never really say anything.

another good intercooler would be NOS... back in the old days of the 1980s that is what we used NOS for. It works really well as an intercooler.

marshall

12-09-2002, 10:59 AM

i think you answered your own question, air to water is expensive. it's also pretty heavy. it's complicated. it takes up a fair amount of room. it loses efficiency as you use it...

Looking at the IC core chart in my turbonetics catalog, my air to air core is 88% efficient at 20mph, pressure drop at 20psi is only 0.6 psi. seems pretty good to me.

marshall

Twelvz

12-09-2002, 11:21 AM

Rguy

12-09-2002, 11:40 AM

"another good intercooler would be NOS... back in the old days of the 1980s that is what we used NOS for."

Anyone else find this funny? NOS is a company, not a reference term for Nitrous/N20.

bill strong

12-09-2002, 11:49 AM

so is the name Hoover... ask any english person what they call a vacuum...

generic.

Rguy

12-09-2002, 12:34 PM

Excellent,ill just start referring to all my shoes as nikes even though i dont own any.

V8BRICK

12-09-2002, 12:52 PM

hmm, since he owns an MR2 I'd guess he meant to say he used NOS as an intercooler COOLER, heh heh

And maybe the reason he calls nitrous NOS is because they were the first company to provide nitrous for racing purposes back in 1978, you know, BEFORE you were born?

http://www.holley.com/HiOctn/ProdLine/Products/NOS/GenInfo/History.html

Do you call Kleenex facial tissue? Quit stereotyping people as "ignorant" and do some fucking research yourself.

16g-95gsx

12-09-2002, 04:18 PM

Originally posted by Twelvz
bullshit

maybe you missed the part where I said...if you use C16: 116 octane leaded

Actually C16 is 117.5octane

Anyway, V8Brick, on your comments about airflow. You are correct about the amount wind at 3 and 4th gear pulls, but they DO have fans as you mentioned, how little those fans put out as opposed to real life figures can't be enough to compensate the difference of 7 full octane points. There is logic to your comments and perhaps you are right as I have no real proof to argue, just going on my assumptions and you know what those do.

If you are worried about IC inefficiencies on the dyno, do this. Go by yourself a can of dust off from the local computer parts store, take it with you, and when the dyno pulls are done spray the can upside down into the IC. The stuff will come out in liquid form (-40*), which combined with the wind from the fan should definately counteract any IC efficiency variations between the dyno and the real world.

16g-95gsx

12-09-2002, 04:21 PM

Edit, misread something

16g-95gsx

12-09-2002, 04:25 PM

Originally posted by marshall
i think you answered your own question, air to water is expensive. it's also pretty heavy. it's complicated. it takes up a fair amount of room. it loses efficiency as you use it...

Looking at the IC core chart in my turbonetics catalog, my air to air core is 88% efficient at 20mph, pressure drop at 20psi is only 0.6 psi. seems pretty good to me.

marshall

Yea it's my understanding that water IC's lose efficiency quickly. Water works awesome as can be in the beginning, but they arent good for a real street application. Anyone else have anything to say on this? I have never really worked on any water IC's nor have I read too much about them, so like I said this is just going on my own current understanding.

JS4KIKZ

12-09-2002, 04:41 PM

Originally posted by 16g-95gsx

If you are worried about IC inefficiencies on the dyno, do this. Go by yourself a can of dust off from the local computer parts store, take it with you, and when the dyno pulls are done spray the can upside down into the IC. The stuff will come out in liquid form (-40*), which combined with the wind from the fan should definately counteract any IC efficiency variations between the dyno and the real world.

I was wondering about that . I usually spray my IC with water combined with the fans. (Usually use 2 fans) I suppose that the boost problem is with the boost controller itself (HKS EVC EZ) When I first had a MBC, it would jump from 10 to 17psi, then I realized that a hose would pop off. Now, the first few runs are about 18-20psi then the problems start. Im gonna change some of the hoses to SS and re-clamp some other hoses. Anyone have a good place for T-bolt clamps for my IC?? Thanks

GreyGT-C

12-09-2002, 05:07 PM

Originally posted by JS4KIKZ
. Anyone have a good place for T-bolt clamps for my IC?? Thanks

Hampton Rubber has them......they're expensive.....but worth it

GreyGT-C

12-09-2002, 05:10 PM

Originally posted by 16g-95gsx
Yea it's my understanding that water IC's lose efficiency quickly. Water works awesome as can be in the beginning, but they arent good for a real street application. Anyone else have anything to say on this? .

