My E90 M3 Dedicated Track build (with pix!)

[dogbone]

Originally Posted by Richbot

What settings did you play with? Ride height? Camber?

Stiff springs are overrated generally

There is a certain ride height that I attempt to achieve regardless of what springs are on the car. The ride height itself is not based on super science, but it's one that has worked well for me, so whenever we change something like springs or the weight of the car, we try to get it back there as much as is reasonable. With new springs, there seems to be a small bit of settling that occurs after "breaking" the springs in over a day or two. So, we watch that too.

As far as camber goes, I ALWAYS run with max camber--basically as far as I can slam inwards--on the Vorshlag camber plates. What degree of camber that ends up being is not important to me. The more camber I put, the more I can save the front tire edges. It ends up measuring between -3.9 and -4.1º of camber in the front. (I run about -2.2º rear.) I run such fat front tires, that I always have good braking grip, so I'm not worried much about camber there, and tons of camber seems to stick very nicely in turns. But, the first time on the stiff springs, I had not re-aligned the car. So, I had an alignment done to make sure the settings were where I wanted them. It didn't help at all.

I have my own nitrogen rig, so I can accurately adjust nitrogen pressure in the JRZ remote canisters. With the stiffer springs, I lowered the nitrogen pressure to allow the damper to move more easily. Did not help.

Then, of course, there is the Rebound and Compression settings. You're doing a lot of fighting when a car feels both understeer in the front AND at the same time feels edgy in the rear. Basically, go slow and the rear wants to step out; go fast and the front understeers away from you. I was fighting multiple battles at the same time more than I was with the softer springs.

I decided to concentrate most of my effort on trying to solve the understeer at high speeds. I figured I could manage the throttle enough to deal with low speed step-outs from the rear. But I needed the car to stick on high speed cornering stuff. There's no "adjusting" your driving inputs if the car won't turn at high speed.....you just gotta slow down.

I was trying many things, but mainly, I was gradually backing the rebound down on all 4 corners (more in the front) trying to reduce the edginess/jitteriness. And I was lowering compression in the front more than the rear. So, I was reducing the settings overall, but more in the front. I would try several rounds of adjustment. The lower I went, the more grip I seemed to regain. So, it worked to some extent and I got a bit more speed back on Riverside, but an unpleasant floaty feel appeared. It started to give me a "disconnected" feeling which I did not like at all. I am used to the JRZ giving me a very connected feeling. This connected feeling was reduced as I slowed the dampers down. And, the side effect of trying to solve the understeer at high speeds is that I was making the low speed oversteer possibilities even worse.....so, the whole thing was just not working out....I still wasn't as fast in Riverside at Buttonwillow and I didn't like the feel.

I had hoped that by increasing front and rear spring rates by exactly the same percentage that the car would retain some of it's balance, but it was just an unwieldy beast. Riverside at Buttonwillow is my high speed rounder test. I know the speeds and the feel there. It was ugly entering Riverside and it was just as ugly at apex and ugly again after the apex. The car was just ignoring my steering inputs. I'm like, ok---we're running out of track here....you better turn soon car!

Anyway, returning to the 600 lbs springs in the front was absolutely the right thing to do for me. It was magical when I put them back on. And I'm glad to have 100 lbs more rate in the back. Going from 800 to 900 lbs in the rear is a fairly subtle change, but I like it. I get just a little bit more support back there. I think the 900's hold up a bit better under the wing's downforce and the car feels good on acceleration, so I believe this is where I'll stay for the foreseeable future with spring rates.

[Richbot]

Generally, IMO, a big spring change means you're going to need to mess with ride height and alignment to get the car happy again ( in other words, throw a brand new setup at the car, especially if you have meaningful aero). The fact that you were changing damper settings, and reducing damping force rather than increasing it, tells me you were headed in the wrong direction and it was just never going to work for you at the ride height and camber you want to run.

I like Brian's "can't hurt" response. It can cost you a day of testing and chasing your tail, which sucks

[dogbone]

Originally Posted by Richbot

Generally, IMO, a spring change means you're going to need to mess with ride height and alignment to get the car happy again ( in other words, throw a brand new setup at the car, especially if you have meaningful aero). The fact that you were changing damper settings, and reducing damping force rather than increasing it, tells me you were headed in the wrong direction and it was just never going to work for you at the ride height and camber you want to run.

