sold rear axle and one wheel spinning?

Hey guys, this is on my old 3rd gen fbody road racer. For as long as I can remember, I have never been able to put any power down coming out of a right hand turn. As soon as I get on the gas, I instantly light the rear right tire.

I have always thought it was a worn out diff, but I finally got around to installing a new auburn racers unit that is specifically designed for road racing only to find that there is virtually no difference.

I'm now wondering if it's a suspension problem and if the right rear is just becoming extremely unloaded during right hand turns. The car has a pan hard bar setup and I wonder if relocating it would help?
 

flatchat(Chris)

Supporter
Try driving from the right hand side then :blank: -- your weight ??

Could be a number of things --is the front anti roll bar connected ?
 
Right turn, the inside wheel is loaded less as the weight transfers, when power comes on there is a torque reaction from the prop shaft that loads the left wheel but unloads the already lighter loaded right.. smoke

On a left turn the torque reaction adds to the left but the right is loaded by weight transfer from turning.. no smoke (until more power overcomes grip)

I believe this is why diffs are off centre in the axle to minimise this effect.

Driver on RHS also may help:thumbsup:

Steve
 
Yeah, I know about the torque effecting this, but I think my issue is beyond this. I can not put the power down at all, and I have seen other cars like mine actually break traction in a right hand turn. I wonder if I should have just gotten a spool.
 
Try driving from the right hand side then :blank: -- your weight ??

Could be a number of things --is the front anti roll bar connected ?
Yes, the front anti roll bar is connected. But this bar is the popular setup from what I understand. Could my corner weights be horribly off?
 
Yeah, I know about the torque effecting this, but I think my issue is beyond this. I can not put the power down at all, and I have seen other cars like mine actually break traction in a right hand turn. I wonder if I should have just gotten a spool.
No, go buy a Tru-trac, Torsen or DPI unit for your car, get the version with about 70lb or more breakaway torque & enjoy! You can get higher breakaway versions but these tend to cause issues under braking for corner entry. The 70lb preloads the unit just enough to make it work even if your lifting an inside rear. Beuty of these units is they seem to be virtually maintenance free, still sods law will probably bring someone up who has managed to break one! Yet to see it myself tho!
 

flatchat(Chris)

Supporter
NO ! git the front end sorted first --cocking a back leg is symptom of soft / worn --front springs, bushes, shocks, bad geometry etc etc
We need lots more info to comment correctly:heart:
 
Nobody ever gets any traction on the Right in Chicago! :lipsrsealed:

NO ! git the front end sorted first --cocking a back leg is symptom of soft / worn --front springs, bushes, shocks, bad geometry etc etc
We need lots more info to comment correctly:heart:
Seriously though... even if you have suspension issues in the front... That auburn diff should be able to keep your RR from spinning like that.
 
The car has Nascar style weight jack screws on all 4 corners. But, I haven't been able to get it corner weighted yet since I have been working to finish the car so it's track worthy; and also because corner weight scales seem rarer than a hens teeth around here. So I have no idea what the corner weights are...

My front shocks are very soft. They are not valved correctly for my springs. Not sure what I'm going to do about that yet... bushings are hard urethane or steel on all 4 corners.
 
I made some adjustments to the weight jacks to, what they call in Nascar terms, reduce wedge. It seems like the car is handling better, but it looks like I really need to get some corner weight scales...
 
If rear shocks are to short and you dont get enough droop in the rear it will pick a rear wheel up on the inside.

Coming back and adding to this if you have a rear bar it will stop the rear end from drooping as well, some may not agree but disconnect 1 link and try it with no rear bar.
I recon a rear bar is a hindrance.

After that I would think about the trailing link location (squat anti squat) and also rear roll center.

Check those shocks first.

You dont have shitty old tires on this thing do you John, everyone is happy to help but at the end we find out it has 10 year old tires on it, so I will ask the question how are the tires John.

Jim
 
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Ron Earp

Admin
I have always thought it was a worn out diff, but I finally got around to installing a new auburn racers unit that is specifically designed for road racing only to find that there is virtually no difference.
I race a Mustang in the SCCA and this Camaro, depending on a few minor differences, will be setup very similarly for good performance.

"But, I haven't been able to get it corner weighted yet since I have been working to finish the car so it's track worthy"

Stop trying to adjust anything without scales - the car isn't track worthy until you've set the suspension up. I think we might have covered this before, but if you can't get a proper set of scales do this:



You can find the how's and why's about that on various internet sites. It works, is cheap, and it's better than taking shots in the dark.

What is the Auburn diff that you just put in the car? Might be interested in that piece myself. I use an Eaton Trutrac torsen and do like it, debate about merits of it vs. clutch pak LSD and so on are beyond what you need right now.

