Do they make a bolt-on coilover kit with full-length threaded shock body (separate ride height and preload) like the DFV?

I know Penske makes a customizable coilover kit, but they are even more $$$ and they have traditional threaded spring mounts (height and preload are adjusted together).

 

I know Ohlins has made the Flag series for the FD with external reservoir and separate rebound/compression adjustments.

These are still technically Road & Track DFV series though, not their race series coilovers.




For the race series coilovers Ohlins will need a lot of specific information about the set-up of the FD they are going on.
The off the shelf DFV coilovers are for otherwise STOCK FDs as it says in their instructions.

I know the next step up from Ohlins DFV are their Rally Cross coilovers for certain chassis that are available as a set or per corner. I think about $2,000 a corner like Penske, Motons, etc.

These are going to be cheaper than an engineered race set for the FD because the engineering is already done.

 

The Ohlins Road & Track series are products of the Japanese Ohlins subsidiary.

The Ohlins Motorsport series are a product of Ohlins Sweden.

https://www.ohlins.com/products/automotive/

 

I think I would rather set the car on fire than make another coilover adjustment so this might be as close as I can get for the time being.

The ride heights aren't perfect, with me in the driver's seat it's about 25.35" plus or minus .15" at each corner. Trying to correct the ride heights sends the corner weights in the wrong direction and I'm also not sure if the fenders are true enough for a really accurate measurement.

Reconnecting the swaybars didn't make a difference to the corner weights so that's good. I will probably move on to the alignment next, what do you guys think? Close enough?

 

this is almost perfect haha, good enough man I think

 

That is perfect. I didn't even think it would be that good.

 

Just curious to know what ride frequency (Hz) that the 16kg springs calculate out to on your setup?

edit: nevermind. With that wheel rate it won't be any where near as high as I thought it'd be. Didn't realize the motion ratio was that low on this chassis.

 

It is totally possible to adjust ride heights without screwing up corner weights. It does require adjusting more than one corner of the car, though.
If you adjust right rear +2 turns at the adjuster, you must also do one of the following to maintain corner weights:
a) adjust left rear +2 turns at the adjuster (combined RR +2 and LR +2 => rear ride height change)
b) adjust right front +1.75 turns at the adjuster (combined RR +2 and RF +1.75 => right-side height change)
c) adjust left front -1.75 turns at the adjuster (combined RR +2 and LF -1.75 => RR up, LF down, with RF and LR staying put)
(adjustment at front gives a greater change in ride height than the same adjustment at the rear due to different motion ratios. 2 turns in back => 2(.61/.69) = 1.77 turns up front to give same change at the wheel assuming 0.61 front and 0.69 rear motion ratios)

0.1% is *plenty* close enough. Personally I wouldn't be bothered at +/-0.5% or even 1%, but just about any shop with scales would probably insist on doing a lot better than that...

front wheel rate = 16kg/mm * 0.61^2 = 5.95 kg/mm = 58,405 N/m
front unsprung mass ~310kg - 28kg = 282kg
front frequency = 1/2pi * sqrt(58,405 N/m / 282kg) = 2.3 Hz

rear wheel rate = 16kg/mm * 0.69^2 = 7.62 kg/mm = 74,728 N/m
rear unsprung mass ~333kg - 28kg = 305 kg
rear frequency = 1/2pi * sqrt(74,728 N/m / 305kg) = 2.5 Hz

 

Yeah, 16kg is about 2.9/3.2 Hz on my RX8 due to the higher motion ratios

 

Good information here guys.

I personally picked up lots of things that i was totally not aware of and thanks for that.

OP, would you like to give an update regarding the driving of the car?

How does it feel after the new adjustment you made? Is it still bottoming out or is it finally riding proper?
More in particular does the suspension run out of travel anywhere? Maybe during spirited driving on mountain roads?

Thanks in advance,
Konstantinos.

 

Me too, I got taught stuff I should have learned in high school!

WIth the packers in place the tires never touch anything other than the road. I can't perceive the bumpstops engaging while driving either. There is a mountain road nearby that is very rough in places and it never feels like there is insufficient travel. I've hit some pretty big bumps at full tilt and the car stays composed.

I do notice the lack of droop sometimes, for example if I turn into a steep driveway the inside rear wheel will spin if I'm too enthusiastic.

I have had a few friends ride in it and they thought the ride quality was quite reasonable. You won't mistake it for a luxury car but I don't think it's too bad. I'm sorry, I haven't been able to get to the track yet, I've moved on to tuning the ECU and it's forever on jack stands. I will try and post a video when I can.

 

Good enough feedback for now.

This gives a clear idea about what i wanted to know and you seem to be quite specific to your choice of words so i will take you up for it.

Tracks in Australia are quite flat if i am not mistaken (with the exception of Bathurst from the ones i know at least) so given that the suspension is on 16kg springs and is valved accordingly it should perform very well.

 

Why do you think Ohlins decided to abandon the helper spring in their next generation of coilovers, given the PCVs success. And was the helper spring of the PCV substituted by the dual-flow valve in the DFV?

 

Ohlins PCV?


PCV didn't have the adjustable lower shock mount. So, if you wanted ride height adjustment and didn't want the spring to clanky clanky at full extension you needed a helper spring.