1M setup, what have we learned in a year and a half?

[m3kerry]

Matt hope all is going well and wish you luck in 2014.

[m3kerry]

Building a proper setup within the rule set of scca is the real issue for me.

You know what needs to be done but doing it bumps you into a class that other drivers are taking older cars and cutting on the them.

Its a shame the car does not have a scca st class to go too. The car would be fun and fast in STU running with the c5 vetts.

[timbo_3101]

Originally Posted by m3kerry

Not without more money and time. The other thing is classing in scca.

My main point from the post was be careful on the street on street tires. This car will break free and more here are not track fay or auotx folk, which means they have never been to the edge with the car or their doing it on the street, which can yield bad results.

That side tracked into race car setup talk.....


I am going to start a different thread on setup, this one is way off topic at this point.

Thanks m3kerry, M3Adjuster, Neil and others for contributing
Because we are only a small community, unlike the E9x drivers, it is difficult to source information such as:
(Alignment settings)
http://www.m3post.com/forums/showthread.php?t=367003
(End results)
http://www.m3post.com/forums/showthread.php?t=922428

After fifteen events (circuit racing), I consider myself inexperienced and am still terrified of what can happen in oversteer scenarios, I am also of the opinion this vehicle is less balanced and handles less predictably than (for example) a 991 C4S or C2S.

My track tyres are 19" PSCup+ in stock (245/265). With KW Clubsport at approximate camber -3.3 and -1.3, and toe -1 and +1, there were early issues with low-speed understeer. However, this has been addressed and I am satisfied that my vehicle is more stable and without rubbing; whether or not alignment is truly optimised for the circuits I attend concerns me less so. I nickname my vehicle "tin can" but in reality it is probably less comfortable than riding in a tin can

Despite this set up, it is not close to the 991! My spin outs have tended to occur on esses-type formations, as the front becomes loaded on entry and as weight is transferred from right to left (or vice versa) in transition. I am hoping that further improvements will be a matter of driver technique

Happy for any advice or suggestions

[Pete_vB]

I have a dedicated AX car, so I only take the 1M out for fun.

All I can share that might be helpful is that the car is tremendously sensitive to tires. I've never used hoosiers, but I've autocrossed on PS2s, PSS, R-S3 (on 18s) and Dunlop Sport Maxx Race, all in stock 1M/ M3 sizes, in that order.

While these are all street tires, you'd swear the car was on a totally different setup. PS2s were a bit snappy when they broke away, great turn-in but the car felt a bit unstable. PSS eliminated much of the snappiness, progressive over the limit when new, encouraged pushing harder, great in the wet. RS3s on 18s are drift monsters. It's not the fastest way around the course, but they encourage you to never have the car fully hooked up, and always connecting one drift to another. Very tail happy but very controllable, never feels like it will get away from you.

Then the DSMR- understeer after they get up to temperature, pretty badly. The tail's never going to get away because you'll have trouble getting it out. Second gear coming out of a hairpin, on throttle early and the car won't rotate, it simply pushes the nose wise. Fastest, but the least fun. I broke down and got camber plates because the fronts were rolling over, -2.7, but while it kept wear in check it didn't cure the understeer. Of course when the tires are cool it's the same tail happy monster we all know and love.

Sooo... Not much help to you guys setting up for hoosiers, but I'd look at tires (sizes, pressures, etc) if I was having issues getting a setup I wanted under stock rules. I run goodyears in front and hoosiers in back on my Porsche, for example, so playing games (where rules allow) might yield interesting results.

[05C4R]

Have you tried the apex 18" track wheels with some semi slicks, totally transformed the car for me, would be awesome with your KW clubsport, i have the DDC version so not as extreme, but still enough. i can keep up with stock 997 c2s's but there is no chance with the 991 c2s, its in another league

Originally Posted by timbo_3101

Thanks m3kerry, M3Adjuster, Neil and others for contributing
Because we are only a small community, unlike the E9x drivers, it is difficult to source information such as:
(Alignment settings)
http://www.m3post.com/forums/showthread.php?t=367003
(End results)
http://www.m3post.com/forums/showthread.php?t=922428

After fifteen events (circuit racing), I consider myself inexperienced and am still terrified of what can happen in oversteer scenarios, I am also of the opinion this vehicle is less balanced and handles less predictably than (for example) a 991 C4S or C2S.

My track tyres are 19" PSCup+ in stock (245/265). With KW Clubsport at approximate camber -3.3 and -1.3, and toe -1 and +1, there were early issues with low-speed understeer. However, this has been addressed and I am satisfied that my vehicle is more stable and without rubbing; whether or not alignment is truly optimised for the circuits I attend concerns me less so. I nickname my vehicle "tin can" but in reality it is probably less comfortable than riding in a tin can

Despite this set up, it is not close to the 991! My spin outs have tended to occur on esses-type formations, as the front becomes loaded on entry and as weight is transferred from right to left (or vice versa) in transition. I am hoping that further improvements will be a matter of driver technique

Happy for any advice or suggestions

[Roadsterdoc]

Great stuff! Subscribed.

