R/TErnie

iTrader: (32)

Background information

I'm competing in a time attack series called "lap attack" at Pacific Grand Prix in Kent, WA. The track was designed for karting and is a very tight track with very little room for my car to get its legs (use the hp advantage) From my data logs I spent approximately 7 seconds of a 1:16 lap time at WOT! The classes are split into 3 groups; FWD, RWD, and AWD.

This is my first event turning left and right... I'm a drag racer at heart. I co-drove with my roommate who is an experienced kart racer that also drove FSAE for our team for 3 years. My lap times were in the 1:20 range, Scott's were in the 1:16 range, and the fastest lap by an AWD car was 1:11. Track record was set during this event by a z06 on 300+ Hoosier A6's @ 1:09.

The biggest disadvantage we faced was that we were on street tires. The STi that took 1st and 2nd place (co-driven) was driven by a VERY experienced auto-x champ AND was on 245/45/17 Hoosier A6's.

Since I know most of you are wondering what I'm working with here's the details on my car/setup.

Evo 9

Suspension
Bridgestone RE-01R's 265/35/18
18x9.5 NT03's +40
25mm spacers up front
Works Camber plates
25mm rear bar full stiff
Works lowering springs w/ factory GSR struts 43k miles
Camber -2.2F, -1.2R
Toe 1/32" out F, 0 R
HOT 34psi F, 34psi R

Brakes
Axxis ultimate pads
2 year old ATE blue fluid
slotted girodisc rotors
stock brake lines

Engine/Drivetrain
well... stock 9 turbo @ 30+psi on C16.
Makes about 380whp/380lb ft.
Exedy twin disc, ultimate ratio box w/e8 3/4
I'm confident that I've got one of the better Power to weight ratio's out there.
Except for the Ariel atom
2900 lbs WET w/out me
I weigh 170 pounds.

Issues I faced during the event
1) The car understeered HORRIBLY! Mid corner push, pushes on power leaving a corner, pushes on turn in.... pushed its way around the track. Scott and I both agreed upon this. I tried several times to power oversteer the car out of a corner and it simply pushed like a FWD car

2) The brakes became soft after my 2nd outing in the car, signifying that we/I boiled the 2 year old fluid. They're still soft today :P The axxis ultimate ceramic pads are great low dust, low noise pads.... BUT THEY WERE TERRIBLE at the track. Absolutely terrible. I had very little confidence in the braking ability and their initial bite was more of an initial suck.

3) The Bridgestone's grip went away after I overcooked them by pushing around the track. I'm learning about how to drive, so take that into account, but I realized that I had over temped them and the grip went away. I adjusted my driving style to brake harder in a straight line and roll through the corners instead of trying to maintain throttle through the corners and end up making the tires talk to me the whole corner!

Solutions planned (this is where I need your advice/comments to see that I am correct in my thinking!

1) GRIP Hoosier A6 or Kumho V710 in 285/30/18. (has to be DOT)
- From what I've read the Hoosiers are a great competition slick, but their life expectancy is less than the Kumho v710. We have 3 more events this year as well as practice sessions planned for car setup. Each Event consists of a 3 lap qualifying session, and 3 sessions of 1 out lap and 3 timed laps. So each Event will have close to 30 laps on this course. Considering we're co-driving the car... it gets twice the tire use! So 90 laps on this course, and at least 2 practice sessions with another 20 laps or more. So 110+ laps or 2 hours of drive time. I guess my question here is... will I be buying two sets this year? will 1 set last the entire duration? Please recommend strategies based on your own experience with these slicks.

2) Fix that understeer by...
- Installing my whiteline RC correction kit and bumpsteer correct kit.
move the roll center above the pavement and reduce the lever arm! This will increase the roll stiffness without putting on a stiffer front bar.
- Changing my alignment to...
Camber -3.5F, -1R
Toe 3/32 out F, 1/32 in Rear
I assume I need more camber because of my lack of stiffness... and therefore I have more body roll, which is eating up my static camber. I also read on Hoosier's site that the slicks prefer MORE camber than regular tires. More toe out in the front will make the turn in NUTS! When I bought the car it had a ton of toe out. Bad for street use, amazing for the track. the toe in in the rear is supposed to make the car rotate better ( i can only assume by decreasing grip in the rear)
- Running more pressure in the rear to decrease grip.
I know decreasing GRIP is the wrong solution to fighting understeer, but it's easily adjustable. I plan to run 3-4psi more in the rears. Setting tire pressure by marking the side walls and checking how much I'm using.
- I'm considering putting a front bar on, but I think that's too much change for one outing, not to mention installing the front bar is a PITA. so maybe later, but definitely on my mind. Increasing front roll stiffness keeps me in the part of the camber curve that i want to be in... shouldn't have a negative effect because the suspension stiffness is more like suspension softness!

