THSCC Forums

Karl, on the double wishbone suspension the S2000 has, you cannot replace the bushing in the LCA in stock class. Tophats are considered suspension bushings according to 13.5.B and not shock bushings. So from a perspective of your 'shock' there are no bushings.

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2011/2012 Autox VP
2013/2014.5 President
2013 Top Gun

2015 Fit

22R-EC => 4G63 => D16Y7 + D16Y8 => EJ255 + K24Z2 => K20Z3 + K24Z2 => K24Z2 + M54 => L15B

Alright, I understand now. I've never had a car with bushings on the shock itself - that's why the rule didn't work right in my mind.

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Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

Fixed

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02 Focus SVT
STF 9

Well, there's that...

Seriously, the upper hat drilling thing, that was a dumb miss on my part, especially because I've actually done that before, on my old Integra. The bushing thing, though, the bushings being *on the shock* versus *on the control arm* was an honest mistake.

I still find myself wondering about short bodied shocks in stock class. Assuming that the distance from the bottom of the shock to the spring perch is the same, can one have the upper portion of the shock be as short as they like, so long as the extended length of the full shock (body plus piston rod) is within the +/- 1 inch rule? Seems like a way to pick up some wheel travel on cars that suffer a lack of it, if need be.

Anyway, if I were in James' position, I'd get Konis, because I'm a big fan of their adjustability. When conditions surprised us at Nationals in 2009, we were able to make a shock change and a tire pressure change, and get the car right back where we like it. I've never had Bilsteins on anything other than a truck though, so perhaps I don't know what I'm missing.

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Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

Yes, you can do that, but the shorter shock body is going to mean less overall travel, but it will change the proportion of compression vs rebound travel and I'm assuming by " pick up some wheel travel" you mean compression travel. Yes you would, but at the expense of rebound/droop travel.

I'm my case, I would be decreasing overall travel by 10mm (150mm vs OEM 160mm). Additionally the shock body itself is 10mm smaller on the Koni. This means that the fully extended length of the shock is 20mm less which is within the +- 25.4mm radius. However, of my new 150mm worth of overall travel, a higher percentage of it will be available for compression compared to stock and vice versa for droop. I'm no suspension guru so I'm wonder what the pros and cons of this are.

With your experience with Koni's do you feel like the adjuster is basically full on or full off. I've read a few places that the adjustment is very exponetial and soon as you part from full soft you hit full hard very fast even though you are a full turn or so from 'physical' full hard on the adjuster.

_________________
2011/2012 Autox VP
2013/2014.5 President
2013 Top Gun

2015 Fit

22R-EC => 4G63 => D16Y7 + D16Y8 => EJ255 + K24Z2 => K20Z3 + K24Z2 => K24Z2 + M54 => L15B

Mine aren't that way. We usually make changes 1/4-1/2 a turn at a time, and each shock has a total of about 2 turns. When I show up for an event, I have all four set right in the middle. That way I've got the most available room for adjustment in both directions, on both sides of the car. I'm sure other people do it differently.

Mine are custom valved specifically for a stock class S2000. I haven't driven on a set of standard valving Konis in a number of years (S2000 or otherwise), so I can't speak to how those respond to adjustment.

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Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

On my Miata, I would routinely make adjustments of 1/4 - 1/2 turn on the rear Koni's, depending on conditions, to balance the car. Thus, my experience hasn't been an on/off one, and I ran 50-75% range on both shocks.

My BMW also has Koni's, but the rears I have are not top adjustable, so they are "set it and forget it" as far as I'm concerned. That car is much more of a "hammer" than a scalpel, though, so I don't really care to adjust them. FWIW, I would go with Bilsteins over Koni on the BMW if I were to do it again.

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Dustin Fredrickson
-- I'm a nobody --

So on another board, I've been chatting with someone who did this LGT Koni strut/shock retrofit. He said that the decrease in rebound travel has never been an issue once during the 2009 autox season. Nor has the overall decrease in travel. However, he said if the Bilsteins were around he would have gone that way without question.

Other benefits of the Bilsteins is that I'd have my front struts and rear shocks in tact and essentially brand new and there is a flood of 08 WRX owners who put stiff springs on their cars with stock dampers and blew them in less than 3000 miles so I'm sure I can sell my stockers for a few hundred. Additionally, if the modification bug hits me in a year or two and I want to do STU, then I'll probably go with full coilovers anyway and the Bilsteins will have better resale than the frankenstein Konis.

Is anyone on here pretty good at analyzing shock dynos? I should have a few charts in the next week for the Bilsteins.