I like Brian's "can't hurt" response. It can cost you a day of testing and chasing your tail, which sucks

I'm curious, where would you have gone with the car's height? Up or down? Down is tough because we're at a point where the fat tires already rub the upper portions of the wheel well occasionally, so down is not too realistic. And going up just seems like the wrong direction in general.

As far as damper settings, I was already at +8 out of 10 on compression, so there wasn't much room to go up. And on rebound, turning rebound up just made the car more jittery and nervous which definitely felt wrong to me.

Plus, hitting berms seemed quite unpleasant with higher settings.

I'm not a hyper expert on suspension adjustment, but I'm always willing to experiment. And my senses were telling me lower was getting results.

And for alignment, I would need some serious counsel on how to change alignment for stiffer springs.....in the end, it just did not seem worth all this trouble and a bunch of extra $$$ to keep trying alignments and then throwing a bunch more track days away for something that initially felt so bad. It seemed like any potential gains would be very small----if there were even gains to realize.

[Richbot]

I'm thinking down a little in front to get the splitter on the ground, drop the rear significantly for less rake, and a little less front camber

I don't doubt less damping force was feeling better, if the springs were already too stiff

It may be the car is just too light for that much front spring on a near 1:1 motion ratio

I'm also curious what would happen if you bolted on a true slick with the stiffer springs. You may have reached a point where the R1S is contributing significantly to deflection

lol all of that is to say if you like the car don't mess with it

[dogbone]

Originally Posted by Richbot

I'm thinking down a little in front to get the splitter on the ground, drop the rear significantly for less rake, and a little less front camber

I don't doubt less damping force was feeling better, if the springs were already too stiff

It may be the car is just too light for that much front spring on a near 1:1 motion ratio

I'm also curious what would happen if you bolted on a true slick with the stiffer springs. You may have reached a point where the R1S is contributing significantly to deflection

lol all of that is to say if you like the car don't mess with it

Interesting.

In my specific case:

-Regarding lowering the splitter: The splitter was already rubbing the ground in corners. That was the problem that started the whole experiment. 750 lbs isn't THAT stiff, so i think a lowered splitter would still rub. Also, I tend to go off into the dirt sometimes. I'm very afraid that a lowered splitter just would not survive. My current one has survived probably 2 dozen offs in the last 2 years.

-As far as lowering the car in general, the car had already been lowered three times before this little adventure----once when the JRZ was installed with 450/650, a second time when I moved to 600/800, a third time after it was gutted. I lowered it a fourth time to accommodate the stiffer 750/1000 springs and get them to the same ride height. Lowering again would be a FIFTH lowering.....I'm just reaching certain limits both front and rear. I'm already lightly rubbing in many spots because of the size of the tires. Also, at some point, I'm pushing the control arms out of their intended travel zones. I already ran into that with the rear toe arms. I had to go with adjustable arms because we couldn't get the toe we wanted as the car kept going down and down.

-In the rear, I just don't have the room to drop the car significantly. You look at my rear fender liners and it's rubbed through and it's like--ooh--we're pretty close to that fuel filler line....hehe

-As far as slicks: I did run the 750/1000 with Pirelli DH slicks. They scraped across the ground just like everything else. I switched to 600/1000 just before the Pirelli were finished, and I ran faster on them right before they corded on 600/1000 than 750/1000.

-With less front camber, I'm going to trash my front tire edges very quickly. My friend with an E90 had been running camber like mine---just slam it in. He went to a high end alignment shop and they wanted him to run less camber: -3.2º. He did. His tire edges got trashed immediately. He switched back to max camber and was able to slow down the edge wear. When I used to run less camber on a 265 Hankook TD, I could trash the edges of them in two sessions at Buttonwillow. (And I was on a 1:57 pace at the time. At a 1:48 pace now.....holy cow they would die a terrible death very quickly.) The rest of the tire was cherry, but the outside edge was almost cording. So, a lot of negative camber is simply a necessity on this car if you want your tires to last a few days.

Ultimately, I walked away with a similar conclusion----the car is too light for those springs. Perhaps with some insane tweaking, they could be made to work, but why would anyone go through the trouble? Would the gains really be worth it? Berms would still be more difficult on super stiff springs. And I'll go back to what Bryan at JRZ said back in 2012---"Stiff springs are a race car myth. Our suspension gives the car a supple feel (given proper setup)." I guess I just wanted to know where the limit was. I think I've found it---or at least---I think I've found a setting I can live with. I keep chipping away slightly faster lap times these days at all the tracks I'm visiting. And the car feels great. What more can you ask for?

