Ignorant helper spring question

[A1337STI]

So my new suspension will require helpers in the rear. (I Wonder if the suspension guy made the coilover ears a little wrong, as i now have about 4 or 5 " of droop in the rear of my rally car)

anywho i have about a 2 or 2.5" gap between the spring and the spring perch at full drop. i can either raise the rear of my car by 2 inches , or get a helper spring. seeing how the rear is already 1/4" over where i wanted it ride height wise, I'm going to get a helper spring. (sucks that even the helper is gonna raise me up a bit)

Anywho the summit helper spring says its 3" long, is supposed to be Below the main spring and can cover 2" of gap Its got a 10/ inch rate. So i'm assuming that if my main spring weights ~ 10 pounds, it will compress the helper 1inch. leaving 2 to cover the gap.

Is there any reason why i shouldn't jut put the helper Above the main spring During normal usage the helper is fully compressed so i don't get why it matters if its on the bottom or top. putting it on the top will basically allow it to bridge a bigger gap.

though its likely that the helper + spring coupler is going to add in an extra 1/4 inch in there compounding my ride height / handling issues a bit.

I believe my service manaual says 15.25 front and 14.96 rear. right now my front is at 14.5" and my rear is at 15.25 .
I wanted to go 15.5 front, and 15.0 rear (thinking I would gain front clearance, which has less room than in the rear, And i would put a bit more load on the rear tires)

right now with the front too low, the rear looses traction before the front, even with out weight transfer. (which was fun yesterday) but i don't think i'm gonna like that on higher speed stages.

[Dean]

This sounds very wrong. Helpers sound like a very bad idea on a rally car. You would much rather have the right length spring if allowed or move the perch IMHO.

Did you change springs too? Do new struts have more throw?

If throw is unchanged then distance between perches should be the same for the same spring. If more throw, you need longer springs if allowed.

[A1337STI]

Its a brand new set of Coilovers. They have a lot more travel than my last set. 190mm front 200mm rear total travel. (about 8" )

When i got the coil overs I adjusted the spring perches so that the springs did not have any play, then we installed the front. everything went Fine.

We tried to install the rear, but the coilovers were too long.

So we lowered the spring perch, which then made a Gap between the top of the spring and top spring perch. But now i could bolt the top of the coilover into the car, push up on the coil over enough so the spring was touching the spring perch and now i could Bolt coilover to the Hub. put everything back together and set the car down. now the Rear of the car is ~2 inches too high (with the front about a 1/2 inch too low)

so we lowered the spring perches to about 3 threads from their absolute lowest position, now the ride height is correct , but of course that increased the Gap between the spring and spring perch at full droop. (i know have like ... 4 inches of droop, maybe 5)

If i used a 12" rear spring things would be good, BUT i would be in danger of coil binding.

I also got sent the wrong front springs. I got 12s when he should have sent 14s. Everything seems ok in the front. but i was told again i'm in coil bind danger. since the fronts have almost 8" of full travel.

Guess you can't compress a 12" spring to 4" ? but you can compress a 14" down to 6"

BTW the Valving + spring rates on these feel amazing off on the dirt. Everything is heavy duty. His suspension has a Great track record (er stage record) many of the Top privateers in the US use his stuff. like like Wimpy team, who manages to beat a lot of Open WRXs with a group 2 golf!

Boot anyways that's where I'm at ...

Suspension is free for me, so i can do what ever i want to / need to. but i already lowered the spring perch all the way

maybe i should get a 12" rear spring + a helper then i could raise the collar 2 inches (which should move the travel to more compression than rebound)

I think my front is like 2.5" droop, 4.9" compression from standing
and Rear is 2.5" droop at which point the spring stops touching perch and will droop an other 2"
leaving 3.4" of compression

Grr... I think his math was off somewhere...

http://www.rallyrace.net/jvab/spgm/i...mGal=Sub-a-rat

Mine look slightly different. namely my rears are longer (i think he used measurements from a FWD impreza)

[A1337STI]

If i didn't have so many upcoming races, or i was patient i'de send them back and have him Retube the rears to fix the issue. but with idaho coming up in 4 weeks, and a contingency money race this weekend ... think i'll just try to come up with some workable solution for the temp

[sperry]

I can't quite follow what you're talking about Alex, but you should be able to get springs in the proper length and rate with few enough coils that they won't bind. It's just a matter of getting them.

As far as helper springs, I've run "keeper" springs that have essentially 0 rate. They compress completely flat when the weight of the car is on them. They only act when the car is at full droop in order to keep the main spring from coming loose. But like Dean said, you probably don't want that on a rally car that is going to droop frequently and needs a full length spring acting as the car lands. Really keeper springs are there just so you can jack a road car up and not have the main spring misalign when you put the car back down.

[A1337STI]

I think pictures will work better than me trying to explain ...

After work I'll jack up the rear of the car, take the tire off and snap a photo. this is the rear as it sits now.

[sperry]

That picture doesn't help much.

