F80 M3 Track Review

[CosmosMpower]

Posting this up a bit late but wanted to give my thoughts on the F80 M3 on track straight off the showroom floor. My business partner bought a 2015 M3 with DCT, steel brakes and 19" wheels. He broke it in, changed the oil, flushed the brake fluid with high temp stuff and we took it to a local track we both instruct at for a track day (Eagles Canyon Raceway)

First off...the car is FAST, much faster stock for stock than an E90/E92 M3. The handling is very neutral and feels similar to the E9X generation but the power delivery is hands down better. It pulls much harder out of the corners and still screams on the top end. On the longest straight it's about 3-5 mph faster than the E9x series.

A few observations on where the car needs improvements for serious track duty:

1. Brakes- I'm sure most of you already know but the stock pads are not up to par. The pads transferred so much pad material in a few sessions that the car was nearly undriveable on the street afterwards. There was pad material melted/smeared all over the rotors. We were driving the car pretty hard in the instructor run group, I don't think this would be a problem at an intermediate level.

2. Suspension- The car felt great all day, neutral handling, soaked up the bumps great but it was floaty under hard braking. The rear end wanted to step out and you had to fight to keep it in a straight line. Also the car needs a ton more front camber. We wore down a good bit of the outside shoulder on the factory MPSS tires.

3. Not really a point for improvement but if you're an intermediate or higher level driver you'll need to turn off the traction control all the way. It is VERY intrusive even in M mode, any gas coming out of the corners and it will cut power very soon. I will say if you turn it off all the way you really need to modulate the throttle or you will get a good amount of wheel spin.

Overall the car did great, no limp mode, no overheating, it was about 70 degrees out. I ran a lap time of 2:02.8 which is screaming fast. To give you some reference on the same day a good local driver ran the new 2015 Mustang GT V8 at a 2:06.1 and a 2012 Mustang Boss 302 at 2:10. My 2010 GT-R ran a best lap of 1:59 on MPSS tires as well and I ran a best time of 1:59.X on the same day in my business partner's E92 M3 track car (18X11, GT4 aero, AST shocks) on somewhat worn out Hoosiers. Right before the Hoosiers were corded on the E92 I was able to keep up in the F80 which is pretty impressive for an off the showroom floor car on street tires.

The gopro died at the end of the day so I didn't get any track footage of the F80 but here are some pics of the F80, E92 and my wife's E90.

[CanAutM3]

Great review.

Your comments mirror my own, .

[Mandi90TT]

great review, thanks

[nicknaz]

Thanks for the review! nice times.

No thanks for sharing the photo. It makes me want to change my order to YMB

[MaynardZed]

1) Yes agree brakes are the weak point still. I'm using Carbotech xp12/10 and SRF fluid and it has helped a lot but I'm still getting a bit of a soft pedal at 15 minutes into a hard driven session. Yes, I've had a couple of pucker moments with the suspension on hard braking from high speeds. Felt like the car was skating/wiggling around a bit, very unnerving braking from 140mph. I'm fairly certain a good CoillOver system would eliminate this.

2) Definately needs more camber. I'm getting by with R888 for now which have a much stiffer sidewall.

3) All nannies off only way to drive fast with the car. MDM is rubbish. Sometimes I use Sport instead of Sport+ so its a little tamer to modulate throttle coming out of turns.

Thanks for the review!

[gthal]

Great review. Makes me long for summer and track days. I hate winter

[Mortis]

Originally Posted by MaynardZed

Yes, I've had a couple of pucker moments with the suspension on hard braking from high speeds. Felt like the car was skating/wiggling around a bit, very unnerving braking from 140mph. I'm fairly certain a good CoillOver system would eliminate this.

Guys - I also felt this hard braking from around 135mph at the end of a straight. I thought it was the tires (I'm on the stock tires, and they were very hot - last session of the day) but my instructor assured me that this is what normally occurs during threshold braking. I'm relatively new to track driving and just beginning to get a handle on proper braking, so I don't really know any better. If this is due to the suspension, what can I do to at least minimize risk of losing control going into a turn? Would placing the suspension into sport+ help?

Sorry for going slightly off-topic.

[Mortis]

Cosmosmpower - thanks for the great post - we need more M3/M4 track threads like this in this forum!

[MaynardZed]

Originally Posted by Mortis

Guys - I also felt this hard braking from around 135mph at the end of a straight. I thought it was the tires (I'm on the stock tires, and they were very hot - last session of the day) but my instructor assured me that this is what normally occurs during threshold braking. I'm relatively new to track driving and just beginning to get a handle on proper braking, so I don't really know any better. If this is due to the suspension, what can I do to at least minimize risk of losing control going into a turn? Would placing the suspension into sport+ help?

