CSG and RCE tag-team suspension Q&A thread! Ask us anything!

[Racecomp Engineering]

Originally Posted by RYU

Can we talk *comfortable* coilovers for a second?

I've been on the search for a comfortable coilover package that is adequate for street tires with enough adjustability for the occassional trackday. The car will never be on anything stickier than RS3s and even then that'd be a rare occassion. I will mostlikely just drive it to the track in the same trim as how I'd drive it to work (year round, summer tires).

I rode in a prototype CSG Spec Tein SRC and the suspension was amazing but it may have also been Mike's inhuman driving skills. With that said, I still prefer something more compliant for the street. I've had the RCE Yellows on the stock damper. Spent a good amount of time on the KW V3s and now i'm on the RSR Sports-i setup. These are not what folks consider high end coilovers and I'd have bought "expensive" coilovers by now but I want my final decision to be final. I'm also not yet convinced I can find a good coilover for this car in a single adjustable format. I'm even considering just dropping down to a Koni insert or whatever Bilstein comes up with or going back to stock.

I am thoroughly convinced this car has either
A. very limited suspension design (mcpherson, multi-link rear vs. say double wishbone) (why is the rear shock travel so damn short???) OR
B. few have put in the R&D into a proper suspension package for this car

I've also noticed that the label on the coilover is not nearly as important as the amount of effort given to tune that coilover specifically for that car. In other words, i've been in cars where say.. a KW V3 was crap but on another car a KW V3 was pretty darn good. Both were adjusted by "professionals". I have to correlate that to the amount of tuning effort allocated for that platform. Am I incorrect?

Not sure how many folks here know of Tsuchiya's previous suspension company(s) (K-Office > DG5). His philosophy for tuning was not to sell race car level suspensions but instead to build a properly balanced sporty car that can be adjusted for a fun day at the track but also incredibly comfortable for daily driving. This resulted in a broad range of adjustment but via just one knob. Guys like me don't want to tinker anymore with adjustable this.. adjustable that. I'd rather have a company find the critical damping point for the car in an easily adjustable suspension. Which coilover system out there employs this philosophy?

Also to add to my previous point, it's my understanding the DG5 coilover is overrated - fine. I can see that happening on platforms were there wasn't enough R&D allocated to the car (say the S13). On the NSX the DG5 is absolutely amazing. I heard its pretty awesome on the original 86 also. On the NSX it rides like a sporty sedan on the street but can be dialed up to perform better than a Type R on the track all via a one-knob, easy to get to adustment. It also ships with stiff spring rates (11k/14k) so I know spring rate isn't the only factor to a comfortable ride. Tsuchiya himself uses this suspension on his NSX-R which can likely explain all the R&D attention this coilover has gotten. Do we need some cocky Japanese "Drift King" ex JGTC champion to design a coilover for our 86? I sure hope not!

I'm hardly a DG5 fanboy but on the NSX i've tried many coilovers including the KW V3s (not bad), Motons (too many adjustments), JRZ (R/R1s), Tein (mono, RAs), and Bilsteins. I prefer the DG5 and it's not even the most expensive of the bunch.

Maybe i'm asking for too much here and I should just go back to the stock suspension.

SIGH

The car doesn't necessarily have a compromised suspension design, but it is very sensitive to proper set-up and this is only magnified with a 2 way shock.

The problem with a 2 way is that sometimes people screw up when setting them up and they don't even know it. It's complicated to do correctly. Sometimes "professionals" don't get it right. Sometimes people will set things up so that it feels good to them, but in reality it's making them slower and annoying their passengers. It happens.

A single adjustable or even non-adjustable shock honestly can be almost as good if they are valved right from the start. They are obviously less flexible if you're changing spring rates but for what it sounds like you're into I don't think you would be sacrificing much.

An upcoming Bilstein fixed perch shock (with RCE Yellow ) option from us would be a very good comfortable easy solution. Nothing to screw up. But this is not something available now or even soon.

Honestly every time I read what you're looking for I think Ohlins R&T or Bilstein PSS10. Or our Bilstein fixed perch dampers with RCE Yellows. 2 out of 3 of those aren't out yet unfortunately. I also think you should ride in one of our RCE T2s with 6k springs that is properly set-up.

- Andy

[Racecomp Engineering]

Originally Posted by ayau

How do you find the balance of lowering the car's center of gravity (lowering the car) and not destroying the factory suspension geometry? Is one more important than the other? For example, is keeping the factory suspension geometry (stock ride height) better than a lower center of gravity?

What exactly gets ruined when you lower the car too much? Can you provide some examples? Is it the fact that the front struts gain positive camber when you lower it too much?

Is there any weirdness with the wheels under compression? For example, do the rear tires toe out/in under compression?

Thanks!

