Bump Stop

[klv8lm]

What is the advantage of using a softer RF spring and a bump stop?

[stock car driver]

none

when you hit the bump stop you will shock the tire contact patch and send you skating up the track, to run a bump you need shocks built for it and that set it down on it very gently. not worth the work in a street stock.

test it by just bolting one on that you know youll hit, you will see. I tried it in 08/09 off and on.

Even well tuned it will kill you on a rough track or in bumps.

[25jrjr]

Call Richie Stephens at Rocketman Racecars in Phoenix City, AL. He has it figured out!

[7uptruckracer]

Ive had a ton of success with a bump spring. I loathe COT style bumps they ramp up and for the distance you need to travel them on dirt they get extremely progressive. I have seen COT Bump Stacks they attempt to soften the rampup but i'm not sold on them at all. Ive seen them on the RR to and well even though some successful builders have used them i'm not sold on a COT style bump on a dirt car we don't even use them on asphalt anymore. You really need to know your shock game and be proficient enough to know how to change them so you can work with your shock builder to find what works for you. In my opinion its hard to hit a constant moving target. Bump springs we have had killer success with though....

[LRtireCHANGER]

Many of the Nesmith street stock cars are running something similar to the spring that is shown in the link listed below. I have seen some that use a rubber below and above the spring. Some of the street stock guys really run well on this setup. I cannot comment on the shocks used, nor can I comment on the actual rate of the spring or the bump rubbers. https://resuspension.com/index.php/b...pring-950.html

[RCJ]

The advantages would be- if you had body rules, the high travel of the right front would put the body in a better aero advantage.
Once front is locked down it doesn't lose any grip from scrub or poor front geometry.
Lower center of gravity.

[fastford]

Call Richie Stephens at Rocketman Racecars in Phoenix City, AL. He has it figured out!

last time i looked at his car at TST , he had the puck style bump on the shock which is mounted out board of the spring, he is bad fast , but just as with a late model , if you just throw it on , your backing up , it takes a lot of things as mentioned above to make it work....

[a25rjr]

last time i looked at his car at TST , he had the puck style bump on the shock which is mounted out board of the spring, he is bad fast , but just as with a late model , if you just throw it on , your backing up , it takes a lot of things as mentioned above to make it work....

yep....every Nesmith race in my area, one of his cars win!

[7uptruckracer]

Puck Styles can mean different things you can have a Plastic Style Puck or a Foam. They can range from 1/2 to 1" tall and bumps the rule of thumb is you travel them half the height. The puck styles are more IMO travel limiters not a wheel loading tool. Which is perfectly fine! IMO the goal is Camber Gain. SO you want to achieve max travel. I had a car win 16 races last year on a bump spring and the whole year we didn't work on max travel we traveled 3" on the super street and i hounded and hounded him about getting to max travel because of how i designed the front end. Well they outlawed the bump stuff, long story short we went to just a soft setup no bump but max travel around 4" and car is just as fast if not quicker. Its just about knowing the goals of your package and tuning accordingly.

[fastford]

hey 7up , are you coil binding that soft spring at 4 inches? reason i ask is we were doing this on late models years ago , but it was dangerous...

[7uptruckracer]

No, it's two 1" bump springs in a stack for 2" total and a conventional coil main spring. We travel the bump spring 1" now and 1" last year we just changed how it mounted so we could travel the car the extra distance but still only travel 1" on the bump and we redid our loading so we got the same overall load just more travel. I learned from asphalt alot if you get close on the main spring just go to the taller main spring like an 11" is easier to get the softer rates in the 5" diameter coil spring. I have it spring more for the camber gain and keeping the car down without a ton of rebound and just tweaked the bleed for the bump spring. If you ran like a 900-1500 bump you would have to run a ton of rebound which can cause other issues but i see more benefit to keeping to front geometry optimal. Its not a super soft RF for a super street around 550-700 with a bump spring under 500 Ill say that much if you wanna know more shoot me a PM

[fastford]

ok, thanks 7up, i will be getting in touch, my daughter just finished college and is starting to teach now, finally , so were just getting back started on her street stock , hope to make a few laps before end of season....