STACK vs BUMP !!!!!

[MasterSbilt_Racer]

Exactly true. Stacked and two step are two different animals. I'm definitely in the camp that thinks "bumps" and "coil binding" are crutch's and junk engineering, although coil bind is the absolute worst, no offense intended. I guess in a few years will be discussing whether "welded" or "bolted" in place are the way to go... At least bumps are tiny little rubber springs...

A coil-bound spring just has too much "give". You really need a high-modulus, high yield material for your stops. I recommed a nickel-based superalloy like Inconel 718.

[PayinDaPurse]

Poppy your inbox is full

[Moreland24]

if you have 1 1/2 mesurment from the jam nut to the slider by making that a 1/4 of a inch longer/more 1 3/4 gives you more soft spring, which you would want on dry slick like wise making it 1 1/4 would work well on tacky where you do not need to pin the RF as hard.

So basically when you lower the jam nut to allow the car to roll more when the track slows down, (and assuming since your not worried about the wedge when making this adjustment), you are more focused on this allowing the car to put more weight on the RR to tighten the car (mainly entry and mid corner).

[poppy]

That is correct, and I figured out how to empty my inbox. It is way easer to show someone with all the pieces than to explain it. i also think that the spring package I run in the rear. I like a real soft stacked spring set up in the rear. Along with pinning the front you need to get the weight there in a hurry also.

[MasterSbilt_Racer]

So basically when you lower the jam nut to allow the car to roll more when the track slows down, (and assuming since your not worried about the wedge when making this adjustment), you are more focused on this allowing the car to put more weight on the RR to tighten the car (mainly entry and mid corner).

The wedge won't change when you move the nut he is talking about.

[Moreland24]

Right, not static wedge. Just dynamic wedge, right?

[MasterSbilt_Racer]

Right, not static wedge. Just dynamic wedge, right?

Yes and no. You get on the heavy spring at a different point so somewhere between ride height and fully down on the rf there will be some difference. When the car is on the rf, it should basically be the same.

If total travel is the same, dynamic wedge will be the same at that point.

[cushionbumper]

@poppy, check you pm.
Thanks, CB

[29racin]

so i read the whole thread and now am really confused..... stacked and dual stage ARE 2 different things. stacked with a slider does what? (just gives a really soft rate) correct. Dual stage with a jam nut does what? ( qiuck weight transfer and hold down)correct? What are the best rate for the dual stage set-up and do i want for a gap to the jam nut? If I am incorrect please ellaborate for me... thank for the input.. I run 3/8 dirt. DRY.

[F22 RAPTOR]

so i read the whole thread and now am really confused..... stacked and dual stage ARE 2 different things. stacked with a slider does what? (just gives a really soft rate) correct. Dual stage with a jam nut does what? ( qiuck weight transfer and hold down)correct? What are the best rate for the dual stage set-up and do i want for a gap to the jam nut? If I am incorrect please ellaborate for me... thank for the input.. I run 3/8 dirt. DRY.

Stacked = 2 springs stacked one on top of the other with a slider gives you softer combined rate.

2 Step Spring = Same as "Stacked" only you have a jam nut that halts the travel of the slider at a set point of travel and thus changes from combined softer rate to what ever heavy rate spring you are running in the stack.

So running the 2 Step Spring lets you have your body roll on the RF of a light weight spring, which gives you less dynamic cross and increased side bite. However when you throttle up and push over on the RF harder the heavy spring engages and gives you more dynamic cross/bite to drive off corner. Can be best of both worlds if you hit it right, in theory.

We use to use the 2 Step Spring setup, back in the days before the hook setups, to help lift the frontend under accel to transfer the weight better to the rear. Now its used to pin the RF instead of just having it lay over and collapse, which gives good side bite on entry, but lacks dynamic cross to accel off. Good luck.

[Dirtwizard]

Yes , and thats the million dollar question

[Moreland24]

Yes and no. You get on the heavy spring at a different point so somewhere between ride height and fully down on the rf there will be some difference. When the car is on the rf, it should basically be the same.

If total travel is the same, dynamic wedge will be the same at that point.

Ahhhh, ok I see...

[29racin]

what i s recommended spring rates to use on 2 stage set-up. now i use a 400 or 375. this will also help on throttle corner entry?

[cushionbumper]

@poppy, check you PM
CB

[cushionbumper]

poppy, check your pm.

[throwindirt1]

we currently run a 375 on rf and would like to try the stacked spring setup, what springs would we need to replace the 375?

[big88fan]

Well for those who have always said the bump stop setup doesn't work I now have to totally disagree with you my car handled the best it ever has and on a tacky rough and super slick track it was awesome so those of you still searching for an advantage keep looking.

[fastford]

you tell them big88, ive said 0n here bef0re th0se bad m0uthing the bump st0p d0nt kn0w h0w t0 use it

[F22 RAPTOR]

I never said the bump couldn't or didn't work, but I did say it was unnecessarily harsh and can be difficult to get right. It also breaks a lot of stuff and can result in a roll over and totaling the car, but hey if you guys like it and don't mind getting on your lid, have at it. It is slightly better than coil binding, which is stupid. A bump, at least, is just a small rubber spring. To each his own.

[01racing]

do you need to run alot of rebound with the stack ?