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

[Racecomp Engineering]

Originally Posted by Spuds

Looking for some smart folks to check my logic and understanding before jumping into suspension mods. I read a decent portion of this thread as well as general research, but reading only gets me so far. I'll try to keep the info dump brief.

TLDR? Scroll to the last "Notional Parts" section

Background and current setup: I've owned my FRS for a bit over 9 years now and am finally going to try out suspension and chassis mods. Currently suspension is stock, with Yokohama Advan sport v105 tires in stock size on rpf1s. I DD the FRS in a sense, but it's not every day and I have another car I can drive.

Motivation: 1. I want to try some new things and learn about modding suspension and chassis dynamics. 2. I got myself hooked on autocross this year, and will probably try out hpde sometime next year as well.

Goals: Buy and install the parts necessary to have a more motorsport-oriented car (feedback, response, weight transfer, balance, etc) while allowing for necessary adjustments for dialing in the geometry. Then learn things the fun way and adjust as necessary. Specifically, I want to reduce some sloppyness at both ends for predictability, prevent the car from crashing into the bumpstops on quick direction changes, and reduce understeer.

Budget: Keeping cost under $5k for suspension/chassis would be preferable. Somewhat flexible on that if there's a good reason to go over.

Tradeoffs:. Willing to sacrifice quite a bit nvh for response and useful feedback. Willing to spend a bit more for objectively higher quality parts. I wish to avoid significant compromises on reliability/durability/maintenance if possible.

Constraints:. I think I want to remain within the rules of the STX class. I want to do all/most actual installation this winter in my garage, then I can adjust things as necessary.

Notional parts (haven't picked out exact parts yet, wanted some feedback on what is needed):
-Wheels/tires:. I intend to stick with street tires for autox for at least the next year, because I feel I will learn better driving habits than with 200TW tires. Might go a bit wider at some point.
-Suspension:. I am gravitating towards RCE T2s.
-Top hats/cam plates:. Yes? Recommendations?
-Rear LCAs: Recommendations?
-Sway bars and endlinks: Just looking for adjustability if nothing else.
-Rear subframe bushings/inserts.
-steering rack bushings
-any other bushings recommended?

Wow that was longer than I intended lol... Please let me know if I'm doing it wrong, or if there's anything I forgot. Thanks in advance for your time!

What Breezio said.

RCE T2s are a good choice.
Vorshlag or Raceseng. Get yourself a new set of OEM rears.
The Verus STX legal rear LCAs seem to be the way to go, though I have not tried the Whitelines personally which are also legal.
Subframe bushings/inserts...not required, nice to have.
Same with steering rack bushings.

If your car is 9 years old definitely inspect ALL of your other suspension bushings and replace if needed. The big front control arm bushing for example.

- Andrew

[Spuds]

Originally Posted by strat61caster

If you’re not diy aligning it get white line rear lca for stx legality, I got mine through tirerack. I went with delrin steering rack bushings and noticed zero benefit, others swear by them. -4 degrees front camber is where I’d start, I don’t think you can get there without camber plates , raceseng are good but pricey. Oe rear top hats are fine imho, -2.5 rear camber. Karcepts front sway bar is great, oe rear is a fine starting point, I have a Perrin 16mm rear bar right now.

Looking at the Karcepts sway bar, it's obviously quite a bit more expensive than other options. What about it makes it function/perform better than other options in your experience? Also, it looks like there are issues with clearance?
https://www.ft86club.com/forums/show....php?p=3473027

[Spuds]

Originally Posted by Breezio

Your on the right track, though your understanding of SCCA Solo rules isn't quite right.
For the most part, mods put you in different class 'groups', like Street, Street Touring, Street Prepared, etc.
Chassis puts you within the specific sub-group, like STX, STS, STR, STU (IE: Street Touring whatever)

The Verus RLCA with STX legal bushing works great. Only annoying part is how close the adjustment bolt is to the subframe.

RCE T2's are a great option for the price.
Definitely want front top hats with camber adjustability. I have Vorshlag top hats. I like them a lot, but pricier then others.
Front Sway bar is needed, rear isn't initially. Many people run the Perrin 22MM. I run a Hotchkiss 1" hollow bar
Rear subframe and diff bushing inserts are nice (not needed). Whiteline makes a good set.
Wheels, lightest 17x9 +35mm you can reasonably find.

My build for non-consumables was a bit over 5K I think.

Autox classes:. Yeah, I was looking at street touring rules specifically. I thought the twins' wound up in stx sub group, but I'll go back and look a bit closer if that's not the case.

Wheels:. I was initially thinking about going a bit more conservative with 17x8 to try out. Does width really make that much of a difference to justify the added rotating weight? I mean there's a case for maxing it out now I suppose...

[Spuds]

Originally Posted by Racecomp Engineering

What Breezio said.

RCE T2s are a good choice.
Vorshlag or Raceseng. Get yourself a new set of OEM rears.
The Verus STX legal rear LCAs seem to be the way to go, though I have not tried the Whitelines personally which are also legal.
Subframe bushings/inserts...not required, nice to have.
Same with steering rack bushings.

If your car is 9 years old definitely inspect ALL of your other suspension bushings and replace if needed. The big front control arm bushing for example.

- Andrew

Is it safe to assume the T2s are compatible with both the front tophats you mentioned? Anything special I should know about compatibility?

Bushing check is already on the to do list. The front LCA bushings seemed normal to me at least when I checked last month. Any other nice-to-have bushing mods I should look into?

[Racecomp Engineering]

Originally Posted by Spuds

Is it safe to assume the T2s are compatible with both the front tophats you mentioned? Anything special I should know about compatibility?

Bushing check is already on the to do list. The front LCA bushings seemed normal to me at least when I checked last month. Any other nice-to-have bushing mods I should look into?

