Steel Coilover Sleeve : Where to buy ?

The purpose of this is come up with a general purpose rally suspension with adjustable ride height. That I can do just about everything with. Hillclimbs, rally X, Auto X, and maybe some real stage rally in the future when it's in the budget.

I've found Aluminum sleeves like afco or qa1 from summit but I think steel would be better for rally.

Where can I buy lengths of coilover sleeve that's already threaded and ready to weld onto a shock body?

---

Michael LeCompte



Edited 1 time(s). Last edit at 10/03/2008 10:41PM by pikespeakgtx.

I found this setup for AE86 Corolla.

I've got those same bilstien strut inserts to fit the gab/tokiko housings for the GTX.

The spring perch needs to be removed and weld the steel coilover sleeves onto my existing strut housings.

Zinc coated sleeves would be ideal.

Need to spec out a set like this and decide on the longest spring length possible.

I'll likely run regular old 2.5" springs, none of that twin spring stuff.

P.A.S.S Racing
148 S.8th Ave, Unit-F
(626)961-6284
City of Industry
SYM@passracing.com
www.passracing.com

---

Michael LeCompte



Edited 1 time(s). Last edit at 10/03/2008 10:02PM by pikespeakgtx.

I found JVL's picture gallery useful. Looks like he made his own. What kind of steel tube is that?

http://www.rallyrace.net/jvab/spgm/index.php?spgmGal=JVAB_Specials&spgmPage=3&spgmFilters=

---

Michael LeCompte

The bilstien Front shocks have 5.375" (of free travel before hitting the bump stops.)
The bilstien Rear shocks have 6.5"

That means my bump travel is 5.375 x .6 + .5 safety margin = 3.725"
6.5 x .6 + .5 SM = 4.400"

What length of springs seems right? 10"? 12"?

Can I get this to work out to an inch or (two most) above stock ride height and be able to adjust to 1 inch lower than stock? Or +/- 1.5" from stock?

I'll have to get over to Joe's to use his scales to get accurate corner weights to really get an idea for spring rates. I'm thinking somewhere around 300lbs springs in front and 200-225lb rear.

Lengths:
12" up front and 14" rear
OR
10" up front 12" rear

Can someone who has more experience with rally suspension setup help me out with some words of wisdom?

I don't know the exact dampening specs of my bilstiens but they were revalved for a GTX (they're VW inserts). I figure I'll try em out on a good spring rate for my car and if they're wrong I'll send them out again.

Also I'm running 29mm front and 21mm rear roll bars.

---

Michael LeCompte



Edited 3 time(s). Last edit at 10/03/2008 11:38PM by pikespeakgtx.

I'm in the same boat - posted about coil over suppliers with no responses - but I did find these steel threaded sleeves:

http://www.colemanracing.com/catalog/product_info.php?cPath=49_1595&products_id=10647

They're ~$32 ea so curious how much the ones you postes go for. What I'm curious about most now is how universal these threads are.

Can't really help with your questions though.

Rabin

I'll probably need to make some threaded tube on one of the lathes at the shop.

The longer the threaded tube the better.. Ride height will depend largely on length of spring and at what height I have it adjusted.

Can some one please tell me what thread type, diameter, and pitch the threaded sleeves use (with the spring perches) typically use on steel?

The gland nuts are 48x1.5

How can I tell the optimal height to install the dampner insert into the threaded tube ???

---

Michael LeCompte

I'd say that the spring rates you listed are probably too high. The big ol heavy ass 3100lbs vsc subarus use like 250f 200r. And your mazda thing should weigh way less than those cars.

pikespeakgtx Wrote:
-------------------------------------------------------
> The bilstien Front shocks have 5.375" (of free
> travel before hitting the bump stops.)
> The bilstien Rear shocks have 6.5"
>
> That means my bump travel is 5.375 x .6 + .5
> safety margin = 3.725"
> 6.5 x .6 + .5 SM
> = 4.400"

So this is for a Corolla? McPherson strut front end? Is the 5.375" shock travel for real? You need to be shooting for around 8" +/- at the wheel; a bit less would seem OK for rally-x but not 5+ inches! That would only be OK for auto-x and a smoother paved hillclimb. (For reference, I would expect stock travel is 7-8".) Your math does not make sense for a strut front end, and the math operations appear to be inverted for a shock/spring-on-A-arm front suspension. So confirm the front suspension type (strut or a-arm) and restart from there.

