[Graham]

However,



Audi ur Quattro's in rallying in the 80's had this problem when they lifted a wheel apparently



I don't think you can get around this issue with a Torsen or other torque sensing diff but I think the other disadvantages (apparent lack of wear) outway the advantages



Graham

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[GREYGHOST]

[quote name='Greimann' date='Mar 23 2005, 12:03 AM']This why he is on the bump stops. That and a 1.18 corner G-load!  <img src="/forum/images/smilies/968/ohmy.gif" class="smilie" alt="" />

[right][post="2233"]<{POST_SNAPBACK}>[/post][/right][/quote]





that is true I need to run on the bump stops, that is why the shocks

rebound is so stiff. The springs are checked once a year and the rear

is left alone. we have found that the bump stop is like a real stiff spring it

does compress a little. <img src="/forum/images/smilies/968/ohmy.gif" class="smilie" alt="" /> the chassis works well when we do

this it helps control wasted body movement in mid-corner, that

will onload the tires.



Autocross set ups are different from what you would normally run,

a car for DE or track days.





thanks Rob

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[flash]

i agree autcross setups are very different - i still think you shouldn't be hitting the bump stops - that would result in odd weight transfer and speed scrubbing, which is not the fastest way around the course - it's also dangerous



i'm wondering if it's as simple as an improper load balance - a .5" change in rear ride height results in about a 75# change in front/rear load - i would take a very close look at what is going on in the springing both front and rear to make sure the torsion bars and springs are giving you the 175# rear rate and 160# front rate, and at the ride heights to see that they are correct - properly balanced, i don't think you can load the corner to the bump stop in a turn like that

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[GREYGHOST]

i agree autocross setups are very different - i still think you shouldn't be hitting the bump stops - that would result in odd weight transfer and speed scrubbing, which is not the fastest way around the course - it's also dangerous



Flash it is dangerous to hit the bump stop with a lot of body movement, if the body movement has built up a lot of momentum and then hits the bump stop hard

it will unload the tire or cause them to dig in and possible to flip the car.



what we do with the stiff shocks is slow this momentum down so that when we

do hit the bump stops it is much smoother in transition to the load, then we do not allow the spring to full decompress, this is known as jacking the car down.



On my car we have worked within the letter of the rules by shorten the free length of the strut shaft by 1" this put this compresses the spring more and allows

the strut body to be closer to the bump stop. the front strut body is within a 1.5"of the bump stop you don't get a lot of movement. the rate of the bump stop is linear under compression. its not running on the infinite of the frame. the rear

is a little closer to the bump stop as I run the eccentric at its lowest point.



If and when I update to a Mo30 it will be lower in the front and weight balance on all 4. I can't use anything of a Mo30 until I have everything and do it at one time.

right know I'm trying to collect it piece by piece. <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" />



I do not hope that I do not come a cross as being harsh, but a National level

set up for the Stock category is pretty limited in some ways and open in others.

if you are a National type competitor you look for grey areas in the rule book but you do every thing in your power to make sure that you do not cheat. the guys that are on the top are looked at with great attention to what they are doing.

they is a great stigma to be thought of or caught as a cheater. I am a National

competitor who is looking for a national championship.



I am a Instructor for the Evolution performance driving schools, they teach autocross. I fly around the country doing this, on average 10 to 15 weekends

a year.



thansk Rob

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[flash]

i understand the limitations - we had the same thing when setting up a vintage car or a prepared car when i was running - i'm scratching my head here and i just can't help but think that you'd be faster though if you weren't at full compression - any deviance in surface under those conditions would cost you time - shortening the strut to get closer to the bump stop decreases travel, which helps weight transfer, but it sure seems the wrong way around the problem - i think i would have played with bending the sway bar and fussing with the links to increase the leverage and reduce roll - that would likley be in the "grey" area too - have you tried that yet? if you bent the tubular sway bar (noticed from the signature that you are running the M030) so that it was "shorter" and then moved the link inboard, you would increase the rate of the bar - since they let you use the M030, they probably would also let you tweak it



just a thought

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[rustech]

we have found that the bump stop is like a real stiff spring it

does compress a little

Since the bump stops have an effective linear rate themselves, how about running 2 bump stops at each corner? Would this be a benefit and within the "gray area"?

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[flash]

that's an interesting idea - kind of like an airbag inside a coil spring

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[flash]

hey rob-



do you swap wheels for autocross day? if so, how does the alignment spec you are running affect tire wear? i'm about to go in for another alignment when i slap on the new wheels, and wondered if i can get even more aggressive than i have now without sacrificing much wear



also, do you get to los angeles? we sould love to have you join us and do some instructing on a track day we plan to set up



drop me an email some time - i'd love to pick your brain

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