[CorruptCommie]

Mr. Bimmerworld on the E46 chassis spring rate:
http://www.m3forum.net/m3forum/showp...3&postcount=15

I would imagine with slicks and aero you should be running higher spring rate, not lower, especially since the E90 platform is heavier.

Shock companies like TC Kline and JRZ that say you should run soft springs, to me, sounds like they are selling their packages as street/track.

[dogbone]

Originally Posted by CorruptCommie

I would imagine with slicks and aero you should be running higher spring rate, not lower, especially since the E90 platform is heavier.

Shock companies like TC Kline and JRZ that say you should run soft springs, to me, sounds like they are selling their packages as street/track.

Yeah I hear ya. I was concerned that I was under sprung. But my experience seems to indicate otherwise.

Believe me, I have no illusions about being a big expert. So I experiment and try stuff for myself. And I report my experiences back here on this thread. That's one of the biggest things I have enjoyed about this hobby is that I'm constantly learning.

[redpriest]

Originally Posted by dogbone

Yeah I hear ya. I was concerned that I was under sprung. But my experience seems to indicate otherwise.

Believe me, I have no illusions about being a big expert. So I experiment and try stuff for myself. And I report my experiences back here on this thread. That's one of the biggest things I have enjoyed about this hobby is that I'm constantly learning.

It's interesting to me that you were getting horrible understeer with 750 front springs - I'm running 700/800 atm and the car feels "just right". Then again I haven't run the Pirelli slick on my E92 yet, so I'm curious if I have to upgrade rear spring rates at all. 700/800 seemed fine on NT01/RC1/R1S though.

[Richbot]

The reason I mentioned lowering the rear is the Conti GAGS cars ran what appeared to be zero or even negative rake and very low in the rear (like, low enough that some on here would make fun of them if they were a street car because slammified ride height) on the square 275/35-18 ish width Hoosiers-no-wait-they're-Contis-ok-fine-we'll-just-buy-Hoosier-so--now-they're-really-Contis,sorta. Rake can have a big impact on balance

here's an example of one of the Fall Line cars, iirc your car seems to sit a bit higher in back and about the same up front but that picture I saw might be old:



I know eyeballs are not the most accurate setup tools, but you can learn a lot just by ripping off other people's approximate setups, heh.

Anyway, yeah, suspension tuning especially with aero is not easy or everyone would do it and the best way to learn is to suck at it, that's how I have learned and continue to learn, certainly

[Richbot]

Originally Posted by CorruptCommie

Mr. Bimmerworld on the E46 chassis spring rate:
http://www.m3forum.net/m3forum/showp...3&postcount=15

I would imagine with slicks and aero you should be running higher spring rate, not lower, especially since the E90 platform is heavier.

Shock companies like TC Kline and JRZ that say you should run soft springs, to me, sounds like they are selling their packages as street/track.

The E46 probably wants more spring up front because it's a simple Mcstrut and has worse geometry than the E9x (seems like people tend to settle on a pretty big front bar on the E46 too), the best way to fix a crap suspension setup is to not let it move, see eg World Challenge RSX's with 2000lb springs in the back. The E46 rear suspension is also different from the E9x, motion ratio on the spring is about the same, but there's no huge RTAB/upright combo etc. on the E9x, the E9x has an additional degree of freedom with that bushing at the bottom of its RTA attached to the upright, iirc it allows some toe-in on compression that the E46 doesn't, or vice versa, I saw a toe/camber curve comparison of the rear a long time ago when these things came out and can't find it, mygoogle fu is weak. So I think you have to take E46 setups with a grain of salt when making the transfer. I'd love to hear James come in here and tell me how wrong I am though, because I'm just a guy on the internet and he's lived it with this chassis

Besides there's no one "right" spring for a car, we just usually stick with whatever we have and tune with the remaining tools accordingly, rather than spend an hour swapping springs when it gets cloudy, because amateurs.

If TCK and JRZ are recommending the softest spring that keeps the suspension from getting out of its happy place, it's not because they're selling something for street cars, it's because that's a pretty well-settled means to arrive at a suspension that maximizes mechanical grip

That said, I don't think dogbone has reached the end of the line on testing stiffer springs with his setup, but I wouldn't mess up a good thing if I were him either

[okusa]

Originally Posted by redpriest

It's interesting to me that you were getting horrible understeer with 750 front springs - I'm running 700/800 atm and the car feels "just right". Then again I haven't run the Pirelli slick on my E92 yet, so I'm curious if I have to upgrade rear spring rates at all. 700/800 seemed fine on NT01/RC1/R1S though.