I would suggest, until you can get the proper springs, you either run the car higher so the spring can't come loose at full droop, or not race it at all. Is 2" higher than you wanted really all that much on a rally car? Can't you run raise the front to match the rears?

[Dean]

Helpers imply to me the ride is too low... He is using them as fillers to raise the ride.

[sperry]

Originally Posted by Dean

Helpers imply to me the ride is too low... He is using them as fillers to raise the ride.

That's not what I got out of that. It sounded to me like the car was too high, so he lowered the perches, but because of that, when the car it at full droop, the springs are loose. The helper was to keep the main spring trapped. No?

[A1337STI]

Originally Posted by sperry

That's not what I got out of that. It sounded to me like the car was too high, so he lowered the perches, but because of that, when the car it at full droop, the springs are loose. The helper was to keep the main spring trapped. No?

Winner!

That's exactly what is happening. (and its a whole lot of suck)

Does anyone have helper / keeper springs i could Borrow for a few weeks while i sort this out? 2.5" Inner diameter . I was going to mark the strut ears with some paint, take them off, install keepers, and put it back together and **hope** my alignment is more or less correct for next week.

hmmf.

[sperry]

Originally Posted by A1337STI

Winner!

That's exactly what is happening. (and its a whole lot of suck)

Does anyone have helper / keeper springs i could Borrow for a few weeks while i sort this out? 2.5" Inner diameter . I was going to mark the strut ears with some paint, take them off, install keepers, and put it back together and **hope** my alignment is more or less correct for next week.

hmmf.

You can't get away with just running the car too high for the time being?

'Course, the real concern here is... why is everything so off? Did you get someone else's custom coilovers delivered to you? It may be best not to even have them on the car. You're not re-inventing the wheel here... those things should just bolt right on and be perfect straight from the manufacturer... if they're not, you should be sorting it out with your vendor before you go and race on them and make them unreturnable.

[Dean]

But if he lowered the perches and now at droop there is a 4" gap. Filling that gap with a helper will raise the car again. They can't magically take up space during droop and not under load. They will take less space under load, but will likely still make the ride too high and he is almost out of perch lowering room. Even if they are 4:1 and only thus 1" tall compressed, ride height is still going to be 1" too high and he is about out of perch lowering room.

This sounds like too long of a strut for this spring and probably for this application unless you are willing to accept the higher ride height.

[sperry]

Originally Posted by Dean

But if he lowered the perches and now at droop there is a 4" gap. Filling that gap with a helper will raise the car again. They can't magically take up space during droop and not under load. They will take less space under load, but will likely still make the ride too high and he is almost out of perch lowering room. Even if they are 4:1 and only thus 1" tall compressed, ride height is still going to be 1" too high and he is about out of perch lowering room.

This sounds like too long of a strut for this spring and probably for this application unless you are willing to accept the higher ride height.

The keeper springs I ran were like 4" uncompressed, and 1/2" compressed.

[A1337STI]

Yes I could just run the back 2" too tall I guess. But with contingency money on the line this weekend I don't want to mess with the handling that much...

If the margin of victory after 12 minutes of rally cross (combined weekend) is only 6 seconds, do you really think i could Raise the rear 2 inches and still win? (I don't)

I guess i should be asking, what should i do for this weekend, where i'm trying to win against some other very good drivers. I was assuming if I Marked where the lower bolts go (slotted strut) i could take it off, put it back on with out altering the alignment much ...

I believe he used FWD Impreza measurements. having just converted from FWD, i know for fact the rears are about 2" taller than AWD Struts..

the vendor and manufacturer are one. Just some guy working out of his Garage. He has a reputation for making Class winning , Incredibly durable Suspension. he works with Bilstein to custom valve the dampers. (the dampening feels amazing)



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Maybe if KS Tech can fit me in for an emergancy alignment Before Friday @ 5:00 pm this week, i could just raise the car (front and back for weight distribution) get an alignment, Race on it and hope i get this figured out before Reno Rally July 8th. Idaho Rally is just 4 weeks away.. but the roads are smoother than I-80 is right now.

[Dean]

Helpers do not appear to be available to take up more than 3"
http://www.summitracing.com/search/b.../?autoview=SKU

You may have to go to a tender spring which will not completely compress under static load and give you lower initial rate.

2.5" Tender Springs: http://www.summitracing.com/search/B...c&autoview=SKU

Don't forget the Connector/Spacer: http://www.summitracing.com/parts/EIB-SPACER250/

For this weekend, I guess, throw in the 3" helper and take whatever ride height that will give you with the perch set so they are slightly compressed.

[sybir]

Alex, how critical (not being an ass, genuinely curious) is a minor camber change? Seems like you're worrying about the wrong things. 1/4" of ride height is not going to change your balance significantly enough to fundamentally change the car, and being a quarter of a degree off with camber is going to matter even less. Make a marker line, yank them, do what you need to. Toe makes a much bigger difference than a minor camber change front and rear on a dirt car, and that isn't going to change with a strut pull/reinstall.

