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      09-19-2021, 03:34 PM   #1
beachBmmr
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Hows everyone feeling about understeer

Feels like it this is the most significant thing that can reduce lap times so far. My m4c rwd is a little pushy through sweepers at speed, but bites well under braking.

Whats other's thoughts.

Im Curious what MPerf will come out for coil overs
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      09-20-2021, 03:54 PM   #2
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This is by far the best front grip that an M2/3/4 has ever had.
I tracked my M2C with camber plates at 2.5 degrees negative front camber (street/track hybrid setting) and still and had more understeer than the bone stock G82C on factory alignment.

Most cars are setup from factory with some tendency to understeer, this includes most super cars as well.

Wider front tires and camber plates are your best bet at further reducing some of the understeer for now.

A good coilover system might also help such as JRZ, Nitron etc., when they become available. All depends how much you want to pay.

I also highly recommend waiting for Team Schirmer racing axle kinematics which are going to be a game-changer in terms of added grip and track performance, just like they were for the F8x chassis. These are adapted straight out of their GT3 race cars, but they won't be cheap and probably will increase NHV a bit.

Also, what does your alignment look like? If you've never had one done, some members here have posted pretty terrible factory stock alignments so it might be worth looking into.
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      09-20-2021, 04:18 PM   #3
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Quote:
Originally Posted by McLaren720s View Post
This is by far the best front grip that an M2/3/4 has ever had.
I tracked my M2C with camber plates at 2.5 degrees negative front camber (street/track hybrid setting) and still and had more understeer than the bone stock G82C on factory alignment.

Most cars are setup from factory with some tendency to understeer, this includes most super cars as well.

Wider front tires and camber plates are your best bet at further reducing some of the understeer for now.

A good coilover system might also help such as JRZ, Nitron etc., when they become available. All depends how much you want to pay.

I also highly recommend waiting for Team Schirmer racing axle kinematics which are going to be a game-changer in terms of added grip and track performance, just like they were for the F8x chassis. These are adapted straight out of their GT3 race cars, but they won't be cheap and probably will increase NHV a bit.

Also, what does your alignment look like? If you've never had one done, some members here have posted pretty terrible factory stock alignments so it might be worth looking into.
Vorshlag is about 5 miles from my house. They said their plates are hitting very soon, they're out for plating. Since the front camber is fixed not expecting to achieve anything with an alignment
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      09-20-2021, 08:56 PM   #4
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Quote:
Originally Posted by beachBmmr View Post
Quote:
Originally Posted by McLaren720s View Post
This is by far the best front grip that an M2/3/4 has ever had.
I tracked my M2C with camber plates at 2.5 degrees negative front camber (street/track hybrid setting) and still and had more understeer than the bone stock G82C on factory alignment.

Most cars are setup from factory with some tendency to understeer, this includes most super cars as well.

Wider front tires and camber plates are your best bet at further reducing some of the understeer for now.

A good coilover system might also help such as JRZ, Nitron etc., when they become available. All depends how much you want to pay.

I also highly recommend waiting for Team Schirmer racing axle kinematics which are going to be a game-changer in terms of added grip and track performance, just like they were for the F8x chassis. These are adapted straight out of their GT3 race cars, but they won't be cheap and probably will increase NHV a bit.

Also, what does your alignment look like? If you've never had one done, some members here have posted pretty terrible factory stock alignments so it might be worth looking into.
Vorshlag is about 5 miles from my house. They said their plates are hitting very soon, they're out for plating. Since the front camber is fixed not expecting to achieve anything with an alignment
No, but you can fix the stock alignment if it's off. One member here had -1.4 camber on one side and -2.0 on the other from factory. That's terrible, so that was my point.
I'm getting mine done on Thursday.
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      09-21-2021, 10:36 AM   #5
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Quote:
Originally Posted by McLaren720s View Post
Quote:
Originally Posted by beachBmmr View Post
Since the front camber is fixed not expecting to achieve anything with an alignment
No, but you can fix the stock alignment if it's off. One member here had -1.4 camber on one side and -2.0 on the other from factory. That's terrible, so that was my point.
It's almost as if you you didn't read the post you quoted! beachBmmr is correct - camber is not adjustable.