No offense but not sure you are comparing apples to apples as his BRP times are MUCH faster than yours.

[redpriest]

Originally Posted by okusa

No offense but not sure you are comparing apples to apples as his BRP times are MUCH faster than yours.

Fair enough.

[M3 Number 86]

Originally Posted by okusa

No offense but not sure you are comparing apples to apples as his BRP times are MUCH faster than yours.

Well 200hp and aero helps too.

So the apples to oranges would be car setup - pretty sure dogbone would be much faster than Ayrton Senna is a mildly modded e92

Btw op your car is a freaking BEAST!



Edit: redpriest is slow af though. Lol

[dogbone]

Originally Posted by Richbot

The reason I mentioned lowering the rear is the Conti GAGS cars ran what appeared to be zero or even negative rake and very low in the rear (like, low enough that some on here would make fun of them if they were a street car because slammified ride height) on the square 275/35-18 ish width Hoosiers-no-wait-they're-Contis-ok-fine-we'll-just-buy-Hoosier-so--now-they're-really-Contis,sorta. Rake can have a big impact on balance

here's an example of one of the Fall Line cars, iirc your car seems to sit a bit higher in back and about the same up front but that picture I saw might be old:

I know eyeballs are not the most accurate setup tools, but you can learn a lot just by ripping off other people's approximate setups, heh.

Anyway, yeah, suspension tuning especially with aero is not easy or everyone would do it and the best way to learn is to suck at it, that's how I have learned and continue to learn, certainly

A few things come to mind when I look at the picture of the Fall-Line car.

- I'm quite certain I have more power than the Fall-Line car since I have a blower, which makes my car potentially squat more on acceleration, especially from low speeds where the car is launching out of turns. I don't think I'd want to squat much from that position.
- My 67" rear wing is enormous compared to the rear aero on that car. I suspect I'm dealing with quite a bit more rear downforce.
- I pulled up the most recent non-moving pic I have on the fattest/fastest tires I have sitting on the flattest ground I could find---Auto Club Speedway at Bimmerfest a few weeks ago. It's not an alignment rack, but it's the best I have. (I did rotate the Fall-Line picture a bit because the background was tilted, so I rotated it enough for the garage door edges to be totally vertical.) Comparing their car to mine, I don't think I'm running a rake monster. For sure, the rear of their car is lower than mine. (I think my front may be a tad lower.) But I would argue that with more power and more aero, I would want a bit more rake. Since the rear springs, aren't super duper stiff, they do compress under these larger horsepower and aero forces.
-And then of course, we're still left with the problem that I can't really lower the rear much more anyway.....




I don't know.....I believe that final setup really is specific to a certain vehicle based on it's particulars, and that driver taste shapes the feel over time. This conversation makes me think of my friend who just got a 996 Cup Car that was actively being raced before he bought it, so it arrived setup by some East Coast race shop. That thing is setup LOOWWWWW. We're talking slammed. It's unreal. In fact, we all stare at it wondering how the hell the damper can compress without the tire rubbing EVERYWHERE. Those things are notorious for having super stiff springs. People joke about how they're bouncing off berms with them.





My MOST familiar track is Buttonwillow. I can detect small changes in the car's setup there---much more-so than any other track. Plus, that track has SO MANY kinds of challenges, you can get a good overall feel for how the car acts in various situations. I have not been back to Buttonwillow with the 600/900 setup yet. It's so hot there now that it's just not much fun. But, so far at Big Willow and Auto Club, the car has felt great.


(BTW, I think you got the name of those Conti tires wrong---I think they're REALLY called: "Ummm-So-Yeah-We're-Conti-And-We Decided-To-Purchase-That-Quaint-Little-Tire-Maker-In-Indiana-And-We-Have-This-Big-Race-Series-So-We-Just-Took-Their-R6-And-Added-A-Hardening-Compound-To-Make-It-More-Of-An-Endurance-Race-Tire-And-Slapped-Our-Name-On-It---But-C'mon-You-Gotta-Admit-The-Tires-Look-BadAss-With-The Yellow-Lettering-Right?---Oh-And-By-The-Way-They're-Not-Really-THAT-Grippy-And-They-Lose-Traction-Without-Any-Warning-At-All-So-We-Hope-You-Have-Quick-Reflexes!" I mean, if we're gonna throw around all this tech stuff, we better get the names right.)

[M3 Number 86]

have any pics of your car from the rear that shows the wing size?

