metric street stock

[mudcrasy]

Hi just looking for an explanation and maybe some advise.
Car sits at 3275 total weight now.
springs lf 1100 rf 1150 lr 300 rr 225
cross 53.9
ls 54.2
rear 54.1
front stager 1 3/4 rear stager 1/2
267 bite
offsets rf 2 lf 3
rr 4 lr 4

At a test n tune day the car seem to work great. Went to a race the past weekend and put a new tire on rr. The start of the race was good then car lost all forward drive. For the consi I added a 1/4 shim in the rf to get more drive. When I checked tire stager I found that the rr grew an 1 1/2, found my drive problem.Didnt have time to take out shims so I just put a different tire on lr to get stager back to 1/2. In the heat it kinda felt tight on entery so thought the extra bite would be ok. It did just the opposite, made it unturnable with excellent drive off. My question is if you have a tight entery is it the lr your trying to get off of or the rr and why did the extra bite tighten the car on entery, should have loosened it sio I thought?
Thank you and any suggestions are welcome
John

[speedbuggy]

what kinda tires you running?

[mudcrasy]

hoosier emod 26.5

[mudcrasy]

I checked the car over this weekend and the right front shock is bottoming out again. This is the same problem I had last year and never got it fixed. There is one more race for me this weekend.Just wondering if I could get some suggestions to remedee this problem. The scale numbers and springs are above.

Thanks

John

[dirtman45]

If you're allowed to, put some nuts under the RF shock where it mounts to the lower control arm to space it down. This would give you more travel.

Otherwise shim up the RF some more and take away LR shims (if you have them) by twice the amount you add to the RF. This will maintain your cross %.

Overall your LF seams too stiff though. We run very similar spring rates except we have a 200# split across the front with the RF being a 1200# spring. A softer LF helps the car turn in better, also adds cross weight.

[Dirtrunner35]

Wouldn't more cross make a tight car tighter ?????

[mudcrasy]

I originally had a 1000 on the left front and ithe rf bottomed out then. I put the 1100 on lf to help with the bottoming out and it did help. It seem to start bottoming again by adding the 1/4 inch shim in rf. I am starting to think the car is not transfering off the rf but if you can get the car to turned it still drives off the center and out of corner well so there must be some weight transfer.

AS for adding cross that should loosen entery and tighten off the corner. In this case it did not it made the entery worse. I have been fighting this since last year. Tried all the way up to 1300 on right front with no change, Put a 3 in offset on rr no change.

Thanks for the advise. Hopfully I canget this remedead soon no fun racing when your struggling.

John

[speedbuggy]

What I use to space the RF shock down are called "coupler nuts" (most any hardware store will have them). I get a couple that are 1 inch long and 5/16-18 internal thread. Then I drill the thread part out with a 5/16 drill bit so a 5/16 bolt will go through them easily. Then you use longer (3 inch, I think I use) 5/16 bolts to mount the shock. These nuts are good and tough and you can get them in different lengths if you need to.

Also, remove the rubber bushing that goes on the underneath side of the upper mount (at the top of the shaft) and turn the washer over so that it is curved downward. This will give you another 3/4" of travel.

Now, your problem will be the lower control arm hitting the frame, not your shock bottoming out...

[speedbuggy]

Also, I am not seeing in here where you say how much upward wheel travel you have at ride height. I'd suggest at least 3 1/2, maybe 4 inches. This would translate into 1 1/2-1 3/4 shock travel...

Again, your limiting factor here needs to be the LCA hitting the frame, not the shock bottoming.

[mudcrasy]

Between the lca and the frame, at the factory rubber bump stop location, I have 3 1/4 space. Spacing the shock down would be illeigal for my rules. I did cut the rubber at top sock mount down to 1/4 thick. If I raise the right front any more the upper a-arm will start to angle down hill towards the tire. Right now it is slightly down hill. When it was level or up hill the front seem to turn better, both left and right tires were gaining equal air preasure. By raising rf more will that hurt the way the front works?

[a1driver]

what shocks are you running

[Dirtrunner35]

I originally had a 1000 on the left front and ithe rf bottomed out then. I put the 1100 on lf to help with the bottoming out and it did help. It seem to start bottoming again by adding the 1/4 inch shim in rf. I am starting to think the car is not transfering off the rf but if you can get the car to turned it still drives off the center and out of corner well so there must be some weight transfer.

