Shock / struts inquiry

[Y30]

Gentlemen,

I have a somewhat basic but necessary question. Ive searched through the forum a bit with no concrete answer.

I am looking to lower my 87 325is on H&R races but need to know how to purchase the appropriate shocks. I understand you need aftermarket ones because stock will blow if lowered enough.

That being said how do you know what the correct length/damper/rating is in order to purchase the right one?

Everyone suggests Bilstein sports but why is that? What about them makes them appropriate for this setup? I guess i am trying to do my homework and i want to know what specifics to look for in a proper shock or strut.

Any input is welcomed. Thank you.

[u3b3rg33k]

Gentlemen,

I have a somewhat basic but necessary question. Ive searched through the forum a bit with no concrete answer.

I am looking to lower my 87 325is on H&R races but need to know how to purchase the appropriate shocks. I understand you need aftermarket ones because stock will blow if lowered enough.

That being said how do you know what the correct length/damper/rating is in order to purchase the right one?

Everyone suggests Bilstein sports but why is that? What about them makes them appropriate for this setup? I guess i am trying to do my homework and i want to know what specifics to look for in a proper shock or strut.

Any input is welcomed. Thank you.

Anything bilstein makes is good stuff. IIRC, the sports are designed for lowered cars(shorter springs), and they have the valving to handle stiffer springs. I think if you run stock shocks with race springs you'll be horribly under-damped.

[JGood]

Gentlemen,

I have a somewhat basic but necessary question. Ive searched through the forum a bit with no concrete answer.

I am looking to lower my 87 325is on H&R races but need to know how to purchase the appropriate shocks. I understand you need aftermarket ones because stock will blow if lowered enough.

That being said how do you know what the correct length/damper/rating is in order to purchase the right one?

Everyone suggests Bilstein sports but why is that? What about them makes them appropriate for this setup? I guess i am trying to do my homework and i want to know what specifics to look for in a proper shock or strut.

Any input is welcomed. Thank you.

People suggest Bilstein Sports because they have a shorter stroke then stock shocks, so they won't bottom out. They have valving designed to work with most aftermarket lowering springs, which are stiffer then stock. There are other options like Koni, they are also designed to work with stiffer lowering springs, and some people do go with them. Bilstein Sports are very common because they are available everywhere, have a lifetime warranty, are durable, and work pretty well for H&R Sports and Races.

[DRTSRFR]

People suggest Bilstein Sports because they have a shorter stroke then stock shocks, so they won't bottom out.

This is not true on lowered platforms.

Check this...http://www.r3vlimited.com/board/albu...pictureid=5181

[th3blue]

all I can say is that I have bilstein sports with IE stage 3 springs and they work great. People love these because they are the best value. You can spend more for a little better, or less for a lot worse, but these have been around forever and work great for 95% of people who use them.

[JGood]

This is not true on lowered platforms.

Check this...http://www.r3vlimited.com/board/albu...pictureid=5181

OK, so they won't bottom out as easily. Obviously you can't dump a car 2.5+" and expect a 1" shorter shock to not bottom out. But for most of the common ~1.5" drop springs (H&R Race and Sports, Eibachs, IE's, etc..., like the OP was asking about) you will stay off the bump stops for the most part with Bilstein Sports. Especially with a camber plate that increases shock travel.

[Y30]

I appreciate the feedback thus far. But again, for this amount of drop that inam aiming for what are the stats i would want to look for in a shock?

If i was in a room full of different shocks what would i need to know in order to rule out most of them? How do you know if a shock is a short enough shock?

[JGood]

You'll never be in a room full of shocks with different valving and lengths that fit e30's. Have you done any looking online at what's available? There's like 10 options, that's it. There is no hundreds of shocks to choose from. Bilstein Sports, Koni Sports, Tokico, and a few more. They are sold as bolt-in, exact-fit units, there are no options. You don't choose your length or valving. They don't even really release that info or make it available for you to compare between various brands.

