E30 Ground Control Coilovers- Need fresh shocks/struts, looking for suggestions

[CMG]

I have the GC DIY coilover kit and suspension is getting soft and shafts are getting oily so time for rebuild/replacement. I currently have Bilstein Nordsclhleife and no complaints with performance. From what I saw on GC website, looks like they only offer standard koni sports and do not have any custom options. One avenue I was going to look into was bringing the shocks/struts to Bilstein corporate HQ (which is local) and asking for a rebuild. They used to do that sometimes back in the day but anybody done that recently? I do have a set of Stagg that technically would work but not sure how well, anybody tried those? Otherwise I would just get Koni Sports, but I happened to see some KYB AGX which are 1 way adjustable, anybody use those?

[mtech325]

Ground Control has sold me their short body revalved shocks separately in the past, I think at the the time it was like $1200 bucks a few years ago but it may have been because I already had the DIY kit plus their camber plates. You'll probably have to call or email them to see if they'll still do that. At the time it made sense since I had stiffer spring rates, but I eventually went back to the street rates of 375f 475r and would have just bought the regular Koni Sport shocks if I were to do it again. The downside is the rear shocks have to be removed to make adjustments vs the top adjustable GC specific Koni rears, but usually I adjust it once and then leave it alone for a mostly street car.

Bilstein are good quality shocks, but having tried them with stock springs, lowering springs, and even coilovers, they always rode a lot harsher than a similarly equipped car with Koni shocks (at least in the e30 and e36 applications). The yellow Bilsteins do take the cake for longevity though as they seem to last forever.

[CMG]

I definitely prefer koni over bilstein, but if bilstein still honors their lifetime warranty that would be perfect for long term ownership. I looked into it and they still have a warranty but haven't confirmed if they still honor it for normal age wear and tear. I am really tempted to use the Stagg, just because I already have a set...and also for shits and giggles and curiosity.

[Northern]

I have Koni 8610-1437-RACE inserts up front with shortened housings, and one of the mustang part numbers in the rear and it feels good with 450/650 rates.
Depending on the price of the race inserts, I might be tempted to do a different off-the-shelf Koni SA

The iX insert fits and seems to work fine with 450lb/in up front but it is definitely softer, so it probably isn't going to work with stuff much stiffer than that.

If you swap insert brands, you will need new spherical bearing collets from GC (or I think you can basically just cut the existing ones down/use washers to adapt whichever way it needs to go, I can't remember where the difference was.)

Edit: Koni now makes a ton of different length single-adjustable RACE inserts. So I would probably pick up one that fits a shortened strut without a spacer underneath.

[CMG]

Sounds like you've been doing some experimenting with shocks/struts.

[CMG]

I just went with Koni sport cuz those were best price.

[CMG]

So far Konis have been fine for basic daily driving. They are set one above low, I would have to stiffen them up to be able to compare them to Bilsteins. The Konis also required an additional insert for the cartridge, so that means they are a little different in size compared to bilsteins.

[e30davie]

yer ive had koni yellow sports for a few years, I cant compare them to Bilsteins as ive never had them, but they have been excellent for me. sporty enough to enjoy light track driving, but compliant enough to be perfectly fine on the street.

when i bought my konis i had them put on a shock dyno for interest, and you can see why they many say they aren't as harsh as the Bilsteins. they have alot of control in the low speed sections, but in the really high speed they don't have as much as the Bilsteins so they let the wheels move around a bit.

If interested I can post the graphs?

I contacted ground control years ago and tried to be a stingy bastard and tried to buy their koni shocks separately (as they told me they were valved specifically for them) but they wouldn't sell them to be separately without their coil over kit, which is fair enough i suppose. So they are different to regular sport shocks, but who knows by how much.

I actually used the KYB AGX in an ke70 corolla years ago (basically ae86 suspension in a corolla box). its going back a few yrs, but i wouldn't hesitate to use them again given the opportunity. but its been along time, and i cant compare them to the konis. but the kyb agx were more affordable than the koni i think. The kyb AGX were alot better than the regular kyb excel-g that's for sure.

[Northern]

If interested I can post the graphs?

I contacted ground control years ago and tried to be a stingy bastard and tried to buy their koni shocks separately (as they told me they were valved specifically for them) but they wouldn't sell them to be separately without their coil over kit, which is fair enough i suppose. So they are different to regular sport shocks, but who knows by how much.

Would enjoy the graphs.

I had Bilstein Sports at one point, but the RWD E30 ones don't compress enough to use with coilovers even if you trim the bump stop. Even with H&R Race, I found they bottomed out a lot more than I would've liked.

If you cut the strut housings, the iX fitment Bilstein HD are shorter and fit but have much softer valving for some reason.

My old M3 had a GC kit but stock length housings because the PO didn't want to cut the struts. I tried to get some shortened Konis out of GC and was not successful either, so I ended up selling the kit with the car and buying the Koni Race inserts for the front, and mustang konis for the rear (I think there are better rear options now)

[moatilliatta]

Whats the spring rate?

Seems like Bilstein valving is to aggressive till you get into spec E30 Rate kit.

Koni's always like to leak and overheat on track and get soft quick. They feel great on the street though.