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johnracer 03-12-2008 12:31 PM

Reaction time help
Hey guys I need help. I have a SG Corvette roadster, 4-link, strut front, 840hp 522 bbc, 4.30 gear, PG with 1.80 low gear and weighs 2155 lbs full of fuel & me. It runs great, drives great, and is very consistent, but is lazy launching. I ran it for the first time with the 522 this weekend in Tucson running in Supergas on a 4 tenths pro tree. The best light I could manage was .030 with no delay in the box. Needless to say, I went out early. I had the same issues with the small block. It just rolls out of the beams with very little/no front end lift. Are there any chassis/4-link adjustments that would make it react quicker or pull the front up out of the beams? Thanks for your help....

jmarksdragster 03-12-2008 02:08 PM

What valve body, it will make a difference. You should be lifting the tires, drop the front of the top bars down to make it hit harder, drop the front of the bottom to make it lift on the front more, may take both. What angles are you bars currently? Bottom should be level to slightly down, top should down farther intersecting toward the front of the car.

johnracer 03-12-2008 04:18 PM

I run a TCI pro tree brake. I started with a 53" IC that was about 8.5" above the ground. That setting seemed to work well bracket racing with the sbc on nitrous but didn't lift the front. With that setting, the lower bar is angled up in the front. I tried moving it down one hole in the front while in Tucson, but it didn't change much. It has a 61.5" IC at 6.7" high. At that setting the lower bar is still angled slightly up. I really thought a longer IC would help it lift the front but it didn't change....

johnracer 03-12-2008 04:56 PM

After rereading Ed's post on 4-link tuning....again, I think I may need to move the IC down more instead of so far forward. I think this may be what jmark was getting at. I've adjusted the 4-link all over the place with the sbc, mostly shorter & higher, but never lower. Any thoughts?

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