Here’s the Dyno sheet and Video. Looks like it’s running really rich and I’m thinking I can run more boost.

Here’s the specs on the car from by boosted listing:

Block: 355ci LT1 Splayed 4 bolt mains
Compression: ~9.0:1
Oiling: Stock
Crankshaft: Eagle 4340
Connecting Rods: Eagle H-beam
Pistons: Diamond 30cc dish
Cylinder Heads: Ported LT1
Camshaft: Comp Cams 224 / 224 .528/.499 115
Rocker Arms: Stock
Intake Manifold: Ported LT1
Ignition/Computer: Stock
Exhaust: Stock
Cooling System: Stock
Fuel-Pump: Racetronix Walbro 255
Injectors: 42lbs
Rails: Stock
Turbo: T04E 60-1 (STS) (currently running 8.5 lbs but good for 15)
Tune: Madz28 (about to update)
Rear end: stock 3:42

I was hoping to make 450 Horsepower, but I came up way short. I drive the car everyday, so wanted a conservative tune. How much boost do you guys think I can run? Any other suggestions?

I know a lot of people don’t like the sts turbo, but I’m committed at this point.

 

It appears to be running rich. I say another trip to the dyno for custom tuning is in order.

 

Are you sure about the compression ratio? I have a 22cc dish and .010 off the deck and my CR is 9.2. If your block hasn't been decked maybe you are closer to 8.5 to one.

It is a little rich. Anyone want to chime in on what one point of AFR might add to his power.

How are the exhaust flow numbers on your head? The stock IE is 69% IIRC. If the porting job helped the intake flow more the the exhaust flow thats not really optimum especially with the single pattern cam you've chosen that has less lift on the exhaust side. Ideal is a IE of 75-80% on an FI motor. Also on the exhaust side you might want to switch to headers, I have the edelbrock TES and no they aren't long tubes but I have had one leak in 7 years AND I bought them used. You may give up a few ponies and torque but they seem very reliable for everyday use.

What are your IAT's like and how much timing is in it?

 

You really need to get an AF reading. A bone stock motor should make that much if not more on 8.5psi.

 

Yeah, the A/F got you. You could have a 8.0 A/F and the meter would still output 10.0, so you dont how bad it really is yet. It is a load bearing dyno right? That should spit out lower hp numbers anyway. Get the A/F fixed and you'll be in good shape. Get the A/F to 11.0-11.5 on the load bearing dyno and that should be good for you.

 

It is way rich, I bet you see a lot of black smoke out of the exhaust!

 

Sorry didnt realize the AFR was on the second page of the pdf. Yea the wideband will stop at 10.0 so I'm sure you are way low. Is the computer even tuned for the big injectors? That will definitely kill your hp.

 

I’m really kind of guessing at the compression ration. The stock head was ported and polished with some bowl work. So using the stock 10.4 c/r and volume as a starting point and calculating from there. It’s very possible I calculated it wrong.

I don’t have numbers for the head. They were done at the machine shop I’ve used since I’ve lived here in California. Not sure what the IAT is, the car does not have a FMIC.

As for the cam and headers, I did a lot of research on this board and talk to several of the aftermarket manufacturers. I actually have a set of SLP mid-lengths that I didn’t install based on what the STS people told me. Looking back at this project, I might have done a few things differently, but what’s done is done.

It’s suppose to have a .5 bar spring in the wastegate, that equates to 7.25 psi. It seems to be making 8.5 which equates to a .6 bar spring.

I’m thinking about moving the boost to 10 psi then going for a custom tune to the get AFR in order.

 

RealQuick:

I'm not sure if it's a load bearing dyno or not, I'll call JBA this morning. The guy getting out of the car told me that the AFR was closer to 9:1.

RagTop95 / 97s10ondubs:

It's not blowing any black smoke and there is a tune that has the injectors set at 42.

 

Well get a better tuner and get that AFR sorted out. If you want to throw more boost at it that's fine, but I'm guessing that it will make another 50rwhp easy if you get the AFR fixed at 8.5 psi. Either way you need to get it tuned by someone with some knowledge on lt1 tuning.

 

Lots of fuel coming out the back. Tune it and see what happens.

 

Thanks guys, I appreciate the input.

 

I'd look at getting some Comp Cams 1.6 RR for that setup also and springs if you need them. They should help the lift as the numbers look low for that cam.

 

Throwing boost at a fat running car won't fix things. I agree, get it leaned out, and the power should come to where you wanted it to be.

 

I agree that more boost isnt the answer, especially on a car without an intercooler.