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Author Topic:   metric rear spring????
robhbk24
Dirt Freak

Total posts: 372
posted May 22, 2005 12:46 PM  
rebuilt the whole chassis this year, changed mounting points the whole 9 yards, springs, are 900lf 1200 rf 200lr 175rr, last year i had cargo coils in the rear and the car worked real well i just had a push that was front end related, this year the push is gone but the car is rolling over on the rr hard, the car weighs 3162, i come in the corners good hit the gas and the rr drops and rolls over so hard i am bottoming the shock out (about 7+ inches of travel) i think the rear springs are too soft,am i right, i'm gonna try 300lbs in both sides and also pick up a 250lb to use on the rr if the 300s are to heavy, the car has boat loads of power,forward bite is awesome,better than i have ever had b4, right now i am pretty much pulling the lf tire coming out and it's really hard to drive like that specailly when the rr shock bottoms out. the rear springs are tru coil 14inch shocks are pro ss shocks, no sway bar on either end, car scaled out with good #s my rear % was a little lower than i woulda liked but that does not seem to be an issue right now. any ideas, am i headed in the right direction with the heavier springs? other than that the car is top notch, luckily we rained out just b4 the main last night double fetures next week so i'd like to get it back like it was b4 asap. air pressure is 18rf,14rr,12lr,10lf with 265/60/15 american racers

racer17j
Dirt Forum Champ
Total posts: 5390
posted May 22, 2005 03:30 PM  
thanx, i called it roll but i don't think it's actually rolling over it's just loading the he&* outta the rr, that's why i'm thinkin it's the spring not being heavy enuff,the lr is traveling alot more than it did last year with the cargo coils and the caros are the same heighth as the trus are.it's a metric chassis with basically a offset tube frame from the front clip back,rear control arm angles have all been reset

robhbk24
Dirt Freak

Total posts: 372
posted May 22, 2005 03:41 PM  
squatting it was i'll call it for lack of a better word, ever seen a well hooked up coil car leave the start line on a drag strip, that's what it feels like, right rear drops and left front lifts, feels like a late model.lol

racer17j
Dirt Forum Champ
Total posts: 5390
posted May 22, 2005 04:10 PM  
I run a metric with a panhard bar. Adjusting the pan hard may help some. Also I run A 250 and a 200 rear and a 9 inch stroke rear shocks. I have had problems with the frame hitting the axle tube. I just increased the ride height until it quit. This year I was going to try a 15 lb heavier spring in right rear. Car works really good and I just want to adjust as little as I can to get the bottoming out issue salved. When it bottoms out it causes a big push. Only happens when track conditions are right or wrong depending on how you look at it.

hsracer158
Dirt Full Roller

Total posts: 33
posted May 22, 2005 07:36 PM  
My car has the same thing going on. I can drive so hard in the corner, it rolls over on rr, and lf comes off ground. But I'll tell you what I have felt, it is the best it has been in 2 years, and drives fast. It handles well, and pulls off the bottom very well, especially on dry slick track. I am running 13 inch rear springs.
Rick

iowa_dirt_track_girl
Dirt Freak

Total posts: 461
posted May 22, 2005 08:11 PM  
I would move your weight more ot the left rear and get some of your car weight off the right rear you could also put a tie down shock on the left front or heavier shock on the rr

waltonjr1
Dirt Forum Champ
Total posts: 516
posted May 23, 2005 06:36 AM  
Im running 13 inch trucoils and I seem to have alot more bite coming off the corners than the cars that are slammed to the ground.


robhbk24
Dirt Freak

Total posts: 372
posted May 23, 2005 03:33 PM  
thanx for the replys, all my weight 145lbs is mounted on the lr as is the bat, fuel cell is centered. 17j would love to learn to drive it like that but my body can't take the slamming of the rr bottoming out for 15 laps.lol. called speedway this morn, gonna run 300lb on bothe rear and i also ordered a 250lb for the rr if the 300lb is to stiff plus i have the other springs to play with, also i just finished putting the front sway bar on (i know some will say don't) but this is the first time i have run witout it and i'm trying to get back to last years (minus the rear springs) setup to use as a baseline and work from there it's no biggie to unhook the swaybar links before a heat race and try it. ldid go to a smaller sway bar though in the past i ran 1 1/4 went down to 1 1/8.really prob shouldn't have messed with the car over the winter,lol, was trying to make it better, last year the car was good, it had a lil push coming in and had a small lack of forward bite coming out, found the cause of the push over the winter and tech i did eliminate the foward bite prob so i got what i wanted.lol. guess i should be careful what i ask for

Raz_900
Dirt Forum Champ
Total posts: 635
posted May 23, 2005 09:16 PM  
FYI..

