Xr1 help

[bmchone]

With the new shock and spring rules in series such as Fastrak and SECA, what are you guys having success with. Tried the coil bind setup for front but just haven’t gotten it. Any other suggestions. Thanks...

Billy

[mickley.28]

I'm assuming your not aloud to run bump stops or dual rate spring setup.... are you aloud to run a progressive spring or spring rubbers on the right front?

[fastford]

coil bind is a tricky thing , you need all the rebound in the rt front you can get , track got to be very smooth , with every thing right it is fast , probably as fast as a bump stop , but in any rough , it is dangerous and will tear up a bunch of stuff , trust me , this is why they should allow a $30.00 piece of rubber , JMO...

[Mr.Kennedy777]

Honeslty, the most success I’ve seen coil binding linear springs has come from cars with conventional spring buckets working it between the frame and control arm on an arc. It’s also easier to control with the shock because of the motion ratio. You’re dealing with such a small amount of movement because with coil bind the idea isn’t to bind all of the coils, you actually have some space between some and you’re operating on a much higher rate.. You do need ungodly rebound in the shocks and you’re gonna end up getting nailed for that because you won’t get those numbers with an average shock package, and like has been mentioned... brutal on everything in the rough and realistically it’ll only be a matter of time before they jump on that. Best to either find another sanction to race with, OR, go back to conventional spring setups. I think there needs to be one class where they just let everything go. All the guys with big money can just spend like crazy, guys can innovate things, and have it really be about the big show, big money. I think to a degree dirt racing NEEDS that. But it also needs some balance elsewhere. My honest suggestion is just learn to be fast on a semi conventional setup if you’re in Fastrak. If that’s their plan, then that’s probably some of the best advice lol.

[bmchone]

Mickley.. we can't run stack or progressive springs. We can run a bump stop on RF, but rocket said it was junk. Told to run 300 on RF and 200 on LR. We can run spring rubber.. but only 1 per spring. We tested another setup this week and found more speed, but still behind a little.. is there any load numbers that could help that you guys could maybe recommend?. Lol.. I know we will get there, but when you run the double stack stuff since 2009, then go bk to this, it's like starting all over.. thanks for any advice guys.. it's appreciated

[Mr.Kennedy777]

I think it depends on what bump you’re running in terms of stiffness and height. With a 350# or 400# spring using the right bump height you could make it act very similar to a stacked 350/700 or 400/700 RF with a lockout, except you’re on a bump and not a linear spring. I know guys wanna get the shock just buried hard on the bumps but I’ve said lots, you don’t need to be into the bump very much, especially on dirt... Just enough to compliment the ride spring and help it build rate will give you gains. I’ve heard anywhere from 2600 down to 2150. This month I actually just starting to use 2250 as my number. Was setting them quite a bit stiffer but I’m trying something just a little different this year.

[Mr.Kennedy777]

There’s a lot of decent bump stops that offer quite a bit of travel (for a bump stop) on a relatively low rate. It eventually progresses quickly, but I’ve seen a 2” bump move 1” and only take up 100 pounds. Others they barely move when you put 500# on them. Lol. If you’re allowed bump springs eibach offers some decent softer bump springs even as low as 350# in rate. They can only take about 400 pounds so you’ll need to have a bit stiffer ride spring.

[billetbirdcage]

"With a 350# or 400# spring using the right bump height you could make it act very similar to a stacked 350/700 or 400/700 RF with a lockout, except you’re on a bump and not a linear spring."

How does that work? (rhetorical question)

Load numbers would not even be close, example 400# vs 400/700 you listed with a static ride load of 500#. Even if you had the lock out engage really earlier it would still be a ton different but below shown is thru travel with engagement of either the lock nut or a bump. Your comparing a 400# initial rate vs a initial 254# rate.

Travel 400# 400/700#

0" 500# 500#
1" 900# 754#
2" 1300# 1008#
3" 1700# 1262#

[fastford]

coil binding a rt frt coil over is easy , put a 200 lb or less spring on it and pre load it to ride height , it will smash it flat as a pancake , now playing with spring length also comes into play , also the car is not at ride height going around the track so you can keep lowering rt frt till you reach your desired travel , there was a bunch of races won like this 15 years ago by a local guy here. If you can run a bump stop , that is the way i would go...

