Tyler's 04 slicktop 6spd Silvergrey MCS/Brembo/CSL/Karbonius/Nogaros/Supersprint

[0-60motorsports]

The only thing I have really is the N: there's some decent whine at freeway speeds, but I put some sound insulation under the rear bench and almost eliminated it. There probably is some extra harshness as well, but nothing bothersome. I appreciate the much firmer power transfer from driveshaft to wheels so it was an easy trade for me. I've been happy for 9 years so much so that I never made changes, and Lord knows, I make changes if I'm unhappy.

Oh that's exactly what I have. What insulation did you use?

[Tbonem3]

The only thing I have really is the N: there's some decent whine at freeway speeds, but I put some sound insulation under the rear bench and almost eliminated it. There probably is some extra harshness as well, but nothing bothersome. I appreciate the much firmer power transfer from driveshaft to wheels so it was an easy trade for me. I've been happy for 9 years so much so that I never made changes, and Lord knows, I make changes if I'm unhappy.

[0-60motorsports]

Indeed! AKG 90a poly sub & diff

Thats interesting that you have no or Nice NVH with those. I am running the CMP solids with everything else OEM. RTABS have limiters but i'll be removing the inner limiter pad and leaving the outer onces.

[Tbonem3]

Indeed! AKG 90a poly sub & diff

[0-60motorsports]

Thats great news! What subframe bushings do you have T?

[Tbonem3]

Thanks Jon, maybe I'll see you around some day. I never seem to make it over to the roads off the 14/210 - I think I'm too spoiled by the ones in my backyard! But I should some time, just cause.

Ok, latest round of updates...

In January, did my annual oil change. Using up the last of my Castrol "sale" stock. With two "S" engines needing about 16L annually, I think I'll switch to Motul for 2024.




I also checked on my make-shift plug for the Karb's IAT port that I don't use. I had measured the ID of the port (think it was like 13mm) and then sourced a rubber stopper in the appropriate diameter. It was unnecesarily long, so I cut it down, leaving enough incase it migrated at all. But after a decent amount of driving, it hasn't budged.



Onto suspension...

The 400lb front springs (TCK 6.25"/60mm) were a great choice when I would push the car, at least in dealing with dips and keeping the front end from bottoming over certain sections, but it proved to be too stiff, when coupled with my hotchkis bar on medium, resulting in quite a bit of push or understeer. This is even after going up to 9" front wheels (though still a 245 mps4s). My first step was to move the swaybar down to the softest setting. While that did give me more grip, it still felt slow, just not as sharp as it was when it was on medium, but with 325b springs.

This was also at a ride height slightly lower than the typical 13.5", so while I was still concerned about bottoming out, if I did decide to lower the spring rate back down closer to the 325lb, I could at least raise the car a tiny bit to help combat it, and still be at an attractive height of 13.5".

So while starting the hunt to find the right spring (not always easy!), I got lucky and saw that ECS had an H&R (bilstein) set in 60n/mm (343lb) that was 7.1" tall (good for travel) and in the 60mm I needed for the MCS and my TMS plates on sale for $63 a pop so I went for it. I figured 343lb was close enough to my trusty 325lb, but with a slight increase in firmness that the MCS surely wouldn't mind at all. I have to say, the MCS were incredibly compliant even with the 400lb springs (on full soft setting!)



My MCS shaft bearings (to pickup tolerance between 14mm race dampers and camberplates made for stock 16mm) still looking good. Removing the TCK 400lb springs.



Had the hood up, so why not some glam shots of the engine/airbox?



I'll get around to affixing the M POWER decal at some point. Don't care for the unfinished look after all.

All done, rolled the car back and forth, and it seems like I've got it right at 13.5", but I probably will have to make small adjustments later, esp after I redo the rear springs.



Much better! *I also moved back to medium position on swaybar. This seems like the sweet spot so far. My main issue is still the rear being so under-sprung...

So now for the rear, I spent a lot of time thinking what rate I wanted to go with, that would also play nice with the hardware/perches I already had (or as I like to do, use the stock pad in some way). I saw that mrgizmo04 had put GC weight jacks and swift springs in his rear, so I asked if I could buy his rear Ohlins springs/perches as I wanted to try 628lb. I know the flatride spreadsheet would call for more like 700lb, but I just really don't like how harsh it is for what is still a street car. My rear end is also failry gutted, so 700lbs for me wouldn't be what it'd be like for a stock convertible, for example.