_________________
2011/2012 Autox VP
2013/2014.5 President
2013 Top Gun

2015 Fit

22R-EC => 4G63 => D16Y7 + D16Y8 => EJ255 + K24Z2 => K20Z3 + K24Z2 => K24Z2 + M54 => L15B

It sounds like you've already made up your mind.

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Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

Quite possibly. Unless the dynos from the prototype testing show the shocks are more meant for a mini van .

AND, if in a few years, I'm enjoying DS and don't feel the need to branch out, maybe Koni will have a OEM fit solution for the new Impreza chassis if I want to try something new. Who knows.

_________________
2011/2012 Autox VP
2013/2014.5 President
2013 Top Gun

2015 Fit

22R-EC => 4G63 => D16Y7 + D16Y8 => EJ255 + K24Z2 => K20Z3 + K24Z2 => K24Z2 + M54 => L15B

James, all,

Thanks for the discussion! It will be interesting to see if he posts OEM vs Bilstein shock dynos when the Bilsteins come available. Comparo vs Koni would be interesting too, to see where the non-adjustable Bilsteins overlap with the adjustable Konis...If the Bilsteins show good improvement in low and mid speed range (typical zones for cornering, braking, ride quality from what I understand) then I'll be willing to put my money down. Not sure how much high speed damping velocity affects us on an autoX course, but it could make the DD suffer if we drive over rougher roads, potholes etc. I didn't see an OEM shock dyno graph in that NASIOC thread, did you?

This was a useful overview of shock dyno graphs, and how adjustments affect low, mid and high speed damping.

http://nttyres.com/downloads/guide_to_dyno_graphs.pdf

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Steve Carter
1972 Datsun 240Z-- resto pics at http://picasaweb.google.com/srcartermd
2007 GPW Honda S2000-- STR 86

I just emailed RCE about OEM damper dynos.

I was wondering when you'd peak your head into this convo .

EDIT:

Myles reply:



By the way, in a nutshell, could someone explain to me the effect dampers have on corner entry/exit? I understand you will roll to a given degree for a given turn no matter what and that the shocks just slow the rate at which you attain the max roll for a given turn. So in a long sweeper you will hit your max roll, but in a slalom, you might not since the upgraded shock slow down your attainment of max roll in a given direction such that you are already turning in the other direction before hitting max roll angle? Is this right?

So for a sweeper what does 'better corner entry' mean? Does it come down to the fact that if your vehicle rolls a bit slower than weight transfer is just smoother....more of a feel thing? Could the slower rate of roll also mean that there is more load on the inside tires for a longer amount of time (ie more lateral traction for a hair longer than with blah shocks)?

So I was rambling again. Any insight on these concepts would be appreciated.

_________________
2011/2012 Autox VP
2013/2014.5 President
2013 Top Gun

2015 Fit

22R-EC => 4G63 => D16Y7 + D16Y8 => EJ255 + K24Z2 => K20Z3 + K24Z2 => K24Z2 + M54 => L15B

It means the front and rear of the car enter the corner simultaneously.

Well I made the decision to get the Bilsteins. Knowing how much I can get for my OEM front struts (won't be cutup due to inserts) and rear shocks. The bilsteins will actually be a good bit cheaper than the Koni project (lots of 08 WRX owners with blow dampers due to stiff/lowering springs)....my 5k mile OEM struts/shocks can probably fetch $300+ front what I'm seeing.

Even if I'm not in love with the valving of them, I can have them custom valved for alot cheaper than the Konis and they wear out a lot slower.

_________________
2011/2012 Autox VP
2013/2014.5 President
2013 Top Gun

2015 Fit

22R-EC => 4G63 => D16Y7 + D16Y8 => EJ255 + K24Z2 => K20Z3 + K24Z2 => K24Z2 + M54 => L15B

So Koni decides to drop a bomb and release 3rd gen WRX Koni sports a week ago. No one knew. These don't require rear top hat drilling nor lower rear shock bushings.

Anyway, I pulled out on the Bilsteins in the 11th hour in favor of the Koni's. Should have them by the July autox.

Steve Carter is getting the Bilsteins....should be interesting to compare them.

If anyone knows of an 08+ WRX owner with OEM front struts that they want to sell (blown or leaky is fine!), let me know.

_________________
2011/2012 Autox VP
2013/2014.5 President
2013 Top Gun

2015 Fit

22R-EC => 4G63 => D16Y7 + D16Y8 => EJ255 + K24Z2 => K20Z3 + K24Z2 => K24Z2 + M54 => L15B