BumpStops and rally???

[BlackParis]

I love bump stops.. Currently on Paris with my stock suspension, I have 4.5inch bumpstops, (stock is close to 2.5inches).... on pavement it is awesome, the soft spring with stock height, car starts to roll a bit, and is then sitting on the bumpstop, gripping the corner, better than it did with ANY lowering spring ;)

Anyways, my question is for my Legacy.. I'm still assembling the suspension, making sure I got everything I need... Do you want bump stops on a rally car? if so do you want a little or alot? i would never run a car with less than an inch, just cause I like to jump and would rather hit a bumpstop, than the bottom of the strut...

I'm going to be running Outback KYB GR-2 most likely... with any combo of 175 200 225 lb 12 inch springs ;) Yes.. i spent alot on springs, so I can play with it and make it favorable to myself! :D

So I kinda understand Suspension travel FTW! for rally, but I dont want to damage anything prematurely, so I would imagine less bumpstop is better... I'm just worried about having too little bumpstop...

[Subie Gal]

you want bump stops yes.

when your bump stops break or are not existing
and you mess with the travel of the suspension

the car can and will flip over (yes this is the extreme end of the spectrum but it can happen)
of course this is in "performance rally" at speed and not rallycross...

and of course I am speaking from experience.

this is what broken rear suspension can cause:

http://www.subiegal.com/gallerymain/rallygallery/oregonrally2005/subaruwrxwagon-rally8.jpg

rear struts basically broke - seal let go -
struts filled up with mud/dirt/water throughout the course of the day.

then it happened,
NO BUMP NO TRAVEL into a high speed corner
car was upside-down in mid air before I could even comprehend what had happened

was not until weeks later we found the broken struts and the cause

Jamie http://www.subiegal.com/subiegal-smilie.png (http://www.subiegal.com/)

[BlackParis]

rear struts basically broke - seal let go -
struts filled up with mud/dirt/water throughout the course of the day.

then it happened,
NO BUMP NO TRAVEL into a high speed corner
car was upside-down in mid air before I could even comprehend what had happened

was not until weeks later we found the broken struts and the cause

Jamie http://www.subiegal.com/subiegal-smilie.png (http://www.subiegal.com/)

:shocked: wow....

The eventual plan is a stage rally.. Gotta do a season or 2 of just rally-x and I will probably change struts again before a stage rally..

Did the seal let go because you didn't have bumpstops?

May I ask what length bumpstops you are using now?

[I Like It Sideways]

you want bump stops yes.

when your bump stops break or are not existing
and you mess with the travel of the suspension

the car can and will flip over (yes this is the extreme end of the spectrum but it can happen)
of course this is in "performance rally" at speed and not rallycross...

and of course I am speaking from experience.

this is what broken rear suspension can cause:



rear struts basically broke - seal let go -
struts filled up with mud/dirt/water throughout the course of the day.

then it happened,
NO BUMP NO TRAVEL into a high speed corner
car was upside-down in mid air before I could even comprehend what had happened

was not until weeks later we found the broken struts and the cause

Jamie http://www.subiegal.com/subiegal-smilie.png (http://www.subiegal.com/)



Holy cow...

It makes that would happen, but I never thought the consequences would be that extreme.
I'd use bump stops just to save the struts.

[BlackParis]

I'd use bump stops just to save the struts.



I'm not asking wether to, or not... I am asking a length ? just stock ones? or should I get a little bit shorter or longer?

[williaty]

If you're running stock length springs, stay with stock length stops. If you're running non-stock length springs, change the bumpstop length accordingly.

Generally, you want the longest, most progressive bump stop engagement possible so long as the bump stop is not meaningfully engaged during normal use.

In other words, you want the bumpstop to start engaging as early as possible to make the lowest peak forces as the stop prevents coil bind or the strut bottoming out. However, if you go too long, you'll be riding on the bumpstops all the time like a stock STi, which really does horrible things to the handling.

[Subie Gal]

I was running bump stops
but when your struts have not travel - aka bottom out completely
it's similar to having no bump stops

the car pogo'd before I even knew what was happening....

nasty crash

I was lucky to get away with just a good bonk on the head.....


Jamie http://www.subiegal.com/subiegal-smilie.png (http://www.subiegal.com/)

[409industries]

hmmm bumpstop length isn't something that i've really though about before. Time to go do some reading...

[UP2MTNS]

i love having people like Jamie on this forum.....nice to get that level of experience for questions like this.

my bilstein PSS9's didn't come with bump stops.....I wish this question came up last year. I guess I'd have to custom order them from bilstein?

[Subie Gal]

i love having people like Jamie on this forum.....nice to get that level of experience for questions like this.

my bilstein PSS9's didn't come with bump stops.....I wish this question came up last year. I guess I'd have to custom order them from bilstein?


a lot of those who swap struts reuse the OEM bumps or cut them to fit :)


Jamie http://www.subiegal.com/subiegal-smilie.png (http://www.subiegal.com/)