JVAB for RS 2.5

Evan Cline car 669 RA and I believe he got the idea from Pat Moro.

That spring is so close to coil bind Im sure it did but may have pushed back some. Even if it didnt how is a bump stop compressed to the max different then coil bind? Struts only need to coil bind 1/4" and your bent. so ride hieght a little low or old spring. More aggresive driver lots of ways to have this problem.

Jon I would switch to a different spring company Blue coils are way to cheap and there are other competitive springs out there around the same price that wont lose free height and be the rate they say they are. I have had blue coils loose 1/2" of free heght and be 75#s off what they say they are in 2 or 3 oval races. I could see a spring failing in a couple stages in those conditions. You need to measure that spring that was in his car I bet its short at least 3/8".

I'd wonder more along the lines of the insert binding in the tube or the shock binding when drooped and then the damage occuring on compression. Too many Subes running around without this issue for geometry to be the only suspect. Not saying it isn't but there are other possibilities. Be nice to know if the ear damage was primary or secondary for sure. I'd guess secondary and I can't see that boxing the top of the ears would have made any difference.

Now it gets a bit preachy and windy ,old guy trying to be helpful... sorry...

As to adjustability, I'll side with JV on keeping it simple. Road racing allows a person the opportunity to totally memorize a course and then adjust a car to drive at the absolute edge of adhesion. Even on a road race the track changes during a session so that fine tuning is really a dream. Look at a typical NASCAR race, one pit stop, one tire, one turn of a weight jack can toatlly screw things up from the last lap. Gravel never gives someone the chance to reach those limits. You never get to drive 30 minutes non-stop on the same 1.5 miles. You never have maximum grip for the entire course. So once a car is set up for rally in a suitable fashion then the adapability becomes a driver feature, not a suspension feature. The biggest adjustment is the nut behind the wheel, not the nut on the shock tube.

I've seen rubber strips burned into the dirt on smooth dirt roads and .3 miles later ruts, 2" crushed and potholes. YOU have to be the adaption because the struts can't. Once a car is setup so that it is say 80% good 80% of the time then very few competitors will be able to push beyond that limit. Just ain't going to happen. That is the 2 and 3 minute window you so often see between the the 3rd or 4th place and the next car down.

Best thing YOU can do is get a car set up so it seems good to you then have a more experienced driver take the time to give a thrashing and prononunce judgement. If all you've driven is an old 510 or stockish Impreza you just don't have the 'equipment' to really know if the car handles well. You can determine when you make a change that is better (or worse) but you still can't accurately analyze the base setup.

I like the track the BMW gets to practice on, that is a very neat place and idea and obviously a huge benefit to the setup. Still it won't show what happens on a washboard road with a waterbar going over a crest that turns left. Most of us aren't lucky enough to find a place or time and skill to test a car like that. Decent suspension will work it just needs driver adapability and miles of practice so that adapting becomes second nature. Learn to become a fast starter, learn to go fast downhill, learn to ignore exposures, learn when to go fast and most importantly learn when to slow down. Buy good suspension and great tires, not the other way around. If you're buying used tires and picking thru those to finish a weekend adjustable suspension was the biggest waste of money in your budget.

Quick economics lesson...(old dirt track theory, the numbers may vary, the principal won't)...Joe buys new tires for $100 each. Runs them for say 40% of the life and sells them to Ralph for $50 each. So they both spent $50 per tire to run. Joe got to use 40% of a new tire with awesome grip, Ralph got to use maybe another 30% of a used tire with shitty grip (and then he has to get rid of it)...who raced more economically?? Joe invested more but spent less. You can use a tire for 100% of its life but that is never 100% of its tread....

When you can afford to run an event without having to even look at a used tire you can worry about adjustable suspension..IMHO...

Carry on.
And support your local JVAB manufacturer....

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john vanlandingham
How could the "unsprung" travel--I take it meaning the spring was under less than zero preload, cause a strut and ears to bend, there is still an insert with damping.

I was reading that as fully compressed spring (coil bind) but you have clarified that in your other post. Which is the track others are on about, I think I communicated that poorly.

I think you should keep on keeping on with what you do, possibly cap the ears, maybe look at a better spring option, but don't change too much, I don't think this one issue is an indication of some design shortcoming. Maybe just write it off as rally carnage?

I completely agree with Gene about the tires and where to spend your budget.

