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      07-23-2013, 08:26 PM   #1
fullerra
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AST 5300 install

Hey Guys,
After going back and forth for nearly a year, I finally pulled the trigger on a new suspension set-up. Previously I was running Bilstein PSS10s with Turner camber plates (still up for grabs!), and was fairly happy with them, but was starting to see their limitations on a car mostly used for the track. Mainly the spring rate seemed too soft and at times would bottom out if i hit a curbing with a bit too much zest. Additionally I got A Lot of rear end squirm under heavy turn-one type braking, which would make me end up braking much earlier, in order to maintain control.
After looking at a couple options from Nitron, and JRZ (which are both top-notch) I decided on the AST 5300. I should say that AST technically does not have a specific kit designed for the E85/86, but the suspension geometry is similar albeit shorter travel to the E36. After a couple conversations with John over in Plano, Tx (AST/Moton USA HQ) we decided on the following:

AST 5300:
600lb spring in the front, 785lb in the rear
keep the divorced set-up for the rear... If I went to a true coil-over, I would run a lower spring rate because of the difference in spring location and hence motion ratio.
The rears for this kit have a piggy-backed reservoir, as opposed to a true remote canister with a hose. This can be built, but for ease of installation (not drilling into back of chassis) I decided to keep the original.

Installation was performed at Fastrack Auto in Peabody, MA. I cannot say enough good things about these guys. We ran into a hiccup with the spring size, Initially I was sent a 5.5" rear spring, which would not allow the ride height to be optimized in the rear. Knowing that I had a couple track days coming up within a week, John at AST overnight shipped the correct size spring, and the owner from Fastrack came in on his day off to install the rear springs, perform the alignment and corner balance!

The other major upgrade would be the Superflex poly FCAB
Thanks inTgr8r !


On to the good stuff!

Corner balance 3/4 tank of gas:
Total weight w/o driver 3161lbs
Cross weight percentage w/ driver 50.0
Front % 50.5 Rear %49.5

Front: Camber -2.7, Toe 0
Rear: Camber -1.8 Total Toe 1/8

Front and Rear initial damping (all out of 11 clicks) 2 turns from full soft high speed compression, 4 turns from full soft low speed compression, Rebound 5 turns from full soft.


I was a bit apprehensive with this spring rate in Boston, but I would honestly say that this was as comfortable as stock, if not slightly more so. There was NO bottoming out, ride was not bouncy, not jarring in the least. My 6hr ride to the Glen would have been outright comfortable had it not been for the pulled A/C compressor, and the deafening sound w/ the Fabspeed headers and RPI exhaust (earplugs are a guy's best friend)

On track, these things were AWESOME. Extremely stable through the Esses, I was able to hit the rumbles at the bus stop about 5-10mph faster this than the Bilsteins without unsettling the car. It was so confidence inspiring that DSC came off (I know I've been a puss for keeping it on for so long)

As for the FCAB... hard braking... straight as an arrow, no squirm whatsoever! braking at least 100ft deeper in every corner.

Total time shaved from last yr...8s! Once my actual driver skill closes in on the level of the car, there are easily another 8s to be shaved.

Installation points... I am running CCW classics front and rear 8.5" and 9.5" respectively w/ Nitto NT01 245 and 275 section width tires. There is a 3mm gap in the front between the tire and strut w/o spacer. I did add a 5mm spacer for extra gap, keeping enough lip on the hub to not worry about vibration.

Thanks for the excellent forum, I hope I was able to contribute meaningfully!
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      07-24-2013, 11:44 AM   #2
a_riddler
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Looks great! And thanks for the write-up!
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      07-24-2013, 11:48 AM   #3
dorifto88
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amazing !
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      07-24-2013, 01:21 PM   #4
Kgolf31
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jealous of your 5300s. give them to me
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      07-25-2013, 01:20 AM   #5
Finnegan
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Very nice outcome, great write-up! Enjoy! 8s is huge!
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      08-06-2013, 08:06 PM   #6
ProdigyM
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looks really nice my man. angel lights look really damn cool as well. Glad you enjoy them, i'll consider these when i begin to look for coilovers.
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      08-06-2013, 10:36 PM   #7
seank
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One of the best for the price. When you go mono tube or external, you can run very high springs with a comfortable ride on the street.
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      08-13-2013, 09:36 AM   #8
nekky
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Badass setup. Very cool!
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