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

[Racecomp Engineering]

Originally Posted by Belzak

Alright guys, question about spring rates.

I've been crunching numbers on my abacus using the data from the Suspension Model thread, and I calculated that to hit 2.5Hz front and rear, I would need 7kg/mm front and 8k/mm rear springs. What are your thoughts on these numbers? I was thinking this is a good place to start and I can adjust from there.

I was looking at Feal's 441 coilovers and going to have them put those rate Swift springs and have them revalve the damping accordingly.

I daily my car, however I don't mind a bumpy ride. I do 10-15 track days a year, so I'd rather lean towards lap times over comfort to a reasonable extent. I was only looking at lowering the car approximately 1 inch.

Right now my setup consists of:
-Whiteline front camber bolts
-Godspeed rear LCA's
-Whiteline front and rear sway bars
-Wedssport TC105N 17x9+35
-Michelin Pilot Super Sport 245/40

Also, after I lower the car, what are your thoughts on roll center correction? I think I overheard someone say the dynamic roll center doesn't change too badly if you don't lower the car so much, and it wasn't necessary. Is Whiteline the only company that makes anything for this car in that aspect?

Thank you!

You sound like you're on the right track. 7k/8k is a fine set-up...a little more oversteer (suspension frequencies are only part of the equation) but a popular way to go that does work. We generally go with even rates or sometimes slightly stiffer rear depending on driver, tire choice, etc. If your swaybars are adjustable that will help.

Roll center correction is worthwhile on cars that have a large drop (1.5 inches and I'd def recommend it). Whiteline as far as I know is the only company that makes a set that includes tie rod extenders so you don't end up with a lot of bumpsteer.

- Andrew

[Racecomp Engineering]

Originally Posted by Vincent Nguyen

What the differences between tarmac 2 and koni yellow+ground control coil sleeves combo? I heard nothing but good things about tarmac 2, but my budget is a bit tight to spend $2400 on tarmac 2 + camber plates. What do you guys suggest? My goal is to give the car best handling for spirited driving, autox, and track. Even tho this is my DD, I don't care about ride quality. Comfortable ride is not an issue for me. Also with coilovers, i have the ability to do corner balance, but is this relevant for my purposes? I might see track few times a year, some autox, and bunch of spirited canyon runs.

The issue with a coilover sleeve combo is if you lower the car, you don't end up with much travel left. The RCE Tarmac 2s use a shorter shock body so their designed to be lower than stock.

You might consider our Tarmac 0 coilovers. Similar to Tarmac 2s but with preset valving and a lower price.

Corner balancing is something that is recommended for those that auto-x and track their car. It is not a "must do" for a daily driver.

- Andrew

[CB762]

Hi, I'm wondering if any of those body suspension braces will help with body flexes.
I'm running Ground Control kit with stiff springs and race slicks.

I apologize if this was already answered, but it's hard to go thru all 167 pages.
And thank you in advance.

[Racecomp Engineering]

Originally Posted by CB762

Hi, I'm wondering if any of those body suspension braces will help with body flexes.
I'm running Ground Control kit with stiff springs and race slicks.

I apologize if this was already answered, but it's hard to go thru all 167 pages.
And thank you in advance.

IMO with race slicks yes some chassis stiffening is worthwhile. Not all of the braces I see look functional though.

- Andrew

[CB762]

Originally Posted by Racecomp Engineering

IMO with race slicks yes some chassis stiffening is worthwhile. Not all of the braces I see look functional though.

- Andrew

Thank you for reply! Maybe you can tell what braces look functional?

[jegglz]

Originally Posted by churchx

Stock brakes? Imho they are rather good compared to average OEM brakes. Yes, they lack big thermal capacity for long track sessions w/o fade, and wearables are a bit on expensive side, but usually average stockers at least on cars of this price level are way crappier.

I was very spoiled in terms of brakes thanks to my rx7...I am interested to try the frs calipers with higher quality pads though.

[Iceman]

Wondering if you guys can throw some light here.

I did a trackday this weekend and even though i got some upgrades from the last time, i felt like i wasn't able to brake as hard as before. Differences are as follow:

December trackday:

-ATS DTC 17x7.5 +30
-Pilot Super Sports OEM size
-Motul RBF600
-Everything else stock.

March:

-ATS DTC 17x7.5 +30
-Pilot Sport Cup 2 OEM size
-OEM Camber bolts (around -1.2º)
-Carbone Lorraine RC5+ front pads
-Motul RBF600
-Everything else stock.


With the new setup i was 2.4 seconds faster, the tires provide a greater amount of grip no question about it, but i was expecting to see some improvement under braking as well. What bothers me most is that last December i was braking a little later(maybe 10m) and at greater speed, as according to Harry's Laptimer top speed was consistently over 183kmh(186maximum of the day), while last Sunday i only got 182.8kmh ONCE, and yet i ended up going wide in a couple of braking zones where i don't usually make mistakes.

I know camber may have a negative effect on braking, but i am surprised if the difference is THAT big considering i'm running what i think is a pretty conservative setup, with better tires and better pads, so...Am i missing something?