I agree.. If you are running low boost and have a circulatory system,OR don't boost for any duration..it *may* me ok for you. If you run the car hard and long, it's not gonna be as effective as an air-to-air. IMO , an A-W is best left to the drag strip.

16g-95gsx

12-09-2002, 05:20 PM

Originally posted by JS4KIKZ
I was wondering about that . I usually spray my IC with water combined with the fans. (Usually use 2 fans) I suppose that the boost problem is with the boost controller itself (HKS EVC EZ) When I first had a MBC, it would jump from 10 to 17psi, then I realized that a hose would pop off. Now, the first few runs are about 18-20psi then the problems start. Im gonna change some of the hoses to SS and re-clamp some other hoses. Anyone have a good place for T-bolt clamps for my IC?? Thanks

Do you know how to leak test your intake? Dont go buying better clamps thinking it will solve your problem, rather leak test your intake to find the weak spots. If you are going to do this I recommend getting a breather filter for your PCV valve and capping off the old PCV nipple on your intake.

JS4KIKZ

12-09-2002, 05:29 PM

I just need better clamps for my IC, they suck:p

bill strong

12-09-2002, 05:41 PM

I disagree.

why?

Because the intercooler must be in the airflow. Hence it is open up to damage from debris, other cars, rocks, birds, rats and plugging from lots of rubber from the race cars a head of you.
They are more suseptible to damage. You bend a fin or two and you kill flow.

Water to air can fit under the hood, does not require loads of pipe that can increase off throttle responce or lag. It has a higher flow rate than air to air, and can cool better.

Quote from Spearco's web site

There are diverse opinions about the advantage of air/liquid intercoolers versus air/air intercoolers in drag racing applications. Some say there is no advantage over air/air and they also say if there is an advantage it is offset by the added weight.

The real facts are that other than a small additional weight factor, a proper application of an air/liquid intercooler will increase power much more than enough to offset any additional weight and will always yield superior performance over an air/air unit. And, sometimes the additional weight is needed for ballast and this disadvantage is erased.

To understand why air/liquid intercoolers are superior for drag racing, consider that the cooling medium in an air/air intercooler is the ambient temperature of the outside air at any given time. If we have an engine running 30PSI boost pressure, depending on compressor efficiency, the discharge temperature will be approximately 400° , with an ambient temperature of 90° F.

Assume that you have an air/air intercooler that can give 90% effectiveness at over 100mph and less at lower vehicle speeds. 90% at the above condition will give a temperature out of the intercooler of approximately 120° F., and higher temperature out at lower speeds due to lower cooling and velocity across the surface of the core. Additionally, you are leaving the line with a hot intercooler caused by heating during burn out.

Now, consider a drag car using an air/liquid intercooler circulating ice water. The pump is turned on before the burn out and when you leave the line the charge temperature will remain more stable throughout the run and charge temperature can actually be much lower than ambient temperature, depending on the size of the intercooler. A properly sized air/liquid intercooler could easily give a charge temperature of 60° (on a 90° day!), which would be 60° lower than the air/air unit. This reduction in charge temperature not only gives a significant increase in power and torque, but also allows the use of more aggressive ignition timing for even greater increases in power.

