I was very dissapointed with the number I put out. 346 built with 6.0 heads and a custom turbo cam wit 8.7 lbs of boost, 405 hp and 420 torque. this is on a 2002 Camaro. What could be the problem?

 

Could be anything.Probly not enough boost.

 

eek, whats the tune look like?

have a printout of the dyno?

most make more than that on a stock motor at 5psi.

 

Intercooled yet?

 

I made 425 rwhp at 5 psi on the stock motor, so something is definitely not right. But, we need more info. What did the a/f look like? What compression is the motor? That's at least a start.

 

The motor im running is at 8.8:1 compression. Im running 6.0 heads and a custom turbo cam, 223,225,115+4. Im not running an intercoller, and I have the stock 60-1 turbo. Im guessing that my problem might be a boost leak, but my guage reads that im getting 8.7 lbs of boost. Ill try to post my dyno sheet. The motor that I had put in was built by HPE.

 

where are you reading the boost at?

 

Tuning OR FUEL is probably the issue. I capitalized the latter as this is the "strange" problem I am working through. The tune (too rich or too lean) will murder the HP a lot. In my case the 42lb injectors aren't enough at boost to make up for even 5PSI + cam + LT headers. The result is I had long term fuel trims being added by the PCM on it's own after tuning. Found this out when the freakin car only made 371RWHP at the dyno. My friend turned off the fuel trims with HP tuners to test the theory out and the car instantly jumped to 426RWHP (that's a 55HP gain from a keystroke!) Anyhow, can't do that permanently, so I'm adding a boost referenced fuel pressure regulator (which also requires some moddng of the fuel system in general....but that's another topic.) Then the car will get enough fuel at WOT to not be adding long term fuel trimming....and I'll probably be in the 450+RWHP range. This is on 5PSI with a FMIC.

So...tuning and lack of/ too much fuel could be the problem....and probably IS the problem. You need a laptop and a wideband hooked to the car on dyno pulls to see what exactly is going on. I thought I was getting plenty of fuel with 42lb injectors and a 255gph in-tank pump + hotwire kit. Well, no I'm not. I'd also never heard of other STS users switching to boost referenced FPR's.....but a lot of front mount guys do. Makes you think.......

Also make sure that everything's hooked up right and you are not sucking oil into the intake piping. Sucking oil into the intake pipe and setting off the oil buzzer are NOT one in the same thing. Did that once....and the MAF had oil on it. The PCM then pulled massive amounts of timing which of course murdered the HP.

Anyhow, you have TONS of potential with the described setup. Working the bugs out is a frustrating process (welcome to FI ), but with patience and a scientific approach you'll find the prob (or problems)......and the car will be smokin fast after. Good luck and hope this helps.

 

There's your problem....

time to T76

 

who is tuning your car? I might be in the san diego area this weekend, maybe I can help you out

 

did you guys notice his CR was 8:8:1??? crank it to at least 12psi... your compression ratio was way low

 

I made 383rwhp and 378rwtq naturally aspirated on my 8.1 compression motor.

 

What is the most amount of boost I can run with my compression at 8.8:1 with a stock fuel pump from a 2002 ls1. Right now im getting enough fuel.

 

You are out of pump or injector. Get a drop in walbro and 50# injectors and retune the car.

 

cant 76 an STS with a 346... I dont think its fuel either... I think its the low compression engine, heads (even lower compression).... I would even say 60# injectors... get a walbro 255... intercooler... get your 60 turbo reworked to a 67 or 70 (Dont remember how big you can go) and crank the boost up to 15lbs...

I think you could do 15 lbs on 93 octane with a 67 (8.6:1 CR) and see 650-700 RWHP... But I am no expert.

 

longrange4u... whats the difference when you say in your sig 60 trim and 67 trim? is that the 60-1 and you upgraded to a 67-1? (I'm not a turbo guy but i'm learning)

 

Wheres the dyno sheet John?

 

He up graded to a 67

 

I made 475 rwhp on the 60-1 (at 8psi). The dyno graph wasn't pretty, but it made that #. You have a couple of limiting factors in your setup though. As you start to up the boost, without an intercooler, you're not going to see the gains you should see. Do you have any record of what your IAT's were on the dyno? And you definitely don't want to go to high on the boost without upgrading the fuel system. I didn't notice anywhere...what size injectors are you running?

 

Where is the boost gauge getting its refeence from (the compressor cover or the intake manifold)? If your getting it from the compessor cover (turbo) then you could have a leak somewhere between the turbo and throttlebody. If you are getting the reference at the intake manifold, then your definitely getting 8.7psi.