1989 Iroc Z 5.7 tpi 2.77 gears looking for any pointers this may be my last race with the stock long block.

Previous bests:
14.87@92.91 on a 2.201 stock with k&n filters
14.70@92.33 on a 2.128 k&n filters and Summit 2600 converter

Any ideas for last minute tuning or tweaks for me? On the last race I set my timing to 12* initial and Last week I added under drive pulleys.

Thanks and I will definitely post results.

 

Nitrous, deeper gear swap or both. Lol

 

160 t-stat, jumper the fan relays together, unplug the ac compressor clutch connector, turn ac on in the car. 2 tenths.

 

Anything to un-cork the stock exhaust. Ram air. Different belt to bypass the power steering and air conditioning? I never tried that, but it might be possible. Borrow some sticky tires so you can get off the line. I had pretty good 60' times with Summitomo HTRZ tires. Pretty consistent 1.9 60' times. Throttle control plays a big part too.

 

Shorter belt won't do anything. With the AC off, the pulley is just an idler. The power steering pump only draws HP when the pressure is under load while turning the wheel. The amount it draws is very minimal.

You'll see a big improvement by getting rid of those 2.77 gears and get something in the mid 3.xx range.

 

I do have nitrous on the car, think if I could get it to break into the low 14s I would run it. By my math if I start off on a 75 shot getting it dialed in, it still might not crack into the 13s LOL then I would be really bummed!

 

To answer some others, I have already removed the AC compressor. When I added the under drive pulleys I also removed the smog pump. I could definitely do a 160* thermostat I have heard that can cause issues on tpi with stock programming is that true? I could get that done tomorrow, I have also already wired my dual fans to run all the time.

 

Ok so I got a new PB and my MPH is coming up, 60' times were bad tonight though:
RT 60' 1/4 MPH
0.041 2.289 14.638 94.49

When I first started with the car, I was running consistant 14.9's at 92, so it has picked up some. I am seriously considering putting my Vortec heads, shorty headers, a Vortec intake and a carb on the car before the end of the season to see what it picks up. I have all those parts, makes sense to me to do it all at the same time.

 

Throw that ring and pinion in the scrap pile. Id try some 3.73's

 

I am really wanting 3.42's or 3.70's. If I had a 10 bolt, that would have been one of the first things I did. Unfortunately, I have a 9 bolt, so I haven't found a 3 series carrier yet for a reasonable price.

 

i have a complete 10 bolt with 4.10 gears auburn posi new axles with long studs and a trickflow support cover for sale if your interested. its 4th gen width and if the price is right ill send the ls1 backing plates with it. the place i bought my s60 from will give me 150.00 for the backing plates if i send them to them. just trying to sell it complete first. shipping would be a pain though.

the good thing about the 4th gen width is you can run newer wheels with no spacers in the rear.

i ran 13.696 on the rear and it laughed at me. its built very well

 

I appreciate the offer but shipping makes it tough thanks though.