Ait to air intercollers will also slow your car as they are not very aerodynamin. They have to be put into the airstreem. Though this looks really cool to all the 16 year old girls, it is not the way to make your car fast. But since the market wants these parts, and they are a lot cheaper, and on the street work just fine since most people only spend less than 2% of the time at WOT, air to air is what manufactures put in their cars.
But for true top speed and racing the big boyz use water to air...

http://www.bankspower.com/Banks_Sidewinder/intercooling.cfm

There is a misconception that air to air is good for the roadies... well how can you finish a race if you have a big ass hole in you intercooler, plus it can effect your straight line speed due toi drag.

http://www.autospeed.com/A_0084/page1.html
http://www.autospeed.com/A_0090/P_1/article.html
http://www.autospeed.com/A_0436/page1.html

GreyGT-C

12-09-2002, 06:03 PM

i run a screen meshing over the inlet for my IC and have NEVER had a bent fin or puncture problem. As far as front mounts.......yeah....i don't like them.. I run a under hood mount and can keep my temps only a few degrees above ambient even after 30 minute runs........i just don't think this is possible w/ an AW. Not on high boost for long durations. I'm in the boost probably 26 minutes out of a 30 minute session. If i wanted to make some soup afterwards.......an A-W may be ok

16g-95gsx

12-09-2002, 06:08 PM

Originally posted by bill strong

There is a misconception that air to air is good for the roadies... well how can you finish a race if you have a big ass hole in you intercooler, plus it can effect your straight line speed due toi drag.

Hole? WTF? a FMIC moutns in the same location that your RADIATOR DOES. WTF? Does you radiator have HUGE holes in it? No. I have no clue what you are getting at here, but talking about drag CE and holes in the IC is retarded IMO.

16g-95gsx

12-09-2002, 06:10 PM

Originally posted by JS4KIKZ
I just need better clamps for my IC, they suck:p

How do you know they suck if you've never tested your intake? I have run 20psi on my IC with regular worm clamps and they hold fine. Shouldnt be any different on your car.

GreyGT-C

12-09-2002, 06:17 PM

Originally posted by 16g-95gsx
How do you know they suck if you've never tested your intake? I have run 20psi on my IC with regular worm clamps and they hold fine. Shouldnt be any different on your car.

I blow wormdrives off on mine coonstantly....it depends on your mounting flange. My turbo to IC connection is a sharp bend (yeah yeah...i know) and the coupler bead can only be rolled about 2/3 around. I'll be using heim-joint connection rods to suppliment the t-bolt clamps from now on.

bill strong

12-09-2002, 06:21 PM

have you ever seen the front end of a car after a roadrace? I did a 24 hour at Watkins Glen back in 1988, the rad and intercooler would be filled with rubber after about 2 hours of running, we had to have someone wipe the gunk out at each pit stop. Had to use a stiff brush. We tested using a mesh grill... but temps skyrocketed due to them working great on street cars, but not so well on a race car. They did not flow well.

We tried some different methods when I raced in England on the Shelby, but we always had issue with rubber clogging up the rad and the intercooler.

I am not going to sit here and argue with you. With your vast experience at racing, or at least reading the very latest in import magazines, I doubt I can sway you. It is guys like you I love racing... cuz I normally win... no mater how many thousands of hp those BPU parts give ya

Rguy

12-09-2002, 06:30 PM

Alright bill, you make good points. But getting rubber and grime on the front of a race car is part of racing. They clean the windshields, might as well do the intercooler too. Still havent defended this statement:

There is a misconception that air to air is good for the roadies... ..... plus it can effect your straight line speed due toi drag.

or this
Ait to air intercollers will also slow your car as they are not very aerodynamin. They have to be put into the airstreem. Though this looks really cool to all the 16 year old girls, it is not the way to make your car fast

As far as my "reading the very latest in import magazines" tells me, a FMIC is placed in an area that is already susceptible to drag, ie, simply sits in front the of the radiator.

GreyGT-C

12-09-2002, 06:35 PM

so i suppose your hot water heater would be nice and chilled after a 24 hour enduro race? RIGHT!!!.. What did you do about the radiator? maybe a water to water radiator???., yeah..that would be cool..........

as far as your normally winning......i'm very proud of you. :rolleyes:

JS4KIKZ

12-09-2002, 06:41 PM

They suck cuz they dont hold very well. Want me to show them to you?

bill strong

12-09-2002, 06:52 PM

The rad for the air to water cooler can be much smaller than an engine rad. It can be mounted in front like the normal rad. But it you notice a water rad does not need as much airflow as an intercooler does.
The intercooler itself can kill your engine rads efficiancy.