BTW, JVL designs and sells this stuff for a living. I can't speak for him in any way, and he may choose to chime in, but I would not necessarily expect him to tell you how to do it. He is in this for his living, and has a family to feed, so only the motivation to be a good and helpful person exists for him to submit info for free. I can tell you stories about some customers of mine expecting us to give away our design work for free on top of the expense and time to view site...!

Regards,
Mark B.

starion887 Wrote:
-------------------------------------------------------
> pikespeakgtx Wrote:
> --------------------------------------------------
> -----
> > The bilstien Front shocks have 5.375" (of
> free
> > travel before hitting the bump stops.)
> > The bilstien Rear shocks have 6.5"
> >
> > That means my bump travel is 5.375 x .6 + .5
> > safety margin = 3.725"
> > 6.5 x .6 + .5
> SM
> > = 4.400"
>
> So this is for a Corolla? McPherson strut front
> end? Is the 5.375" shock travel for real? You need
> to be shooting for around 8" +/- at the wheel; a
> bit less would seem OK for rally-x but not 5+
> inches! That would only be OK for auto-x and a
> smoother paved hillclimb. (For reference, I would
> expect stock travel is 7-8".) Your math does not
> make sense for a strut front end, and the math
> operations appear to be inverted for a
> shock/spring-on-A-arm front suspension. So confirm
> the front suspension type (strut or a-arm) and
> restart from there.
>
> BTW, JVL designs and sells this stuff for a
> living. I can't speak for him in any way, and he
> may choose to chime in, but I would not
> necessarily expect him to tell you how to do it.
> He is in this for his living, and has a family to
> feed, so only the motivation to be a good and
> helpful person exists for him to submit info for
> free. I can tell you stories about some customers
> of mine expecting us to give away our design work
> for free on top of the expense and time to view
> site...!
>
> Regards,
> Mark B.


Thanks Mark, very true words there. Especially galling when people talk your ears off about their obscure French car for a couple of hours telling you why they want to keep certain parts of their stuff cause that's what whoever did 30 years ago but want it to work like modern, and then they go to their obscure websites and complain that "JVL is real hard to work with"--- and then come back after slagging you and ask for more design info.
VERY LAME.

Hey Mark weren't we 'spossed to be doing some fronts for the Starion?
Is it a good time for you?
I just did another run of 20 tubes.

---

Monika Hawkinson
Seattle, WA

No Mark this is for a GTX. The corolla stuff was an example of what I need.

I know that I need more like 8" shock travel for a true stage rally car but this is what I have for now. It's what's in the budget.

I actually think that 12" springs might work for both front and rear since my rears have 1 more inch of travel and since it's a softer spring rate in the rear the springs have more usable stroke and it's within the range of the stroke of my shock. But here's some calculations.

GTX Stock Front Strut: 178mm travel = ~7.36in
GTX Stock Rear Strut: 210mm travel = ~8.26in

Stock GTX spring rate is 130# front, 92# rear.

GTX has Front free length is 17.16", rear is 14.05"

Average Corner weights for GTX = 760FR, 515R

Assuming 300# front and 225# rear springs

Rearranging Hooke's formula we get x = -F/k

-760 / 300 = -2.533 so it's gonna compress the 300# spring 2.5 inches.

(So right there does that mean I've already lost half of my shock stroke?)

17.16"-2.533" = 14.63" FRONT Compressed height (stock is 11.3"

So you can see what spring rate does to compressed height.
A 300# 14" spring should yeild nearly stock ride height.
250# 14.5" is near stock height.

Calcs for the REAR

-515 / 225 = -2.288 so it's gonna compress the 225# spring 2.28 inches
14.05"-2.28" = 11.77" REAR Compressed height (stock is 8.4"
The springs are so soft it really compresses when stock spring.

11" spring with around ~200# should be about stock ride height.