[dogbone]

Originally Posted by M3 Number 86

Well 200hp and aero helps too.

So the apples to oranges would be car setup - pretty sure dogbone would be much faster than Ayrton Senna is a mildly modded e92

Btw op your car is a freaking BEAST!



Edit: redpriest is slow af though. Lol

Thanks! She's fun to drive!

Regarding your apples-to-oranges list, there are a number of differences beyond what you listed, and each one saves time.

Comparing my car to Redpriest's car:
-Power: I have more power with the blower.
-Aero: The full aero on my car does an incredible job of holding the car down. I've talked about this extensively.
-Tire Width: I'm running fatter tires.
-Tire Compound: I'm running stickier tires.
-Weight: I'm running a lighter car. My car is 400 lbs lighter than a stock E9x M3. I don't know the weight of Redpriest's car, but I'd guess my car at 3250 lbs is lighter.
-Driver Experience: I have more time in the driver seat. I believe Redpriest said he has 40+ days. Over the last 5.5 years, I've clocked 100+ days on track. (I stopped counting.) Time in the driver seat CANNOT be overestimated. It's plain and simple. You put in the time in the driver's seat---you get faster. Watching videos, talking about it, playing video games, reading about it are all fine, but none of these things can directly teach you about the "FEEL" of the balance of the car. You need to feel the G-forces. You need to feel where the limits of the equipment are---things like tires, brakes, grip, etc. These can only be attained with time in the seat and experimentation.

So, given that virtually all the items in the above list swing in my favor, if I wasn't achieving faster lap times, everyone would be wondering what's wrong with me.....more than they already do....

[dogbone]

Originally Posted by M3 Number 86

have any pics of your car from the rear that shows the wing size?

I think this is a nice rear shot from Laguna:



Here's a pit shot:



This front angle actually shows the wing quite nicely too:

[M3 Number 86]

Originally Posted by dogbone

I think this is a nice rear shot from Laguna:



Here's a pit shot:



This front angle actually shows the wing quite nicely too:

Wow that's wide. Is this a standard fitment for sedans or are you running a wider wing than normal.

I'm looking into possibly getting rear aero now but my buddy who had one I don't think was that wide. Or maybe I'm wrong.

I ran bfg r1s and got 7 good heat cycles LOLOLOL

I figure aero and nt01 will give me similar lap times but at least run more than two days. Did a 1:54:7 in my car but it seriously was like crack. 20 minute high and going to broke chasing it. Ha.

[dogbone]

I was thinking about my recent days at Auto Club Speedway. I was there on 6/3 for Bimmerfest, and then again one week later on 6/11 for a regular Speed Ventures day.

What I was turning through my mind was that I kept blowing the braking zone for Turn 3---the 90º left turn off the Oval into the In-Field road course.

I have mentioned before that I don't have much track memory for Auto Club since I don't go very often. But I found it fascinating--or frustrating--that I blew that braking zone at least 4 times after having a good fast Oval---really frustrating to push it on the Oval and then blow it immediately on the next turn. I didn't run a ton of at-my-limit Ovals, so blowing that braking zone 4 times was actually a high % number of misses. When I was not braking it correctly, I was overshooting.....so I was braking too late.

So, I was curious----when I missed, how much was I missing it by? I wasn't careening out of control, but I would just go past the outer-edge cones for the turn into the In-Field and have to weave through them back onto the course. The results were interesting. I thought I'd share.

Guess what tool I'm using to analyze the situation! (Cue Trumpets!) Yes! The AIM Solo DL! How did you know?!

So, on the AIM solo I can see how many feet down the track I press the brake, and you can overlay laps, so it's pretty quick to look at.

On the laps where I was missing, I was braking about 53 feet later than my successful braking on my PR lap. Looking at my speeds at the moment of braking---around 145mph---I'm traveling 212 feet per second. So, 53 feet is about 0.25 sec later. hehe a quarter-of-a-second......that's not a lot of margin to get it right!

So, getting back to track memory, I can tell you I have never identified a braking "marker" for Turn 3. And with me working to go faster on the Oval, the "marker" for braking is changing for me anyway. But with such a narrow margin for missing, the first thing I will do the next time I go to Auto Club is try to identify a braking marker. Although, looking at my current videos, that stretch of track is a bit funky with the wall and fences. And at 145mph, things are moving pretty quick.

Here's what it looks like at the moment I touched the brake pedal on my fast lap. 53 feet later than this, and I couldn't get the speed down in time for the corner. It's not exactly lit up with braking markers. Although, I have to laugh----I JUST noticed right now while writing this, that they put braking cones UP ON THE WALL!! haha I never saw that before!



