JVAB for RS 2.5

I was talking to Evan Cline one day about the rear struts on his Subaru rally car and he mentioned teams were swapping rear spindles left to right to help rear geometry may be worth looking into. Not sure what it does but supposed to help with travel.

You guys need to Gusset the ears, just like the RSSP's.

I did these on my JVAB stuff, and after like 16 rallies they have slowly "crept" and bent, but no where near as bad as you guys. And that's at Open class speeds, and hit some really big stuff along the way.

At the very least, if you don't want to fully "gusset" them, you need to "box" in the top and the bottoms.

$2 in material + 10 minutes with a welder + a little spray of Kawasaki Green = a much more solid system.

A note if you decide to do so, only weld to the ears while you have the strut bolted to a hub. Front hub or rear hub doesn't matter bolt pattern is the same.

Quote
Do It Sidewayz
You guys need to Gusset the ears, just like the RSSP's.

I did these on my JVAB stuff, and after like 16 rallies they have slowly "crept" and bent, but no where near as bad as you guys. And that's at Open class speeds, and hit some really big stuff along the way.

At the very least, if you don't want to fully "gusset" them, you need to "box" in the top and the bottoms.

$2 in material + 10 minutes with a welder + a little spray of Kawasaki Green = a much more solid system.

A note if you decide to do so, only weld to the ears while you have the strut bolted to a hub. Front hub or rear hub doesn't matter bolt pattern is the same.

I've done some "capped" and just did Mark Piatowskis with a box inside welded on the ends. The RsspsPPssPPS are beautiful but I do not belive the little 2.5mm tall slivers of material materially strengthens the ears... the ones kinda in the middle of the ears...
I cannot get the nose of my welder in the gap for doing the "box between the ears" but maybe I can gety a smaller tip...

---

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.

this is a pic of our front DMS, I am talking about the little square of metal with the hole in it connecting the tops of the two ears. We did the same to the rear, top & bottom. Have not had a bend yet on the same roads that bent Alex's stuff. The welds do crack after a while as I said, but we clean them up & reweld as necessary when we service the struts. Is this what you call "capped"? Cause it has worked really well for us. (of course it is a Zimmer idea, not sure where he got it from)

Quote
xman
this is a pic of our front DMS, I am talking about the little square of metal with the hole in it connecting the tops of the two ears. We did the same to the rear, top & bottom. Have not had a bend yet on the same roads that bent Alex's stuff. The welds do crack after a while as I said, but we clean them up & reweld as necessary when we service the struts. Is this what you call "capped"? Cause it has worked really well for us. (of course it is a Zimmer idea, not sure where he got it from)

Yes that's the capped thing.
Look at your rears and you might see the "internal Box' thing I said I did on poor Matt Piatowskis Rally Light thing. Ears held up, But!! the INSERT still bent.

There IS a big bending force which is what I thing might be "resolved" by allowing the top to pivot or rotate....

---

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'm wondering , if the Ears did not give at all, what would have happened to my car with a fully strut stuck fully compressed after 3 stages of Gorman?

would the top mount have broken? or would the upper mounting point get torn/ destroyed?

broken top mount is still a bolt on part. but the upper mounting point would have given me a DNF

Maybe ears that won't bend or tear as long as the strut is working, but fail after the strut fails is a good thing?

I jumped the car at NNR, Mendocino, and on a test road by my house all with out any issues. all the other ears look perfect too btw...

I'm more curious why the insert bent in the first place? (I'm suspecting the driving i did when i had some unsprung travel may be the reason) but I'm not certain. I did do 1 rally, 2 rally crosses, and a really rough dirt drive (following jeepers) with the car having about 2 " of unsprung travel, and at times the spring would get stuck on the bottom lip of the upper spring perch (instead of seating correct) and I'd stop, jack up that corner and push it to the correct position... cause i had a bit of a noise develop after that...

Alex,
I've bent 2 inserts in my DMS in the past 5 years.

First time was in the front when I ran on a flat tire for 5 miles, the tire was gone off the rim after 2.5 miles. This was at Desert Storm in about 08. The strut seized and bent. My fault entirely.

