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

[Racecomp Engineering]

Originally Posted by RYU

Going back to my dilemma... I love the stock suspension dynamics but I want to look cool and lower my car.

Evidently adjusting the lower shock mounting point like this can effectively lower the rear end 20mm at the shock and 25mm at the wheels. This will allow me to achieve my desired ride height while using the stock suspension system. Sounds rather brilliant. What am I missing?

How about the front? I hate mixing and matching but not sure how best to go about thinking thru a setup like this. Help Mike and Andrew!

(I'm thinking maybe... mild lowering springs in the front coupled with the stock shock to give me a spring rate of 250lb and a drop of 20mm out front... and a stock FRS spring rate in the rear on the stock shock to get to a close-enough balance as possible)

Your idea is not a bad one at all. We were the first (AFAIK) to come out with a lowering camber plate that worked with OEM type springs for Subaru way back in 2005 or something. 3/8th of an inch drop, just from the camber plate. Ground Control had a plate that worked with coilovers only. Back then GD Impreza had a very nose high appearance...rear "looked" fine but the front was in the clouds. Anyway, just getting the RCE camber plates and keeping stock springs was a pretty popular set-up as it evened things out visually, lowered the car, kept stock bump travel, and gave you camber adjustment. We hope to have the same plates for this car out soon, but we are taking our sweet time.

GC plates only work with coilover springs.

For the rear I would rather use a lowering top mount rather than a lowering rear LCA, but I would like to see it all on the car and think about it.

I do think in the end you'll want different shocks regardless.

- Andy

[Racecomp Engineering]

Originally Posted by Figo

@Racecomp Engineering, I am still waiting for a good quality Camber Top Mount. Last time I asked you about the issue of Whiteline mount, and u told me that its not fixed. So I did not placed an order.
I have a Cusco strut bar so its seems like all mounts like HVT and Ground control will touch that bar.
So would u plz tell me when those Whiteline mount will be avaliable for sell?

I wouldn't mess with the Whiteline mounts for a while.

Keep stock mounts or use Group N and get your camber from the hub.

- Andy

[Racecomp Engineering]

Originally Posted by FR-S Matt

So I have my Tarmac 0's on, absolutely love them. I got one small alignment with the stock LCA's, but now I have SPC LCA's to help with the camber in the back and I was also worried about the toe. Should I go with some SPC camber bolts up front and do those let me go a little negative? I know the stock ones let you adjust back to 0, but nothing negative camber.

Also, do I need to worry about UCA bushings on the rear or am I okay with only using the SPC LCA's? I know they are a pain to install, but I definitely don't want to put heavy strain on a part and have it go out on me later.

My car is a daily driver, occasionally drive spirited here and there. Looking for some great advice on what kind of camber I should aim for without ruining my tires. I've got a square setup, and roughly a 1.3-1.4" drop for a flush look on 18X9.5's, 245/35.

If you have the SPC LCAs keep them and enjoy. Don't worry about the UCA bushings.

For the front you can get a good amount of negative camber with our RCE T0 and T2 clubs with just the stock stuff since the mount is slotted. With bolts you can get a ton of camber. Myles has -2.65 up front with the OEM camber bolts FYI on our car lowered 1 inch on T2 clubs.

- Andy

[Racecomp Engineering]

Originally Posted by 7thgear

a detailed guide is not required

read these two articles from start to finish. You will then udnerstand the theory behind what makes a good suspension and what makes a bad suspension.

1st this:
http://farnorthracing.com/autocross_secrets23.html

then this:
http://farnorthracing.com/autocross_secrets18.html


i cannot stress enough the importance of reading these two articles, and not just reading them but comprehending what you're reading.

because if you can, then the rest of your suspension journey will be much clearer.

This is a good site. I don't agree with everything DG says but it is a good wake up call for people.

- Andy

[Racecomp Engineering]

Originally Posted by Turbowned

I think a detailed coilover guide would be super-helpful to get all of us to decide between the myriad of options for different suspension components. When I looked for coilovers for my MR2 all we had were BC (OK), D2/F2 (junk), Koni/Ground Control (best performance for the money), and Toda Fightex (expensive and hard to find). There's too many options for this platform; this is overwhelming!

I will be using my BRZ for primarily road use with limited track and auto-x use. I will put approx. 10k per year on the car. I want to improve it's cornering ability without sacrificing ride comfort. If anything, I'd like to improve ride comfort over the stock dampers! The roads in New England are terrible; buncha broke-ass towns that can't budget to fix their streets.

