Bump springs

[Mr.Kennedy777]

I had to edit that.. I'm tired and my math sucked lol!

[fastford]

my 2 stage set up is 2 500# springs, which is a 250# rate until it reaches the lock out, then it goes to the full 500# rate, this is what i would want to achieve with the bump spring , keep in mind this is for a heavy rough condition. in the smooth slick im on a medium cone bump stop and a single spring between 175 and 225 # . I realize the need for more clearance but you could use a 9" shock instead of a 7" and travel should not be affected. I doubt i will ever try this because we stay on the bump most of the time, just thinking out loud and wandering if this could take advantage of both set ups combined into one......

[Mr.Kennedy777]

you mean like a three stage spring?

[fastford]

no, at static height, your just on the primary and at your desired travel you hit the bump, but on a rough track you have more travel than being on a rubber bump or just one short bump spring , like i said i think this could combine the advantages of both type set ups( bump stop and 2 stage) into one. I know there is probably some one on here reading this with more experience than me so maybe we can get some useful input. To me this is the best part about 4M because i have gained a lot of knowledge from here.

[Mr.Kennedy777]

Have you ever ran the dual stage on the RR as a digressive stack? I am wondering how well that works out. You would think it would be a nice way to tune entry and exit just wasn't sure how touchy the adjustments are.

[zeroracing]

Mr. Kennedy, I think this is an interesting thought, digressive type spring set ups on any wheel honestly. I think the issue you may run into on some cars if bottoming the RR tire into the deck or birdcage into the frame rail with a real soft spring once it compresses down. This is an issue we have ran into with some cars, that we get the wheel rate we want, but run out of travel when we hit a bump.

[fastford]

Have you ever ran the dual stage on the RR as a digressive stack? I am wondering how well that works out. You would think it would be a nice way to tune entry and exit just wasn't sure how touchy the adjustments are.

no, but i would think you could control the dynamic load on that tire better, might be touchy on dry slick though.

[Mr.Kennedy777]

I was thinking also on the topic of bump devices. And the bump washers. On the LR corner when it hiked up a lot of the loading is being supported by the bars. Would it be beneficial to use some sort of bump device built into the rod itself, either at the chassis mount or on the birdcage. I was thinking something like a pull bar design, but much smaller, having the heim end cut and welded onto a plate with four bolts, and two other plates in the system... the bolts pass through one plate so that it can slide separating two stacks of the washers and the last plate is secured with the nuts on the other end of the bolts. The bar is connected to the threads and the threads pass through the last plate into the second plate allowing you to pre load the bottom section. One side pre loaded to near full compression and the other side semi pre loaded for a bit of give when it gets up on the bars. We aren't talking a whole lot of travel, maybe 0.25" or so, either way. I was thinking this could help the tire out a little bit at least. Any thoughts??

[MasterSbilt_Racer]

I was thinking also on the topic of bump devices. And the bump washers. On the LR corner when it hiked up a lot of the loading is being supported by the bars. Would it be beneficial to use some sort of bump device built into the rod itself, either at the chassis mount or on the birdcage. I was thinking something like a pull bar design, but much smaller, having the heim end cut and welded onto a plate with four bolts, and two other plates in the system... the bolts pass through one plate so that it can slide separating two stacks of the washers and the last plate is secured with the nuts on the other end of the bolts. The bar is connected to the threads and the threads pass through the last plate into the second plate allowing you to pre load the bottom section. One side pre loaded to near full compression and the other side semi pre loaded for a bit of give when it gets up on the bars. We aren't talking a whole lot of travel, maybe 0.25" or so, either way. I was thinking this could help the tire out a little bit at least. Any thoughts??

That ain't legal... Lol

[Mr.Kennedy777]

Why did they make it so that you can't cushion the LR through either the rod or the birdcage assembly? Is it a possibile safety issue or what is it? Scared of trying new things? If we're talking unfair advantage this piece would cost maybe 200 to make at home lol.

[MasterSbilt_Racer]

Why did they make it so that you can't cushion the LR through either the rod or the birdcage assembly? Is it a possibile safety issue or what is it? Scared of trying new things? If we're talking unfair advantage this piece would cost maybe 200 to make at home lol.

Its part of the current idiocy of the sport. I used a shock and bumpstop for my top link in 2015 with a chain parallel to it for preventing extension. The cushion seemed to help a bit.

[Punisher88]

Coleman racing products builds a piece that works great for that. Works really nicely and has a travel indicator made onto it.

[Punisher88]

Part #24640. I replaced their bushings with a hard bumostop. I could tell a difference in forward. It would actually bog the motor a bit. I also slotted the shaft and out a pin in it to keep it from over extending.

[billetbirdcage]

OUTLAWED!

[MBR Performance]

Depends on where you race lol.

[Matt49]

I've been saying for years that our left rears are too stiff on the bars the way they are and that dampening the top bar could be helpful (see Penske device above). This is why the "heavy" LR components (steel wheels, lead on the axle, etc.) are in trend. They are compensating for the lack of critical dampening when the car is barred up by making unsprung weight. It's a crutch for a crutch. I digress...

[Brian Gray]

We have been hiding these springs inside the shock for quite some time now. Nothing new

[Punisher88]

OUTLAWED!

Although this would most definitely work better with being more adjustable and tunable... I didn't have that kind if cash. I made mine for around 200 bucks.

[MasterSbilt_Racer]

We have been hiding these springs inside the shock for quite some time now. Nothing new

But that just works like the bump stop limiter.

[Brian Gray]

But that just works like the bump stop limiter.

Yes and no. Most of the new bodies I am using have an adjuster to raise and lower engagement, there is also a bump rubber on the shaft as well. The important part though is we also added a contact spacer that increases rebound preload on the stack at engagement. Working pretty well too. Been moving on from this though to work more on my dual piston setup .