AS for adding cross that should loosen entery and tighten off the corner. In this case it did not it made the entery worse. I have been fighting this since last year. Tried all the way up to 1300 on right front with no change, Put a 3 in offset on rr no change.

Thanks for the advise. Hopfully I canget this remedead soon no fun racing when your struggling.

John

adding shim to right front added cross, (tight, ) all depends on your driving style

[mudcrasy]

Bilestien 1043 in front and 1044 in the rear. I took the 1/4 shim out of the rf and moved some lead to the left. The numbers are
LS 54.8
cross 54.3
rear 54.3
bite 310

Was also thinking of taking out about a 1/4 shim on the right rear and then pull a feww out of left rear to get bite back down to around 290 to 300. Think this might help or am I going the wrong way about things.

Thanks again

John

[DaveBauerSS6]

Remove the RF 2 off and put on a 3 off. If you need to loosen the entry some more put a 1000 in the LF. Remove and check the RF shock, could be bad.
I would like to know how wide your rearend is? Cant figure how you can get 4 off's on both sides??

[mudcrasy]

The rear is a 60" from moser. I did chech the shock by hand,that is the only way around here. Nobody in town has a shock dyno. Thanks I will try that on the right front. What do you think about lowering rear a little. Right now the rr is 1 1/2" higher than rf, rf is 3/8" higher than lf and the lr is 1 1/2" higher than lf.

Thanks

John

[DaveBauerSS6]

There are different setups that can win the same race. That said:

I like feel of the chassis higher in the rear. It raises the stock frame mounts in relation to the rear end. I run the lowers on the rear end about middle holes on Jeff's mounts. I vary the rear holes for rear steer. On our only track for IMCAs, it works well.

Shocks are difficult to test by hand. If the RF shock is weak it will allow the car to roll over and bottom out the RF. I would go to the 3 off in hot laps and then switch the front shocks for the heat IF they are the same. One change at a time.

On a stock rear suspension, I work on the front end to steer the car into the corner.

I've never ran that much bite, 50 to150 is the range. I'm not sure how that would handle??

[Ricky76]

Will more cross weight tighten you up on entry or exit ? And also what about left side weight ? The effects of more or less ? Thanks, Ricky

[dirtman45]

More cross will tighten exit.

More left will loosen you up in general.

[mudcrasy]

So would more leftside weight help with the bottoming out right front and tight entery together?

[mudcrasy]

Dave, my old chassi worked great with 280 - 300 bite . This chassi I built my self, is it possible that this chassi needs way less bite? If so can I do that with current springs and ride heights or do I need to do a little research and find what works with that amount of bite?

Thanks John

[DaveBauerSS6]

I've never ran that much bite. I've read that some run that much. Maybe someone with experience will chime in. I know its above average. I've never ran that much left side also. You are getting into LS asphalt racing numbers.

Like dirtman said those front springs are on the heavy side. I run a 150 split across the front to turn.

I would work on the entry first. I've never ran into a stock rear chassis, leaf or coil that affected the entry enough to push. The correction was always in the front end. You should turn the wheel hard left and spin out not push. 3/4 links , floating brakes are a different story.

I do know that any adjustment taken to extreme will create another problem.

[mudcrasy]

Thanks for the replys, went racing last night and got 3rd inthe heat and 3rd in the feature. Way better than before. The only down fall it was a rough tacky track so I will have to wait till next year.

Thanks again

John

[dirtman45]

So what did you end up doing to the car then?

[mudcrasy]

I took the 1/4 shim out of the front, brought the ls weight up to 54.6, changed the rr spring to a 200, lowered the rear a 1/2 and took bite down to 270. It was hard to tell anything do to track conditions but on a smooth track I think it my still be tight on entery. I have some high weight above rear end (about 16" above and 150 pounds), if it is still tight I am thinking of moving it down to frame high 25 pounds at a time.

John

[dirtman45]

I know I'm on a completely different track and all, but we moved weight left and lower as the season went on. Seemed to just work better overall. The car still had some mid corner roll for side bite but would go into the corner a little easier, I think because of more weight on the left, and get out of the corner better because it would settle down on the LR a little faster. This was all with a lot of bite, like 350ish.

But it depends on corner entry speed, we have pretty good banking so we go in hard and have to give it a little bit of a "throw" to get it set. Then kinda let it ride through the mid part and roll onto the gas as you start to come out.