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      10-21-2017, 03:14 AM   #1
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Talking High performance AX Coilover that allows stock springs

I am preparing to set-up a Z4MC for B Street Autocross(in case you missed that...). The car will also be street driven on reasonably smooth roads. The car will be run at stock height/with stock wheels shod with 265rr & 235ft RE71Rs for Autocross.

The car will run 18x9.5 PS-7 w/265-35-18 PSS square on the street. While on the street I will run Turner Camber bolts and shims plus appropriate spacers. The Turner bolt/shim & spacers will be removed for autocross.

The ideal set-up would be a quality Coilover set that can accommodate stock springs and "stock style" mounts, perhaps utilizing spring adapters with stock size contact areas.

The damper should be of a style and quality that does not require yearly rebuilding in the face of ~3.5K miles a year of street use plus ~8-10 AX events per year.
A rebuild maybe every 15-20K miles is acceptable if it is a mainstream company that is likely to be around in 5-10 years.


Since TTOD is unlikely, a PAX'd B Street may be more satisfying in the short term, Maybe....
I would set aside the pillowballs and small diameter coils springs for when faster is better than placing well. I imagine Shaft size will be a challenge?

Having been down the road of buying "sport" dampers and perpetually upgrading, I am hoping that my imaginary set-up is available that will allow me to run stock springs and stock or "similar" to stock mounts.

I have experience with a wide range of set-ups on RX7 2nd gen road race car and Supra MKIV ranging from road race GC Advanced design DA to JIC FLTA2 SA on my street Supra. Along the way, I tried everything from Tokiko and Koni sport dampers to full race DAs so please do get reasonably technical in thoughts and suggestions.

In the end, if I can buy an off the shelf coilover set such as the B16 PSS10 and custom spring adapters that will allow stock springs. I don't know and would like to learn what dampers have the range to accommodate both the aftermarket and stock springs.

I will also need sway bars to complement this, suggestions to complement the above imaginary dampers?
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      10-21-2017, 05:40 AM   #2
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Contact Kale Bushmeyer at TC Kline Racing. He's successfully campaigned a Z4 on the national Solo Tour and at SCCA Nationals. I was looking at having them build a set of dampers for me, but have held off while I tune the driver a bit more. Here's what he had proposed for me. This was late 2014 so the pricing may be a bit higher currently.

kale@tcklineracing.com

My query to TC Kline:

I believe per the 2014 rule book, struts with adjustable spring perches can be used but they have to be used with the stock coil spring and the lower spring perch has to be at the same height from the spindle and the OEM strut.

Kale's response:

Here are the options that you would basically have:

You can purchase a Sport shock with the OEM spring perch and we would gut the internals and turn it into a DA shock (this is just for the front). It would be about $300/side to modify the shocks, plus the cost of the sport shock $224.50. So it would be approximately $525 per side for the fronts. The rears, you can just bolt up with the stock springs in their normal location.

Your other option would be to purchase a pair of our Double Adjustable Struts for the front, and then you would need to have a machine shop attach your stock spring to an adjustable spring land that can be threaded onto the threaded body of the Coilover. The advantage to that would be you could eventually take off the stock spring and it would be ready for an adjustable spring land with linear spring rates. The Double Adjustable Coilovers would cost $539 per side, plus whatever cost to attach the spring land to your stock springs.
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      10-23-2017, 02:46 AM   #3
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Quote:
Originally Posted by dc_wright View Post
Contact Kale Bushmeyer at TC Kline Racing. He's successfully campaigned a Z4 on the national Solo Tour and at SCCA Nationals. I was looking at having them build a set of dampers for me, but have held off while I tune the driver a bit more. Here's what he had proposed for me. This was late 2014 so the pricing may be a bit higher currently.

kale@tcklineracing.com

My query to TC Kline:

I believe per the 2014 rule book, struts with adjustable spring perches can be used but they have to be used with the stock coil spring and the lower spring perch has to be at the same height from the spindle and the OEM strut.

Kale's response:

Here are the options that you would basically have:

You can purchase a Sport shock with the OEM spring perch and we would gut the internals and turn it into a DA shock (this is just for the front). It would be about $300/side to modify the shocks, plus the cost of the sport shock $224.50. So it would be approximately $525 per side for the fronts. The rears, you can just bolt up with the stock springs in their normal location.