I've had fairly hardcore suspension setups before and they're nice for auto-x but terrible for street duty. I would like camber adjustment at least for the front. Tire wear is not a concern as I'm running staggered directional tires with low treadwear and plan to replace them annually or bi-annually. The car will not be driven in winter. The car will have over 300bhp in the future, if that makes any difference.

Currently I'm runnng Eibach Sportline springs on stock dampers, and to say that it's over-sprung and under-damped is an understatement. I've heard good things about KW and not a whole lot about anything else. I'd be interested in knowing the differences between the KW Variant 3 and Clubsport systems, and what advantages the KW-based RCE coilovers offer.

One other quick question: poly bushings or spherical bushings for a mostly-street car, and why? I'm assuming poly is better but I could be wrong?
Thanks guys!!! :happy0180:

I try to stay away from recommending specific brands in information threads, but a thread that gets into the guts and talks about what works and why might be a good idea. You can PM me for my thoughts on specific stuff.

As for your poly vs. spherical question, it honestly depends on the bushing location and what it's doing. And of course the quality of the spherical bearing. Most of the time a good poly bushing will be better for a street car, but it depends.

- Andy

[Racecomp Engineering]

Originally Posted by mike156

I always see talk of roll height and control arm angles and how they should control ride height. The idea that a car that is to low handles terribly because of these issue I personally think is a bad assessment. Most of those cars handle poorly because they are out of bump travel.

This is my opinion of focus:

1. Adequate suspension travel (shock travel and joint articulation)
2. Proper spring bias
3. Eliminate bumpsteer
4. Lower cog
5. Worry about geometry changes

Lowering the car obviously takes care of #4 and I'm saying that for all out performance, COG is likey more important then suspension arm geometry. The limit here being how low can you really get away with on a given track.

For a more general approach, going too low is obviously going to make the car difficult to drive anywhere. This also requires spring rates that will overwork a street tires grip capacity. At that point, improving geometery will provide gains in performance. This really means, start at the tires and work backwards on what the suspension needs to be to take best advantage of the tires selected.

Excellent post!

- Andy

[Racecomp Engineering]

Originally Posted by 7thgear

anyone have any inside info if Bilstein is gonna be making damper inserts or full struts for our cars?

They will be full struts. I have no ETA that I feel confident in.

- Andy

[Racecomp Engineering]

Originally Posted by ultra

OK, sorrry for being so profuse here and in these suspension related threads but I'm still looking for some pointers.

Current setup:

Lowred 30mm on RS*Rs.
225/40/18 Continental Sport Contact 2s.

Usage: 90% spirited street driving, 10% track days/AutoX/drifting.

Front:
-2.0 Camber
0 toe
OEM crash bolts + Whiteline front camber bolts + AVO caster bushings. Non adjustable rubber top hats.

Rear:
-1.7 Camber
0 toe
Whiteline rear camber bushings

Stock sways.

Impressions: Very balanced and controllable overall. Very capable on street, handles track decently given the mild setup. Crisp turn in, weight transfer characteristics feel i tuitive, pretty very well balanced overall and the rear end responds nicely to throttle lifts. Tad much more corner entry underster on tight bends than I'd like when pushing up to the very limit (perhaps due to driver error). No excessive tire wear. Great all-around setup, haven't felt like fiddling with it in 7 months.

If were competing for trophies, or maybe 2% out of the 10% of the time I spend driving the car really hard, I'd really like to try out some stickier tires combined with more camber in the hopes of gaining a little more ultimate grip and front grip bias.

The other 98% of the time I'm completely OK with with it as-is.




Question:

That 2% of the time where I'm going for it and feel that I'd like more front grip going into corners - whare my best options to increase front grip and/or overall grip, short of changing up my coilovers? Tires? Alignment? Swaybars? Damper settings (even though my coilovers are only single adjustable, average level units)?

I'd basically like to reduce the amount that the front scubs out in tightish turn-in, AutoX type situations.

As mentioned earlier I run a street biased setup but if I could milk a little more put of that 2% I"d be really happy.

Run a little more camber up front and/or caster.

- Andy

[Racecomp Engineering]

Somebody else was talking about caster...one of the chassis engineers we work with mentioned how it was course dependent for the Porsches he sets up. Most of us aren't racing every weekend and setting up the car differently for each venue, but it's food for thought.