It may seem like a little difference, and maybe i am just a bit too paranoid and it is just due to the track being slower that day(something i can't tell for sure, unfortunately), but i left the track with some mixed feelings about the brake/tire combo even though i was faster than ever.


Thank you!

[marchocais]

Wondering if you guys could help me out, I did some searching around the forum and this thread and I didn't quite see anything specific to what I'm looking for.

I am being offered a deal on the new Koni strut kits 1145-1053 which are the koni sport shocks with Eibach Prokit lowering springs. I'm targeting a HPDE/DD build that is going to move over to dedicated track eventually (years) and the koni yellows seem to get good reviews here. I've done a few HPDE events the past year with some autox but I think i'm going to stick with just HPDE this year.

This would be first suspension mod on the car, only have a set of 225/45 RS3's on a set of 17/8 RPF1's for track days. I'm thinking I'll need a set of camber plates for front end camber adjustment - but are there other mods I should consider with this since I'll be lowering about 25mm? Anybody have experience with the Koni yellows matched to Eibach springs?

Thanks in advance and for this great thread!

[Mikepage]

Maybe i can ask this question here :

I run coilovers Tein Street Flex, -2.0 of camber all around and lowered around 1po 3/8.

Am thinking about, if the Whiteline kit can make a really big difference the KCA435 kit.

Thanks!

[infinity21]

Originally Posted by Iceman

Wondering if you guys can throw some light here.

I did a trackday this weekend and even though i got some upgrades from the last time, i felt like i wasn't able to brake as hard as before. Differences are as follow:

December trackday:

-ATS DTC 17x7.5 +30
-Pilot Super Sports OEM size
-Motul RBF600
-Everything else stock.

March:

-ATS DTC 17x7.5 +30
-Pilot Sport Cup 2 OEM size
-OEM Camber bolts (around -1.2º)
-Carbone Lorraine RC5+ front pads
-Motul RBF600
-Everything else stock.


With the new setup i was 2.4 seconds faster, the tires provide a greater amount of grip no question about it, but i was expecting to see some improvement under braking as well. What bothers me most is that last December i was braking a little later(maybe 10m) and at greater speed, as according to Harry's Laptimer top speed was consistently over 183kmh(186maximum of the day), while last Sunday i only got 182.8kmh ONCE, and yet i ended up going wide in a couple of braking zones where i don't usually make mistakes.

I know camber may have a negative effect on braking, but i am surprised if the difference is THAT big considering i'm running what i think is a pretty conservative setup, with better tires and better pads, so...Am i missing something?

It may seem like a little difference, and maybe i am just a bit too paranoid and it is just due to the track being slower that day(something i can't tell for sure, unfortunately), but i left the track with some mixed feelings about the brake/tire combo even though i was faster than ever.


Thank you!

Do you still have OEM rear brake pads? That could explain the worse braking performance. Running pads that has a lot more bite up front without changing the rear will shift the bias forward and overwork your front brakes (and therefore under-work your rear).

[Iceman]

Originally Posted by infinity21

Do you still have OEM rear brake pads? That could explain the worse braking performance. Running pads that has a lot more bite up front without changing the rear will shift the bias forward and overwork your front brakes (and therefore under-work your rear).

I do. However i didn't think about that as RC5+'s aren't supposed to be too aggressive, but i guess it may be a reason...Thanks for the input!

[Mad_Mike]

Originally Posted by Vincent Nguyen

What the differences between tarmac 2 and koni yellow+ground control coil sleeves combo? I heard nothing but good things about tarmac 2, but my budget is a bit tight to spend $2400 on tarmac 2 + camber plates. What do you guys suggest? My goal is to give the car best handling for spirited driving, autox, and track. Even tho this is my DD, I don't care about ride quality. Comfortable ride is not an issue for me. Also with coilovers, i have the ability to do corner balance, but is this relevant for my purposes? I might see track few times a year, some autox, and bunch of spirited canyon runs.

Help your budget by not buying camber plates. You can get -2.6 degrees of camber up front with camber bolts. Buy someone's used stock top hats for pennies and pre build the coilovers for easy install.

[xFury]

Looking to purchase Coilover for Daily Drive and to drop about 1"-1.5" drop with 18x9.5 wheels. Was looking at the ST Coils and Flex Z coils, I would like to do AutoX once in a while, but mainly Daily drive it for sure. I go to Cali sometimes if that help from NV. @Racecomp Engineering @CSG Mike

Any advice?

Thanks!

[DerHauptDigga]

Could you all tell me what the OD is for TRD springs?
I have been looking everywhere on the forums and have found nothing.

My brother is an engineer at Bilstein and says the PSS10s have almost the same OD as stock suspension. (Which I had a hard time believing, but he has all the info)

I only ask because I bought 18x9.5 +40mm wheels and they will rub on the stock suspension. I was debating between buying KW V3s or Bilstein PSS10s. Any suggestions?

PLEASE HELP!