We sell the Vorshlag tophats and can package them with our T2s.

Raceseng has a drop down on their website where you can pick RCE Tarmac to make sure everything lines up.

For bushings, I generally don't like poly but you can't use spherical in STX unfortunately. So in most cases I would stick with good fresh OEM or maybe the hard to find STI Group N rubber if you can. Poly is great for inserts and swaybar bushings, I just don't love it for things that pivot. It's okay in the LCA too.

- Andrew

[strat61caster]

Originally Posted by Spuds

Looking at the Karcepts sway bar, it's obviously quite a bit more expensive than other options. What about it makes it function/perform better than other options in your experience? Also, it looks like there are issues with clearance?
https://www.ft86club.com/forums/show....php?p=3473027

Buy one bar, swap to any position in like 2 minutes. In my experience the traditional sway bars are difficult to adjust on site and next to impossible to get done between runs in the front. If that doesn’t bother you a 20mm and a 22mm solid bar will get you all the stiffness ranges you need to get the car set up to your liking.

[Breezio]

Originally Posted by Spuds

Autox classes:. Yeah, I was looking at street touring rules specifically. I thought the twins' wound up in stx sub group, but I'll go back and look a bit closer if that's not the case.

Wheels:. I was initially thinking about going a bit more conservative with 17x8 to try out. Does width really make that much of a difference to justify the added rotating weight? I mean there's a case for maxing it out now I suppose...

For Street Touring classing, '13-'20 twins are in STX, '22+ are in STR.

On wheels, the added weight is minimal. If you want to save some money, sure you can grab 17x8 and some 225 or 235 tires. But, if you don't want to hamstring yourself in autocross, you'll need to run 17x9 with 245 tires.

[Spuds]

Originally Posted by Breezio

For Street Touring classing, '13-'20 twins are in STX, '22+ are in STR.

On wheels, the added weight is minimal. If you want to save some money, sure you can grab 17x8 and some 225 or 235 tires. But, if you don't want to hamstring yourself in autocross, you'll need to run 17x9 with 245 tires.

Ah, I see. Yeah '13 car so still STX.

Well, I am hamstring-ing myself with less grippy DD street tires on purpose so there's that lol. Now I'm going to have to go find my rotating mass -power sink calculator again...

[Spuds]

Alright, so thanks again for the help folks, I really appreciate you all sharing your experience. I have a few more questions. But first, my current shopping list:
-RCE T2
-Vorshlag camber plates* see question below
-New OEM rear top mounts
-Verus LCAs ($$$ but they are so pretty I can't resist...)
-22mm Perrin front and 16mm rear (yeah, I know, see question)
-Whiteline subframe inserts
-??? steering bushings

Questions:

Vorshlag: The images on RCE's site seem to show the spring perch for these as taller than stock. Does this eat into the bump travel available, and are there any issues when lowering the car ~20mm below stock on T2s?
Edit: Talked to Myles about it and he was pretty confident (with numbers and examples) that bump travel would be fine.

Rear sway: Why am I better off with stock rear sway? Is this a process thing, low benefit/cost, or is the rear sway considered the perfect rate?

Endlinks? Stock, aftermarket, what actually matters?

Anything important I missed?

[strat61caster]

Rear sway: cost. No reason to change it until you determine you need it to be stiffer… or softer, or it’s perfectly fine. Mann Engineering rear bar can be used to get softer rates then stock as well but unhooking the bar is cheaper.

Aftermarket endlinks are there to remove preload and allow you to split holes on the bar do you get more adjustment.

[jeepmor]

Nice, 299 pages to read, I'm currently on page 7.

My goal is a comfy and more capable 14 FRS commuter. Was looking at Tein Flex A's for hydraulic bump stops being I'm in the coastal section of the PNW, land of the sunken grade.
I have some rear LCA's for lowering and camber bolts up front, just haven't utilized them yet. I would like to cut the wheel gap down a little bit, but still make it over speedbumps.
I like the zero toe feedback, but what would be the F/R camber values for a daily driver. I do go find the twisties a lot, but I commute a lot more.

I've had this car since new and still just love it all the time and just want to make it more fun, and still not have to wear a kidney belt to work.

[Tatsu333]

Originally Posted by jeepmor

I have some rear LCA's for lowering and camber bolts up front, just haven't utilized them yet. I would like to cut the wheel gap down a little bit, but still make it over speedbumps.
I like the zero toe feedback, but what would be the F/R camber values for a daily driver. I do go find the twisties alot, but I commute a lot more.

FWIW, with a measured 1.25" drop front and rear on H&R Sport springs using Pedders caster/camber top mounts in the front with camber bolts in the lower holes and stock rear LCA's, I've been running -2.2 degrees camber front and -2.1 degrees camber rear without any unusual wear.

[MyHybridBurnsGasAndTires]

Originally Posted by Racecomp Engineering

Still working on it! No ETA...tons of projects right now but things are moving forward.

- Andrew

any updates?

[Compelica]

@Racecomp Engineering

I have MCA Traction mods installed with HKS Hipermax 4GT 4k springs at the rear, and I find the rears too soft, and I bottom out very easily on speed bumps and roads if I go on them a little too fast. Before I had the MCAs installed, bottoming out was far more manageable - I am assuming that the MCAs have altered the motion ratio to lower than 0.75, effectively running even softer.

Now, I have an option of changing those springs to 6k springs, matching the fronts to the rear. However my concern is that would it put me back right where I started in the first place without the MCAs? In the HKS manual, it is mentioned that an increase from 4k to 6k is 'possible', which I suppose they are referring where the damper is matched to the spring?

I run UHP tyres, no plans to change to anything with higher grip for now.

Thanks!