DTRUONG_112

post the dyno when u get the chance man.

engifineer

Very nice. What kind of boost are you running again? Also.. when you gonna be setting me up as as test car? Sorry if I am highjacking.. just a quick question

TurboCustomz

I dont see why those numbers could not be reached. Especially if the car is running slightly on the lean side. Leaner is meaner. It might lead to high combustion temps and detonation, that would cause the ecu to pull timing, but the more you lean the car out, the more power it is going to make.

A SAFE tune might not produce as good of horsepower numbers.

I'd be interested to see the Air Fuel chart with the car on the stock ECU at even 6psi. Some people say that its a safe way to run the car but I would like to see the graph since no one has posted one.

Charles

rcruz2525

Whats up TurboCustomsz, I have not talk to you for awhile and I have the exhaust manifold gasket I promise you, call me latter.

Guys Im not trying to hide anything, my setup was put out long time ago and I did not think it was necessary to do that again.

https://www.scionlife.com/forums/vie...694&highlight=

I don’t have time to get into the discussion of why a GT35R and a t20 perform different at x amount of boost but take this in consideration.
1. The technology in the 2 different turbos is night and day.
2. Look at the map different and look at the hp each turbo makes, don’t forget the price!!
3. I have a large intercooler and a 3” exhaust all mandrel bend.

Every little thing makes difference; I don’t have a t20 so I can not tell you the hp a t20 will do in my setup.

Rick C.

Joe_Dezod

The original run was at 8.5psi. That ran us a 246whp and 257wtq number with the MAP sensor and -3 degrees. At minus 4 degrees and 11psi we hit the 272whp and 292wtq number. This was with dumping the wastegate back into the exhaust and running a conservative tune.

Our new intercooler came in today so we'll be experimenting with that. We also have the pipes being finished up today to dump the wastegate. We're exppecting over 300whp now at the same 11psi, and about 320-330 wheel torque.

rcruz2525

Hi joe_Dezod, you are running:
8.5psi and producing 246hp
11psi you are doing 272 and 292.
I guess that sounds great for the setup you have but please don’t said that by adding an intercooler you will have 300whp until you actually do it. You will probable do better than that. People here will get very easily confuse.

Rick C.

Joe_Dezod

I also said that I'd be dumping the wastegate. More than one company has claimed to have gained about 40whp from this mod alone, one company on this site, and on multiple occasions at our local place. I figure dumping the wastegate AND the nicer intercooler is safe to say I should be gaining 30whp.

paul_dezod

Tube and fin to Bar & Plate.

paul_dezod

Rick you have misunderstood. We already had an intercooler on both runs and have for the entire time. We are upgrading in style of intercooler.

rcruz2525

I decided not to dump the wastegate in my setup, I don’t like the noise. I like it fast and quiet.

Rick C.

Joe_Dezod

Yeah quiet is definately great for the street. Lot more driveable.

We're on the verge of making a race car out of our tC and want every ounce of power we can safely have.

rcruz2525

Get a J&S knock sensor, will help in the tuning of your beast.

Rick C.

Simplyscion

Hey, my statement wasnt directed towards you...it was actually towards engifineer...sorry for the confusion...setup definitely looks sweet

rcruz2525

Thanks, will keep you all posted.

Rick C.

engifineer

Everyone keep in mind that there is more to a bigger turbo than higher cfm ratings. If you measure boost at the manifold with a given valve overlap and given exhaust outlet size, raising the velocity and volume of air will raise the boost pressure. A larger turbo with a larger exhaust port will allow for less backpressure, thus more air for a given pressure (an indirect effect). Please, if someone can correct those physics in any way speak up. So the real effect in this respect is the actual physical construction. My point here is that for a given sized hole, you cannot cram more air through faster and hold the same pressure, which is where the exhaust port sizing and valve overlap come into play.

Second, if the larger turbo is running in a higher efficiency portion of its curve it will also create more power for a given pressure (Already covered, but a possible indirect cause of its different construction).