3) Making the brakes ROCK.
- I read essex's site last night about brake pads. very informative, explained to me why the ceramic pads that I have suck for the track. My solution to the pad dilemma was to replace them with the Raybestos ST43's, Hawk DTC-60's, or the CL RC6 pads. Hamish highly recommended the CL RC6's.... looking for input from someone who has used both. Remember track use... I don't care if they make my wheels black or scream at me while slowing down... as long as they DO THEIR JOB.

- Flush the brake fluid. I know people will have different preferences. The Castrol SRF looks amazing, but I feel that I won't be able to take advantage of how amazing this fluid really is. Fresh fluid is the answer here... RBF600... available, I run this in my other car... works fine.

- CONTEMPLATING the Girodisc titanium backing plates to keep the brakes from cooking. I probably only need them for the fronts. Knowing my particular situation... please make a suggestion!

4) Practice.
Scott and I plan to take turns running around the course on a lapping day and have him tutor me on my line/mistakes. Practice makes perfect... works for me in every other facet of life, should work miracles here! We also plan to run the rental carts on the track to learn the lines. The other drivers here have 5-10 times to laps we have on the track, so learning the lines is very important. It's quite evident in my lap times compared to Scotts...I have just over 4 seconds to learn!

I think with these improvements to the car's weakness' and an improvement in my driving and our lines we should be able to bring some pain next session. I can only anticipate that the event will attract bigger fish with better prepared vehicles. Thank you in advance for your help.

-Eric Urness

Smike

iTrader: (8)

Issues:
1) Not a lot of rear camber. I would go up to -1.5 in the rear.

2) Axxis ULTs are not a track pad. And brake fluid at 2 years old is junk As you found out.

3) Once heat soaked, RE01s will be tough to bring back.

My recommendations for solutions:
1) I spent my off season researching all the r-comps for me. Similar situation as you are in. I would also research the NT01s. I have 2 events on my NT01s (AX and a full track day where I was driving hard for an instructor). Very little wear on the tires. More importantly, they are predictable and easy to push hard. They tell you when you are close to the limit with some in/out traction. Not instant break-away and all hope lost.

I would say learning on street tires first will make you a better driver. Dunlop Z1* have a better working range than the RE01.

2) Do not do -3.5/-1, that will make the car worse. Do -2.2/-1.5 to -1.6 in the rear. Front sway bar - Whiteline or Robi are adjustable. Swifts is the lighter one, but not adjustable.

What are the spring rates on the Works springs?

3) Good set of track pads listed. Also check out the CL6E - will last longer. And a few people are testing the EBC Blues right now. Hope to have more info on those in the near future. Also check out the Amsoil DOT4. I never have had an issue with that fluid.

3a) Ducts for more air.

https://www.evolutionm.net/forums/ev...e-30-hour.html

http://www.suncoastparts.com/product...734148492.html

4) Never can have too much practice

R/TErnie

iTrader: (32)

Replies within!

Truf!

Thank you for the response! I really appreciate it.

bxracer1

iTrader: (2)

1. Spring rates may play a big part in your understeer/push. You need to definitely find out the spring rates, the evo loves a higher rate in the back due to the suspension geometry

2.Toe out in the rear will help with rotation of the car also.

R/TErnie

iTrader: (32)

I'll call up works tomorrow and see if I can find an actual spring rate Thanks!

I'm starting to think the RC kit from whiteline makes a much larger difference than I was originally thinking...

bxracer1

iTrader: (2)

I have the whiteline RC kit and it does do some pretty good things to the front roll of the car. However, it is not an essential. More over getting a proper alignment and the correct spring rates should be your first step.

Smike

iTrader: (8)

Will below.

Sorry mate.

Cool beans!

There was a Grassroots article that I read comparing the tires (03 or 05, I cant find it now...grrr...). The NT01s where only a few tenths off from the V710 and A6, but lasted much longer. I ran the V700 for AX. Good tire, but short life. In one AX, I shaved off 2/32nds. My NT01s have not done this. But I am after using a set the whole season.

Big learning curve But from this tread, it sounds like you want it.

Sway bars limit sway, which we know. They also will limit camber change when loaded (in a turn). If you run -1 and a big RSB, then you have limited camber to start and more limited movement as the suspension compresses. I would give it more camber to offset the camber change that is going to happen in turns.

Too big of a RSB will increase front traction. Sound confusing? Well, its forcing the front tires to plant more. More planted - more traction, more understeer in the Evo. Now, add a FSB and you increase the rear lateral traction and a need thing grip - you will get more out of the both tires in a turn.

