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  • 3 weeks later...

This car’s setup is at home and in its element while on the smooth pavement of the track. I consider it a streetable track car when I need it to be a trackable street car.

I started down the path of shopping more street oriented coilover setups but was persuaded by Ground Control to try a “proven setup” by going from the 6” 525 lb/in front,  6” 650 lb/in rear springs, to some 6” 375 lb/in front/ 7” 430 lb/in rear.

For reference, VAC Motorsports classifies the following spring rate combinations:

Performance with Comfort 300/450 

Aggressive Street Car 450/500

Track days (minimal street use) 550/600

the 375 springs were unavailable and I felt that the rear to front spring rate ratios were a bit too close so I chose 350/430 as it matches the proportion of the current spring rates better.

I was concerned that the 6” fronts were going to be too low and ordered some urethane spring pads to add compliance and 3/4” of material to help with the ride height. 

The pads ended up not fitting as nicely as hoped on the front but I am running 1 on the rear springs. (Old 6” 650 lb/in rear spring on left, new 7” 430 lb/in rear spring on right)

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old 6” 525 lb/in front spring on left, new 6” 350 lb/in spring on right

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The new spring rates are almost smack dab in the middle of stock rates and the previous rates.

with everything together the rear sits 7/8” higher than before and the front sits 1/2” to 3/4” lower than before with no ability to adjust it any higher.

4C93E1A1-CC0F-4153-8B43-A7661B104F5A.thumb.jpeg.cbb87f27296c5e1a67b7a3432fa81fe7.jpeg

 

I welcome a slightly higher ride height for practicality but am targeting 1/2” higher overall from before as a starting point before getting it dialed in, mainly to provide more suspension travel before contacting the bump stops. Right now there is about 1”, which is what GC suggested. (For comparison, Stock E90 M3 has 1/2” of travel before hitting bump stops according to a bump stop article I was reading by Dinan).

 

DB302AEB-F8F5-4345-8111-90DFA76EDF90.thumb.jpeg.c23ad074f19aef6ec9a4e0381891364f.jpeg
 

My test drive was limited because there was some rubbing on harder turns from how low the front is. Hopefully not speaking too soon, but the ride quality is still firm. It feels like a lowered car. I definitely need to lower the rebound damping in the rear.   The best way I can describe the ride quality difference is there are certain bumps that make you clench, but hitting them now was not a clench-worthy moment.

Turn in is no longer razor sharp, but compromises have to be made.

I ordered some 7” long front springs which will actually allow for some height adjustability and wont clank around when the car is in the air.

Hoping by next weekend ~ May 1st I can have things sorted and ready to take to Big Bear for the final touches

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Delivery times for parts have been very slow lately.

I ordered 7” long 350 lb front springs instead of 6” long 350 lb fronts as well as some new pinch bolts for the knuckle/kingpin. It all finally showed up today and I got the 6”ers swapped out for 7”.

How is it?

Let’s use letter grades to compare the old 6” 525 lb/650 lb setup to the 7” 350 lb/ 430 lb setup.

Ride Quality Before: D+, fine on smooth roads, brutal on concrete roads/sea-sick on some freeways

Ride Quality Now: A-, its not a brand new Lexus, but for still being approximately double the stock spring rates, I dont believe the firmness of the ride would draw the attention of a normal person very readily.

-

Handling Before: A+, razor sharp turn-in, completely flat, and neutral. Automotive nirvana.

Handling After: B-, turn-in is not what im used to, body roll is there but pretty minimal, balance is biased to mild understeer at the limit which may be neutralized with another 0.5 degree of front camber. I’m probably getting ahead of myself as I still need to get the alignment and check to see if any sway bar preload needs to be neutralized.

-

Ride height before: B+, form follows function, but it looked great, if not just a tad higher in front than rear. Never any scraping or bottoming out.

Ride height now: C+, no rubs or bottoming out thank goodness, but the front is too low and I need to raise it up 3/8-1/2”.  
 

im expecting that I can get the handling up to a B+ and ride height to an A-.

im not there yet with the setup, but even as it sits daily driving will be even better than before. 

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  • 2 weeks later...
  • 3 weeks later...

Forgot to update this thread.

Decided to store some drugs purchased from a very seedy location in new berlin under the valve cover since the crankcase vapors are supposed to throw off drug-sniffing Kaisers.  I think one of the meth crystals bent a valve stem because cylinder 6 now has low compression. I didnt want to mess with it and figured id screw someone over while I could.

LOL new owner8FC0C23F-3501-4E87-95EF-D21B0EC43565.jpeg.e7f433dd9f8afb934c746aa2d7e27425.jpeg

 

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All kidding aside, I have a long list of cars that I want, but what you want and what you need are two different things. There are a few non-car-related goals i’m aiming for that influenced my decision to sell and once the dust settles i’ll see where i’m at and what makes sense at that point. 

image.jpeg.9f6b22980436be27c7c5ab64456b2e7c.jpeg

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