Second time was a rear at Prescott. The rebound was set too high and the rear strut top mount ripped out of the rubber and banged around, not catastrophic as I found a spectator to loan me a strut top in service and the insert was not bent enough to seize the strut but I did replace it after the event.

I'd put my wager on your unsprung travel being the culprit.

Personally I like rubber parts to give before metal ones. So I like the way the setup has been working. I've seen several rear rubber top mounts give way, but before Burke, I've never seen carnage like his damage to the chassis mounting point before. I hope others can chime in, but that seems much rarer than failing rubber.

Quote
xman
Alex,
I've bent 2 inserts in my DMS in the past 5 years.

First time was in the front when I ran on a flat tire for 5 miles, the tire was gone off the rim after 2.5 miles. This was at Desert Storm in about 08. The strut seized and bent. My fault entirely.

Second time was a rear at Prescott. The rebound was set too high and the rear strut top mount ripped out of the rubber and banged around, not catastrophic as I found a spectator to loan me a strut top in service and the insert was not bent enough to seize the strut but I did replace it after the event.

I'd put my wager on your unsprung travel being the culprit.

Personally I like rubber parts to give before metal ones. So I like the way the setup has been working. I've seen several rear rubber top mounts give way, but before Burke, I've never seen carnage like his damage to the chassis mounting point before. I hope others can chime in, but that seems much rarer than failing rubber.

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.

---

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.

It looks like from the pics that the strut top location is off. When the springs coil bind it bends the ears. You gusset the strut more or change the angle of the strut or make it so they cant coil bind. more hiem travel wont help in coil bind situations. the angle is still wrong for hard impacts.

The struts are tipped back and the geometry of the suspension looks to bring the tire forward. Subaru suspension is good but there still not made for coil bind. Probably why teams swap spindles side to side. I agree with Jon I dont see unsprung travel bending an insert. Coil binding the suspension at the wrong angle will bend the shit out of the struts.

Quote
Reamer
It looks like from the pics that the strut top location is off. When the springs coil bind it bends the ears. You gusset the strut more or change the angle of the strut or make it so they cant coil bind. more hiem travel wont help in coil bind situations. the angle is still wrong for hard impacts.

The struts are tipped back and the geometry of the suspension looks to bring the tire forward. Subaru suspension is good but there still not made for coil bind. Probably why teams swap spindles side to side. I agree with Jon I dont see unsprung travel bending an insert. Coil binding the suspension at the wrong angle will bend the shit out of the struts.

This sounds like the problem. How about a set of those springs like Kern got for the BMW that have less windings?

Alex, can you do the math and see if the spring runs out of travel before the strut?

I'll be the first one to admit I dont know much about suspension geometry... however I saw this picure and I noticed the giant coil bind before i noticed the bent ears.

It looks like you might get less than 2 inches of travel out of it.... if someone could explain to me why this is ok i'd appreciate it; just doenst look right to me. If it's binding and there's no travel then wouldnt all the force be transfered to the top hat, and the ears that bent.







Edited 2 time(s). Last edit at 09/16/2011 01:35AM by czwalga.

Boys that strut is FULLY compressed. The bump rubber must have some dimentions of unknown thickness when its full compressed but its 90mm before compression, so even its say 10mm fully smooshed to the max that strut is FULLY compressed--or within a few mm of it.

There are still gaps between the coils. That doesn't look bound to me.
I will check in the morning with the folks at Blue Coils and see what they say, I cannot recall now ---since I've been suppying the same spring from the same place sitting on struts with the same travel for I don't know but 5-6 or 7 years now...

---

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.

Quote
Reamer
The struts are tipped back and the geometry of the suspension looks to bring the tire forward. Subaru suspension is good but there still not made for coil bind. Probably why teams swap spindles side to side. I agree with Jon I dont see unsprung travel bending an insert. Coil binding the suspension at the wrong angle will bend the shit out of the struts.

Do you know who is doing this and on what car #. I would like to take a look because this really doesn't make sense with the way the GC8 rear hubs are.

so some teams switch the rear hubs from left to right?

Quote
tdrrally
so some teams switch the rear hubs from left to right?

Sounds very strange.
If nothing else it would a) decrease wheel travel by X amount
b) serious fuck with required spring and damper rates.

---

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.