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So basically stay away from the EM coil overs at least on the rear? I was told by Van Steel that their rear coil over bolts up to an early c4. Taking notes here in case I do decide down the road to go with coil overs.
My big concern at the moment about the EM kit is how the rear upper mount works. If there's no bushing in it and no spherical bearing, then there's no compliance for the two different arcs the shock has to follow at its lower mount. That's a very bad setup if true. And that's after one makes one's own upper mount to move it forward enough. And after all that, you still have a coilover bolted to a cantilevered aluminum mounting ear on the knuckle, and a goofy perch that's almost impossible to adjust without taking things halfway apart. I might be wrong about this, but I think lots of company's coilovers would fit in the rear of any C4. The Van Steel and Ridetech kits appear to address every single issue I just noted. The problem with the front setup from EM, as I see it, is that it must use some kind of strange spring diameter that isn't easily available in lots of different spring rates. IMO that's a no-go. They don't even tell you what the rates of the springs that come with it are. Ultimately, the better answer may be one that owners of early C4s don't want to hear: if you have to go with coilovers, the best option is probably to modify the upper shock mount to accept a later-year coilover setup.
My big concern at the moment about the EM kit is how the rear upper mount works. If there's no bushing in it and no spherical bearing, then there's no compliance for the two different arcs the shock has to follow at its lower mount. That's a very bad setup if true. And that's after one makes one's own upper mount to move it forward enough. And after all that, you still have a coilover bolted to a cantilevered aluminum mounting ear on the knuckle, and a goofy perch that's almost impossible to adjust without taking things halfway apart. I might be wrong about this, but I think lots of company's coilovers would fit in the rear of any C4. The Van Steel and Ridetech kits appear to address every single issue I just noted. The problem with the front setup from EM, as I see it, is that it must use some kind of strange spring diameter that isn't easily available in lots of different spring rates. IMO that's a no-go. They don't even tell you what the rates of the springs that come with it are. Ultimately, the better answer may be one that owners of early C4s don't want to hear: if you have to go with coilovers, the best option is probably to modify the upper shock mount to accept a later-year coilover setup.
The top of the rear coilover has a spherical bearing in it, and is pushed forward by some washers. Everyone who considers it should do their homework obviously, I'll continue to update every 6 months or so on how they are working for me.
I will say with the 30/25 sway bar combo and coilovers have helped me and the car become very very competitive in my class and the suspension was the only thing to change from my most recent race to the last. Went from mid/bottom of the pack to a top 5 finish
The top of the rear coilover has a spherical bearing in it, and is pushed forward by some washers. Everyone who considers it should do their homework obviously, I'll continue to update every 6 months or so on how they are working for me.
Aha! That's the info that was missing, and you can't tell from the pics on their website. Okay, so no bind issues, which is really good. Given that, I agree that I'd put that SRG bracket in there for insurance, and then I'd send it.
Last edited by MatthewMiller; Jul 5, 2020 at 03:17 PM.
Van Steel now sells those brackets ready to bolt-on.
To install this bracket on the 84-87 ; the original welded bracket needs removed. The rail will need modified for the bracket. The 88-96 uses a stud on the end of the shock, it mounts to a plate bolted to the rail.
. Ultimately, the better answer may be one that owners of early C4s don't want to hear: if you have to go with coilovers, the best option is probably to modify the upper shock mount to accept a later-year coilover setup.
Merle certainly didn't tell me that. I called and did my homework the best I could and I never found or was told anything about the bottom bracket needing to be pushed forward on the rear knuckle shock bolt. I'll try my stock bolts and see if I have any luck since I certainly don't have the tools nor the skill to fabricate something like that.
There's a lot of things Merle won't tell you. Did he tell you that you will most likely snap the top off the shaft of the shock? Did he tell you that the C4 rear knuckle will break right at the shock mount? I have been through all of this and the only thing that was not failure of his parts was the rear knuckle breaking and I can guarantee you it will unless you do something about it. Type rear knuckle breaking at shock mount or shock mount breakage with coilovers into the search. After one rollback truck ride home and another time where I almost needed a rollback again, I decided to make/modify my rear mounts and then do some homework with the QA-1 catalog I tossed all the EM **** and got QA-1s all the way around.
Last edited by Midnight 85; Feb 5, 2021 at 11:56 PM.
Reason: added info
I wonder if Ridetech would sell just their rear coilovers setup. It addresses all the problems with a different top shock bracket mount, and reinforced lower shock bracket for the spindles?
Any updates on the SRG bracket? I'm thinking of ordering it as well.
Honestly, I haven't installed them yet. I have 8 Autox sessions without them so far and about 4,000 miles total without a rear knuckle explosion. I will eventually get them installed at some point but between my work schedule and the Pandemic I don't get much time to put in work on the car, I kinda just get in and race and take it back home.
Just thought I'd update this I sold the Purple C4 with the EM coilovers. They still functioned properly and with the added bracket and some fabrication it seem strong, If you want coilovers cheap they are a decent option with the SRG/custom bracket. As far as I know the car is still being raced in South Texas
I will say on my new 89 I spared no expense and went with the Full Ridetech treatment, Installation was a absolute breeze and all the brackets fit with no issues. The front sway bar was a bit of a pain to get in but other than that it's the far superior setup
Last edited by L98Justin; Apr 12, 2021 at 09:19 AM.
Thanks, good to know. How do the Ridetech brackets compare to the SRGs, and what fabrication did you have to do?
They were similar in looks, the SRG were much much heavier though. A shop had to weld up a different bracket with a slightly wider opening for the coilover to mount too, EM uses the standard bushing type vs everyone else using an heim joint. I never got the car up to speed after they were installed since I was having some EMI issues with the aftermarket ECU but Imagine they are fine.
All together even with the SRG and the welding cost these came in at @$1600-$1700 vs the Kit I bought from Ridetech @$3,070. If I bought another pre 88 I'd buy the EM coilovers again without much thought, on any other C4 I'd say just pony up the money and go with Ridetech or Vansteel
Yedister, here are the measurements of the bracket to be able to adjust the rear coilover unit forward and aft to get the spring to miss the axle.
The 2 1/4" inside measurement between bolt holes allows you to place the shock in position so that the spring clears the axle, then measure and make spacers to suit.