I am sure you have seen the tri-pod Evo pictures. That is what I am talking about here. Say your on an AX course with one rear wheel off the ground. I am also in that AX, but I keep all my wheels planted in the same turn. Who is going to be able to apply power sooner? Well, I am. A wheel in the air wont help you

Its about balance. Right now you have too much rear bar causing too much front grip. Adding a FSB will equal and help out the rear much more.

Brain hurt yet?

I exploit this on my FWD SVTF. I run a big RSB and -2.2 F / -2.4 R camber. I want my car to plant the front tires and pull me through turns. Note, I gave it more rear camber to offset the limiting that my big bar is going to do. So in a hard turn, my fronts will stay down, and I can get on power sooner than others. And my car still rotates on sharp turns.

Rates play a ton here too. Stock rates are 180lbs F / 225lbs R. 20% = 216 F / 270 R. That is pretty soft. Might want to look into changing those.

Well, why? I ran the Motul - yes it loves water. ATE Blue is good, but does not have as high as a boil temp as the Amsoil. I have not heard of any issues with the Amsoil DOT4.

EDIT: Ill talk more on brakes The MOT on the ULTs is ~930*F. That means you are getting more than 1000F in them if they are giving up. Two things, new drivers always use the brakes too much. You will learn to use the brakes more efficiently. But it also is showing a lack of cooling on the brakes.

The Mitsu glides are too small. Try out the Porsche GT3 glides - for $30 bucks, hard to not try them. But I run them on my SVTF also. NHMS was similar to your track. I topped out at 95 on the front and back straights. But lots of on brake moments. Any air you can give to your brakes, the better.

Ludikraut

iTrader: (17)

First off, let me preface by saying that I'm no suspension 'expert' by any stretch of the imagination. I've only modified my suspension to get the car to my liking, but no race results to prove anything, since I haven't participated in any kind of TA, auto-x, etc - just HPDE.

IIRC the Whiteline front swaybar is not adjustable, only ones I know of are H&R, HKS, and Robispec.

To make the car handle better than it is now, I'd suggest a couple of things to start with:
- start replacing your suspension bushings, beginning with the rear trailing arm bushings
- Send your rear diff to TRE to have it upgraded, this should get rid of your corner exit understeer completely

On street tires, your spring rates are probably ok. However if you step up to R-comps, with the intent of doing well in your competition, you'll probably want to skip springs and go to a good set of coilovers (Ohlins, KW, JRZ, etc.).

Practice on street tires, until you are at least competitive with your bud. Only then think about switching to r-comps.

l8r)

R/TErnie

iTrader: (32)

replies within

we're planning on running the course with our lap timer on street tires in the upcoming week. He's raced on this track for several cart races, where it was my first time on this particular track. I suppose that has something to do with the time difference.

GTWORX.com

iTrader: (35)

1. Grip.

Yes put stickier tires on and go faster. That's the easy part. Listen to others about which tires to get. Hoosier A6 will be the best, but you'll go through them like crack and it's way more expensive. As Smike and Ludikraut said though, for a new driver still learning, a sticky street tire is a better way to learn. But Hoosiers will be faster. However, doing so without increasing spring rates will feel terrible.

2. Understeer.

More front camber, stiffer springs, possibly a front bar, and like Ludikraut said BUSHINGS will make a big difference, especially for a tight track with lots of quick movements. IMO the front bar doesn't help with "understeer" per se, but does make the car handle better and improve overall grip. Better turn in and a higher limit.

I suspect you would be impressed with the -3 degrees camber. This is especially a must do if you add the r-comps. You probably need even more with r-comps.

I like zero toe front and rear...some rear toe out will help it rotate but don't worry about that until you get the rest of the car sorted. Maybe a hair more rear camber IMO, if you stick with those springs.

It's too bad Works doesn't release the actual spring rates, but my understanding is that they are a little soft.

I think there are a variety of ways to go and they depend on your budget. It's tough to give numbers to shoot for without looking at the complete package....for example if you stick with those springs you may want X, and you'd want Y if you went with coilovers. Upgraded bushings and geometry bits are an excellent way to improve ANY set-up.

The cheap thing to do would be:
1. More front camber, a little more rear camber (-1.5 ish), MAYBE a little rear toe-out.
2. Bushings

Maybe add the front bar.

After that, coilovers or stiffer springs (GTWORX or Swift Spec R). Coilovers if you do go to r-comps.

3. Brakes.

You need new fluid. I only have first hand experience with ATE Super Blue and Motul. Motul is more track worthy, but ATE lasts longer.

I always like brake ducts. You may not see their full potential on a super small tight track, but still nice.