I've done many, many coilover installs and never had an issue dialing camber back in about where I need it. Hell, buy a level and use that in a pinch - that's all most camber gauges are anyways, just with more specific attachment points. If you don't want to buy a cheapie set of Summit camber tools, then make something else work - DIY is ok as long as it's repeatable.

Also, I think it was already said, but tenders always go on the bottom, because you don't want an unsupported joint (the spring coupler) in the middle of your strut shaft, ESPECIALLY in something like dirt work where you are going to go to max droop where the spring can wobble around a bit. That coupler should be around the widest non-moving part of the strut body so that it's only going up and down, not in and out. Less important with a helper than a tender, since you normally have no free space with a helper under droop, but I'd still put it on the bottom; technically it's all unsprung weight so it shouldn't matter from any other perspective and you're just worried about spring control.

[A1337STI]

Uber, ya I've been looking at those. Summit lists their 2.5 ID springs, with a length of 3" , but it says they go Under the main spring and only bridge a 2" gap. is there any harm putting them on top ? (as it should bridge a bigger gap if its not pushing up the main spring but just pressing against the perch..

or maybe there's a reason to put them on the bottom?

[Dean]

I think you want the tender/helper where the connector will be over the tube, not the shaft so it can't easily missalign. So, standard = below, inverted strut = top. You have inverted monos, so the shaft is in the lower tube, so it doesn't much matter, but because of how low you have the perch, I would still put them at the bottom if the connector clears the tube well enough.

[sybir]

Just edited my post. Put it on the bottom, with either strut type - the body of the strut and the spring perch is in the same place on both and that's what matters. Putting it up top is asking to get something misaligned or off-kilter and causing more strut/top perch damage. Remember, with a hefty spring with no uncompressed travel, you have no issues - as soon as you add a helper/tender and a joint, you've added one more thing to move up, down, around, etc - put it on the bottom where it won't affect anything.

If you're running a tender that is soft enough that the weight of a 20 pound spring on top of it is going to significantly affect managing spring travel, you're trying to fix the wrong problem. Get a firmer tender. Even a 100 pound tender is more than enough to control the spring in the right location.

And, because I'm usually an opinionated asshole with no frame of reference, or whatever, my current rear setup on my STi is a 390lb rear spring with a *gasp* 100 pound tender, mounted under the main spring. The tender is still difficult to compress by hand with a 10" spring above it and the car lifted (so that's all the weight of the spring on the tender). I swear it's ok.

[A1337STI]

Originally Posted by sybir

Alex, how critical (not being an ass, genuinely curious) is a minor camber change? Seems like you're worrying about the wrong things. 1/4" of ride height is not going to change your balance significantly enough to fundamentally change the car, and being a quarter of a degree off with camber is going to matter even less. Make a marker line, yank them, do what you need to. Toe makes a much bigger difference than a minor camber change front and rear on a dirt car, and that isn't going to change with a strut pull/reinstall.

I've done many, many coilover installs and never had an issue dialing camber back in about where I need it. Hell, buy a level and use that in a pinch - that's all most camber gauges are anyways, just with more specific attachment points. If you don't want to buy a cheapie set of Summit camber tools, then make something else work - DIY is ok as long as it's repeatable.

Oh ya .. slight camber change, probably won't matter in the end results. Good point.

and yes you are right on the money, toe really changes handling on the dirt. I did one rally with some toe out in the rear, and that was damn scary any time i was over 60mph

I'm probably Incorrectly assuming that my car has more oversteer due to the ride height changes My front got lowered about a 1/2 inch do to the install and not adjusting the front, I was too busy being in a panic over the rear. got my alignment done that way , and didn't want to change it afterwards. I do have toe plates so i could raise the front and adjust the Toe back to zero or 1/32 out. ...

I might need a slight bit of toe In , on the rear now. But Sunday was the first time I've pushed my car at all since the AWD conversion, and RS 2.5 swap . so i went with my "FWD alignment" as my starting point .

Front : -1.6 front 1/32 tow
Rear : -1.0 0 toe
(I found some old WRC Principle setup documents to find what they were using in 01, i think still on the GC chassis i went with slightly more camber since i'm using 185, versus them on 205s)


thanks. think i just got too caught up in being frustrated over the situation to think about everything clearly. (6 weeks late, and rear fitment issues, for twice as much as i paid for Ksport) We did the coilover install late Friday night and my alignment was Saturday morning.

[sybir]

I wouldn't stress - a minor ride height change (1/2" or less) is not going to make a massive difference in toe, and it looks like you're already familiar with how to handle that. Using the alignment settings from an optimal FWD setup on an AWD setup is going to be much more of a learning curve than any minor weight-jacking you're going to have from a slight nose-up or nose-down stance; you'll have a lot more rotation control than you had previously and will be able to dial it in by feel and loud pedal adjustments to help with weight transfer, and you can then play with corner-weighting and all that fun later - managing initial understeer to exit oversteer is going to require a much bigger adjustment to the nut behind the wheel than any fastener or setting on the car.