[timbo_3101]

Originally Posted by beemer

Have you tried the apex 18" track wheels with some semi slicks, totally transformed the car for me, would be awesome with your KW clubsport, i have the DDC version so not as extreme, but still enough. i can keep up with stock 997 c2s's but there is no chance with the 991 c2s, its in another league

Thanks beemer.

Given another chance, I probably would have set up 18" instead of 19" for accessibility (sizing), convenience (transport) and performance.

Although perhaps having less dry performance than first-generation PSCup (now discontinued), PSCup+ is still Michelin's competition (semi-slick) rubber. I still categorise these together with Dunlop SMR and Pirella Trofeo R - both of which fit 245/265 sizing. However, seeing other experienced M3 racers use RE-11 or AD08 suggests to me that there may not be too large a difference in traction between the competition and extreme performance categories. Although PSCup+ have tried to kill me a couple of times, I have now adapted to its consistent squeal and progressive release, and shall continue these for 2014.

With 18" wheels, I would most likely be using Hoosier R6 or equivalent. In part, I am under pressure to keep up with a superior 135i driver on full slicks

I have occasionally run into 996TT, C63, ISF, E60 M5, E63 M6, etc at driver training (HPDE) type events, and it is apparent that our stock torque (450+50Nm) is adequate to keep up with these TT/V8/V10 on corner exit until perhaps above 160km/h (100mph). However in club sprints, it is a rarity to see stock vehicles ... so unless I actually learn to drive properly, this tin can has little chance of keeping up with Boxsters or Carreras on flowing circuits

[scotth944]

"PS2s were a bit snappy when they broke away, great turn-in but the car felt a bit unstable" -Pete vB

I would definitely concur with this statement! I have driven 944 turbos that made 380 and 500 HP on 008 and R1 tires back in the day which never had the oversteer "snap" that my 1M has had on the PS2 tires regardless of their age. The 944 was always predictable and controllable when it would break away to me.
I have been trying to figure out what was different between the cars that would affect this given the balance is very similar with more power to weight than the 1M has:
tire side wall to rim ratio, suspension geometry, CG height above the wheels??

I'm not sure what else I can easily change in the 1M setup to make it more predictable in it's break away other than replacing PS2 and alignment settings such as more toe in the rear??

[Pete_vB]

Originally Posted by scotth944

"PS2s were a bit snappy when they broke away, great turn-in but the car felt a bit unstable" -Pete vB

I would definitely concur with this statement! I have driven 944 turbos that made 380 and 500 HP on 008 and R1 tires back in the day which never had the oversteer "snap" that my 1M has had on the PS2 tires regardless of their age. The 944 was always predictable and controllable when it would break away to me.
I have been trying to figure out what was different between the cars that would affect this given the balance is very similar with more power to weight than the 1M has:
tire side wall to rim ratio, suspension geometry, CG height above the wheels??

I'm not sure what else I can easily change in the 1M setup to make it more predictable in it's break away other than replacing PS2 and alignment settings such as more toe in the rear??

Ha. Yea I started with tuned 951s, three of them actually, and I agree the difference is striking and had me scratching my head for a while. You have to realize that Porsche at the time, and now, for the most part, tunes their cars to be efficient. BMW, on the other hand, tunes their cars to be fun- they have always been tail happy. I don't fully know what it is that makes breakaway so abruptly; roll center height, anti squat, compression damping, kinematics, compliance steer, tire spec or perhaps the on/off arrival of the M diff. As I'm not competing with it I haven't bothered to investigate properly.

Instead I embrace it. Get a tire that's really progressive and it's an absolute blast, at least at low to medium speeds. No chance in hell I'd run the PS2s again.

You need to realize the BMW spec PS2s on the 1M likely have little to do with what you've run on the 951. I know for a fact that both the compound and construction are significantly different, tuned for the M3, and probably designed to allow that low torque motor to break away at all. Take four PSS or R-S3 and call me in the morning.

[scotth944]

Originally Posted by Pete_vB

Ha. Yea I started with tuned 951s, three of them actually, and I agree the difference is striking and had me scratching my head for a while. You have to realize that Porsche at the time, and now, for the most part, tunes their cars to be efficient. BMW, on the other hand, tunes their cars to be fun- they have always been tail happy. I don't fully know what it is that makes breakaway so abruptly; roll center height, anti squat, compression damping, kinematics, compliance steer, tire spec or perhaps the on/off arrival of the M diff. As I'm not competing with it I haven't bothered to investigate properly.

Instead I embrace it. Get a tire that's really progressive and it's an absolute blast, at least at low to medium speeds. No chance in hell I'd run the PS2s again.

You need to realize the BMW spec PS2s on the 1M likely have little to do with what you've run on the 951. I know for a fact that both the compound and construction are significantly different, tuned for the M3, and probably designed to allow that low torque motor to break away at all. Take four PSS or R-S3 and call me in the morning.

Thanks. Do you have an opinion on if an 18" vs an 19" setup with the same contact patch cross section and diameter can make a difference in break away characteristics; I was thinking the 18" setup could help with conforming to surface irregularities?

