1968 Pontiac GTO Punisher

[PunisherGTO]

https://ls1tech.com/forums/conversio...-t56-swap.html

https://www.hotrodhotline.com/scyler...r#.W04I1XNOmdP

Article about my car

https://youtu.be/5-VqNzolY04

[PunisherGTO]

pictures

I think i should of joined this group a while ago. reading Ron Sutton's suspension threads are exactly the in depth stuff i want to learn that you just dont find other places. currently my setup works great at autocross and cruising but exiting corners the car is pretty loose and very difficult to power out of corners until the car is straightened up. My rear sway bar is adjustable and i have have tried different settings but with the bar on the stiffest setting the rear is definitely more prone to spin the rear tires but the car goes through slalom and corner speed much faster. Im going to corner scale it and possibly corner balance it this winter. and see if i need to make a rear spring change. Ive been looking at ridetech triple adjustable with secret sauce valving for the rear to see if i can get control of the traction problem. the front works really good with my current setup.


ls1 el toro cam, ls7 lifters, c5r chain, trap door oil pan baffle, ls6 intake and 243 heads btr springs, ported throttle body, cold air intake
vintage air, fbody pan and accessories, hooker ls blackheart headers, 3" exhaust X pipe and eletric cutouts with 2.5 turbo mufflers and 2.5 tailpipes.
t56 monster clutch stage 2, pro 5.0 shifter, umi driveshaft hoop. synchroshift 2 fluid, hooker ls crossmember
9inch quick performance rear end with 3.70 gears, s10 rear brakes, currie johnny joint in upper bushing mount
PMT rear boxed control arms with johnny joints at frame side.
hellwig rear pro touring sway bar (3 hole adjustable)
currently spc lowering springs 550 front and 150 rear.
varishock ss shocks front and rear with umi rear shock brace
SC&C front chassis brace,
SC&C SPC upper control arms and lower tubular arms standard ball joints
Speedtech AFX Spindle and new ackerman steering arms with 05 GTO 13" brakes
line lock, s10 aluminum master, and mpbrakes dual diaphram booster
hellwig front sway bar
jeep cherokee steering gear with ls1 turn one power steering pump
18x9 front wheels 275/35/18 bridgestone re71
rear 17x9 275/40/17 falken rt615k+ going to replace with same as front in future

[WSSix]

Welcome. The car looks great. I'm glad it's working well for you.

[rixtrix1]

Car looks good. Once you get it dialed in, it oughta be great in CAM.
Noticed the NE plate. Would be nice if you posted your location in your profile. I'm originally from Gering. Now in Chandler, AZ doing autoX with AZSolo.

Saw your reply over on Lance's thread. Replacing the body mounts with some stiff aftermarket ones, patching the rusted frame holes( I'm sure some are bad . They usually are. ) and maybe even boxing the frame rails should make a huge difference. If you look on Chevelles.com, there used to be a thread or two on making a simple body brace between the rear wheel wells( sort of an "X" behind the back seat using 1/8" flat strapping).

[rixtrix1]

I noticed you are using an F-body oil pan. Did you have to do anything to keep the inner tie rods ends from hitting it at full lock? Have you thought of using the roadrace baffle for inside the pan. I think there is one available for the stock pans as well as the Holley pans.

[Che70velle]

Cool car. What rear bar are you running? Car will likely turn better with softer rear bar. Stiffer rear bar unloads inside tire too much, hence the wheel spin.

[PunisherGTO]

I won cam T in my region last year. But couldn't make it to all the events this year.

I want to install a hellwig frame fx bracing kit when fix the floor and frame and do all new body mounts. I have new rubber mounts but am debating getting a poly or aluminum mounts instead.

I am running the hellwig protouring rear sway bar. I got them to send me rates for front and rear bar.
402 front
Rear 177 softest
209 medium
249 stiffest.
My springs are 550 front and rears are variable rate 112-188.

I have a trap door baffle in the fbody pan from improved racing. Last year my buddy blew his olds up with a non baffled pan. My videos show me doing over 1 g in corners.

My tie rod ends don't touch the pan now that I've raised the mounts 1/4 inch. Then pic is of the mounts before I installed the spacers.

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[PunisherGTO]

Sorry about the delay I wasn't subscribed to notifications on my own thread. Doh!

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[z28cp]

I've always thought your GTO was a good looking car. Seems to do well!

[PunisherGTO]

Thank you!! It's came a long way and feels like I got a long way to go because I'm always improving it. It's so much fun to autocross. It can move cruising a little boring because the car is so capable now.

I actually found a black Friday/cyber Monday sale this week and purchased my coilovers 240 off!! for the rear. MCBparts

They asked what spring rate I wanted. I wasn't prepared. I had previously checked the installation PDF on ridetech site and assumed they came with 225 for all the A body cars. And other rates were add ons. I figured I would be trying a couple different rates after reading about SSLance 's Barney. I think he used a 200, 250 and 600lb rear spring.