Q as others have pointed out:

*Stock Camaro suspension? Panhard and torque arm?
*Type and age of tires?
*What are the spring rates on all four corners?

You are highly unlikely to need to change from a panhard/trilink to a Watts to get the car to work properly. I run a trilink/panhard and the car works extremely well, just a matter of setup.
 

Larry L.

Lifetime Supporter
I wonder if I should have just gotten a spool.
Spools are great for drag racing...but, 'not-too-so-pretty-good' for any kind of road/track racing wherein 'sharp' turns need to be negotiated 'at speed'...or at least I would think not. :shrug:

I had a Detroit Locker in one of my street machines once ('kind of a combo of a spool and a posi unit in one). Taking sharper-than-normal turns on the highway at normal highway speeds could be 'quite interesting' at times depending on at exactly what point the differential chose to 'unlock'. (But, perhaps the fact the car was running skinny 'drag tires' on the front and wide 'drag slicks' on the rear had something to do with that as well.)
 
What is the Auburn diff that you just put in the car? Might be interested in that piece myself. I use an Eaton Trutrac torsen and do like it, debate about merits of it vs. clutch pak LSD and so on are beyond what you need right now.

Q as others have pointed out:

*Stock Camaro suspension? Panhard and torque arm?
*Type and age of tires?
*What are the spring rates on all four corners?

You are highly unlikely to need to change from a panhard/trilink to a Watts to get the car to work properly. I run a trilink/panhard and the car works extremely well, just a matter of setup.
It is a stock camaro setup with aftermarket (stronger) panhard bar and torque arm. Stock geometry. All joints have been replaced with urethane or solid ends.

Tires are old. I have new ones waiting to be put on though, I hope to get them on in the next few days. But the car has always done this regardless of tires.

front suspension:
1000# springs
32mm sway bar
urethane bushings
single adjustable struts. (out of effective damping range)

rear suspension:
200# springs
25mm swaybar
urethane and solid bushings
relocated (lowered) LCA mounts
double adjustable shocks.

as said before, every corner is on a weight jack screw.

The diff is an Auburn Racers unit. Really cant comment on it yet, but in the past, they did not sell this diff to the general public. Auburn has recently changed their website and removed the diff description, but this is what they use to say:

"In the road race series Auburn Gear has developed a performance limited slip differential specifically for road racing - a differential case designed to allow the center pin to float along with the axle shafts. This design feature aids the driver when cornering, so that when the driver is turning, the outside wheel axle shaft will apply a force to the center pin hence, the pinion gears will firmly seat the inside cone/side gear assembly giving the racer an extremely tight rear axle. The greater the G-force the more bite you get! If you are an avid road racer you'll want this unit. It'll allow you to pass your competition!"
 
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It is a stock camaro setup with aftermarket (stronger) panhard bar and torque arm. Stock geometry. All joints have been replaced with urethane or solid ends.

Tires are old. I have new ones waiting to be put on though, I hope to get them on in the next few days. But the car has always done this regardless of tires.

front suspension:
1000# springs
32mm sway bar
urethane bushings
single adjustable struts. (out of effective damping range)

rear suspension:
200# springs
25mm swaybar
urethane and solid bushings
relocated (lowered) LCA mounts
double adjustable shocks.

as said before, every corner is on a weight jack screw.

The diff is an Auburn Racers unit. Really cant comment on it yet, but in the past, they did not sell this diff to the general public. Auburn has recently changed their website and removed the diff description, but this is what they use to say:

"In the road race series Auburn Gear has developed a performance limited slip differential specifically for road racing - a differential case designed to allow the center pin to float along with the axle shafts. This design feature aids the driver when cornering, so that when the driver is turning, the outside wheel axle shaft will apply a force to the center pin hence, the pinion gears will firmly seat the--------- inside cone/side gear ------------assembly giving the racer an extremely tight rear axle. The greater the G-force the more bite you get! If you are an avid road racer you'll want this unit. It'll allow you to pass your competition!"
It uses cones on each side gear, road car stuff & wont perform like a Detroit locker or torsen/trutrac unit.
 

flatchat(Chris)

Supporter
*Urethane bushings are prone to binding if not well lubricated with a graphite grease.
*Have you tried without the (dissconected) rear sway bar ?
*Simple test for the Diff of clutch type LSD --jac up one wheel and see what it takes to rotate -- a torque wrench can be used (if it can be rotated by hand -its not working)
 
I was able to torque my lugs down while the car was jacked up and in gear. It wasn't enough torque to differentiate the diff so its doing something... I havent tried disconnecting the sway bar yet.
 
Heres the corner weights of the car as it sits right now with no driver. I do have to relocate the battery, but its clear there is an issue with the rear suspension. I believe the problem lies in the swaybar mounts. I will need to find some time to get it cornerbalanced correctly.
 

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