Sorry for going slightly off-topic.

Yes, use sport+ for the suspension. I've learned you have can't just slam on the brakes from high speed, but rather (slightly) gradually squeeze the brake pedal to give the stock suspension a chance to respond in a stable fashion. Quite different from my E36 with GC race suspension in which you can stab the brakes from almost any speed. I'm thinking COs with higher spring rates for the F8x should help this?

Trail braking seems fine in the F8x though, just wouldn't do it until slowed down quite a bit from 135mph.

[F80AYM3]

I can't wait to track mine. Thank you posting your review!

[FTS]

Originally Posted by Mortis

Guys - I also felt this hard braking from around 135mph at the end of a straight. I thought it was the tires (I'm on the stock tires, and they were very hot - last session of the day) but my instructor assured me that this is what normally occurs during threshold braking. I'm relatively new to track driving and just beginning to get a handle on proper braking, so I don't really know any better. If this is due to the suspension, what can I do to at least minimize risk of losing control going into a turn? Would placing the suspension into sport+ help?

Sorry for going slightly off-topic.

As others picked up, this is certainly an area that needs awareness. This is 'normal' for street cars, almost all cars do exhibit this issue, including Porsches, Fords, Audi, Mercs, lotus, etc. The issue is not necessarily 'threshold' braking, but as MaynardZed is alluding to, one of excessive weight transfer to the front axle, unloading the rear so much that traction becomes limited to the extend that even the differential lock is not much help. So, manufacturers manage the situation using the ABS sensors to manage brake pressure going to each corner of the vehicle to keep it stable under heavy braking.

Again as MaynardZed is mentioning, how you apply and release the brakes is key to stability. Smashing the brake pedal at first application creates more instability, hence a rapid but gradual increase of pressure is the proper technique for instances that require you to shed 100+ mph to be able to take a slow speed turn, such as the one at Summit Point front straight going into T1.

Originally Posted by MaynardZed

Yes, use sport+ for the suspension. I've learned you have can't just slam on the brakes from high speed, but rather (slightly) gradually squeeze the brake pedal to give the stock suspension a chance to respond in a stable fashion. Quite different from my E36 with GC race suspension in which you can stab the brakes from almost any speed. I'm thinking COs with higher spring rates for the F8x should help this?

Trail braking seems fine in the F8x though, just wouldn't do it until slowed down quite a bit from 135mph.

The shocks in Sport+ won't help the situation as much besides during the initial application of the brakes, although the rear rebound being stiff will help keeping the initial weight transfer to the front. The main issue, generally, is one of low spring rates on the front of these vehicles. Generally an increase of just spring rates in the front helps a great deal with this situation; but of course that has to be done in conjunction to how that would impact the rest of the balance.

CosmosMpower , thank you for the notes, quite helpful.

[CanAutM3]

Originally Posted by FTS

As others picked up, this is certainly an area that needs awareness. This is 'normal' for street cars, almost all cars do exhibit this issue, including Porsches, Fords, Audi, Mercs, lotus, etc. The issue is not necessarily 'threshold' braking, but as MaynardZed is alluding to, one of excessive weight transfer to the front axle, unloading the rear so much that traction becomes limited to the extend that even the differential lock is not much help. So, manufacturers manage the situation using the ABS sensors to manage brake pressure going to each corner of the vehicle to keep it stable under heavy braking.

Again as MaynardZed is mentioning, how you apply and release the brakes is key to stability. Smashing the brake pedal at first application creates more instability, hence a rapid but gradual increase of pressure is the proper technique for instances that require you to shed 100+ mph to be able to take a slow speed turn, such as the one at Summit Point front straight going into T1.


The shocks in Sport+ won't help the situation as much besides during the initial application of the brakes, although the rear rebound being stiff will help keeping the initial weight transfer to the front. The main issue, generally, is one of low spring rates on the front of these vehicles. Generally an increase of just spring rates in the front helps a great deal with this situation; but of course that has to be done in conjunction to how that would impact the rest of the balance.

CosmosMpower , thank you for the notes, quite helpful.

My understanding is that spring rates will do very little to alter the weight transfer between the front and rear axles during braking (same goes for lateral weight transfer during cornering). However, spring rates will alter how much the car pitches forward during braking.

A squirely back-end can be attributed to how the rear suspension geometry changes with load. If the rear suspension is tuned to increase toe-in under load (which is often the case to bring stability under cornering), then hard braking results in increased toe-out when the car pitches forward. Combined with the weight transfer off the rear axle, the rear of the car becomes very darty.

This is where stiffer springs help. By reducing how much the car pitches forward, they help reducing the change of toe of the rear axle.

