Zoom!

OK, a Ranchero with a big block engine has a very heavy front weight bias, that is a given. And a 429 Cobra Jet makes lots of torque so wheel spin is expected.  (The converter in my C6 is still stock with a low stall.  I’ve got a high stall unit waiting to go into the car, but I figure I’d better find more traction first!) Prior to today my 0-60” times were around 2.5 seconds with LOTS of wheel hop.  There was so much it was almost scary.  I thought the car was going to shake apart.

I added South Side Machine #1302 Lift Bars to my Ranchero to control the wheel hop.  I could have gone with simple bolt on Traction bars.  But I wanted the best, and everyone that I talked to said they were the best.

The first headache came during the install.  The SSM bars replace the leaf spring pad.  Since the original pad incorporated the rear shock's lower mounting, now the rear shock would bolt to the lift bar instead.  My stock spring pad had a mounting point for a shock with a side mounted eyelet.  But the SSM bar had a mount for a stem mount shock with just a stud.  A quick mail order and a couple of days later my new KYB gas shocks arrived and the rest of the installation was uneventful.

I’ve had good luck with traction bars on other leaf spring cars so I was expecting my wheel hop to be gone.  But…  At the track I still had terrible wheel hop.  Everyone was complaining the track was slippery, but with only 30 lbs in the tires I had good bite.  (My very low profile tires usually run at 44 lbs.)  And it was pretty uniform right to left.  But anytime I left the line hard enough to generate ANY wheel spin I experienced severe wheel hop.  And my 0-60” times weren’t any better.  I only had one good launch today.  That was when I literally idled off the light and then hit it so I had ZERO wheel spin.  That run was three tenths faster than my second best run.

I talked to the tech expert, Louie, at SSM today and he seemed to know exactly what my problem was. It feels a lot like wheel hop, but is actually caused by a very different process than axle rotation and leaf spring S-wrap.

My 17" tires have very stiff sidewalls. I knew that already. In fact, you can let almost all the air out and they don't start going flat! Anyway, that makes them very bouncy. SSM explained when I nail it and the pinion tries to climb the ring gear the bars convert all that twist into a quick downward push on the tires. So far so good. That is what they are supposed to do. But instead of a soft, large sidewall tire absorbing the downward push and squatting down, my hard, narrow sidewalled tire just bounces up after being hammered down.

One solution is to keep dropping the pressure on my Bridgestone street tires to see if I can get them soft enough to stop bouncing.  I checked with Bridgestone tech support and found out the load ratings for my specific tire sizes.  The Bridgestone numbers only go down to 20 PSI.  But my rear tires will be happy carrying my load all they do to that pressure.  In fact, if you wanted to push it and extrapolate the Bridgestone data, I could take the pressure down to more like 15 PSI, but I don't intended to go that low.

BTDTGTTS: it helped but it didn't work well enough to satisfy me.

The other solution, and the best thing to do (Speed costs money, how fast do you want to go) is a soft sidewall tire on a 15" rim. Here's the story with the slicks.

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