Taking a Stock Engine with Stock Turbo to the limit....

murphster

Well-Known Member
Joined
Feb 15, 2003
After contemplating this for a long time and having some debates about how to make the most power on a stock turbo, I've taken the leap and put together a stock engine to use with a stock turbo to see how fast I can go.

My car should be more than capable since it has all the supporting driveline, suspension, electronics, weight reduction, etc. Its more an exercise of how much power its possible to make and put down with better engine management, torque converters, tires, suspension, etc. My current motor with aluminum heads, big cam, etc wasn't the best match and is nothing near stock so I decided to go with a stockish engine instead.

I found a 109 engine local with stock pistons, rods, and uncut stock crank. At this point I figured might as well keep it as stock as possible and got my hands on some stock heads (with replacement valve springs) and also a stock cam setup. A stock intake was put on and a stock plenum and tb are ready to go on. While this is obviously not an unopened engine I did try to keep it as stock as possible. The only things not stock on the engine are a power plate and Felpro 9441 stock replacement head gaskets with ARP bolts. I have a stock turbo in excellent condition ready.

I will be using the exhaust and intercooler that were on my car, TA race headers with 3.5" external gate DP and a Cottons FMIC. I don't think the heads help any at this power level but I already have the external wastegate plumbed off the headers and want to use an external gate to control boost with CO2, plus I have various sensors all set up for logging. I want to keep the large IC to get rid of any restriction or pressure loss off of a stock IC to get the most out of the stock turbo. So this will be stock heads/cam/intake/turbo but not stock IC.

So the engine is primed and timed and should be going in pretty soon. Here is the list of the rest of my combo I will be using with this setup:

- XFI engine management with lots of data logging
- TA race headers, external wastegate, 3.5" DP, thru 3" dual exhaust
- Cottons FMIC setup
- TR6 ignition
- TH400 with PTC converter, tbrake, 3.23 gears
- full race suspension... TRZ front control arms, Baseline Susp w/ solid rear control arms, TRZ anti roll bar

The goal is to see how fast I can go on this setup with the stock turbo. If I can get the 60fts down and can get in the neighborhood of 400rwhp then the stock turbo record of 11.37 could be within reach.....

Any comments will be appreciated as this will be a work in progress throughout the year. Pics to follow.
 
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I never hear of buick guys experimenting with pre-turbo water injection, but in the import community it is known to shift the compressor maps slightly to the right.
 
Not sure what your goal is but It cant be too high with the stock turbo and heads. Stock crank flexing is issue as well when beating the shit out it.
 
I never hear of buick guys experimenting with pre-turbo water injection, but in the import community it is known to shift the compressor maps slightly to the right.

I am aware of the technique and how its supposed to help. I think Buick guys always had larger turbos available and its common to upgrade the turbo so pushing turbos to the limit wasn't an issue. I'll use any trick I can though, thanks!
 
Not sure what your goal is but It cant be too high with the stock turbo and heads. Stock crank flexing is issue as well when beating the shit out it.

Oh, won't be any beating of the crank here with a stock turbo and stock heads. It won't see over 5000 rpm either and will be closely monitored for knock. It will probably see less stress than most setups.

As far as a goal, I mentioned that in the post.... around 400rwhp. But who knows.
 
Oh, won't be any beating of the crank here with a stock turbo and stock heads. It won't see over 5000 rpm either and will be closely monitored for knock. It will probably see less stress than most setups.

As far as a goal, I mentioned that in the post.... around 400rwhp. But who knows.


Last year at a local track outing ... a stock 150K mile TTA went 11.90 @ 112 on a stock turbo, unopened 150K mile motor, stock trans including D5, upgraded valve springs, pump, chip, airbox removed , on DR's . There was more left in the car as far as the power .. but traction and wanting to drive the car home were the limiting factors to going faster.
I'm sure it had a 11.7x in it all in .. the air wasn't stellar on the 11.90

Now Dump 250 pounds out of the car, add in a drag suspension , on a great track prep .. im sure it would get in the 11.3x range

I think your goal is very doable .. just will take a lot of tweaking and seat time to get it done .. the thing I think you have in your favor is the suspension... the thing I think you have going against you is the TH400
 
Agree, that 400 is going to hurt some

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the car its going in currently is only just over 3000..with the driver


should be a slam dunk then .. if your just trying to beat the 11.37 and the qualifier is stock turbo .. its pretty easy when you shed 600 pounds off a car
 
Last year at a local track outing ... a stock 150K mile TTA went 11.90 @ 112 on a stock turbo, unopened 150K mile motor, stock trans including D5, upgraded valve springs, pump, chip, airbox removed , on DR's . There was more left in the car as far as the power .. but traction and wanting to drive the car home were the limiting factors to going faster.
I'm sure it had a 11.7x in it all in .. the air wasn't stellar on the 11.90

Now Dump 250 pounds out of the car, add in a drag suspension , on a great track prep .. im sure it would get in the 11.3x range

I think your goal is very doable .. just will take a lot of tweaking and seat time to get it done .. the thing I think you have in your favor is the suspension... the thing I think you have going against you is the TH400


TTAs have a definite aerodynamic advantage so they will always be faster than a regal at the same hp.

Why do you guys think the TH400 is going to hurt much, the 1st gear ratio difference? As far as overall power losses, could be some but I prefer the rmvb in the 400and the consistency. I've been in the 11s on a stock turbo before with a TH400 and a 2004R so I don't know if it hurt too mich.
 
should be a slam dunk then .. if your just trying to beat the 11.37 and the qualifier is stock turbo .. its pretty easy when you shed 600 pounds off a car

He may have started with a 3300 lb car like mine, with the only power options being the one under the hood.
 
Cool thread. What's the fuel going to be?

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