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

[jflogerzi]

Originally Posted by jkamelo

Hey guys, thanks so much for doing this thread.

I daily drive a bone stock FRS. I plan to do a HPDE class in 2021 but I don’t anticipate hitting the track more than 4 times a year. So this car is primarily a grocery-getter being driven on highways and suburban roads of varying quality.

All I want to do is lower the car an inch while preserving or improving upon the stock handling characteristics/ride comfort. I’ve ruled out lowering springs, so the Flex Z is my current front runner thanks to its low price.

Problem is, my friends shouted at me when I brought up the Flex Z. They swear by the Fortune Auto 500s because it’s rebuildable and has better customer service + a better warranty. Also something something “digressive piston technology.”

I don’t understand what I’d be spending the extra money for. I’m not a cheapskate - if the FA’s are worth it, I’ll pay. But considering my use case, what would y’all recommend I do? Pull the trigger on the Flex Z’s (or some BC BR’s), or splurge on the FA 500s? In other words - what would I be missing by taking the cheaper route?

Also, if it matters - I’m currently on stock TRD 17’s with Bridgestone Turanza EL400 225/45 all-seasons. I plan to upgrade to 18x8.5s and a better tire (Nitto Neo Gen?) around the same time I buy my coilovers.

Thanks in advance lads.

Neither of those are solid. For use I think the lower costs of SS1 by RCE would fit nice. You get camber plates, plus a good OEM (KW)

Remember don't forget install costs, alignment costs. Its not a cheap thing to do so do it right once. What year is your FRS?

[jkamelo]

Originally Posted by ZDan

Why rule out lowering springs? RCE Yellows or Tarmacs, Swift Sport or Spec-R, with Bilsteins is a great setup IMO! Loving mine on street and at the track. Honestly, though damping is not adjustable I think they have a better combination of high/low and rebound/compression than my Ohlins Road & Track coilovers on my FD RX-7. REally...

For coilovers, I'd go with CSG or RCE recommendations, but for your usage lowering springs + Bilsteins is IMO a solid option.

You can do better than Neo Gen I'm sure. Do you need all-seasons? Tire choice is super important, check out tire tests and reviews at Tire Rack.com to figure out what's gonna work best for you. For track, it'd be good if you stick with either the Extreme Performance or Maximum Performance Summer tire categories.

I’d rather have the adjustability of coilovers and not need it than be stuck with lowering springs and want to upgrade down the line. Plus I just think they’re cool!

I also decided to go with the Pilot Sport 4 A/S because while it doesn’t snow here often, it does get cold and I don’t want a summer compound that will turn to brick on a cold day.

Thanks for your advice!

Originally Posted by jflogerzi

Neither of those are solid. For use I think the lower costs of SS1 by RCE would fit nice. You get camber plates, plus a good OEM (KW)

Remember don't forget install costs, alignment costs. Its not a cheap thing to do so do it right once. What year is your FRS?

Thoughts on the SS1 vs. the CSG Flex A? I’m between those two.

I figured I’d install them myself then get them aligned professionally. It’s a 2016.

[jflogerzi]

Originally Posted by jkamelo

I’d rather have the adjustability of coilovers and not need it than be stuck with lowering springs and want to upgrade down the line. Plus I just think they’re cool!

I also decided to go with the Pilot Sport 4 A/S because while it doesn’t snow here often, it does get cold and I don’t want a summer compound that will turn to brick on a cold day.

Thanks for your advice!



Thoughts on the SS1 vs. the CSG Flex A? I’m between those two.

I figured I’d install them myself then get them aligned professionally. It’s a 2016.

can't go wrong with either to be honest. I have no direct experience with either. Both have great OEMs in Tien and KW and 2 companies who support our platform. I would get in touch with each and see what which best suit your goals.

[TwinFTW]

Sorry for the long post.

TLDR: I’m starting to think about prioritizing a differential upgrade, but I could do many other things for differential upgrade type money... Should I be looking into a differential for tight technical B roads fun? Other setup suggestions or cheaper mods to chase first? I’m putting the question here since there is very good setup advice in this thread that I’ve already benefited from.


Details:

I’ve put 4,000 canyon carving miles on my new to me Performance Pack BRZ in 5 months of ownership. It has become my pandemic escape driving car.