It depends on a lot of factors. You can minimize the effect of overlowering the car by running tons of spring rate and a lot of camber. In general you want to run "just enough" spring rate. Same for camber. However the benefits of a low COG may (and often do) outweigh the negatives from a performance standpoint. Maybe not from a ride standpoint though.

You do start to lose camber in roll when you're too low (i.e. more roll than negative camber gained). CSG brought up the roll center point as well. Both are very long topics.

The rear of the car toes in under compression.

- Andy

[Racecomp Engineering]

Originally Posted by TheseColorsDontRun

Yes, I did start a thread with this exact same question, but I want to know what the pros have to say.

Ok so I know we have all experienced the drivetrain slop in these cars. Lots of transmission and diff bouncing that make this car extremely difficult to drive smoothly at low speeds, especially during your clutch catch-point learning phase. Don't blame my driving style, I have not driven an automatic regularly in a decade.

So, I know there are bushings available to help alleviate this. I am looking at the rear shifter bushing, the transmission mount and the diff bushings. I'm thinking that stiffening all of these up will help with the earthquake of movement that the stock bushings allow. I'm ok with a but more NVH (because racecar) but I don't want to weld the tranny and diff to the body or anything.

Am I on the right track with my goal here? What have your experiences been with this slop and your solution for it?

You are on the right track.

Those parts may not totally eliminate it but it helps. A couple reviews on here.

- Andy

[CSG Mike]

Originally Posted by TheseColorsDontRun

Yes, I did start a thread with this exact same question, but I want to know what the pros have to say.

Ok so I know we have all experienced the drivetrain slop in these cars. Lots of transmission and diff bouncing that make this car extremely difficult to drive smoothly at low speeds, especially during your clutch catch-point learning phase. Don't blame my driving style, I have not driven an automatic regularly in a decade.

So, I know there are bushings available to help alleviate this. I am looking at the rear shifter bushing, the transmission mount and the diff bushings. I'm thinking that stiffening all of these up will help with the earthquake of movement that the stock bushings allow. I'm ok with a but more NVH (because racecar) but I don't want to weld the tranny and diff to the body or anything.

Am I on the right track with my goal here? What have your experiences been with this slop and your solution for it?

Don't take this the wrong way, but regularly driving a standard doesn't necessarily mean your technique is refined. Is it possible you're just letting the clutch out too quickly?

Can you go into more detail regarding the lurching/bouncing/etc? Can you log it with an accelerometer and send the data to me? Any smartphone can do this.

Replacing bushings to reduce play will help, but I'd look for other solutions as well.

[utekineir]

Originally Posted by Racecomp Engineering

An upcoming Bilstein fixed perch shock (with RCE Yellow ) option from us would be a very good comfortable easy solution. Nothing to screw up. But this is not something available now or even soon.

Next spring soon?

[meeks]

omg epic thread. thank you for collaborating and creating this thread for the community. i feel that this car is already slow enough as it is but its the cornering capability that makes this car hold its own. a thread for the ones that actually care about that..i mean 'stance' or 'static' set-ups are cool too (not my cup of tea, but to each of his own)... this is sweet.

so i wonder..what would be the lovechild when 2 suspension pornstars (shops) meet and mate haha. anything coming up? moar custom revalved quality stuff?

[Racecomp Engineering]

Originally Posted by utekineir

Next spring soon?

Too soon to say honestly. Anything date I give now would probably be wrong. We're working on it.

- andy

[Racecomp Engineering]

Originally Posted by CSG Mike

Don't take this the wrong way, but regularly driving a standard doesn't necessarily mean your technique is refined. Is it possible you're just letting the clutch out too quickly?

Can you go into more detail regarding the lurching/bouncing/etc? Can you log it with an accelerometer and send the data to me? Any smartphone can do this.

Replacing bushings to reduce play will help, but I'd look for other solutions as well.

Agreed that just driving technique should be the focus, not parts. You can be smooth.

- Andy

[Racecomp Engineering]

Originally Posted by meeks

omg epic thread. thank you for collaborating and creating this thread for the community. i feel that this car is already slow enough as it is but its the cornering capability that makes this car hold its own. a thread for the ones that actually care about that..i mean 'stance' or 'static' set-ups are cool too (not my cup of tea, but to each of his own)... this is sweet.

so i wonder..what would be the lovechild when 2 suspension pornstars (shops) meet and mate haha. anything coming up? moar custom revalved quality stuff?

Thanks!

And thanks for making me really uncomfortable.

- Andy

[CSG Mike]

Originally Posted by meeks

omg epic thread. thank you for collaborating and creating this thread for the community. i feel that this car is already slow enough as it is but its the cornering capability that makes this car hold its own. a thread for the ones that actually care about that..i mean 'stance' or 'static' set-ups are cool too (not my cup of tea, but to each of his own)... this is sweet.

so i wonder..what would be the lovechild when 2 suspension pornstars (shops) meet and mate haha. anything coming up? moar custom revalved quality stuff?

