[FaRKle!]

Index:
0:00 Intro and why we did this
2:04 Front strut modifications to use 60mm coilover springs
4:45 Rear spring pad modification
5:15 Ride and handling impressions

Some members have been unsatisfied with the ride their Bilstein B14/B16 kits have provided. Not very well known, is the fact that you can retrofit other springs to these kits to try and fix those issues.

The easier end to do is the rear, where you just need a new lower spring pad and can use 60mm, 65mm, or 2.5" coilover springs. ktw has done this with his B16 kit and went to a higher rear spring rate to achieve "flat ride." Here's what he had to say about it:

In terms of settling after bumps/dips, the experience is still kind of dominated by the harshness of the dampers, but I feel like the front and rear are more in sync. It also eliminated rocking that would take a second to dissipate when coming to a stop (not a problem itself but probably indicative of a larger problem), and the car feels more balanced in turns from increased rear roll stiffness.

andino decided to follow suit recently with his B14 kit, and in addition to increasing the rear spring rate, also retrofitted Swift 60mm springs to the front struts to bring the front spring rate down. Check out the video to see his impressions!

[ktw]

Nice work guys!

What length spring did you use on the front? Do you know how much bump travel there is remaining before the coils bind and how that compares to the damper bump travel remaining? I have previously tried to calculate these and was concerned that some low rate 60 mm springs would bind before the damper fully compresses (bump stops may prevent this depending on their length/stiffness, of course). Compared to the OE setup, the 60 mm adapter eats up some room, and the straight springs have less travel than the OE conical springs. I haven't tried it out though, and the proof is in the pudding!

Another potential option for the front dust boot to fit under a 60 mm spring is to buy a pair of H&R boots. I was wondering whether the wide original Bilstein boot would eventually get pinched and cut when the spring compresses, so I got a pair of H&R 592-100004 for ~$20+shipping. I never had a chance to see if it will fit on a Bilstein strut and won't end up using them, so I'm happy to pass them to anyone else looking to do the same thing.

[andino]

Originally Posted by ktw

Nice work guys!

What length spring did you use on the front? Do you know how much bump travel there is remaining before the coils bind and how that compares to the damper bump travel remaining? I have previously tried to calculate these and was concerned that some low rate 60 mm springs would bind before the damper fully compresses (bump stops may prevent this depending on their length/stiffness, of course). Compared to the OE setup, the 60 mm adapter eats up some room, and the straight springs have less travel than the OE conical springs. I haven't tried it out though, and the proof is in the pudding!

Another potential option for the front dust boot to fit under a 60 mm spring is to buy a pair of H&R boots. I was wondering whether the wide original Bilstein boot would eventually get pinched and cut when the spring compresses, so I got a pair of H&R 592-100004 for ~$20+shipping. I never had a chance to see if it will fit on a Bilstein strut and won't end up using them, so I'm happy to pass them to anyone else looking to do the same thing.

I used an 8" 60mm spring up front. In my driving so far, I haven't noticed any coil bind when using all the travel (though I have hit the bump stops).

I ordered a set of skinny (blue) bilstein boots as well as some Eibach coil spring covers. They haven't arrived yet so I haven't had a chance to test them out yet.

[FaRKle!]

Originally Posted by ktw

Nice work guys!

What length spring did you use on the front? Do you know how much bump travel there is remaining before the coils bind and how that compares to the damper bump travel remaining? I have previously tried to calculate these and was concerned that some low rate 60 mm springs would bind before the damper fully compresses (bump stops may prevent this depending on their length/stiffness, of course). Compared to the OE setup, the 60 mm adapter eats up some room, and the straight springs have less travel than the OE conical springs. I haven't tried it out though, and the proof is in the pudding!

Another potential option for the front dust boot to fit under a 60 mm spring is to buy a pair of H&R boots. I was wondering whether the wide original Bilstein boot would eventually get pinched and cut when the spring compresses, so I got a pair of H&R 592-100004 for ~$20+shipping. I never had a chance to see if it will fit on a Bilstein strut and won't end up using them, so I'm happy to pass them to anyone else looking to do the same thing.

The 8" spring (Z60-203-050) andino used doesn't look like it's at risk of coming into coil bind because the damper can't compress enough to do that. It'll be stopped by the bump stops first. If you look at the car in the background during our test drive debrief, that's with the front spring perches at the absolute lowest.

If I ended up going to an adjustable front strut by taking my FCM tuned B6 cartridges and putting them into B14 strut bodies I'd also grab 60mm to 65mm (or 2.5") adapters so I can run larger ID springs that would accommodate dust boots better. It also would allow me to use Hyperco springs, which are generally cheaper (~$55/spring).

[ktw]

Cool. Great work again guys, and a nice video!

[DLag30]

Just did this. Thanks for all the info!

I did end up using a set of rubber booth from eBay "Godspeed Coilover Strut Shock Absorber Dust Boot Cover with Bump Stop (set of 2)". Perhaps on the short side on full droop, but instructions on my Ohlins RT mentions cutting the rubber booth to similar length. I'll update my post when I install them next weekend.

[Cobra358]

Did you get on a skid pad before and after the changes? I always do that before and after when making spring or ARB changes. It seems like the car would go from significant understeer to neutral or over steer now? I didn't calculate it, but that is a big change in wheel rates, front versus rear.

[Olivi4rFTW]

Originally Posted by DLag30

Just did this. Thanks for all the info!

I did end up using a set of rubber booth from eBay "Godspeed Coilover Strut Shock Absorber Dust Boot Cover with Bump Stop (set of 2)". Perhaps on the short side on full droop, but instructions on my Ohlins RT mentions cutting the rubber booth to similar length. I'll update my post when I install them next weekend.

wich h&r springs are this? could you share some partsnumber's pleas?
im located in europe and have been struggling with coilbinding on my B16 kit. tough its hard to find other springs since we use the metric system and most posts here are in inches ^^


TIA!

[_ObiJon]

Originally Posted by Olivi4rFTW

wich h&r springs are this? could you share some partsnumber's pleas?
im located in europe and have been struggling with coilbinding on my B16 kit. tough its hard to find other springs since we use the metric system and most posts here are in inches ^^


TIA!

If you're referring to the red springs, those look like Eibachs. Have you looked at HyperCoils catalog?

https://www.hypercoils.com/shop/coilover-springs

[Olivi4rFTW]

Originally Posted by _ObiJon

If you're referring to the red springs, those look like Eibachs. Have you looked at HyperCoils catalog?

https://www.hypercoils.com/shop/coilover-springs

i even messaged to the head importer/seller of eibach, and even they arnt able to order the one from the picture without them being stupid expensive due to shipping & tax's etc.