lt1 T56 seems to lack power, add mods? look for problem?

[bigballinzx]

Let me start this off by stating that I am definatley not a mechanical genius. My z32 with LT1 / T56 doesnt seem to be reaching its full potential of even half of its potenital. The 94' Forumla LT1 engine is slightly modified with headers, full dual 2.5" exhaust with no cats and intake but I can hardly break my tiny 8" wide tires loose in 2nd gear. I know something isnt right so I took the car to a guy that specializes in building very reputable chevy race engines and he was dumbfounded. Engine doesnt skip, starts right up good spark, revs up very strong, fuel pressure at 40 psi, idles perfect at about 900 rpms cant figure it out. The only thing he could suggest was build a bigger engine if I want more power. At this point Im getting pretty pissed I take 3 YEARS to build this car and it feels like Im driving a V6. Now that its summer I dont want to pull the engine to have work done which will cause large amounts of down time so I am looking for alternative routes for until winter. I was thinking of installing the LT4 kit available in summit racing for $2500 which says it will produce 425+ horsepower althought expensive very easy to install. At this point I just want to go fast so please dont hesitate to make any suggestions. I appreciate it a ton.

[typhoone]

how much power are you theoretically putting down?

[bigballinzx]

The LT1 enigne is 280 ehp stock. I have deleted the AC system, added BBK headers, dual Borla 2.5" exhaust h pipe w/ no cats, belt underdrive pulley kit, mini altenator, airfoil, BBK C5 Corvette intake, larger radiator + high cfm fan. I havnt dynoed but I have owed quite a few z32's and it almost feels like the torque of a NA z32. With the mods I had done I was hoping for about 335-350 eho and 300hp at the wheels

[TheNeedForZ]

Cam lobe worn off ? Good spark is good but what about timing?

[Meaty69Maro]

It probably would not hurt to throw it on the dyno and diagnose it through the RPM range.

 

As far as performance mods...I'd say put a nice stout cam in it. Your goals of 300rwhp can be easily reached with a well tuned/bolt on LT1.

[Z48LT-1]

It would be instructive to datalog it, to determine, for instance, whether the knock sensors are retarding the ignition, which would explain everything.

 

Cheers -- Gary

[280zwitha383]

The only thing he could suggest was build a bigger engine if I want more power.

 

Did he drive it and then tell you that? You need to figure out what's up with your current setup. Throwing heads and a cam won't do you any good unless it is a mechanical problem. I doubt the cam is wiped because they're roller lifters (aren't they?) and you would probably hear some chatter if something gave. Do you know anyone who could help you or maybe someone on here is close. Something simple is probably wrong with it.

[mark]

Do you have any codes set? A bad knock sensor will retard the timing. Also, You figure 280 hp at the flywheel plus bolt ons, say they add 20 hp thats 300 at he crank, 15% parasitic loss get you 255 at the wheels. Not a world beater for sure.

 

Put it on the dyno, data log it and go from there. DO NOT throw parts at it until you know where you are to start with and you are sure everything is working correctly.

[Guest reddeth]

Well, sweet, first post for me

 

Having owned a 96 Impala, I'm no stranger to the LT1, and the main thing I always find with engine problems is (if you're running the PCM for it at least) issues with the computer rather than the motor itself. I'd say add in a nice cam (the LT4 Hot Cam is very nice, you loose a little bit of torque that the LT1 has stock on the bottom end, but as light as the Z is I doubt it would be noticeable), anyways, get any mods you want done, then take it to a dyno shop that can reprogram PCM's. Or send it to http://www.pcmforless.com and make sure you list out what mods you have.

 

Just my 2 cents.