I think it was Either A fluke / bad luck OR it was due to the 4 weeks when i first got the coil overs. where the rear was too high and i leveled it out by dropping the spring perches, and created a situation where the last inch of droop was unsprung. This was quickly sorted out by shortening the rear tubes, but Its possible to maybe have put a slight bend during that...

seems unlikely though, as i ran 2 rallies, 4 rally crosses and 5K of driving it around inbetween first getting them, and Gorman.

I am completely confused as what swapping a left and right rear ear would accomplish. Guessing it changes the geometry slightly?

I agree with Gene, try and keep all your costs down so you can have new tires.
I now have a full set of stock coilovers , but I'm thinking about getting 1 spare JVAB coilover (and eventually two) Or maybe i should get 1 extra insert (dampened for the front) , and a front and rear tube ? so if i break a front i'm back to 100%, if i break a rear my dampening will be off, but spring rate and ride height will be ok...

is that a good plan or a dumb plan? I'm kinda thinking the failure rate is low enough I'm better off using stockers for backups and maybe getting more new tires ... (along with a tow setup + trailer) hmmf

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xman

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john vanlandingham
How could the "unsprung" travel--I take it meaning the spring was under less than zero preload, cause a strut and ears to bend, there is still an insert with damping.

I was reading that as fully compressed spring (coil bind) but you have clarified that in your other post. Which is the track others are on about, I think I communicated that poorly.

I think you should keep on keeping on with what you do, possibly cap the ears, maybe look at a better spring option, but don't change too much, I don't think this one issue is an indication of some design shortcoming. Maybe just write it off as rally carnage?

I can't just write it off, guys are suffering in their results and they're my parts. I COULD possibly be a spring related dealio, coil bind is always bad news, rearl bad...
Were're going finger this out.

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

I can check the 2 springs vs each other... in the middle of a move so it might have to wait until the "off season" ie post prescott. , though i really really want to do do big white winter rally (would give me a reason to stop in and visit mr JVA and maybe drop off some wine to Adam.

I always ran with the rear unbound to where the last inch - two inches of droop were unsprung on my rears.

And no issues with that Grant? even jumping?

have your springs ever got stuck seated incorrectly? i went on a dirt drive setup how you are describing and at least 3 times i stopped, jacked up the rear almost 2 inches and pushed the spring into proper position (it was getting stuck on the lip of the upper spring perch , IE not pressing against it properly

well that makes me feel better / less stupid.



Edited 1 time(s). Last edit at 09/16/2011 06:24PM by A1337STI.

Have a chamfer machined into the upper spring perch to guide the spring back in. I personally have the little helper springs in my JVAB stuff.

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phlat65
Have a chamfer machined into the upper spring perch to guide the spring back in. I personally have the little helper springs in my JVAB stuff.

The coils are round, they come with a built in chamfer.

It could be that Grants very very early lower seats are longer on that lead part. Seem to remember I made them at least 1" longer, maybe a smidge more......then I saw nobody else makes even 3/8" shoulder so I figure , hey what the fock...

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Yeah, but if the perch is thicker than half the spring thickness, no chamfer....... It is obviously hanging up if he has to pop it back in place

Mine hang up. I first time I lowered the car down off the stands and went around the block for a test drive one popped back into place. When you're in the car and that happens with all the weight, JESUS CHRIST I almost shit my pants. 5 Seconds later the other side popped back into place. That's when I actually shit my pants.

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Brap Brap.

I like the popping sound when they snap back into place!
They machined themselves back into place.

If you bought 14" springs they should still be 14"s long if there 13.5 then they have lost 1/2". This doesnt sound like much but when you fully compress the strut the spring will be weeker and may couse your problems.

I agree with Gene also on the driver part. Tires win races or rallies in this case. But the car cant be bending struts every coulpe events or off road trail riding. The driver will not press as hard as they could in fear of a dnf. Im sure this is something small that will be fixed and I dont think its the inserts fault because it was fully compressed If it were bent half way or at the top I would agree.

The springs are machined at the bottom to sit flat so there is no round lip to guide into the seats. couple minutes with a grinder should fix this. And if he tightened his up to take out the play and the other guys are leaving theres loose or adding helpers then thats probably the hole issue.

Swapping spindles was something I have seen so I passed it on after I seen the pic of the rear susp tore apart. I figured they may want to swap them and see what it did.

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Reamer
Evan Cline car 669 RA and I believe he got the idea from Pat Moro.

not saying they didn't but in all the photos I was able to find (onalimbracing.com and Cline racing on facebook) where you can see the rear suspension, all the bits seem to be in their normal place.

here's a pict of an awd and fwd rear hub. both have the lateral links offset so swapping them side to side would require some other work; trailing arm or different strut top.