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

[jvincent]

For just driving around? Use the pressure on the door.

Messing with pressures only really matters if you are going to be pushing the car hard, which will cause the pressures to rise dramatically.

[dp1]

Originally Posted by DeaconRoc

If you change to a different brand and type of tyre but in stock sizes should you just stick with stock pressures or should they change? If they should change how's the best way to work out what to change them too (without the use of a racetrack, tyre thermometer, etc!)

It depends on ambient temps, driving, tire (size, UTQG and sidewall stiffness), camber, suspension, road surface, etc...usually stock pressures down to 2-4 PSI less work well for street/spirited driving, unless you're driving hard (track) and gain a lot of pressure when you go from say 80F cold to 230F hot tire temps. +10F adds up to 1PSI. Many tires like 35-40 PSI hot pressures...check wear on tire edges and pressures when tires are hot and adjust as needed.

[Shankenstein]

Originally Posted by DeaconRoc

If you change to a different brand and type of tyre but in stock sizes should you just stick with stock pressures or should they change? If they should change how's the best way to work out what to change them too (without the use of a racetrack, tyre thermometer, etc!)

Regardless of street/track, drive around in the most aggressive manner that you plan to (evasive maneuvers or maaaad skidz). Look at the wear and discoloration. You want to make sure that during normal driving, you're utilizing the available tread (>80%).

You can always run higher pressures. If you're want better mileage on a highway trip, you can boost then anywhere from 30 psi to the manufacturer's rating (45-50 psi usually). You can find this on the sidewall or TireRack.

Personally, I run my summer tires at higher pressures for highway trips, to put some wear on the center strip. AutoX tends to wear the shoulders more than the center... so the net result is uniform wear.

[stockysnail]

I run 5lbs less in front compared to the rear. I get much better turn in and the rear gently comes around in the corner when at the track instead of dragging behind. I think I was doing about 23lbs in front and 28lbs in the rear cold and after the session was over it jumped up about 5-8psi when hot.

[Pat]

Originally Posted by stockysnail

I run 5lbs less in front compared to the rear. I get much better turn in and the rear gently comes around in the corner when at the track instead of dragging behind. I think I was doing about 23lbs in front and 28lbs in the rear cold and after the session was over it jumped up about 5-8psi when hot.

I think most people with significant track experience would tell you that's lower than it should be. I shoot for ~36 hot.

[kalamitykode]

Hey, I figured I'd post here instead of making a new thread. I've had my 2014 BRZ for a year and a half now, still running stock wheels. Aftermarket exhaust and CAI, but other than that it's stock except for aesthetics. I decided I'd like to go ahead and upgrade the suspension and lower the car. Not too low, but enough to reduce the gap. I don't track it, and I don't really plan to. It's my daily.

My question is, what parts are necessary to keep from causing damage or making the car dangerous to drive? I bought some BC Racing BR Series coilovers, the standard 8kg/mm set. I've had a few different answers from my go-to advice people, but they don't own the car so I'd like some input if anyone can help. I've been told I need some lower control arms (looking at the Voodoo 13 set), and others have said I won't need them since I won't be super low. Do I need toe arms and/or trailing arms? What about front pieces, like front LCAs?

I'd appreciate any help!

[Turkish]

Originally Posted by kalamitykode

Hey, I figured I'd post here instead of making a new thread. I've had my 2014 BRZ for a year and a half now, still running stock wheels. Aftermarket exhaust and CAI, but other than that it's stock except for aesthetics. I decided I'd like to go ahead and upgrade the suspension and lower the car. Not too low, but enough to reduce the gap. I don't track it, and I don't really plan to. It's my daily.

My question is, what parts are necessary to keep from causing damage or making the car dangerous to drive? I bought some BC Racing BR Series coilovers, the standard 8kg/mm set. I've had a few different answers from my go-to advice people, but they don't own the car so I'd like some input if anyone can help. I've been told I need some lower control arms (looking at the Voodoo 13 set), and others have said I won't need them since I won't be super low. Do I need toe arms and/or trailing arms? What about front pieces, like front LCAs?

I'd appreciate any help!

It all depends on the alignment specs that you are looking for and how low you drop your car. The rear will naturally gain more negative camber as you lower the car. Aftermarket LCAs will allow you adjust the negative camber, but it will also impact your toe and the built in tow adjuster has a limited range that it adjusts between. For the front I would get the crash bolts for ~$14 from your closest subaru or toyota dealer, that should allow you enough camber adjustment to not have understeer problems, as unlike the rear, the ride height does not impact your camber in the front. I hope that helps, of course I would listen to the experts first though.

[kalamitykode]

Originally Posted by Turkish

It all depends on the alignment specs that you are looking for and how low you drop your car. The rear will naturally gain more negative camber as you lower the car. Aftermarket LCAs will allow you adjust the negative camber, but it will also impact your toe and the built in tow adjuster has a limited range that it adjusts between. For the front I would get the crash bolts for ~$14 from your closest subaru or toyota dealer, that should allow you enough camber adjustment to not have understeer problems, as unlike the rear, the ride height does not impact your camber in the front. I hope that helps, of course I would listen to the experts first though.

Good advice, thank you. I really don't plan on more than a 1" drop for now, at least until I get new wheels. I'll probably drop 1" then let them settle which if I understand correctly will be another 0.2" or so. I don't want to be "hellaflush" or anything, I still want the car to handle well.

Edit: The more I think about it, may not even go a full inch lol. I have mudflaps which extend down at least an inch so too low and those will scrape.

[Turkish]

A question for the experts. I am looking to purchase Tarmac 2 coilovers a lot sooner than I had originally anticipated and I was wanting to really start the final round of homework; in other words, I need to figure out spring rates

What I do with my car:
My car is a DD that is also used in local autocross competitions, I am building for the autocross side of things.