Here's 1 second before I hit the brakes. Again....not exactly full of markers to catch your eye. Actually, I find the fence whizzing by and all those regularly spaced light posts to make it even more difficult.



Anyway, when I talk about track memory, this is the exact kind of thing I'm talking about. Having a 0.25 second margin between success and failure definitely requires some built-up reflexes. And this particular corner, with traveling SO FAST and having to bleed 100mph of speed exaggerates the challenge.

Anyway, just thought I'd share.

[roastbeef]

i overcook that turn all the time too. i'll have to practice braking sooner. i think part of the temptation is "catching" people in the braking zones from having better brakes. auto club is the track i struggle with the most (besides not being familiar with buttonwillow). and i think a contributing factor is my inconsistency in braking zones.

lets sneak in at night and paint a big red line on the wall to mark the braking zone?

[dogbone]

Originally Posted by M3 Number 86

Wow that's wide. Is this a standard fitment for sedans or are you running a wider wing than normal.

I'm looking into possibly getting rear aero now but my buddy who had one I don't think was that wide. Or maybe I'm wrong.

I ran bfg r1s and got 7 good heat cycles LOLOLOL

I figure aero and nt01 will give me similar lap times but at least run more than two days. Did a 1:54:7 in my car but it seriously was like crack. 20 minute high and going to broke chasing it. Ha.

Racewerkz Engineering recommended the 67" width. As far as I know, it is not a special width. (My friend has a wing of the same width (on a sedan).)

But this 67" recommendation was based on the ultimate overall strategy that front aero would be going on the car some day. I believe that if I had an M3 that was still closer to stock weight and still generally still had the OEM weight distribution and was never planning on running front aero, I would most likely run a smaller wing.

(I've talked about this before) In my case, I was trying to fix a problem. Prior to the car being gutted and caged, I had a nicely balanced M3. Then, we went and gutted the car and the car's balance went to shit. Most of the weight comes out of the rear, and it was a HANDFUL to drive without aero. I was not used to the car being so nervous in the rear. I didn't find it much fun to drive like that to be honest. The rear was BEGGING to step out. Even traction control was struggling to control it at times. My Porsche buddy drove it at Laguna Seca without aero after it was gutted. He came back in the pits and the FIRST thing he said was "this thing needs a wing." If a PORSCHE guy tells you the rear wants to step out too much.........you need a fricking wing.

So, I no longer had a refined car with good balance that I was trying to mildly improve. No....I had a strange unbalanced beast that needed help. And my ultimate goal was full aero, but I didn't want front aero right away, and I didn't want to buy two wings---a small one now and a big one later. So I bought the 67", and yay, the rear was planted, but boy did the front understeer in high speed rounders when going fast----like 80+mph in Riverside at Buttonwillow. Ultimately, it took putting front aero on to finally regain balance.


Regarding R1S, I'm guessing that vehicle weight must affect their life. (I'm not overly surprised.) I don't know what your car weighs, but you get 7 heat cycles. I get 16 before a cord shows up. Joe at Trinity claims he gets 23. His car is 400 lbs lighter than mine.

The fastest I ever went on R1S was on their 8th heat cycle. I believe they are faster when new, but they are NOT slow by the 8th heat cycle. I've said before, I think they are quite fast up to 10 heat cycles. And still pretty darn quick up to 16. After that, when I assemble scrub sets after one of the cords, then they slow down a bit, but are still quite fun to drive.

Are you running them square? And are you careful about rotating them? I always rotate them after 2 sessions. Every 2 sessions, they move. If you don't rotate them, then they'll cord more quickly.

Josh Haddox has a nicely setup E90 M3 (by Racewerkz) with basically stock power. The car is pretty well gutted and has full aero. He ran a 1:54 on NT01 at Buttonwillow.

[dogbone]

I guess it is worth mentioning that it was possible to dial out a fair amount of the rear aero by lessening the angle of attack. But I warn you-------once you get a taste for the rear of the car being planted, YOU DO NOT WANT TO GIVE IT UP. PERIOD.

I did experiment with reducing the AOA and got less understeer, buuuuut the rear wasn't as planted......forget that. I put it back and tried to sort out the understeer. Yup----front aero.

The problem is if you don't want as much downforce as a big wing can provide, and dial the angle of attack back, you still have the big wing hanging out back there causing some degree of drag, so it can hold you back on the straights.