Rom

Hi all,

I'm trying to get my Evo setup for my next track event (in about 3 weeks), and this will be the first time since the rebuild I'm taking the Evo on track (only 1 time before, and that's when the engine exploded). I've upgraded the suspension to KWv3 coilovers with Cusco front camber plates, but I want to make a few more updates before the day.

I plan to do the following:

1) Upgrade REAR springs to 10K. Right now they are running stock KW 6K rates at the back. The front is 9K already, so it should end up being 9K/10K. I planned to go with 6" springs here, even though stock are 7.9" long. Does that sound right? I saw someone mention 6.5" for rear, but I don't see a Swift part for 6.5" @ 10K.

2) Upgrade sway bars to 26mm front and either 24mm or 26mm adjustable rear (Whiteline BMK009 or BMK009M kits). Is it worth doing the 26mm on the rear, or stick to 24mm? I'm leaning towards 26mm because its adjustable. Would it be a sensible assumption that softest on 26mm is probably around mid-setting on 24mm? That would give me more adjustability harder on the 26mm to try out.

3) I'm keeping stock calipers but will be adding cooling ducts. I have the 2" ducts from Binary Engineering. I would prefer 3" but these are all I could find ready made. I plan to run 3" ducting then reduce it right at the caliper. Hopefully this will help carry a larger volume of air, then the reduction will compress it in to the middle of the disc. I'm running Endless RF650 brake fluid so hopefully with the cooling ducts and high temp fluid, the brake fluid will stay liquid!

4) I will be running EBC Orange Stuff at the front and EBC Blue stuff at the back. The thinking is that the Orange, which runs at higher temps, will be worked harder at the front, and the Blues which work with slightly lower temps will maintain performance at the back. This should hopefully counter the Evo 60/40 brake bias and maintain even, fade-free, braking performance all around. This Orange/Blue setup was covered in the following thread, and since I like EBC products, I thought I'd try this:

https://www.evolutionm.net/forums/ev...o-viii-ix.html

5) Just as an FYI I plan to run Toyo R888R tires, assuming the weather is dry. I've run R888's many times on my other cars, but this will be the first time on the new R888R's.

The "go to" people for suspension seem to be less interested nowadays (Robi-spec seems to have gone AWOL, and GTWORX last posted over a year ago), so hopefully the knowledge is still around!

Just some added context... The Evo was one of our daily drivers until recently though which is why I've only taken it to the track once before, and that was when the old engine blew up. This is the first "real" outing in the Evo for me (with all these upgrades designed for track), hence the above request for input on my setup! I am very experienced on track in my other cars (well over 1000 laps across tracks in the UK and US) so would love to hear any input geared towards a more experienced driver (as opposed to a beginner).

Thanks in advance!

S.

MinusPrevious

iTrader: (3)

Ill give you my opinion

First off, is this just a track day run or an official SCCA / NASA day?

1. Cant comment on the spring length. The 9K/10K sounds OK & will work on the track. I personally run a 10K/12K

2. I run the Whiteline 24mm rear adjustable bar & that has worked for me. I really dont think I need more bar, especially running a 12K spring. If youre going to stay at 10K rear, maybe an adjustable 26mm would work OK. Many of us run the stock FSB which has been a highly debatable topic. I run the stock FSB w/the WL end links. When running high rate springs, running a high rate FSB will only exacerbate your understeer

3. I have never run brake ducts & really depends on what type of track work you plan on doing. If youre racing a full 25 min session, i would say, the duct work may be needed. If youre just track daying it, it may not be needed. I was personally just time attacking it, so ducting was not needed by me

4. Cant comment on the EBC grades. I ran Carbotechs on the track

5. Cant comment too much on the Toyos but they seem similar to what i ran (Nitto NT01)

Rom

Thanks!

This is just a shakedown track day, but it's a 2 day event with 25-30min sessions.

Did you try 9K/10K before your current setup? Why did you decide on the stiffer springs? Just trying to understand the pros/cons!

Thanks!

S.

MinusPrevious

iTrader: (3)

My set-up prior was a set of Muellerized Skunk2's for the street & light track

The 10K/12K setup was recommended by the Fortune Auto suspension tuner, based on my interview w/him prior to build. He actually wanted me to run 12K/14K but i chickened out

Simple way to look at suspension & bars is this IMHO: Soft springs & big sways or Big sways & soft springs. Cant have both, less we suffer severe understeer

Rom

Yeah, that's what I thought too. I was just interested in your reasoning for the stiffer springs.

In my case I will likely stick with the bigger sway bar and softer (9K/10K) springs to keep street driving a bit more compliant with softer rebound/bump settings. The bigger bar will hopefully give the effect of stiffer springs during hard cornering, limiting body roll.

Thanks for your input!

S.

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codgi

iTrader: (22)

TBH I wouldn't touch the sway bars. Drive the car as is and see how it performs and then adjust them after. Also pretty sure a long time ago the rear sway bars above 24mm weren't recommended for most road course cases.

In terms of this:

AFAICs there's no benefit to the additional inch. If you had something that was forcing air into the duct then it would be different but in this case there is nothing forcing the air to compress at the reducer so the amount of air (volume) that will hit the brakes is still limited by that 2" outlet.

Rom

I actually will have a 3" inline fan on each pipe too. The fans produce up to 145cfm each, which will help the air along, and help when not moving too. I plan to measure temps to see how they are affected, to see how effective the active cooling setup is.

Thanks!

S.
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kikiturbo

avoid EBC brakes, get Carbotech XP 10 or 12

9K / 10K is a good combo, avoid ARB for start or just get rear whiteline ARB and run it on softest setting initially.. ...

Rom

Just updating this.. I ended up running out of time and didn't get the brakes or rear spring done in time. I ended up buying the KW 10K spring so will install it soon and report back on how it feels. Since they have the precise diameter I thought it would be the best option.

I still took the car to the track but only got one session out of it. A pretty major oil leak developed around the return oil pipe and the oil cooler return line to the filter housing. Hopefully I can have it all fixed by the next track day.

The rest of the day I did all my sessions in a McLaren, so still had some fun, but I really did want to put the Evo through its paces - the one session actually felt really good while it was out there on the new motor!

Thanks!

S.