6 replies to this topic

[RazerX]

Its been a few years since I did a complete new setup on a car.  With the Penske shocks, I started from the recommend lengths during assembly. 

 

I installed on the car, put it on the scales, with driver weight and was at 49.9%.  I should have stopped there done camber, caster, toe and called it a day.  But I decided to lower the rear, in response to some feedback i had received.   This of course shifted the cross to 49%.  So I used the up on RF and LR, and down on LF and RR to get the cross back to 50%.  

 

However, once camber, toe, and caster was set.  I took ride heights, from shock to bump stop.  LF 1.4", RF, 1.75", LR 1.3:, and RR 1.67".  On the bilsteins, my left and right differences were usually .1 - .2", front with usually more difference than the rear.  But knowing there was weight in the car i wasn't too worried at the time.  

 

Anyway, 8 hours start to finish(why i hate setup), unloaded weights, dropped the car, and the put all the scales and stuff away.  However, now I looked at the car is listing, low on the driver side, with no driver weights.  Ugg.... 

 

Thinking back, I did recall right after i put the shocks in, no driver weight, no adjustments the left side was between 1/16 and 1/8 lower.   Should I have adjusted right there to get level right heights?

 

My pinch welds are not very nice and so estimating is big part of using that measurement, so haven't done so as part of my normal process with Bilsteins.  However, the pinch welds no driver, on the ground in garage with 2 degree slope read the following.  LF 4 7/16, LR 4 5/8, RF 5 1/16, RR 4 7/8.   What?  Reverse rake on one side, and mild rake on the other.  Car bent?  or just F'd up pinch welds.   

 

So i am assuming I should fix this.  What is the best and most efficient process to fix?    

 

 

[MPR22]

 But I decided to lower the rear, in response to some feedback i had received.  

 

Did this feedback come from a friend or data? 

 

 

Un-leveling the car is not the best start for setup changes.  Get it back to level and 50.0ish ,make sure your tire pressures are equal.  Make sure your platform is level!!!!

Those two things throw off more shade tree setups than anything else. 

 

Don't forget to bounce and roll......the penskes move much slower than the bilsteins did.  

 

As to ride heights if you have fudged up pinch welds, move to measuring shock travel, ie bumpstop to shock hat.  Have to defer to real experts what that number looks like on a level car with the penskes. Use to be about two fingers (very scientific). 

[Jim Drago]

Its been a few years since I did a complete new setup on a car.  With the Penske shocks, I started from the recommend lengths during assembly. 

 

I installed on the car, put it on the scales, with driver weight and was at 49.9%.  I should have stopped there done camber, caster, toe and called it a day.  But I decided to lower the rear, in response to some feedback i had received.   This of course shifted the cross to 49%.  So I used the up on RF and LR, and down on LF and RR to get the cross back to 50%.  

 

However, once camber, toe, and caster was set.  I took ride heights, from shock to bump stop.  LF 1.4", RF, 1.75", LR 1.3:, and RR 1.67".  On the bilsteins, my left and right differences were usually .1 - .2", front with usually more difference than the rear.  But knowing there was weight in the car i wasn't too worried at the time.  

 

Anyway, 8 hours start to finish(why i hate setup), unloaded weights, dropped the car, and the put all the scales and stuff away.  However, now I looked at the car is listing, low on the driver side, with no driver weights.  Ugg.... 

 

Thinking back, I did recall right after i put the shocks in, no driver weight, no adjustments the left side was between 1/16 and 1/8 lower.   Should I have adjusted right there to get level right heights?

 

My pinch welds are not very nice and so estimating is big part of using that measurement, so haven't done so as part of my normal process with Bilsteins.  However, the pinch welds no driver, on the ground in garage with 2 degree slope read the following.  LF 4 7/16, LR 4 5/8, RF 5 1/16, RR 4 7/8.   What?  Reverse rake on one side, and mild rake on the other.  Car bent?  or just F'd up pinch welds.   

 

So i am assuming I should fix this.  What is the best and most efficient process to fix?    

My head hurts a little    

If you like, just give me a call and i will see if I can help you through this.

Jim

901 647 1700

[RazerX]

Thanks MPR,

 

Feedback came from 3 different sources that rear is too high at 1.7", which is what they were after install.  Looking at the rake, i feel like i lowered it too much.  Maybe a quarter turn back up.  I have zero time on the penskes, due to the fact all the tracks are closed.   

 

I have scales on stands that are level, tire pressures are at preferred race pressure.  Weights give corners weights within 1lb of me in the car, use 1 gal gas.  I did roll and bounce, but damn these don't move nearly at all.  

 

I have heard that ride heights (top of shock to bump stock) of 1 1/8" or less are too low, and need to be above that.  

 

If the right side, looks close, should i level to those, then go after cross weights.  

[Ben-AdvancedAutosports]

If you had everything loose while installing the Penske shocks hopefully you did not tighten all the bolts down in droop.  On a new build, or when doing a conversion I loosen every suspension bolt while on the alignment rack with driver weight in the car.  Tighten everything back down with proper weight on each corner.  I've seen cross weights change by 50+ pounds.

[FTodaro]

I am not sure what tracks you go to but at my home track Mid Ohio i can run the car pretty low because our curbs are soft. So when it comes to alignment, I found that i can run the same settings with the Penske's that i ran with the bilstiens. Same ride height, cross, toe all of it.

 

As far as the order of business this is what I do:

Put ballast in the car a day before I align it. I find that it takes the penske a bit longer to settle.

 

Then I would do Ride height next. (just as an aside) the first thing i do when come back from the track before I jack up the car and expand the suspension i check the ride height while the car is in full compression. I rarely change RH it much but I always check it.

 

I next move on to setting camber then tow. I set cross wt last, because i have to expand the suspension to to it

 

I have a 4 post lift that is level. I always put the car in the same spot and try to reproduce everything the same way every time.

Which means I have to drink a beer while doing it.  

 

As far as what they said above about tightening suspension I agree. Whenever you tighten the suspension up you must have a load on it or the car will not be settled and it will change significantly.

I do not even like to jack up the car and if i do. i put the jack under the control arms so i am not expanding the suspension, till i do the cross wt.

[RazerX]

Hi all, thanks.  Yes.  The upper arms are all torqued with weight in it.  So I don't have any preload twist in them.  

 

I 'think' i found the gremlin.  Although i had the day before greased the front sway bar, it was still hooked up on one side.  I would say it have a 5lb resistance to movement. 

 

So here is my plan at this point.  

Put it back on the scales and load with driver weight.

set ride height, bring up the driver side a bit and lower the passenger side by the same amount.  In theory this should have little effect on the cross, but then adjust cross back to 50%

Then camber, caster, toe.  

 

If i had a lift I would have more drinking time.. but alas.... 

 

Thanks, I might be motivated to get after this weekend if it rains again!