Your other option would be to purchase a pair of our Double Adjustable Struts for the front, and then you would need to have a machine shop attach your stock spring to an adjustable spring land that can be threaded onto the threaded body of the Coilover. The advantage to that would be you could eventually take off the stock spring and it would be ready for an adjustable spring land with linear spring rates. The Double Adjustable Coilovers would cost $539 per side, plus whatever cost to attach the spring land to your stock springs.
The second option is precisely the direction I am headed, Not clear on whether the damper would require re-valving. I suppose that depends on spring rates, The question is given the stock spring rate and the preferred AX /street rate can you use the same damper without having it rebuilt?

The advantage is you can play in B street or make a better handling less competitive car with the aftermarket mounts and springs.

I will let you know what they say.
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      10-23-2017, 11:37 AM   #4
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Quote:
Originally Posted by in2twins View Post
The second option is precisely the direction I am headed, Not clear on whether the damper would require re-valving. I suppose that depends on spring rates, The question is given the stock spring rate and the preferred AX /street rate can you use the same damper without having it rebuilt?

The advantage is you can play in B street or make a better handling less competitive car with the aftermarket mounts and springs.

I will let you know what they say.
Definitely interested in what their current thinking is. One of the reasons I was looking at the DA dampers (in addition to the separately adjustable compression and rebound) was they have the rebound adjuster at the base of the shock, and the compression adjuster on the top of the body. This gives access to both adjustments without having to take the rear shocks off the car. The standard Koni Sport for the rear have to be fully compressed to engage the internal adjuster so the bump stop and dust sleeve has to come off and the quiescent pressure from the gas charge is about 50 lbs so even with the bump stop and sleeve removed, I've never been able to compress the shock and keep it compressed to make the adjustment.
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      10-26-2017, 03:06 AM   #5
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Quote:
Originally Posted by dc_wright View Post
Definitely interested in what their current thinking is. One of the reasons I was looking at the DA dampers (in addition to the separately adjustable compression and rebound) was they have the rebound adjuster at the base of the shock, and the compression adjuster on the top of the body. This gives access to both adjustments without having to take the rear shocks off the car. The standard Koni Sport for the rear have to be fully compressed to engage the internal adjuster so the bump stop and dust sleeve has to come off and the quiescent pressure from the gas charge is about 50 lbs so even with the bump stop and sleeve removed, I've never been able to compress the shock and keep it compressed to make the adjustment.
So far I have talked to TC Kline and to GC.

TC Kline is suggesting their tried and true 400lb/400lb DA set-up. Who is running or ran these?
Since I am running B Street, I would have to fabricate my own lower spring lands to run stock springs. I would use all the bits from the kit other than Camber plates, upper spring lands, and springs. I would set those aside for now.

GC has not sent me my quote yet, I will update the thread as I go.

Is there a comparison spreadsheet for the various coilovers offered for the E85 and E86?

I'd like to hear peoples experience with TC Kline DA as a dual purpose set up.
Can you really hear the noise over the exhaust?

Thanks,

Last edited by Over it; 11-23-2017 at 07:46 PM..
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      10-26-2017, 06:34 PM   #6
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TCK d/A's are great but damn that rear shock rattle can be annoying
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      11-02-2017, 05:21 AM   #7
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Originally Posted by 3002 tii View Post
TCK d/A's are great but damn that rear shock rattle can be annoying
Care to try and record the sound? is it over low speed bumps?
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      11-02-2017, 06:38 AM   #8
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Quote:
Originally Posted by in2twins View Post
Care to try and record the sound? is it over low speed bumps?
Can't really record it but it's there. Not even bumps but even slightest road imperfection brings them out. Do a google search and you'll get plenty of hits.
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      03-30-2018, 10:41 PM   #9
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I have read the OP a few times but not sure why you insist on running stock springs. Maybe I am missing something, or is it to do with your class rules?

I just received a new set of coilovers that I am sure would work for AX.
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      03-31-2018, 01:09 PM   #10
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Quote:
Originally Posted by ANILE8 View Post
I have read the OP a few times but not sure why you insist on running stock springs. Maybe I am missing something, or is it to do with your class rules?

I just received a new set of coilovers that I am sure would work for AX.
It's the rules for SCCA Street Classes. You can use any strut/shock and modify/change out one sway bar (have to pick front or rear), but you can't change the springs from OEM. For non-M E85/E86 if you change the springs you move to Street Touring. It takes roughly $10K to properly prep a car for Street Touring and even after spending that the E85/E86 aren't close to competitive with an STR ND Miata. For the E85M/E86M you jump past Street Touring to Street Prepared where you figure another $5K-$10K in mods, and everyone is running Hoosiers, so add tires and wheels to the expense.
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      03-31-2018, 03:34 PM   #11
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Production numbers

Can someone tell me how I can find out what number my car is
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