Any information you can provide me on BBSS with bump rubbers would greatly be appreciated. We hope to race at the Milwaukee Mile, Gateway, Nashville Super Speedway, ORP, and Iowa Speedway this year-all flat tracks. With seven of the nine races on flat tracks, and with our background at I-70 Speedway high-banks, our race team needs all the help it can get with any of the above tracks. I know that I asked a lot of questions, but with a young driver and a very low budget, because of the lack of sponsors, we really need your technical advice. We just don't have the funding to go test.
Kent J. Crane
Crane Racing Motorsports
Let's back up a little. First off, I don't recommend the BBSS setups at Rockingham, I was just reporting the use of that technology there. One of our project cars is a USARacing series (formerly Hooters Pro Cup) car and we will be racing at Winchester and Rockingham this year, both high-banked tracks. If I have my way, we won't be running on bumpstops or in spring coil-bind. It's just not necessary.
I could/would never give out specific setup information in this magazine. There are way too many variables involved. Most of your questions involve a direction I never go anyhow. The running on bump rubbers and coil bind doesn't improve lap times and works against consistency. What has happened is that a few big-name drivers have done well in a select few races and everyone just has to jump on that bandwagon. Who knows whether a racer has gotten help from the promoter in some instances with tires, and so on? It has happened before. Would you invite a big-name Cup driver to your track and then have him run in the back of the pack, or heaven forbid, not qualify?
What you're doing when you run on bump rubbers, or in coil bind with very soft front springs, is turn the car into a go-kart, period. The suspension is stiffened so much that it's like running 1,000- or 1,500-pound springs. The tires become the springs in combination with the bump rubber. So, there's very little you can do to achieve a dynamic balance with those setups.
Do yourself a huge favor and before trying to go the BBSS route, try a soft-conventional setup. Where you might have run 375- or 400-pound/inch front springs at I-70, try 250 or 225-pound/inch springs on the flatter tracks. Balance the setup and run a 11/4- or 13/8-inch diameter sway bar. Run as soft a right rear spring as you can and still have a setup balance. If you find yourself way behind, and I don't think from my experience you will, then try the BBSS. And let me know how it goes.
Sprint Car Spring RatesMr. Bolles,
I am a 360 Sprint Car driver at Skagit Speedway in Washington State. I read the article on heavy spring rates in the rear of a Sprint Car verses lighter in the front. I'll have to agree that it does work. I'd been racing for 16 years starting in a Limited Sprint Car before moving to the 360 class.
In the Limited car, I ran a heavier rear spring rate and won 13 mains. When I moved to the 360 car, I went away from this setup. The reason for this is because I listened to what other drivers were saying they liked. I learned that if it's working, don't fix it. I just wanted to say that this setup does work.
Bud "Light" Ashe
Thanks for the validation. I take it you've gone to that setup on the 360s? I first tried this with the push-rod car I helped design and have advocated it ever since. In a balance analysis, running stiffer front springs just doesn't work. You could never get the car to a dynamic balance. So, the car is always tight and never turns well. Maybe that's why we see Sprint Cars sideways all of the time.
It's not that a Sprint Car doesn't need to be sideways, but once you get the car to turn well, the entry is more straight ahead and braking is more efficient. Then, going more toward the middle of the turn, you can rotate the car for better mid-turn speed and straighten out for exit. It does improve lap times and drivability. Thanks for letting us know about your individual success using this setup.