Stock Car Products has their springs on sale for $29.95 each or $49.95 a pair and $8 flat shipping. I ordered a 1100 front and a 175 and 225 13" for the rear. They were out of 200s. (I'll be picking one up local)

After reading this and measuring some stuff on my car, I think I'm bottoming out the RR using Afco 11" (measured at 10.5") springs. It goes wicked loose when I try and get on the throttle.

The solid height of the spring calculates out to about 4". Sitting still, the RR measures about 7". That's only 3" of travel to coil bind and you're supposed to setup the spring to run in the 20%-80% travel range. I'm about 95% sure I'm using all 3" or close to it. (200 or 225 LR and 200 or 175 RR). The LR is probably fine as it lifts/rolls some, which just makes the RR situation worse.

[This message has been edited by Raz_900 (edited May 23, 2005).]

robhbk24
Dirt Freak

Total posts: 372
posted May 24, 2005 02:02 PM  
got another ?. last year the car was just offset chassis meaning the frame was stock i just had 2x3 running down the pass side from the front stub to just just in front of the rr control arm mount where there was a kick back over to the frame, this winter i added the same thing on the driver side along with a cross brace from frame to frame at the control arms, from there back it is 2x3 running on the inside of the spring pockets and tieing into the rear frame also 2x3, i cut out part of the factory rear cross member mostly the top and braced and replaced and tie that into the new rear stub, the factory frame is alos there ar per rules, my ? is the car should be a lot more rigid than it was b4 i know these cars have quite a bit of flex in them, the more flex you elminate do you need heavier springs, i would assume that the frame takes up some of the stress being put on it by flexing, if you take that out of the equation so the springs do all the work then you have to use heavier springs right? with the changes i made to the car frame wise it would seem that it would be alot less likely to flex specially on the left side,does this make sense?or am i over thinking.

iowa_dirt_track_girl
Dirt Freak

Total posts: 461
posted May 24, 2005 05:02 PM  
To answer your question as to run heavier springs or on a rigid car NO you can run soft springs and the car will work better casue your corners are THEORETICALY working as together a car with out X bracing underneath has to have stiffer springs cause you are working each individual
corner on its own
Thats why I can get away with softer springs is casue my car has Really good X bracing underneath
There are a lot of guys here that run soft front springs and really stiff rear springs and wonder why the are not getting any forward bite WELL DUH think about it LOL

Also on your 11 inch spring question with 11 inch springs you have to run about 25 lbs heavier casue of coil bind thats why most guys are going to a 13 inch spring casue you can run softer with out coil bind thus giving the car more roll in the corner and MORE forward bite comming off casue the car squats and goes.... have you ever watch NASCAR at bristol look at their front end how its really comes up off the corners that casue they not only have a lot of horse but the run soft springs to helpo get the car off the corners better

CLBaker25
Dirt Maniac

Total posts: 193
posted May 25, 2005 02:53 PM  
We have a Larson I-stock and we run 16" springs in the rear. We are running a 225/175 on the rear and 1000/1200 on the front and our car works very well. I think we might try a 200 on the right rear to loosen the car up a little in the middle of the corner.

robhbk24
Dirt Freak

Total posts: 372
posted May 29, 2005 09:06 AM  
thanx alot , the 250rr and 300lr worked great, gonna try uhooking the sway bar next week, woulda tried last night but 10laps into the first of our dual features i lost the rearend, there is a chunk of pinion gear missing and a couple of ring gear teeth, thought i smelled somthing burning but i fig it was someone else, car was real good just a lil more adjusting and i'll be there.really screwed up my points though started the night in 10th who knows where i am now after missing the 2nd main, no one had any gears with them and we had enuff cars last night that we needed a consi so everyone did not qualify and i did not have enuff time to go back to the garage and get a spare set, if everyone had qualified like on a normal night i couda done it

robhbk24
Dirt Freak

Total posts: 372
posted May 29, 2005 12:34 PM  
ended up all the way back to 20th in points in one night.ugh.pulled the pinion out t-day, almost sheared in half not quite half way but pretty close.

robhbk24
Dirt Freak

Total posts: 372
posted June 12, 2005 07:53 AM  
KISS, keep it simple stupid, after all the spring changes and trying new things i ende up last night with last years setup in it, sway bar on the front and 82 4cyl camaro cargo coils on the rear,no idea what lb springs i pulled them out of a junk car, car was awsome last night, 2nd in the heat started outside pole in the feature lead the first half till the tires went away and fell back to 8th which i was still very happy with.

    

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