You can get the shocks you purchase revalved (with Bilsteins and Koni you can, anyway... but the service is almost as much per shock as the cost of the shock as itself). I'm sure Penske would fix you right up with some custom shocks... After you give them about $5k, haha. There are some less commonly known shocks available... I think Turner is still selling their J-Stock setup. But if you're going to spend all kinds of money on shocks and run them on H&R Races, that would be a waste... Unless you're bound by classing limitations in a track car.

[Y30]

Ok. That will satisfy my curiosity.

Sorry didnt mean to sound stubborn, i just always kept hearing the same names pop up and wanted to know if, with the right info, I'd be able to find maybe one that people don't often consider or a route less taken.

I just usually don't like to run blindly with the masses if there are other quality options that no one has taken the time to consider. You guys are all far more educated in this area so i figured i would pick your brains.

Thanks for the prompt responses.

[Hellabad]

OK, so they won't bottom out as easily. Obviously you can't dump a car 2.5+" and expect a 1" shorter shock to not bottom out. But for most of the common ~1.5" drop springs (H&R Race and Sports, Eibachs, IE's, etc..., like the OP was asking about) you will stay off the bump stops for the most part with Bilstein Sports. Especially with a camber plate that increases shock travel.

I am not arguing, I would just like to clarify:

The Bilstein Sport and HD are exactly the same length, and the same damping when compressed all the way. There is a one inch difference in length when the car is hanging ion the air, thats all.

Pic attached to help explain:

[Hellabad]

If i was in a room full of different shocks what would i need to know in order to rule out most of them? How do you know if a shock is a short enough shock?

Rough rule of thumb: If you lower the car 2 inches, you should consider a strut, or a combination of strut and upper mount, that is 2 inches shorter.

This decision is tempered by, and affected by the spring rate.
Example: a 350 pound spring will move half as far as a 175 pound spring, so you will actually need a *bit* less travel than pure linear math would suggest.

You'll never be in a room full of shocks with different valving and lengths that fit e30's.

Stop by GC the next time you are in Northern California, and you can meditate in a room full of e30 struts, and Zen Out until peace replenishes your life force.

[DRTSRFR]

...and then bath in our shock oil spa!:nice::nice::nice::nice:

[JGood]

I am not arguing, I would just like to clarify:

The Bilstein Sport and HD are exactly the same length, and the same damping when compressed all the way. There is a one inch difference in length when the car is hanging ion the air, thats all.

I stand corrected, thanks for the clarification.

Either way, I think most people on normal stock-size springs will be good to go with the Bilsteins. Obviously a shorted housing and shorter shock would be ideal for the most travel, but at that point you might as well not bother with stock-size springs anymore.

Stop by GC the next time you are in California, and you can meditate in a room full of e30 struts, and Zen out until peace overcomes your life force.

LOL, of course, I suppose if you DO want to be in a room full of e30 shocks, CG is the place to go.

Looks like a slaughter house in there!

[JGood]

Ok. That will satisfy my curiosity.

Sorry didnt mean to sound stubborn, i just always kept hearing the same names pop up and wanted to know if, with the right info, I'd be able to find maybe one that people don't often consider or a route less taken.

I just usually don't like to run blindly with the masses if there are other quality options that no one has taken the time to consider. You guys are all far more educated in this area so i figured i would pick your brains.

Thanks for the prompt responses.

There's many options, but if you are going to run a stock-size spring, the only reasonable option is to run a drop-in strut insert, such as the Bilstein or Koni. They've been proven to work great for thousands of people, and are cheap and plentiful.

If you get into the world of coilovers, then you can do whatever you want.. sectioned housings, shorter strut inserts (325ix Bilstein HD's are 3" shorter, for example). For the rear, some people are running various shocks... I've heard Camaro, MR2, etc... But unless you know the valving you're looking for, and the valving of the shock you're buying, it's all just a guessing game. Maybe contact GC, I'm sure they have all of that info and could assist you.

[Y30]

Thanks again guys. You never cease to amaze me at the vast amount of knowledge and the pics on hand to solidify your points.

Hats off to you all.

And pants off to some.

Just kidding.