[Mr.Kennedy777]

Billet, for some reason, don’t ask me why, I was thinking like 400# primary rate, 700# secondary. Never ran that stacked spring RF lockout stuff. Just ride springs and bumps. Did not know they ran it like a 250 initial rate and then a 700#. In which case, you COULD still do that with a bump. 500 pre load.. 250 ride spring. Bump 2” tall 15-white speedthane bump for example. Let’s say 5” total available shock travel.3” to the top of bump plus pre load is 1250. 1” into bump would be 1580, after that the rate would progress up quicker for about 0.45”, 112.5 into ride spring, 1692.5, + 450 into the bump, would give you around 2145-ish so you would end up with probably 4.45” for 2200.If you used a dual stage RF 250 rate to 700 rate, the lowest you would probably want to set the lock out with 5” available travel would be 3.75”... 500 pre load plus 3.75@ 250 would be 1437. Then lock out engages and gives you 1.09” of travel for 2200# 4.75” of travel. That’s only leaving 1/4” travel or 175# until you’re bottomed out. So they could be made to behave similarly, not exactly the same but both would begin to change loads around the same area, within a 1/4”. In both cases the softer the initial rate the higher the final rate or earlier it needs to start engaging. You do get more suspension travel with the stacked springs in this particular example, however I’m sure there are bump bushings out there to mimic the stacked spring travel. But no, You’re 100% right what I said at first was waaaaaaaay off lol.

[MLR19]

I think what Billet posted is accurate, with a 400/700 stack the combined effective ride rate is 254 lbs per inch.

[MasterSbilt_Racer]

Fastrack is only allowing a 1/2" thick, 60 durometer, RSW. Not really a bump you can do much with.

[Mr.Kennedy777]

Fastrack is only allowing a 1/2" thick, 60 durometer, RSW. Not really a bump you can do much with.

Well then.. I guess if it was smooth you could probably get away with it if you weren’t running on it too hard. With a 325 you could probably keep yourself from running on it too hard either, but that’s a pretty little stiff unit regardless. Might as well just use conventional springs. This all depends on the car and driving conditions too, but like you said there isn’t a whole lot of tuning that little thing.

[fastford]

I think what Billet posted is accurate, with a 400/700 stack the combined effective ride rate is 254 lbs per inch.

we tried a lot of combos and a 500/500 , which is what JL originally started us out on , worked best

[Burke1118]

God what a stupid rule

[7uptruckracer]

Here is what I was told. 275 with a White line rubber 2150 Dynamic, Blue line rubber 2250. Was a good starting point.

[bmchone]

Thanks for all the replys. To clarify, we can only run a certain bump stop and I believe someone already said it earlier in the post that's it is only 1/2 and rocket said it was junk. We can use 1 spring rubber per spring. Rules are crazy.. we're trying a little taller spring for RF and see what'll happen.. again, thanks for all the replys and info.

[billetbirdcage]

Thanks for all the replys. To clarify, we can only run a certain bump stop and I believe someone already said it earlier in the post that's it is only 1/2 and rocket said it was junk. We can use 1 spring rubber per spring. Rules are crazy.. we're trying a little taller spring for RF and see what'll happen.. again, thanks for all the replys and info.

Their rules to save money are ridiculous, Stan and them have no clue how easy it is to get around some of this stuff/rules.

If I had to deal with that rule here is what I'd do.

1. Make a new coil over cone/cup for the bottom of the coil over for a non flat pig tail instead of the flat ones on normal coil over springs. This will allow you to cut any spring to any desired length you need to make the rest of this to work.

2. Cut spring to get the desired travel before you coil bind the rest of the coils without the spring rubber and control when the spring is using the spring rubber for the bump stop. No having to mess with altering ride heights or anything.

3. You can use that single spring rubber and 1/2" RSW bump for your bumpstop. Sure you may need to work with different rubbers or even cut and trim on the ID or OD to get the desired bump rate you're looking for and also work on making sure it doesn't want to squirt the rubber out the side of the spring. But it all doable with some work.

Wow, glad this rule saved me money now instead of installing packer shims to adjust overall travel, I swap out the spring for one that has 1/32 more/less of a round of the coil cut off. So instead of a $1.00 packer shim I now have another spring cut slightly taller or shorter. 10 packer shims = $10.00 vs 10 springs cut different lengths to do same thing = $800.00, Ya that makes sense.

***Note: going off the last time I read their RF rules, they could been amended for all I know so going off what I read rule wise a while back.

[billetbirdcage]

I also think I recall the rule saying nothing besides the 1/2" bump on the shock which means instead of shimming the stop where you wanted it, so you need to alter the mount heights on the coilover to adjust the exposed shaft length, which means installing a jack bolt on the top of the mount to adjust when the shock hits the 1/2" bump.

Again haven't re-looked at rules so.....

[MasterSbilt_Racer]

I also think I recall the rule saying nothing besides the 1/2" bump on the shock which means instead of shimming the stop where you wanted it, so you need to alter the mount heights on the coilover to adjust the exposed shaft length, which means installing a jack bolt on the top of the mount to adjust when the shock hits the 1/2" bump.

Again haven't re-looked at rules so.....

Correct. Only the bump is allowed.