Mix of WRX and STi springs on BG Outback?

[dvancleve]

Howdy folks.

I have a set of low mileage WRX wagon take-offs that I planned on putting on my '97 Outback. Based on a spring rate chart I came across on NASIOC (don't know if this is frowned upon, but see it here: http://forums.nasioc.com/forums/showpost.php?p=35536436&postcount=339), the Legacy wagon and presumeably Outback have 190 lb/in rear springs. The WRX wagon (5MT) has only 132 lb/in, but the STi has 194.

So the stock Legacy wagon was 132F/190R, the stock WRX wagon 163F/132R and the STi 224F/194R.

Any thoughts on WRX front springs and STi rear springs? It would mess up the F/R balance ratio (both WRX and STi are about 30 lb/in stiffer in front), but would not sacrifice the load carrying ability that I presume led Subaru to spec stiff rear springs in the wagons. The front would be stiffer than stock, relative the to back and it seems like it might help with the saggy bottom appearance unless stock USDM STi springs are shorter than WRX.

Someone on NASIOC opined that stock WRX struts should only be used with 215 lb/in or less springs. That would rule out the front STi springs but not the rears. What do you think?

Thanks, Doug

[Huffer]

In terms of spring rate, you could certainly use the WRX front springs and STi rear springs.

The issue is going to be one of strut length and ride height because the STi typically sits about 1" lower than the same year WRX. This is what contributes to it's improved handling, besides the spring rates and firmer rebound on it's shocks.

You're really going to have to compare the rear springs from the WRX and STi side by side.

[dvancleve]

Thanks :)

I am pretty sure the struts don't matter, at least not much. There are quite a few aftermarket struts that use the same part # for all Impreza models through 07. I will see if I can get a spring height for the STi rears. I have a loose set of WRX wagon rears on hand that I can measure. I guess it would come down to figuring out how much the STi would lower the back relative to the WRX and then get saggy butt spacers (and possibly the longer tophat studs) to even things back out. I wonder if it is worth it?

Doug


In terms of spring rate, you could certainly use the WRX front springs and STi rear springs.

The issue is going to be one of strut length and ride height because the STi typically sits about 1" lower than the same year WRX. This is what contributes to it's improved handling, besides the spring rates and firmer rebound on it's shocks.

You're really going to have to compare the rear springs from the WRX and STi side by side.

[Garrison]

In terms of spring rate, you could certainly use the WRX front springs and STi rear springs.

The issue is going to be one of strut length and ride height because the STi typically sits about 1" lower than the same year WRX. This is what contributes to it's improved handling, besides the spring rates and firmer rebound on it's shocks.

You're really going to have to compare the rear springs from the WRX and STi side by side.
Informative post, thanks.

What would sti springs do to forester struts?

[Huffer]

I guess it would come down to figuring out how much the STi would lower the back relative to the WRX and then get saggy butt spacers (and possibly the longer tophat studs) to even things back out. I wonder if it is worth it?

Doug

If you're going to install the saggy butt spacers, you might as well just bolt on the entire STi suspension then (04 STi and earlier only), then install your spacers. Otherwise you're mickey-mousing it a bit too much for my liking.


What would sti springs do to forester struts?

STi springs on Forester struts won't lower it much - the shock height is tall - but the rebound rate will go up dramatically.

[Garrison]

Excellent. So a stiffer ride without chancing the bottoming out of my shocks, right?

[dvancleve]

This may give you some insight into how various springs would affect a Forester, although the focus is on raising an Impreza with Forester stuff: http://www.ultimatesubaru.org/forum/showthread.php?t=122152.

Doug


Excellent. So a stiffer ride without chancing the bottoming out of my shocks, right?