And I'm back.

- Andy

[CSG Mike]

Originally Posted by Figo

@CSG Mike

Would u plz give me some advices on my staggered setup? I build it for street and DD, track on more than twice a year, but I drive crazy on the street. I want a tail happy car that can allow me to slide at some corner at 20mph. I go staggered only for look.

I order a set of 18X8.5 +43 and 18X9.5 +38 rims with 225/40 and 245/40 tires(May go 235/40 front for my next set). Do you think I can still build a tail-happy fr-s?

I planned to do -2.5 camber front and -1.5 rear by top mount, LCA, and swift lowing spring. Do you think these are good camber? Maybe a stiffer sway bar will also be recommended?

ALso, how about sticky UHP 225 tire on the front, and regular ALL SEASON 245 tire on the back?

Thanks

If loose is your goal, the cheapest way is raise your rear tire pressures fairly high (overinflate them... do at your own risk). The next cheapest way is to use a really stiff rear sway bar, without changing the front. A third way is to change your rear tires to be less sticky than the fronts (which u mentioned). The fourth way is to run significantly stiffer springs in the rear, compared to the fronts.

In essence, because there's no way to substantially INCREASE front grip with your setup and still slide at 20mph, we have to decrease rear grip, which any of the above will do.

[CSG Mike]

Originally Posted by Turbowned

Ground Control with Koni dampers and Cusco camber plates. Thought they would've been softer; in fact the guy who sold them to me said they were too soft for his setup. I didn't mean "hardcore" in the sense of quintuple-adjustable Motons if that's what you were thinking

A lot of it has to do with how the specific setup is designed. Koni's are a great value, but are not top shelf stuff.

The GC setups for the FR-S/BRZ seem to have all but disappeared in discussions lately...

[7thgear]

I had originally had a GC kit with Konis on my VW Golf.


The benefit of this setup, is that you get affordable coilovers of decent quality.

To be more specific

a. You get to choose your spring rate and spring length when ordering from GC
b. You mate it with a reliable shock that has proven itself out in the field, which is not only adjustable but also rebuilidable (although at its price point it’s almost pointless to rebuild it… although you could have it custom valved)

This is better than ~1500 dollar “coilover” kits that don’t provide you with shock dynos and rates and have questionable quality/strength in the mounting points.

Why would you buy BC or Megans which are shrouded in mystery when you can get Koni Yellows and a spring of your direct choice?


But these benefits seem to fly over people’s heads so few end up getting the combo.

[ultra]

Originally Posted by Racecomp Engineering

Run a little more camber up front and/or caster.

- Andy

Thank you, @Racecomp Engineering !

[ultra]

Originally Posted by 7thgear

I had originally had a GC kit with Konis on my VW Golf.


The benefit of this setup, is that you get affordable coilovers of decent quality.

To be more specific

a. You get to choose your spring rate and spring length when ordering from GC
b. You mate it with a reliable shock that has proven itself out in the field, which is not only adjustable but also rebuilidable (although at its price point it’s almost pointless to rebuild it… although you could have it custom valved)

This is better than ~1500 dollar “coilover” kits that don’t provide you with shock dynos and rates and have questionable quality/strength in the mounting points.

Why would you buy BC or Megans which are shrouded in mystery when you can get Koni Yellows and a spring of your direct choice?


But these benefits seem to fly over people’s heads so few end up getting the combo.

If somebody offered a proven, off the shelf Koni/GC package for this platform (inclusive of bespoke springs, CG hardware and re-valving as well as being track tested on this platform) then perhaps your average Stance/BC/Fortune Auto/Average Joe type buyer would consider them.

I don't think that many folks in the low end of the market have the bandwidth or knowledge to figure out all of those variables on their own.

Come to think of it, how would somebody go about figuring out all of those variables themselves unless they're willing to do a whole lot of spring and shock testing on their own in addition to having a solid knowledge of advanced suspension setup and the necessary level of driving skills to understand the impact of each change?

I'm not saying it's a bad idea by any stretch. It's actually a downright brilliant solution IMO. Just a bit of a time, skill and labour intensive one given the lack of an off the shelf option and hence impractical for a lot of folks.

I'd have picked up a package like that in a heartbeat over the mid-range coil overs I ended up going with.