For those adding to the knowledge here and discussing, thanks. To those just blatantly and blindly trying to say I am 100% off base with no backing.. please elaborate rather than simply taking what you have read and heard and restating it. I am trying to look at this from a sheer physics perspective. I have heard more BS from "reputable" shops and sources in my life than I have good solid info, which is why I always try to understand from a purely fact and science based perspective, which many of the sources here are helping to provide. This may not be the best thread to go further on this in, but since we started....

rcruz2525

I do not know all the answers but in this particular case one thing I know is that the smaller turbo has to work harder than the bigger one. Example the t20 may be at about 20,000 rpm to produce 6lb of boost, (please don’t quote me in the exact rmp, I am just giving a scenario) the bigger turbo in this case is the GT35R may be at about 9,000 rpm to produce 6lb of boost meaning the smaller turbo needs to work harder and will produce more heat that means less dense air that equals to less power in comparison to the GT35R. Now 6lb of boost is 6lb of boost correct, NO, 6lb of boost at 80 degrees is not the same as 6lb of boost at 65 degrees. Big difference, the way each turbo gets to 6lb of boost makes all the difference in the word. Some turbos may take longer to get there and some may spool faster.

We are really comparing apples and oranges here. You have to take in consideration for the center cartridge in the turbo itself, some are ball barring and some are not. The GT35R for example is a top of the line ball barring turbo (that is one of the reasoned it cost so much) spools for ever by just turning the blades by hand vs other turbos may just turn a couples of turns. The exhaust housing also make a big different, a bigger exhaust housing will aloud more air to flow, but may take longer to spool the turbo vs a smaller housing will spool faster but will not aloud large portions of air to flow. A big turbo with a small exhaust housing may work great for some applications. And lets not forget the compressor housing in the turbo. In top of all those variables there is also the exhaust manifold pressure and the down pipe pressure. Like I said we are comparing apples with orange. Each set up is completely different from each other, hell my GT35R is not stock ether. All thing been equal you can only compare one turbo vs another in the same car.

I believe the GT35R is an excellent turbo for the scion tc, and that is base on my opinion only, I could be wrong but 260whp @ 6 lb of boost sounds good to me.

Rick C.

unlimited77

Before reading this, i thought i had my list of turbos to consdier pretty much solid, but everytime, i read more and more f/i post, the more and more combinations i am seeing. Dezod that is awesome, and i like the dumping better than having my car quiet, i live in the midwest so it doesnt matter. And Rick, 6 psi and 260whp, simply amazing.

Thanks for the info guys.

bbsciontc

Just because a turbo is rated at a higher cfm does not mean that it will send more air into the engine at a given pressure. In order to maintain 6 psi in a given engine at a particular rpm, a certain amount of air must be able to flow into the intake manifold; lets call this number "X". Now as long as we're dealing with the same engine at the same rpm, if you were to flow more air into the manifold than X, this would cause the pressure to rise above 6psi. This is a must since that air has nowhere else to go except to increase pressure. In the same way, if you were to flow less air than X, then the lack of adequate air would cause the pressure to drop below 6psi.

Efficiency comes into play when you exceed the capable flow of a particular turbo. At this point a smaller turbo would not be able to flow enough air to maintain that particular pressure in the manifold (not enough cfm), causing the pressure to drop. But 6 psi will not push the flow limits on any of these turbos, especially on a 4 cylinder engine.

I'm not claiming to be a know-it-all or anything, but I am speaking solely on a fluid dynamics standpoint.

IS300T

Just thought I'd make a comment here. I've seen this car and know the guy who is doing the work on it. It's as top notch as it gets and the reputation of the builder can't be any better. I spoke to him after the dyno and was told of the numbers.

The amount of cfm at a given efficiency is very important in this discussion. This turbo will run cooler and flow a lot more air than the smaller turbo. Now this will inherently give a little more lag, but that is the only trade off. Because the air charge is cooler and it is flowing more it will make more power. On my car I run a 67 because it outflows the hell out of the gt35r and is more efficient at higher boost levels. It makes more power at the same PSI than the gt35r, so this concept is well known.

Someone mentioned that the head could only flow so much. While this is true, I don't think that it is anywhere near capacity at this boost level. I'm not sure where that will be but I'm guessing at a lot more boost than this.

Rick, I'll be down on Thursday to pick up my car and can't wait to check out yours. I'm going to wish I had that thing after I take a ride in it, I know. It's one bad mother.

I even have a pic of your ride.

TurboCustomz

The guys at toyomoto know what they are doing. I have talked to them several times and they do high quality work. Plus they are not afraid to try anything. If you have a toyota or Lexus, you are in good hands there.

Charles