Me being me, I couldn't use the kit as supplied, heaven's no, I had to tweak something. Out of fear for repeating the experience I had when I tried 600lb springs on a GC perch with no isolation, I really wanted to make sure these ohlins were well isolated. I don't put up with much NVH- you' be surprised how quiet and luxurious the car is despite the myriad of modifications.



I didn't love that the top perch was simply plastic. Luckily, the pig tail of the spring matches pretty well to stock adn the stock rubber pad (5mm), so I decided to use it instead.

550lb eibachs - a little different in that they're a barrell spec and 6.5" so I was able to acheive 12.875-13.25" ride height depending on how many rubber sheet shims I used, while putting hte spring directly down onto stock rubber pad. The top GC cone made of poly was soft enough to isolate well - this setup was very compliant and quiet, but just not enough resistance to keep me from bottoming out on big dips at decent speed.
Versus the ohlins setup:



The Ohlins' perch has a rubber gasket to go underneat, and there's a plastic isolator for the perch seat itself. Seemed satisfactory to me.



I rotated the spring and wiggled it a little so that it caught on to as much of the "nipple" as possible. I doubt it moves under the weight of the car, but still... Great fit in the end!



I compressed the suspension a few times to look for any movement. The perch, itself (as opposed to just the spring), does lift its seat's outer edge off the control arm a little at full droop (I don't have a lot of droop), but the action was smooth and quiet, so I'm not concerned. The top didn't budge.

Back down, rolled it back and forth a little. got it pretty close to my desired 13.125-13.25" I'll have to tweak it all a bit, but good enough for test drive.



WOW! Much much firmer, but no issue for the MCS of course, and no noise or hashness! Mission accomplished. Took it to Little Sycamore canyon right before Sandstone peak there's a big dip, no bottoming out! Then a little later on Yerba Buena there's a smaller dip, but a faster section, and I was always scraping, but no more scraping now! Of course a stiffer rate would solve that issue, but I'm stoked because I accomplished it without making the car unbearable.


Car feels great, I'm really happy now after about 10 years of trying different suspensions. Parts are coming in for the next round of changes - HEL lines to replace the junk CM ones from ECS that I don't trust. Fedoro DS2500 came in as well as Motul RBF600. I'll probably install that stuff before I order the 9.5"et22 ARC wheels and whatever tires I go with. That will only help with brake fade in the canyons, I want the wider wheels with 265s for more front end grip.

[ChapterM3]

Terrific build thread - just had a look through the entire first page, and wow, so cool to see the car's journey. I'll look out for you as I see you're in the area - I'm usually around big tujunga or out to Palmdale and back, been hitting those quite a bit lately.

[Tbonem3]

I'll update this journal soon, but I've changed my front and rear rates since the last setup detailed ITT, which was 400lb/550lb. Just not in sync in terms of bounce freq, and too much understeer up front. Going down to softest setting on swaybar helped, but I still didn't love it. I mentioned previously that I went down to 343lb (6kg) up front, but I also went up to 628lb (120n/mm - ohlins) in the rear which is much less "pitchy" or a better ratio than before. I'll document the details.

And I'll put down my plans for the rest of 2023. I'm trying to buy a house, so I'm not fully focused, and I have some things I want to do with the E90, but I want to move up to 9.5"et22 wheels up front (from 9"et30), get hotter brake pads and fluid, and then go up to 265 for the front at elast, elaving the 275 in rear or maybe 265 square if I get all new tires at which point, I'd be looking at 200tw type tires like RE71r, a052, cup 2s. Thinking DS2500 for pads, already got some motul RBF600 for fluid. I'm still getting too much fade in the canyons, and I'm spoiled by the E90's front end grip, so I want to go up from my 9" wheels with 245 - it really doesn't feel any better to me than when I had the more common 8.5"et32 wheel with 245 tires.

[duracellttu]

Wondering if you made any recent updates to your spring setup? I've been driving on 400/600 and been liking it so far.

[DarrickRickard]

It looks very, very cool, I like it very much!

[Tbonem3]

Very nice 👍

[Seano666]

That's a great track setup, and this is a great build thread! My 2004 Silver Gray is basically stock compared to yours.

[Casa de Mesa]

Just so it might get more notice, I'm also posting here that I'm trying to organize a drive/meet this spring. Nothing grand, but something to get us started after such a long drought. Please see here, and provide feedback!

I wish I was closer. I'd take you up on this in a heartbeat!

[Tbonem3]

Thank you!

[Acarv_426]

I must have revisited this build-journal over a couple hundred times by now lol - Love it