This goes so well with your avatar...

[RYU]

Originally Posted by CSG Mike

It's just a matter of demand in the market, and an appreciation for a truly well designed coilover.

The problem with the market nowadays, is that there are just two many low end (i.e., imo, garbage) offerings, that are good for lowering the car, but do not really bode well in terms of both performance AND comfort.

Given the resources, I'm 100% confident that ANY company can dedicate the time and manpower necessary to create such a 1-way adjustable damper. All you'd need to do is choose a middleground spring rate (I'm thinking maybe 7.5k/9k or 6k/7.5k), and then determine a few differing pairings for a less damped street setting, and a more damped track setting. Once the pairings are made, it needs to be transferred into an internal construction in the damper; this is the more difficult part, as the single adjustment has to have purpose-designed crosstalk to simultaneously adjust both compression and rebound, and adjust both by specific amounts so that they're properly balanced.

Would the ROI be there for the suspension company and/or shop? Unfortunately, probably not. 10 years ago when we didn't have all of these cheap taiwanese/chinese brand setups, it was much more viable; selection was limited, and EVERY manufacturer was getting a larger share.

With the amount of R&D cost involved in designing the damper internals to get that exact curve, the end cost very well may end up higher in cost than a good double-adjustable damper.

For every damper setup CSG dials in, we always show the owner how to properly make the adjustments, and give them different settings for different scenarios.

If I had the resources, believe, I'd have already done exactly what you want. It would be so easy to adjust...


Have time to ride in the latest re-valve on the prototype CSG-Spec SRC? We're currently focusing on street comfort. I just put it in last night, so I need to dial it in tonight...

Originally Posted by Racecomp Engineering

The car doesn't necessarily have a compromised suspension design, but it is very sensitive to proper set-up and this is only magnified with a 2 way shock.

The problem with a 2 way is that sometimes people screw up when setting them up and they don't even know it. It's complicated to do correctly. Sometimes "professionals" don't get it right. Sometimes people will set things up so that it feels good to them, but in reality it's making them slower and annoying their passengers. It happens.

A single adjustable or even non-adjustable shock honestly can be almost as good if they are valved right from the start. They are obviously less flexible if you're changing spring rates but for what it sounds like you're into I don't think you would be sacrificing much.

An upcoming Bilstein fixed perch shock (with RCE Yellow ) option from us would be a very good comfortable easy solution. Nothing to screw up. But this is not something available now or even soon.

Honestly every time I read what you're looking for I think Ohlins R&T or Bilstein PSS10. Or our Bilstein fixed perch dampers with RCE Yellows. 2 out of 3 of those aren't out yet unfortunately. I also think you should ride in one of our RCE T2s with 6k springs that is properly set-up.

- Andy

Thank you for the awesome feedback guys. I've fallen victim to Old Man syndrome. The older I get the more I want to keep things simple especially with this car. It's so fun right out of the box.

[Chee-Hu]

What would you folks suggest to those that are only after the "lowered" look without sacrificing, or improving a bit, the comfort with a budget of <$1500? There are so many options out there that it's stupid hard to choose unless he/she is a fan boy/girl of a specific brand.

[CSG Mike]

Originally Posted by Chee-Hu

What would you folks suggest to those that are only after the "lowered" look without sacrificing, or improving a bit, the comfort with a budget of <$1500? There are so many options out there that it's stupid hard to choose unless he/she is a fan boy/girl of a specific brand.

Springs of your choice, a less expensive set of rims in 17x9, and 235/40/17 tires.

The wheel/tire setup will naturally drop your car without altering suspension geometry, and the springs will slightly drop the car without compromising suspension geometry and ride comfort too much.

[ft_sjo]

@Racecomp Engineering @CSG Mike


So I heard someone mention somewhere on this forum the other day about the 'British Approach' (or similar) on springs and anti-roll bars. The statement was around soft sprung damper/spring package and controlling balance with a/r bars.

This is the approach which I have been taught by my mentor (ex-WRC engineer). Our roads here are as you may suspect, very variable. The best roads in England tend to be quite challenging to suspension and overly-stiff tends to perform poorly. I consider the OE damper/spring package on the GT86 pretty good for our 'b roads' (country lanes). Car changes direction quickly, gives reasonable ride quality, not 'crashy' and gives a nice cushion for those rare times I get air.

My car has stock suspension apart from a 16mm rear bar. I found an 18mm bar upset the balance and made it less predictable. Front bar is stock as I don't consider the car has excessive roll. I'm also running AD08 tyres.


So i'm curious what your guys views would be on this style of chassis tuning, versus what I think is your preferred method of stiffer spring and less a/r bar (or even none).

Thanks.