You could also run the cooling rad in a air conditioned box filled with liquid. The Beast MR2 did this. It worked pretty well. Most engines have an AC compressor, might as well use it for something good instead of keeping your girl friends makeup from running.

any time you sit anything into the air flow you create drag. drag is bad.

I am sorry about those statements. I dont know you and I should not have said that. Sorry again.

GreyGT-C

12-09-2002, 06:56 PM

bill....check PM

16g-95gsx

12-09-2002, 06:57 PM

edit: so I dont get kicked off here.

16g-95gsx

12-09-2002, 07:10 PM

Originally posted by bill strong

I am not going to sit here and argue with you. With your vast experience at racing, or at least reading the very latest in import magazines, I doubt I can sway you. It is guys like you I love racing... cuz I normally win... no mater how many thousands of hp those BPU parts give ya

I edited my last post, but I will try to redo it now as I most likely would have gotten some shit for what I just previously typed.

First off asshole, I do not know you, and you do not know me. For you to fucking come out and say I have BPU parts, and make me out to sound like a fucking moron is pretty lame. I have done quite alot for the DSM community, and a few big mods have come about by me. I do all my own work, and choose every mod precisely. I took a car that was an above average daily driver, and have turned it into something that will pull about 4.2 0-60 on pump gas, and turn solid 12's in the 1/4. How in the fuck are you going to make me out to be an idiot. From my understanding you are 40 years old? Thats pretty lame that you have such a childish attitude as to make comments like you did. You would think someone as old as you would be a little more mature. Every comment I have made has had valid proof behind it, and the few comments where I didnt have defined proof I made a point to state that it was just my intuition. As for the drag CE, why dont you just stick the IC up your ass, as I'm sure there is less resistance in there.

Your comments about damage to the bumper and rad, are under extreme circumstances, that are in no way common driving. If we are talking about a true race car, then yes, that is understandable, and things will have to be engineered differently. But one thing that amazes me is that you have a race car there and yet you still run AC?

I dont wish to get into an argument with you, and that definately wasnt the point of this entire thread, but I feel that you majorly disrespected me, and it was absolutely uncalled for, especially from someone who should have much more maturity.

bill strong

12-09-2002, 07:44 PM

am sorry about those statements. I dont know you and I should not have said that. Sorry again.

I guess you missed my statement.

who said I have AC?

I love you too man

Jeff Taylor

12-09-2002, 08:21 PM

Originally posted by 16g-95gsx
I have done quite alot for the DSM community, and a few big mods have come about by me. I do all my own work, and choose every mod precisely.

Heya, so what big mods did you invent?

16g-95gsx

12-09-2002, 09:39 PM

I was the first to ever perform the Supra SMIC mod, which now is very very big to name one.

Jeff Taylor

12-09-2002, 09:53 PM

cool! My ex next door neighbor (Derek) did the same thing to his 1G DSM last year...seemed like a good idea

16g-95gsx

12-09-2002, 10:14 PM

Yep, I was the first one to ever come publicly out and tell about the mod (I was actually the 2nd to perform it, but I only found that out after the fact, because the original person kept it a "secret", although after seeing how he did it his was a very huge hack job and poorly done IMO, but like I said I was the first to ever say "here guys, this is a good swap, do it like this" etc) And yes, there are tons of DSM's with them now. The mod has been known to drop ET's by up to .3 in some cases (obviously a very good setup), and it is a very very inexpensive alternative to a FMIC.

ToyotaTechGeek

12-10-2002, 01:08 AM

now, now boys...
play nicely. you guys get your panties twisted in knots too easily. BTW: Carlos Sainz won WRC championships with a WTA IC.
the geek
p.s. you don't know bill either.

16g-95gsx

12-10-2002, 07:44 AM

Originally posted by ToyotaTechGeek
now, now boys...
play nicely. you guys get your panties twisted in knots too easily. BTW: Carlos Sainz won WRC championships with a WTA IC.
the geek
p.s. you don't know bill either.

You're right, I dont, notice I didnt childishly come out with the personal attacks until I was personally attacked. Personal attacks are too low for me to use in most cases, I usually just stick to facts.