Suspension info:

Where I am currently:
Bilstein B8 shocks with RCE Tarmac springs - front and rear
RCE hollow sway bars - front and rear both on softer setting, considering stiffening the rear bar for a bit more oversteer.
OEM wheels with Michelin Pilot Super Sport 225/45r17

What I am working towards with my build:
RCE Tarmac 2 coilovers, spring rates TBD - front and rear
RCE hollow sway bars, stiffness settings TBD - front and rear
17x9" wheels with TBD tires at 245/40r17 - front and rear for autocross
OEM wheels with Michelin PSS 225/45r17 - front and rear for DD

So I am mostly happy with the current setup, but the simplicity of it (not adjustable) has lost its allure as I have become a better autocrosser than I was when I first started dabbling with the suspension. Right now the suspension is very close to neutral, but I would like to have a bit more oversteer to better suit my autocross driving style, hence why I am considering stiffening the rear sway bar in my current setup (I believe that is the correct thing to do??). Of all the coilovers I have seen, combined with my experience so far with RCE products, I believe that the Tarmac 2 coilovers are the next step in my suspension. I like the adjustability of these coilovers for both compression and rebound, and it will allow me to better dial in my suspension than just playing with tire pressure. By default the Tarmac 2 coilovers come with 400lb spring rates all around; by contrast the Tarmac springs are 280lbs front and 290lbs rear if I remember correctly. If I am looking to keep to a similar suspension balance, would I want the same spring rates on the coilovers or would I want stiffer or maybe softer???? What I would like to avoid is having to replace my sway bars again; I like the ones I have currently. Thanks in advance!

[cjd]

Originally Posted by Turkish

A question for the experts. I am looking to purchase Tarmac 2 coilovers a lot sooner than I had originally anticipated and I was wanting to really start the final round of homework; in other words, I need to figure out spring rates

What I do with my car:
My car is a DD that is also used in local autocross competitions, I am building for the autocross side of things.

Suspension info:

Where I am currently:
Bilstein B8 shocks with RCE Tarmac springs - front and rear
RCE hollow sway bars - front and rear both on softer setting, considering stiffening the rear bar for a bit more oversteer.
OEM wheels with Michelin Pilot Super Sport 225/45r17

What I am working towards with my build:
RCE Tarmac 2 coilovers, spring rates TBD - front and rear
RCE hollow sway bars, stiffness settings TBD - front and rear
17x9" wheels with TBD tires at 245/40r17 - front and rear for autocross
OEM wheels with Michelin PSS 225/45r17 - front and rear for DD

So I am mostly happy with the current setup, but the simplicity of it (not adjustable) has lost its allure as I have become a better autocrosser than I was when I first started dabbling with the suspension. Right now the suspension is very close to neutral, but I would like to have a bit more oversteer to better suit my autocross driving style, hence why I am considering stiffening the rear sway bar in my current setup (I believe that is the correct thing to do??). Of all the coilovers I have seen, combined with my experience so far with RCE products, I believe that the Tarmac 2 coilovers are the next step in my suspension. I like the adjustability of these coilovers for both compression and rebound, and it will allow me to better dial in my suspension than just playing with tire pressure. By default the Tarmac 2 coilovers come with 400lb spring rates all around; by contrast the Tarmac springs are 280lbs front and 290lbs rear if I remember correctly. If I am looking to keep to a similar suspension balance, would I want the same spring rates on the coilovers or would I want stiffer or maybe softer???? What I would like to avoid is having to replace my sway bars again; I like the ones I have currently. Thanks in advance!

Hold off on swaybar changes till you've got the coilovers. I'm not sure what is competitive on the T2 for spring rate, but spring will be able to get you more oversteer of that's what you want - though you may want a higher rear rate than front. It's sweepers vs slalom tuning.

Do upper camber plates up front. You don't mention alignment but changes there will also change grip and thus balance. Anything that changes grip will do that, and more up front will be less understeer. LCAs in the back to have proper control over camber.

[Turkish]

Originally Posted by cjd

Hold off on swaybar changes till you've got the coilovers. I'm not sure what is competitive on the T2 for spring rate, but spring will be able to get you more oversteer of that's what you want - though you may want a higher rear rate than front. It's sweepers vs slalom tuning.

Do upper camber plates up front. You don't mention alignment but changes there will also change grip and thus balance. Anything that changes grip will do that, and more up front will be less understeer. LCAs in the back to have proper control over camber.

I knew I forgot something! I have Raceseng CASCAM plates in the front and RacerX LCA's in the rear. As for alignment specs, I am currently using -3 degrees camber and 1/32 toe out on each wheel in the front for a combined toe out of 1/16, castor adjustment is maxed out but i do not recall the total castor off the top of my head atm. In the rear I have -1.5 degrees camber and 1/32 toe in for a combined 1/16 toe in. My sway bars have two stiffness settings and both are currently on the softer setting.

[Racecomp Engineering]

Are you in STX and sticking with street tires?

- Andy

[Bobblehead]

Just got back from getting my car aligned after I dropped it on H&R sport springs. Here's the sheet they printed out for me.

The front:

I'll need to get camber bolts in order to the -1 camber you guys said was optimal, but I'm happy with the ~0 camber. Is there any negative to running 0 camber over -1 in the front?

The rear:

I don't think the 0.3 variance is anything concerned about, is it?

Before:


After:


Thanks in advanced guys!

[Turkish]

Originally Posted by Racecomp Engineering

Are you in STX and sticking with street tires?

- Andy

Yes and yes

Sent from my SM-G900V using Tapatalk