Very tight technical “B road”s are my favorite type of driving and are most of those 4,000 miles..

My main gripe is battling with uphill 1st and 2nd gear hairpin traction on exit. My favorite road has multiple switchback/ tighter horseshoe sections with 3-4 hairpins a piece that fry my diff fluid. It is frustrating constantly battling with spinning the inner rear wheel in these sections.

I’ve also briefly considered shifter and driveline bushings, I wouldn’t mind a more solid/heavy shifter feel as stock is very light. However, I do love the nimble without being overly harsh ride that the stock bushings on the performance pack provide.

Current setup:
Maxed out front camber to -2.7(offset top hats and camber bolts), -1.5 camber in the rear

Ducted Greddy oil cooler from CSG.

Recently switched the factory diff fluid to Motul 300LS to see if it would help... seems to possibly fry a little less in terms of duration but smells worse then the factory fill, and hasn’t made much of a dent in my problem.

I’m still on the Primacy HP’s which I love for the driving I’m doing (so many cheap used spares I bought a second set). I like the playfulness at lower speeds, predictable, communicative and reliable.

In the future I could see myself signing up for an occasional track day here and there but at the moment I’m more interested racking up canyon miles first, maybe doing car control events and getting driver coaching second with open track days/HPDE being a distant 3rd.

Thoughts on next step setup suggestions?

[Racecomp Engineering]

Originally Posted by TwinFTW

Sorry for the long post.

TLDR: I’m starting to think about prioritizing a differential upgrade, but I could do many other things for differential upgrade type money... Should I be looking into a differential for tight technical B roads fun? Other setup suggestions or cheaper mods to chase first? I’m putting the question here since there is very good setup advice in this thread that I’ve already benefited from.


Details:

I’ve put 4,000 canyon carving miles on my new to me Performance Pack BRZ in 5 months of ownership. It has become my pandemic escape driving car.

Very tight technical “B road”s are my favorite type of driving and are most of those 4,000 miles..

My main gripe is battling with uphill 1st and 2nd gear hairpin traction on exit. My favorite road has multiple switchback/ tighter horseshoe sections with 3-4 hairpins a piece that fry my diff fluid. It is frustrating constantly battling with spinning the inner rear wheel in these sections.

I’ve also briefly considered shifter and driveline bushings, I wouldn’t mind a more solid/heavy shifter feel as stock is very light. However, I do love the nimble without being overly harsh ride that the stock bushings on the performance pack provide.

Current setup:
Maxed out front camber to -2.7(offset top hats and camber bolts), -1.5 camber in the rear

Ducted Greddy oil cooler from CSG.

Recently switched the factory diff fluid to Motul 300LS to see if it would help... seems to possibly fry a little less in terms of duration but smells worse then the factory fill, and hasn’t made much of a dent in my problem.

I’m still on the Primacy HP’s which I love for the driving I’m doing (so many cheap used spares I bought a second set). I like the playfulness at lower speeds, predictable, communicative and reliable.

In the future I could see myself signing up for an occasional track day here and there but at the moment I’m more interested racking up canyon miles first, maybe doing car control events and getting driver coaching second with open track days/HPDE being a distant 3rd.

Thoughts on next step setup suggestions?

Some of that is the reality of the Primacy tires!

A new diff is a big deal, but it's usually not the first thing people jump into.
You've addressed the alignment, which is one of the most important things to do.

Whiteline subframe and diff bushing inserts are a good upgrdae to conisder. There's an increase in noise but minimal to no noticeable change in harshness. They won't "solve" your problem but they will add some confidence to the rear end.

Our OEM shocks are more designed for a "sporty" feel than outright grip. That is IMO pretty noticeable on tight corners on bumpier roads. EDIT: by this i mean that they are not super great at keeping the tire on the ground.

I would definitely recommend some track days and/or auto-x events if you can.

Start with that and you'll have a better understanding of what the car is doing and how a diff can improve the driving experience.

