Ok so i got a 383 lt1 with a built 4l60e with a 2800 stall. i raced my friends stock ls1 A4 trans am and a dodge neon srt4 bossting 21lb on stock turbo. they both beat me. I wanna know if tuning will make a big difference because im running stock fuel system, ignition and stock exhaust. im planning on getting 32lb injectors because im loosing power at 5200rpm. other than getting headers soon and cai, a 3.73 rear. i wanna know if tuning will make a big enough difference and where should i get the tune. my engine builder said i should be making 400hp at the flywheel. but im not feeling it

 

Well the short answer from my experience would be, absolutely. A tune can make a HUGE difference; no wait not strong enough, WILL make ALL the difference. Sadly I have never been able to stick to the short answer so….. I have just completed my 383 LT4 build about 4 months ago and I can tell you during the break in period it was running on the stock program and I would have been surprised to be making 275-280 rwhp. Once I got the engine broke in and got the tuning and dyno done it was making 340 rwhp and that was with a weak tranny. The tranny is still stock and will be then next thing done but with a TCI street fighter 243105 converter and a heck of a lot more hp it wouldn't shift hard enough to even bark the tires going from 1st to 2nd. That should tell you how much I am losing from the weak tranny. However, a tune will not by far be the only thing you should do. At the very least upgrade your intake and exhaust and let that 383 breathe. It is one of the cheaper bolt ons you can do to make a huge difference so you are on the right track with your planned upgrades. I am fairly new to these boards so I haven't gotten all my mods and stuff listed but it was a fairly strong build and I do have some of the project photos posted in my album here on CamaroZ28.com. Feel free to check them out and send me any questions you have I will do my best to help. Hope you enjoy the photos and hope I answered your question.

 

Before you start tuning, you've got to have the right selection of parts. List all the parts on your 383 that are not stock. Did you have the heads ported? What cam did you choose? Have you changed the throttle body? Appears you have stock injectors, tune, exhaust and intake.

In effect, from the data you've provided, you have 33 extra cubic inches of displacement, and nothing else. It isn't surprising that a stock LS1 would beat you, if that's the case.

For starters, give us the info required to assess your engine. What year is it? If its a 93, the answers are going to be different than for a 94+. List EVERY mod to the engine. We know you have a stall, and built 4L60E. What rear axle ratio? Any suspension mods, to help put the extra ower to the ground (when the engine starts making extra power)? What tires?

What kind of races did you run.... rolling start? .... to what speed?

 

its got forged internals and comp cam hydrollic roller 224/230 with all the supporting valvetrain components. port and polished heads. ported throttle body and bypass. so i guess i need to get better fuel and air delivery and exhaust. then a 3.73 rear and better tires, because everything is stock except the motor and tranny. i did a 40 roll and a dig and lost by about half a car length in both. from a dig we got up to 100 and the 40 roll we got up to bout 130.

 

i saw them pics of ur z. its a beautiful lookin motor and car.

 

Thanks I really appreciate the compliments. It is an ongoing project, but then again I guess all our project cars are ongoing aren't they. I am hoping to get alot more of the project photos up on my photobucket page soon for anyone interested.