[prostreet64]

Went to a test and tune session at our track yesterday to make a few shake down passes with the new engine and to see if the current setup would hold. Not even close. I blew the tires off on both runs at the hit of the throttle. On the old engine making about 400 crank hp there was never a problem. This new combo is probably in the 600 hp range and way more torque. So my question is for those of you who are racing a 2nd gen Firebird/TransAm with Smithcraft Assassin bars and Calvert 9 way shocks where have you found the sweet spot to be for both the bars and the shocks? Didn't have time yesterday to experiment with different settings so I am just trying to shorten the learning curve by using a setup that will get me in the ball park. Tires are MT ET streets 275-60x15. I will add that the track prep yesterday was marginal at best. I don't think they put down any compound or not much. After the street cars got through there couldn't have been any left.

[RJRjr]

I dont have a f- body but so cant say anything about the assasin bars or calvert shocks but front suspension tuning really helped my car alot once I started making close to your power. Increased front end travel and slowing the travel down so it didnt top out too quick really helped with the radials.

[prostreet64]

Could be an issue for sure. I have cheap shocks up front and set at 90/10. Front comes up and down quickly which may be unloading the rear tires?

[TinInjun]

Which Model of the ET Street tire are you using, and what tire pressure?

[prostreet64]

They are the SS series and I have had good luck with 20 lbs.

[TinInjun]

You really can do much until you get on a good prepared track. As far as tire pressure, the rule of thumb for a radial tire is, gas it till it spins, then drop it 1 pound at a time till it doesn’t.

[ta man]

More details on front suspension?

[prostreet64]

Front suspension is stock except for the shocks and removal of the sway bar. I did loosen the upper a-arm bolts to help the weight transfer.

[sdbob]

Mine 2 and 73 has 350 2 bbl front springs that have been cut to lower the car in front. Stock aarms,bushings etc. 70-30 shocks. Rear springs are stock 350 2 bbl,I tried 74 Trans Am springs on car, I thought were to stiff. Shocks are HD Hurst Gabriel. Traction bars are unique slapper bars with heim joints at front to adjust air gap to spring,pivot under housing. The harder the rear wants to rotate the more the front bar pushes up on spring eye. I have pics with 9" slicks I'll pull the front wheels slightly off the pavement. I did this myself not knowing any other way.this I was 35 yrs ago. I've heard subframe connectors will help.

[prostreet64]

sdbob, I like your ingenuity. Take what you have to work with and come up with a solution. I have done the same sort of thing on my son's car, especially in the beginning when I knew very little about what was supposed to work. I do have subframe connectors.

[Formulas]

Does anybody cut / modify the control arm bump stops to provide a bit more travel?

more so the upper arm for lift at the hit

[RJRjr]

Originally Posted by Formulas

Does anybody cut / modify the control arm bump stops to provide a bit more travel?

more so the upper arm for lift at the hit

I did. Just have to make sure not to trim off too much . You dont want the shock to become the limiter.

[chuckies76ta]

Wonder what your pinion angle is at. Our 68 Firebird with exact weight as your car, we put it in the 10.89 range. Roughly sane H/P too. Also wondering if a full drag slick would help with traction. Like the MT drag or Hoosier. We have been trying a full drag with stiff sidewall and the W for wider slick and having good results with them. This is on a track with marginal prep also.
We also loosened front control arm bushing nuts and really help transfer weight.

[prostreet64]

Pinion angle is at 3* down, at least last time I checked it. Car gets driven on the street a fair amount which eliminates slicks. Don't really want to change out tires just for the track. I think I can get this thing working once I have time to try different bar and shock settings.