- Andrew

[timurrrr]

Originally Posted by TwinFTW

My main gripe is battling with uphill 1st and 2nd gear hairpin traction on exit. My favorite road has multiple switchback/ tighter horseshoe sections with 3-4 hairpins a piece that fry my diff fluid. It is frustrating constantly battling with spinning the inner rear wheel in these sections. ... Recently switched the factory diff fluid to Motul 300LS to see if it would help... seems to possibly fry a little less in terms of duration but smells worse then the factory fill, and hasn’t made much of a dent in my problem.

How do you know it's "frying" your diff fluid?

[CSG Mike]

Originally Posted by TwinFTW

Sorry for the long post.

TLDR: I’m starting to think about prioritizing a differential upgrade, but I could do many other things for differential upgrade type money... Should I be looking into a differential for tight technical B roads fun? Other setup suggestions or cheaper mods to chase first? I’m putting the question here since there is very good setup advice in this thread that I’ve already benefited from.


Details:

I’ve put 4,000 canyon carving miles on my new to me Performance Pack BRZ in 5 months of ownership. It has become my pandemic escape driving car.

Very tight technical “B road”s are my favorite type of driving and are most of those 4,000 miles..

My main gripe is battling with uphill 1st and 2nd gear hairpin traction on exit. My favorite road has multiple switchback/ tighter horseshoe sections with 3-4 hairpins a piece that fry my diff fluid. It is frustrating constantly battling with spinning the inner rear wheel in these sections.

I’ve also briefly considered shifter and driveline bushings, I wouldn’t mind a more solid/heavy shifter feel as stock is very light. However, I do love the nimble without being overly harsh ride that the stock bushings on the performance pack provide.

Current setup:
Maxed out front camber to -2.7(offset top hats and camber bolts), -1.5 camber in the rear

Ducted Greddy oil cooler from CSG.

Recently switched the factory diff fluid to Motul 300LS to see if it would help... seems to possibly fry a little less in terms of duration but smells worse then the factory fill, and hasn’t made much of a dent in my problem.

I’m still on the Primacy HP’s which I love for the driving I’m doing (so many cheap used spares I bought a second set). I like the playfulness at lower speeds, predictable, communicative and reliable.

In the future I could see myself signing up for an occasional track day here and there but at the moment I’m more interested racking up canyon miles first, maybe doing car control events and getting driver coaching second with open track days/HPDE being a distant 3rd.

Thoughts on next step setup suggestions?

What it sounds like you need is stickier tires.

The diff would certainly help make the rear more predictable, but if you're really pushing the car, the rear will step out whether its a 1st gear corner or a 5th gear corner.

If you're getting a 1 tire fire (very possible on tight turns), then the LSD is the way to go. CSG could customize an lsd to match the tire(s) you plan on running.

[TwinFTW]

Originally Posted by timurrrr

How do you know it's "frying" your diff fluid?

It always smells like burning gear oil when I hit the 3rd-4th hairpin of a driving section.

I typically have the windows somwhere in between cracked and full open depending on how cold it is... Motul 300LS smells particularly shitty, even for gear oil.

[TwinFTW]

Originally Posted by CSG Mike

If you're getting a 1 tire fire (very possible on tight turns), then the LSD is the way to go. CSG could customize an lsd to match the tire(s) you plan on running.

1 tire fire is my current biggest gripe.

But, in a perfect world I would have two sets of tires ... a Michelin PS4S/Hankook RS4 type-ish street grip set of tires when I am running with faster cars and need to keep my ego happy... and a Primacy HP-ish/lower grip set when I don't care very much about carrying speed and I just want the car to feel neutral and engaging even in hairpins.

[Compelica]

Is there any benefit, from a handling standpoint to lower a car about 10-15mm from stock height? I notice that *most* springs/coilovers advertise a 15-25mm drop, but I'm unaware if it has any benefits from a handling standpoint (a further lowered COG or less body roll for example) as opposed to aesthetics - what it seems like is that it's more of the latter to me.

I'm on HKS Hipermax GT (6K front, 4K rear) and I've been driving on stock ride height for quite some time - it was raised from an original 25mm drop from the factory coilover setup, though the raise in height was done hastily so I could clear the high ramps in my parking lot when I moved in.

I've recently got a set of adjustable endlinks as mine were binding at the new ride height. The car is almost due for its alignment, but I wanted to revisit the ride height to see if I could further improve any handling characteristics without getting into more hardware changes. The car's still a DD so it'll still have to manage those kerbs and speed bumps so a 10 to 15mm drop would be the max it could do.