So give or take 14 inch springs in front ad 12 inch springs in the rear should keep my car around stock ride height.
(edit: or...15 /13 or 13 / 11 with conventional springs.)

Hyperco goes up to 16" but they get expensive. Could go with 16 / 14.
http://www.hypercoils.com/Catalog.aspx

If I can position the insert in the extension tube in the right location so that the insert stroke is static until there is bump travel that would be ideal in this case. But I won't really know where perfect is until I install the springs without the struts and gauge static ride height.

http://www.swiftsprings.com/file/Standard_Race_Springs.pdf

---

Michael LeCompte



Edited 4 time(s). Last edit at 10/04/2008 07:59PM by pikespeakgtx.

Those steel ones for Corolla are 250/pair! RIP!

Bean you are correct according to my hardcopy catalog the site is wrong.
Those are the part numbers for the 7" long steel sleeves.

We'll have to get them and see if they'll work with run of the mill RH adjusters.
SN-424 Ride Height Adjuster $16


Edit: I looked at my coleman catalog and found IT!

421-700 Adjuster Sleeve 7" Steel 2.04ID $17 bucks each!

My shock bodies are 1.994. so It'll work out about right with a 46 thou clearance.

---

Michael LeCompte



Edited 2 time(s). Last edit at 10/04/2008 01:03PM by pikespeakgtx.

Ok good to know. What rates are you running in your VW carl?

---

Michael LeCompte

pikespeakgtx Wrote:
-------------------------------------------------------
> No Mark this is for a GTX. The corolla stuff was
> an example of what I need.
>
> I know that I need more like 8" shock travel for a
> true stage rally car but this is what I have for
> now.
Yes, but if this limited 5+" travel is all you can get, I would seriously try to sell them to a auto-x'r, and get ANYTHING longer, even junk-o-struts. When you hit the stop, if it is inside the strut itself, it will tear itself up pretty fast. And on the stops (either in the strut or external), the car is going to do wierd things, like suddenly push out. Seems like you will be hitting the stops top or bottom depending on which way you adjust the ride height, with this short of a stroke. ONe had better put in some really stiif springs to limit motion and forget matching to the dmaping rate....

I like to see folks trying novel approaches to stuff to save $$ and rally more, but this does not make much sense to me. Could be I am missing something in what you are trying.......and the math presented still makes no sense in a strut suspensioned car. I need to go look under the GTX sitting out in the driveway.....but I gotta fix a Caravan.....

Best of luck,
Mark B.

Yeah the math came from some book online about setting up suspension for race cars, you're right the bump stroke stuff probably doesn't apply. But the rest does.

This is what I have to work with. If I end up on the bump stops I'll get stiffer springs. If I run 12 inch springs all the way around then I'll have a range of springs to choose from. If I end up closer to a tarmac setup then that's what I'll end up with. You can find 12" 2.5" coilover springs for so cheap it's not funny. I've seen them as cheap as $25 each up to about $100 each for what I'd really want. Realistically I'll end up with something in the middle like Hyperco.

I'm not going to spend upwards of 2K dollars at this point. My car doens't have a cage yet...Whats the point? I can't really rally anyway. I can do SCCA and trackday stuff at infenion and thunderhill. AutoX all season here in Somoa, Hoopa Hill climb and whatever else.

I'll learn a lot more by doing this than buying them already done too.

---

Michael LeCompte



Edited 1 time(s). Last edit at 10/04/2008 03:35PM by pikespeakgtx.

starion887 Wrote:
-------------------------------------------------------

> I like to see folks trying novel approaches to
> stuff to save $$ and rally more, but this does not
> make much sense to me. Could be I am missing
> something in what you are trying.......and the
> math presented still makes no sense in a strut
> suspensioned car. I need to go look under the GTX
> sitting out in the driveway.....but I gotta fix a
> Caravan.....
>
> Best of luck,
> Mark B.
>
>
>

Listen to Mark...you're missing 2" of suspension travel compared to stock. Sell the lowered road stuff and do it properly.

Stock GTX struts:

Front: 178mm travel = ~7.36in
Rear: 210mm travel = ~8.26in