89 RS - 2.8 block, 3.1 crank, bored .060" to 3245cc(198cu.in.), fully balanced to 8k rpm, overbore pistons at 1.25mm with a 3.1L dish, all new internals with a highflow oil pump. Head work includes unshrowded valves, port, polish, gasket matched, 3 angle valve job, Corvette LS1 valve springs, and 0.430 lift cam pushing stock rods, hydrolic lifters, and rockers.
Block
Bore 90.5mm(3.563in)
Stroke 84mm(3.31in)
Cam
108* Separation
206* Duration
0.430" lift @ 1.5:1 Rockers
All of the sensors and coil have been moved off the bracket mounted on the passenger side head and mounted on the non-AC fan box.
azty.bin (custom burn)
88.xdf
1227730 ecm
The computer system has been changed to a 91 speed density and features a custom chip done by a friend. We are currently working on updating to a V8 alogorithm. 17lb.hr. injectors fuel the beast, as the porting and polishing let way more air in. The o2 sensor suggests the stock fuel pump is still doing its job well.
The transmission is the stock 180k mile 700R4. The engine upgrade prompted an tranny cooler, shift kit, and a 1st/2nd syncro upgrade from Summit. The tranny cooler is 10x17", bigger than my friends civic radiator, hehe. For straight line, this tranny has been the best, but I'm afraid its time to upgrade to the T5.
Things I've done so far for suspension are boxed LCA's, boxed panhard, eurathane everywhere possible, 32/25 sways a front swaybar brace. The sway bar end links are hardware store specials made from 3/8" bolts and hardware. I'm hoping to upgrade to 7/16" threaded rod and make adjustable endlinks to control weight distribution. IROC V8 600in/lb front springs that have 1.5 coils cut, and stock progressive rear springs, 2 coils cut. The LCA relocator bracket helped immensely with wheel hop on launches, 1 hole up from the bottom.
The 11.5" aluminum caliper rear disk brake setup is off of a 94 camaro. To avoid swapping axles, I modified the stock drum rear axle to house the disks. With the new disks, the brake proportioning was all screwy, so I installed a 94 1" straight bore master cylinder and a Wilwood adjustable brake valve.
GM Auburn LSD, 10bolt, 2 series, 26 spline carrier with Strange Engineering R5213 ring gear spacer and 4.11 gears. Not completely rebuilt, but I at least completely cleaned and reassembled.
Current spring selection.
Bottom is the base stock
GM 10027652
Middle is 4th gen 175/225in/lb progressive stock
top is a better stock RS
GM 10027651
I'm currently playing with the progressives. So far I'm liking them. It took a little to get used to, but the car is way more solid than it has been.
The original rims were the 15x7 RS classic body paint matched alloys. I bought AMP Sixers 18x8's with 245/40R18 Federal tires after a hard time finding an aftermarket rim that looked good. These are not very performance sauvy, and they are really heavy. I traded them in for the lightest option I could find, which are the Trans Am Crosslaces (BBS look-a-likes). This style of rim can be found on Corvettes, BMW's, Porshe's, and many others. They are 16x8's wrapped in 245/50R16 Ohtsu HS401G's, TempA, TracA, Tread 160. Ohtsu was bought by Falken 3 years ago. The rims alone weigh in at 16lbs and way outperform my AMP's. Not to mention the AMP's weight 57lbs a wheel and the Crosslaces are 40lbs! Thats 64lbs of free weight reduction per set! They utilize a stagered track width, so the front end track is 72.5" while the rear is 71".
To help with weight, I moved the battery to the back. The car is cranking off of 4awg cable (it was already layed down for my stereo). It starts slow cause the cable is too small, but it starts. To reduce the polar moment and total weight of the car, I have been moving/removing heavy items from the ends of the car. So the rear crash bumper has been removed, and the battery will be re-relocated to just behind the front passenger seat. Future mods include replacing the front crash bumper with a lighter piece, and relocating the radiator further back.
I currently autocross this car, and it is becoming a purpose built vehicle. I usually only drive it on the weekends and to race. Its loud, noisy, shakes (no rattles), and handles way too good to just drive all the time. The clubs I'm involved with are Chuckanut Sports Car Club and my local Revolution Motoring Club. My permenant number with CSCC is 880.
Good run video. Not my car, but a fellow 3rd gen none-the-less.
Thanks Dean!
Autocross run
LT1 Project Car
Page 1 General Upgrades
Page 2 Autocross pics
Page 3 Custom stuff in progress