The Carbon Lorraine pads would work well for you. Would you be swapping them in at the track or daily driving them?

- Andrew

GTWORX.com

iTrader: (35)

A bigger rear bar increases front grip. It allows more weight to transfer at the rear of the car, and thus less at the front of the car (for a given corner, for given car, at a given speed, etc. total weight transfer is the same). So a more even loading on the front tires as less weight has transferred to the outside tire. More evenly loaded tires = more grip. 1 tire with 1000 lbs of force on it does not provide as much grip as 2 tires, 1 with 700 lbs and 1 with 300 lbs.

The same is true flipped for a front bar, it increases rear grip the same way. However, due to the limited body roll it also provides, less dynamic camber loss/gain is a good thing and could provide you with more front grip and/or more overall grip. This plus the better turn in from less roll up front makes people happier with the car. Too big up front though and the front has transferred too much weight and the outside tire just can't deal with it and you understeer.

- Andrew

dbsears

iTrader: (37)

My advice after formally having many of the same parts. I am no expert but just some observations I have made.

Suspension:

Personally I don't feel the whiteline kit will benefit you much right now. You are on Works springs which aren't that low to begin with. Problem is you are on springs and old struts. That is your #1 main issue. I would not recommend combining R Comps with lowering springs. If you want to "win" the event you are really going to need to step up with coilovers first off. Get springrates to suite your driving needs and rely less on a big rear bar. Then add bushings from there. Trailing arm bushings helped tremendously in my car...although the AMS Delrin ones are damn loud.

Little observation I have. I once had Swifts, MR struts, Perrin 25mm bar, and RE01R. Way too much understeer and messing with high rear tires pressures and adjusting the bar did very little to mask this problem. Times told the whole story. Switching to PROPER springrates and Ohlins I now have a smaller rear bar and for the most part my dampening and small tire pressure adjustments can control how I want the car. I now run on average more PSI in the front than rear and can easily get the back end to rotate when needed.

As far as camber goes I would recommend -2.5F and -1.5R. Possibly a touch more in the Front if you go full R Comps. In the rear much more camber than that is not needed like stated above. I run -2.5F and 1.5R and it seems to be just about right for 255 NT05's. Still able to drive on the street with not a whole lot of excessive wear either.

Brakes:

Although I know people who have ran on PGP I have heard for a small track it can be tough on brakes. In WA weather with all our moisture, brake fluid being hygroscopic needs to be flushed at minimum on a yearly basis if tracked. ATE seems to work well here as it lasts a bit longer than Motul. Running on 2yr old fluid is asking for trouble. Also Axxis pads are far from ideal...any decent track pad will be a far step up from them. The CL series pads or the RT43's would definately fit the bill.

I plan to go CL RC5+ shortly. I want to see if I can get a pad to work for driving on the weekends and a few PR, PGP, and Bremerton lapping days. Talking to Jeff in the CL thread he seems to think these pads fit the bill. So I can give you feedback shortly on those hopefully. If you are going to run R Comps probably a good idea to step up to RC6 or RC6E though.

Tires:

For that short track A6 do work well. But I think Nitto NT01 would possibly fit your requirements better and would last longer but provide very similar grip levels. I know somebody that runs them there and is very happy with them. I run NT05 and are very happy with those as well. Night and day different from the RE01R. Stiffer sidewall, much better response, handle heat far better, and the level of mechanical grip is just all around higher. One thing is the RE01R communicated at the limit a little better where as NT05's act as more of a R Comp.

Just a few things I've noticed. Not sure if it will help you much but figured I throw in my 2 cents.

GTWORX.com

iTrader: (35)

I agree that if you want to WIN you will need well set up coilovers, r-comps, and plenty of practice. 5 or 6 seconds is a lot to make up on a small course.

You can have a fast, fun, neutral car with good springs, swaybars, some good bushings, etc. but that's going to be tough to make up that much time.

-drew

R/TErnie

iTrader: (32)

This is a good track video from Jared's car.

325+whp S2000 w/ 275 R888's out back and 255's up front. He held the fastest lap for this track.
http://www.youtube.com/user/JaredFlo.../0/xvYwEVYRwtg

I bought some Hoosier R6's in 285/30/18 today
Got some NIB DTC 60 pads from an Evom member today
Order some ATE superblue from Gleason @ STM

It cost me a grand total of 610 out of pocket I'm way under budget at the moment.

I'm looking the Skunk2 and JIC FLA-TAR coilovers for sale on the forums. I secured my scales to corner balance, and got my alignment master cued up.

Considering how bad the front end of my car understeered...on street tires... I think that 5 seconds will be easily consumed.

dbsears

iTrader: (37)

285 Hoosiers eh...think that Subie might be in some trouble