HerNameIsSway

Hey guys,

I have a stock factory supercharged MR2 motor in my RWD Corolla and I was wondering the pros and cons of installing a turbo with this setup.

I'm not looking to do any tweaking, I just want to know how it performs in daily driving, such as wear and tear and gas mileage if I just drop in the turbo setup.

I heard that a turbo has to kick in over 3500 RPMs and it's just dead weight under the hood if you're cruising under said RPMs.

I found a good deal on a turbo package and I thought I'd grab it, but I want to know if its worth it or not.

Any help I would really appreciate. Thanks!

musicmaniac

pro:
show

cons:
expensive
waste of effort
hard to tune

HerNameIsSway

I was hoping to get more info on the technical side of having turbos on a SC setup engine. I was hoping someone have some kind of data or proof that Turbo increases or decreases gas mileage or something.

You said the cons:
Expensive
Waste of Effort
Hard to Tune

What if I got a turbo setup for ridiculously cheap? (which I did)
What if I thought its a simple bolt-on with everything in my hand (entire turbo setup I found for sale for cheap)
I'm not looking to tune it as I drive it over time. I'm not a tweaker, I just want to put it in because it has some good HP gain.

Fabrik8

You're not getting better gas mileage by putting more power out, that's not the way an engine works. The only way you would get better gas mileage is if you somehow go from a poor efficiency area without the turbo to a better efficiency area with the turbo, and that would be very rare.
Why are you worried about that though, you're trying to gain power, not gas mileage.

So here are the basics. A twincharged setup usually doesn't put out the power that the two units together should put out, because of efficiency and parasitic power losses. There are two ways to do this, with or without a clutch controlling the supercharger, and there are arguments for both. Using a clutch is much more complex, because there are generally multiple paths for the air to travel, and some people use extra throttle bodies to bypass the turbo or the supercharger. A clutched setup gets rid of the parasitic drag of the supercharger when the clutch is disengaged though, which is a nice bonus. Usually this setup feeds the supercharger through the turbo, like the production VW TSI setups do.
Going without a clutch is easier, and everything is different. You're now feeding the supercharger with the turbo, so it's as simple as bolting a turbo kit on to a supercharged car like yours. You really need some good tuning though, and you still don't have any way to get rid of the supercharger heat because that heat is created after the intercooler. This isn't a project to take lightly, but it can be done. I think you should do it; you've already got an engine that is perfect for that and built for boost. Why not?

Please make sure you research this a lot though. I think that the 4A-GZE has a clutch on the supercharger already, I don't know if that will be a problem. I don't really know what the intake path in that engine is like or what sort of bypass arrangement it has.. There are a lot of small details that you should look into though, and many problems you may not think of. So do your homework before rushing into this.

Newbsauce

You should probably do some research on turbos, AR size, and general principles before going off "what you heard" from whoever told you the info above. He obviously knows about as much as you currently do. Here is a good start:

http://www.turbobygarrett.com/turbob...ch_center.html

HerNameIsSway

Im good with NA motors but FI motors is something I have a LOT of learning to do. My GZE swap was done in January and I still dont completely understand how you can work with it.

My GZE runs about 30MPG highway and I dont want to install a turbo if it's gonna drastically worsen the MPG. I dont care if it betters it. I just dont want to install it and find out that I run less than 23MPG with it or something like that.

Someone is selling a Greddy td-05 turbo along with all the hard parts to install on my 4agze for under $700 and I thought that's a great deal, since turbos sell for over $1000 most of the time and other hard parts are included in the same price.

I wasnt looking for turboing my car until I found a great deal on a kit. Thats why I was looking into it, and I just wanted to know if its worth it or not.

This is my engine setup right now, in case you guys have questions I may not be able to answer...

CarsRFun

Wheres the blower in those pics?

HerNameIsSway

Its on the passenger side of the motor under the intake and IC pipe.