I could really use some advice and info. My car is running horribly to the tune of 237 RWHP with the following mods:
LT4 Heads, LT4 HOTCAM, LT4 intake manifold, bbk 52mm throttle body, SLP 1 3/4" shorty headers, corsa cat back, random cats, k&n intake, 28 # injectors, vigilante 2800 rpm stall converter and a transgo shift kit.
The car has been incredibly slow and stock auto LT1's with no mods blow it away. The car was put together by a competent chevy mechanic who deals mostly with vettes and f body blowers. The cam postition is true, fuel pressure is good, individual injectors are good, vacuum is good, oil pressure and temp is normal all the right parts are there the car just doesn't make the hp. We have gone through 3 fast chips sent by Pace parts who we bought the conversion from and all have failed to do anything substantial.
Does anyone have any ideas as to what the problem could be, it is most likely the computer and the car is currently at More Performance to hopefully get everything ironed out and that is a long way from St. Louis, MO.
Is the LT4 package just a horrible combo or are there really people out there who make some respectable HP with it. Any help would be greatly appreciated.

Thanks,
Mike

 

Looks like you are down about 100HP from where it should be. That's a BIG problem, and not likely someone taking a random guess on a bulletin board is likely to stumble on. Let More figure it out - they claimed 429flywheelHP on an LT4 conversion...... well they forgot the mention the $4,000 MoTeC computer and a few other items, but obviously they claim to know all about the LT4 package.

No.. it isn't "just a horrible combo"... but this isn't an Advanced Tech topic. I'll assume you have already posted this on "LT1 Tech", where there are probably 100's of people running this combo..... and close the thread here on Advanced Tech.