C3 stroker:
Wow, that timeslip is VERY encouraging. If you don't mind me asking, what engine/trans/power are you running. What is your race weight, gearing, and what are your shocks set at? Just trying to get a grasp on what works. Thanks.

flynbyu82:
PM replied.

tshort & 63mako:
I will look into those upgrades, thanks! Oh, and I have a history of getting away with abusing parts that should be breaking and getting away with it. Shaving off 500lbs should also help a lot with keeping stuff from breaking on the launch.

 

I also have had fairly good luck but I feel I'm at my limit. My 427 is pushing 480hp to the wheels and the tranny and rear end is stock. I do have a 360lb glass spring, spicer's, and the QA1's though. On a 2.1 60' (yes, I was babying it) I ran a 12.1@121mph. You can see the e.t. is nowhere near what it should be with that mph. I plan eventually to upgrade the outer stubs, rebuild or replace the rear end, and get bigger half shafts. I'd also love to put in a 5 or 6-speed but it's not even close to being in the budget right now.
Good luck.

 

See my sig for info..... weight is approx. 3200 lbs. (best guess), ....shocks are set around 3/4 of total stiffness, 8 or 9 clicks I believe.....TH400 trans, 2900 stall (4200 flash stall), 427 sb - 628 crank HP, 490 RWHP; 585 crank TQ, 550 RWTQ (converter really helps), 4.11 gears.

 

I run with a 4-speed, so your results may vary. On street tires the best 60 ft I got was a 1.91, and absolutely no consistency. Switched to Mickey Thonpson drag radials, not much help there, best 60 was again in the low 1.90s and I was'nt much more consistent. When I spun the tires the car went straight instead of sideways. Switched to Hoosiers and now the best has been a low 1.7 and getting much more consistent.

I have always had a 330lb fiberglass spring in the back. Recently put in 90/10s in front and QA1 adjustable in the rear. Car weighed in last race at 3110lbs.

Best so far has been an 11.959 @ 115. In good weather has run 116.85.

 

I never in 100's upon 100's of 1/4 mile runs ever experience wheel hop with my 3500 or 3800 stall converters. The switch to a 5 speed and wheel hop became bad.

I got all the parts together for the spring to cross member spherical ends rod using solid motor mounts as the end pieces traction bar. Well I had called Tom's differentials about rear gear change and they told me to install the aluminum disks. So they seem to work with my 420 pound spring and shock setup.

I've done quite a few quick take offs with my 12X27 Goodyear RR slicks and the rear tires grab pretty good.

 

Vette's generally hook pretty darn well. That's where all the breakage comes from. Keeping wheelhop out of the picture and not having it bounce around any are vital. You don't want it going through wild changes in geometry either.

Usually the stiffer the spring the better. If you have a 7 or even a 5 leaf...I'd use it instead of the 9 leaf in a heartbeat. I have a 5 leaf with an extra thick additional main leaf added.

Good shocks are necessary if it hooks hard. If the sppring is stiff enough it won't compress too much anyway, but the rebound can get you into some bouncing. I'm just using single adjustable QA-1's on the rear and it usually takes almost full tight adjustment to control it on the launch. I just have basic 90/10's on the front along with Moroso drag springs (trimmed).

I have a stick trans, so clutch management is the trick to consistency. Interestingly some of my best 60's were accomplished with a very hard hitting dual disc clutch, 550 lb front VB springs, 90/10's, stock shocks on rear with a 'glass rear spring. But it was very inconsistent that way and the odds of hitting it twice in a row were low. You never knew where it was going to go.

Now I can stay within hunderedths and it drives straight as an arrow.

I got by a long time with the basically stock center section that I had built up. I broke everything outside of it..but the center did OK. But truthfully I was *walking* it out of the hole.

Until you're ready to get a Tom's type center section or something as crazy as the Dana 60 IRS I have....I'd use the aluminum discs on the crossmember, a solid or polyurethane front mount, solid spicer u-joints, good outer stub axles (not replacements -Tom's etc), stiff spring and good shocks, and a Vette Brakes Smart Strut kit or the Drag Vette equivalent. Set it up so halfshafts don't go overcenter on the launch and get alignment dead on in the rear for drag racing.

Once you get it right,,,they really are pretty tough.


JIM

 

Good to know, thanks for the advice!

 

I have gotten 1.39 60' times.. (when I had a bigger first gear on my tranny)

http://www.grandsportc3.com/sgmp1035.mov





My front suspension features trimmed 213 lbs/inch Moroso Trick front springs and Competition Engineering 90/10 shocks. My rear setup features a Tom's 12-bolt setup with spool, a 550 lbs/inch composite rear spring and QA1's, set to 11 clicks