Not Registered

12-10-2002, 09:04 AM

Wow, I missed a good argument.

blackFa5

12-10-2002, 02:10 PM

I use higher gas on dynos cuz the cars in japan use higher octane, therefore it makes my shit more jdm yo.

just kidding, i rather know what hp i was making on everyday gas than a once in a while type of thing

Mr.2

12-10-2002, 08:37 PM

Originally posted by ToyotaTechGeek
you don't know bill either.

Yeah, you have to have met Bill and you have to know what he's done for the automotive comunity in general to know what your dealing with.

ToyotaTechGeek

12-10-2002, 09:20 PM

hey matt-
haven't seen ya around!

anyway, about this argument...
boo
the geek

16g-95gsx

12-10-2002, 10:12 PM

Originally posted by Mr.2
Yeah, you have to have met Bill and you have to know what he's done for the automotive comunity in general to know what your dealing with.

And I care why? I dont think you guys understand here, I was attacked personally BEFORE I ever attacked him. Bill could be the queen of england at this point and I wouldnt care, he was wrong to do what he did and I felt I should be able to defend myself.

ToyotaTechGeek

12-11-2002, 07:09 AM

i'm trying to figure-out where an 'attack' was made. you guys should meet at a track somewhere and hash-out your differences. it's only way...
the geek

ToyotaTechGeek

12-11-2002, 07:19 AM

okay, so i went back again (and was reading ) and the closest thing i could find was the reference of a 16 year old girl and loving to race guys who think all of the bolt-on parts and make crazy hp figures think they're fast. i also think the one comment about the latest ragazine readers might have offended. all-in-all, not that i'm the one it matters to, there's nothing offensive in nature. just balls-out talking. one thing i will say is that the majority of 'sport compact enthusiasts' don't have much respect for venerable members of the already established import community (those there prior to the early-to-mid 90's craze) or to others. this is just an observation. and another thing: when you get so visibly upset at something someone says, it makes you look like a total defensive fool who knows he's wrong. not opinion, just a psychological/behavioural fact. this includes name calling, cussing, and getting all inflamed. now, if you argue back in a nonchalant way based on scientifically (or otherwise) proven fact, it's described as a debate. just take it for what it's worth.
the geek

marshall

12-11-2002, 08:06 AM

"all-in-all, not that i'm the one it matters to"

ok then, shut the fuck up about it.

16g-95gsx

12-11-2002, 08:15 AM

OK, Dan close this thread or something. It has gotten so far off of topic it isnt funny. Bill just tried to make me out to be an ignorant person in one of his posts, he apologized, but I felt I deserved my shot, I took it, others feel they should add their 2 cents in which I really couldnt give a shit about cause I still know that bill was disrespectful first and yet you guys refuse to see and admit that. But this all has absolutely nothing to do with dyno tuning, and I do wish this thread to end now as it is no longer useful to anyone.

MKNTRAXX

12-11-2002, 08:19 AM

ToyotaTechGeek.... And it amazes me that for the fourth time you have brought absolutely nothing constructive to the discussion.

I think it works to put higher octane in so you can make the most of your dyno time. Say you are using just 93 octane and you go to dyno.. First pull you start at a bit higher boost... Get up to about 5500 RPM and your A/F ratios just spike or start to.. you notice it right away and have time time to back off the gas before anything goes wrong.

but now you just wasted that pull pretty much... You make your adjustments to your AFC and check your data logger(wish they worked for my car), and make another run and hope its enough and can make a full dyno.

I see that as a reason.. if you had high octane in.. you probably could have made a complete run in,maybe not.

I see high octane as something good to use for people running stock bottem ends, meaning not forged pistons mostly. People that mighty need that extra safety.

All depends on people preferances and what they want.. I don't know how close to the edge i would want to try to push my car on 93 octane.

I understand you guys with data loggers can tune your car closer to the edge, but you can also keep much closer track on whats going on, then the rest of us.

I am glad to have found this thread, as i am starting to get to the point where all this information is useful to me and how i proceed with my car and its tuning/building. This is helping me greatly, though what little i put in is just from my very in-experianced view at this time, so take it with a grain of salt if you wish.