[FTS]

The pitch does not happen by itself, right? Something pushes the front of the car down more than something pushing the rear down

With the extended position of the rear 'multilink' rear geometry, the effect is toe-out; how much depends on how much the suspension is extended upwards. So, if front spring rates are higher, there will be less pitch forward and less toe-out in the rear under braking.

[bigjae1976]

The E90 was the same way under heavy braking. I think it's a combination of the rear suspension design, weak rear brakes, and a slow locking diff.

The E36/46 used a semi? trailing arm design which toes out under squat. So you could hammer the brakes and the rear end will be stable. As mentioned, the E9X (and I would guess the F8X) uses a multi link rear so it toes in under squat.

Does the F8X use the same viscolock Gkn LSD unit? My E46 and E90 are slow to lockup. You'll feel it once you drive a clutch LSD. If it is a slow locking viscolock then the diff could also be contributing the squirrely rear.

For me, a BBK eliminated and rear end sway under heavy braking on my E90.

[FTS]

Originally Posted by bigjae1976

Does the F8X use the same viscolock Gkn LSD unit? My E46 and E90 are slow to lockup. You'll feel it once you drive a clutch LSD. If it is a slow locking viscolock then the diff could also be contributing the squirrely rear.

I do not know if it is GKN unit, but it is a multi-disc clutch type. Specs say that it can go from 0 to 100% lock in 0.2 secs, so it depends on the situation if that is fast or not I think, I don't have first-hand experience with electronically controlled diffs. Pure mechanical ones with pre-load are easy to predict how they will behave, I suspect not so much with the variable locking M diffs.

Also, I came across this very interesting thread in the 1M forums about the behavior of its ABS unit, I do not know if the ABS in that car is similar to the F8x or not, but it was very informative: http://www.1addicts.com/forums/showt...ght=cbc&page=1

Apparently there is another electronic module besides the ABS called CBC or Cornering Brake Control, which kind of reads like Porsche's torque vectoring. I wonder if they use a similar unit in the F8x as well.

[CanAutM3]

Originally Posted by FTS

The pitch does not happen by itself, right? Something pushes the front of the car down more than something pushing the rear down

As I posted, weight transfer remains essentially the same with stiffer springs. But because the spring rate is higher, the same increase in force yields less displacement (F=kx), hence less pitch.

Originally Posted by FTS

With the extended position of the rear 'multilink' rear geometry, the effect is toe-out; how much depends on how much the suspension is extended upwards. So, if front spring rates are higher, there will be less pitch forward and less toe-out in the rear under braking.

Isn't that exactly what I posted

BTW, there was nothing wrong in your original post. I just wanted to bring precision about the impact of suspension geometry and that spring rates don't change weight transfer a

[CanAutM3]

Originally Posted by FTS

I do not know if it is GKN unit, but it is a multi-disc clutch type. Specs say that it can go from 0 to 100% lock in 0.2 secs, so it depends on the situation if that is fast or not I think, I don't have first-hand experience with electronically controlled diffs. Pure mechanical ones with pre-load are easy to predict how they will behave, I suspect not so much with the variable locking M diffs.

Also, I came across this very interesting thread in the 1M forums about the behavior of its ABS unit, I do not know if the ABS in that car is similar to the F8x or not, but it was very informative: http://www.1addicts.com/forums/showt...ght=cbc&page=1

Apparently there is another electronic module besides the ABS called CBC or Cornering Brake Control, which kind of reads like Porsche's torque vectoring. I wonder if they use a similar unit in the F8x as well.

There is this very cool video from Ti-Jean that shows brake force at every corner during hot laps. You can clearly see CBC in action where different pressure is applied depending on the attitude of the car. However, CBC is only effective while braking where I believe Porsche Torque Vectoring (PTV) is also effective under acceleration. But I do believe the new e-diff in the F1X and F8X can actually do some torque vectoring under acceleration, I would need to look it up to confirm.

One of the Ti-Jean videos also shows how intrusive MDM (Euro-MDM here) actually is even on the E9X platform, which is quite revealing.

http://www.m3post.com/forums/showthr...hlight=Ti-jean

[Mortis]

Originally Posted by CanAutM3

My understanding is that spring rates will do very little to alter the weight transfer between the front and rear axles during braking (same goes for lateral weight transfer during cornering). However, spring rates will alter how much the car pitches forward during braking.

A squirely back-end can be attributed to how the rear suspension geometry changes with load. If the rear suspension is tuned to increase toe-in under load (which is often the case to bring stability under cornering), then hard braking results in increased toe-out when the car pitches forward. Combined with the weight transfer off the rear axle, the rear of the car becomes very darty.