[05C4R]

As i mainly go to EC which is a fast flowing track designed for motorbikes, i have found tyres are the most critical for the 1M. The cobb tune did nothing, but the tyres gave me about 5 seconds per lap easy and an extra 10 years on my life span for sure.
18" wheels with Yoko A050's are very fast out of corners. In MDM mode i rarely ever see the traction light flash. your faster and safer. The car even sits about 30mm lower which i am convinced helps.
i wouldn't worry about the 135i on slicks, slicks make an enormous difference, huge, its not a fair comparison

Originally Posted by timbo_3101

Thanks beemer.

Given another chance, I probably would have set up 18" instead of 19" for accessibility (sizing), convenience (transport) and performance.

Although perhaps having less dry performance than first-generation PSCup (now discontinued), PSCup+ is still Michelin's competition (semi-slick) rubber. I still categorise these together with Dunlop SMR and Pirella Trofeo R - both of which fit 245/265 sizing. However, seeing other experienced M3 racers use RE-11 or AD08 suggests to me that there may not be too large a difference in traction between the competition and extreme performance categories. Although PSCup+ have tried to kill me a couple of times, I have now adapted to its consistent squeal and progressive release, and shall continue these for 2014.

With 18" wheels, I would most likely be using Hoosier R6 or equivalent. In part, I am under pressure to keep up with a superior 135i driver on full slicks

I have occasionally run into 996TT, C63, ISF, E60 M5, E63 M6, etc at driver training (HPDE) type events, and it is apparent that our stock torque (450+50Nm) is adequate to keep up with these TT/V8/V10 on corner exit until perhaps above 160km/h (100mph). However in club sprints, it is a rarity to see stock vehicles ... so unless I actually learn to drive properly, this tin can has little chance of keeping up with Boxsters or Carreras on flowing circuits

[Zippy69]

I have autox'ed my car 4 times since new. I am happy to say that I won my class all 4 times and got FTD 2 of 4. I don't race SCCA with this car. The MSNE Club & Porsche clubs that I run with in NJ are less restrictive than SCCA. Further the courses are usually more wide open than SCCA.

Basic set up - Hoosier A6, M3 Front Sway and Ground Control Camber Plates. I have detailed my set up in previous post:
http://www.1addicts.com/forums/showthread.php?t=772056

Don't loose sight of the fact that you must have fun.

Cheers,

Paul

[Pete_vB]

Originally Posted by scotth944

Thanks. Do you have an opinion on if an 18" vs an 19" setup with the same contact patch cross section and diameter can make a difference in break away characteristics; I was thinking the 18" setup could help with conforming to surface irregularities?

Absolutely. Though I have never done this test on the 1M myself, everything I do know says that all else equal a taller sidewall requires more slip angle for the same grip, and that in turn equals a more progressive breakaway. I'm certain part of the reason the R-S3s enjoy being so sideways is that they are taller. Unfortunately the 19s are probably slightly faster all else being equal.

[scotth944]

Originally Posted by Pete_vB

Absolutely. Though I have never done this test on the 1M myself, everything I do know says that all else equal a taller sidewall requires more slip angle for the same grip, and that in turn equals a more progressive breakaway. I'm certain part of the reason the R-S3s enjoy being so sideways is that they are taller. Unfortunately the 19s are probably slightly faster all else being equal.

I just realized that we would also maximize the amount of tire cross section we ran for the rim widths we had, the stock 1M does not when I looked up the stock tire specs so this probably also plays into how it handles break away and amount of slip angle it can work with.

[Pete_vB]

Originally Posted by scotth944

I just realized that we would also maximize the amount of tire cross section we ran for the rim widths we had, the stock 1M does not when I looked up the stock tire specs so this probably also plays into how it handles break away and amount of slip angle it can work with.

Yes, a wider rim vs tire, as the 1M has, gives less lateral compliance. This means it reacts quantifiably faster- the tire has a shorter "relaxation length" as engineers put it. However this also means it has a narrower slip angle. But I think tire construction is still the main variable- the stock PS2 was tuned to allow you to play with the tail on the M3, a car with far less torque and a a much longer wheelbase.

[ozinaldo]

Originally Posted by Pete_vB

Yes, a wider rim vs tire, as the 1M has, gives less lateral compliance. This means it reacts quantifiably faster- the tire has a shorter "relaxation length" as engineers put it. However this also means it has a narrower slip angle. But I think tire construction is still the main variable- the stock PS2 was tuned to allow you to play with the tail on the M3, a car with far less torque and a a much longer wheelbase.

So true! Main reason(s) why I wanted to have a overall better tire since the first days with the 1M but also wanted to stick with stock sizes and category.

That's what I did after only 550 km. in December 2011 when I got my PSS set. For a multi-purpose driven 1M they are as good as anyone could hope for and fit like a glove to 1M's tail-happy/short wheelbase/high and fast arriving torque nature. Smooths out all the excessively snappy and unpredictable feel of the stock car and makes it just "fun" but yet predictable.