Thanks!

Also, here's my current setup:

Tyres: Falken Azenis FK510s, will stick with UHP tyres as we get a lot of rain here
Front camber: -2 deg. Was planning for -2.5 deg after looking at tyre wear but with the planned lowering I could probably keep this at the same amount
Rear camber: Stock at ride height, at the top of my head it should be around -1.25 deg so lowering a little would -ve slightly more
Rear toe in: can't recall values but very slight
5mm spacers for slightly wider track.

[Racecomp Engineering]

Originally Posted by TwinFTW

1 tire fire is my current biggest gripe.

But, in a perfect world I would have two sets of tires ... a Michelin PS4S/Hankook RS4 type-ish street grip set of tires when I am running with faster cars and need to keep my ego happy... and a Primacy HP-ish/lower grip set when I don't care very much about carrying speed and I just want the car to feel neutral and engaging even in hairpins.

I run 225 Michelin PS4S on a 17x8 in the summer and they're plenty fun.

I also run 195 winters which I can roast if I look at them funny but that's not the diff's fault.

- Andrew

[Racecomp Engineering]

Originally Posted by Compelica

Is there any benefit, from a handling standpoint to lower a car about 10-15mm from stock height? I notice that *most* springs/coilovers advertise a 15-25mm drop, but I'm unaware if it has any benefits from a handling standpoint (a further lowered COG or less body roll for example) as opposed to aesthetics - what it seems like is that it's more of the latter to me.

I'm on HKS Hipermax GT (6K front, 4K rear) and I've been driving on stock ride height for quite some time - it was raised from an original 25mm drop from the factory coilover setup, though the raise in height was done hastily so I could clear the high ramps in my parking lot when I moved in.

I've recently got a set of adjustable endlinks as mine were binding at the new ride height. The car is almost due for its alignment, but I wanted to revisit the ride height to see if I could further improve any handling characteristics without getting into more hardware changes. The car's still a DD so it'll still have to manage those kerbs and speed bumps so a 10 to 15mm drop would be the max it could do.

Thanks!

Also, here's my current setup:

Tyres: Falken Azenis FK510s, will stick with UHP tyres as we get a lot of rain here
Front camber: -2 deg. Was planning for -2.5 deg after looking at tyre wear but with the planned lowering I could probably keep this at the same amount
Rear camber: Stock at ride height, at the top of my head it should be around -1.25 deg so lowering a little would -ve slightly more
Rear toe in: can't recall values but very slight
5mm spacers for slightly wider track.

A lower center of gravity is good and helpful, as long as you have the travel and you're not so low to start worrying about roll center location (and 15mm is not too low).

- Andrew

[timurrrr]

Originally Posted by TwinFTW

It always smells like burning gear oil when I hit the 3rd-4th hairpin of a driving section.

I typically have the windows somwhere in between cracked and full open depending on how cold it is... Motul 300LS smells particularly shitty, even for gear oil.

Any chance to check the temperature of the diff after that?
Borrow someone's IR camera, or something?
Or maybe even a temperature sensor with a data logger

Have you considered diff cooling?
Have you seen this

?

Tried using higher temperature and/or higher viscosity diff oils?
A few of my track friends experienced overheating with Motul Gear 300 at the track, and switched to using Motul Gear Competition 75w-140 instead.
If the only thing you really need is for the oil to live through one more hairpin on your one-way, that might just be enough to fix the problem for you (assuming currently you only experience problems towards the end of that hairpin-y section).

[timurrrr]

Originally Posted by Compelica

Is there any benefit, from a handling standpoint to lower a car about 10-15mm from stock height? I notice that *most* springs/coilovers advertise a 15-25mm drop, but I'm unaware if it has any benefits from a handling standpoint (a further lowered COG or less body roll for example) as opposed to aesthetics - what it seems like is that it's more of the latter to me.

Just as a data point, see the ride heights 949 Racing use for their Xida prototype: https://www.ft86club.com/forums/showpost.php?p=3230584
Note that they run taller 225/45/17 tires, so subtract 4.5 mm from their numbers if you're on stock tire diameter.
Don't forget to have a person in the driver's seat of the car when measuring ride height.