This is where stiffer springs help. By reducing how much the car pitches forward, they help reducing the change of toe of the rear axle.

Many thanks to you and FTS for the additional explanations. I'm looking forward to the spring!

[FTS]

Originally Posted by CanAutM3

One of the Ti-Jean videos also shows how intrusive MDM (Euro-MDM here) actually is even on the E9X platform, which is quite revealing.

http://www.m3post.com/forums/showthr...hlight=Ti-jean

I have been looking for this vid for so loooong, thank you!!! I had seen this vid when it was first posted and hadn't bookmarked it; it is one of the most interesting comparisons

[CosmosMpower]

Originally Posted by bigjae1976

The E90 was the same way under heavy braking. I think it's a combination of the rear suspension design, weak rear brakes, and a slow locking diff.

The E36/46 used a semi? trailing arm design which toes out under squat. So you could hammer the brakes and the rear end will be stable. As mentioned, the E9X (and I would guess the F8X) uses a multi link rear so it toes in under squat.

Does the F8X use the same viscolock Gkn LSD unit? My E46 and E90 are slow to lockup. You'll feel it once you drive a clutch LSD. If it is a slow locking viscolock then the diff could also be contributing the squirrely rear.

For me, a BBK eliminated and rear end sway under heavy braking on my E90.

You're welcome, glad I had a chance to drive this amazing car happy to share.

I didn't experience the rear dancing around in the E90 M3 even on full race slicks, it's much more pronounced in the F80. I do know that on the GT3's when the LSD wears out you get a really bad wandering rear end under hard braking.

[turbo8765]

Originally Posted by CosmosMpower

Posting this up a bit late but wanted to give my thoughts on the F80 M3 on track straight off the showroom floor. My business partner bought a 2015 M3 with DCT, steel brakes and 19" wheels. He broke it in, changed the oil, flushed the brake fluid with high temp stuff and we took it to a local track we both instruct at for a track day (Eagles Canyon Raceway)

First off...the car is FAST, much faster stock for stock than an E90/E92 M3. The handling is very neutral and feels similar to the E9X generation but the power delivery is hands down better. It pulls much harder out of the corners and still screams on the top end. On the longest straight it's about 3-5 mph faster than the E9x series.

A few observations on where the car needs improvements for serious track duty:

1. Brakes- I'm sure most of you already know but the stock pads are not up to par. The pads transferred so much pad material in a few sessions that the car was nearly undriveable on the street afterwards. There was pad material melted/smeared all over the rotors. We were driving the car pretty hard in the instructor run group, I don't think this would be a problem at an intermediate level.

2. Suspension- The car felt great all day, neutral handling, soaked up the bumps great but it was floaty under hard braking. The rear end wanted to step out and you had to fight to keep it in a straight line. Also the car needs a ton more front camber. We wore down a good bit of the outside shoulder on the factory MPSS tires.

3. Not really a point for improvement but if you're an intermediate or higher level driver you'll need to turn off the traction control all the way. It is VERY intrusive even in M mode, any gas coming out of the corners and it will cut power very soon. I will say if you turn it off all the way you really need to modulate the throttle or you will get a good amount of wheel spin.

Overall the car did great, no limp mode, no overheating, it was about 70 degrees out. I ran a lap time of 2:02.8 which is screaming fast. To give you some reference on the same day a good local driver ran the new 2015 Mustang GT V8 at a 2:06.1 and a 2012 Mustang Boss 302 at 2:10. My 2010 GT-R ran a best lap of 1:59 on MPSS tires as well and I ran a best time of 1:59.X on the same day in my business partner's E92 M3 track car (18X11, GT4 aero, AST shocks) on somewhat worn out Hoosiers. Right before the Hoosiers were corded on the E92 I was able to keep up in the F80 which is pretty impressive for an off the showroom floor car on street tires.

The gopro died at the end of the day so I didn't get any track footage of the F80 but here are some pics of the F80, E92 and my wife's E90.

Thanks for the quality info. Couple questions...

Did the car have the adjustable suspension? If so were you in sport plus?

Bimmerblog indicated that MDM was a bit more restrictive on the f8x than the e9x, would you agree? Not really relevant for the track, I ask more for street use.

Were you shifting at red line? If not where?

Tire pressures hot?

[adc]

My E90 on stock ZCP springs is also pretty squirelly under hard braking from high speed. It is in fact my limiting factor when braking from high speed, but everything is relative since even with the stock-is E90 I can still brake very late.

Anyway I thought on the E90 I could feel the CBC at work. I never could decide if I should let the system do its thing, or try to help it by steering into the mini slides. if you guys have any advice here I'd be grateful...

If the F80 improves the braking even a little bit, I'll be very happy.