As for the OP's question: I think BMW did a marvelous job removing most of the understeer from these cars, and they handle much better than anything else I've driven with a Roundel on the hood. That includes the M2 and the M5. And F8x.

If you want your car to go faster, drive better. No, seriously, the best money is spent on the driver. Coil-overs and camber plates and all that stuff is really cool, but if instead you spend the money on HPDE and practice, practice, practice, you will be faster.
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      09-21-2021, 11:52 AM   #6
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Quote:
Originally Posted by LuvMyE92 View Post
Quote:
Originally Posted by McLaren720s View Post
Quote:
Originally Posted by beachBmmr View Post
Since the front camber is fixed not expecting to achieve anything with an alignment
No, but you can fix the stock alignment if it's off. One member here had -1.4 camber on one side and -2.0 on the other from factory. That's terrible, so that was my point.
It's almost as if you you didn't read the post you quoted! beachBmmr is correct - camber is not adjustable.

As for the OP's question: I think BMW did a marvelous job removing most of the understeer from these cars, and they handle much better than anything else I've driven with a Roundel on the hood. That includes the M2 and the M5. And F8x.

If you want your car to go faster, drive better. No, seriously, the best money is spent on the driver. Coil-overs and camber plates and all that stuff is really cool, but if instead you spend the money on HPDE and practice, practice, practice, you will be faster.
It's almost like you're completely clueless if you think your front alignment can't be out of spec. That's what I was suggesting. Nowhere did I say the front camber is "adjustable". Instead of coming here and telling people they should learn to read or drive better please read the track alignment thread where people have posted different values for alignments in the front ranging from -1.4 all the way to -2.2 camber.
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      09-21-2021, 12:02 PM   #7
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Quote:
Originally Posted by LuvMyE92 View Post
Quote:
Originally Posted by McLaren720s View Post
Quote:
Originally Posted by beachBmmr View Post
Since the front camber is fixed not expecting to achieve anything with an alignment
No, but you can fix the stock alignment if it's off. One member here had -1.4 camber on one side and -2.0 on the other from factory. That's terrible, so that was my point.
It's almost as if you you didn't read the post you quoted! beachBmmr is correct - camber is not adjustable.

As for the OP's question: I think BMW did a marvelous job removing most of the understeer from these cars, and they handle much better than anything else I've driven with a Roundel on the hood. That includes the M2 and the M5. And F8x.

If you want your car to go faster, drive better. No, seriously, the best money is spent on the driver. Coil-overs and camber plates and all that stuff is really cool, but if instead you spend the money on HPDE and practice, practice, practice, you will be faster.

Yes I can go fast with practice, however I'm also wanting to make sure the setup is optimized and Im not just blowing away my outside shoulders with too high camber.

I will take temps Monday and see what truth tire temps tell.

FWIW - Vorshlag says with stock springs they can get -2.5, and with a smaller diameter spring -3.5.
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      09-27-2021, 02:11 PM   #8
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Ran 4 sessions today optimizing for pressures, and looking at temps.


Took Temps with an infrared thermometer directly off track.

The track I run on (Eagles Canyon) is hard left turns mostly, so passenger side gets a beating. This was after a long session on track with a cool down lap, and is surface temps, so they drop relatively quickly.

Out Cen Ins Ins Cen Out
DRV FR 149 146 156 PASS FR 159 168 174
DRV RE 136 133 148 PASS RE 155 149 157

What this tells me, is there is some additional negative camber needed up front and not really any needed in the rear.
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      09-27-2021, 11:36 PM   #9
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Quote:
Originally Posted by beachBmmr View Post
Ran 4 sessions today optimizing for pressures, and looking at temps.


Took Temps with an infrared thermometer directly off track.

The track I run on (Eagles Canyon) is hard left turns mostly, so passenger side gets a beating. This was after a long session on track with a cool down lap, and is surface temps, so they drop relatively quickly.

Out Cen Ins Ins Cen Out
DRV FR 149 146 156 PASS FR 159 168 174
DRV RE 136 133 148 PASS RE 155 149 157

What this tells me, is there is some additional negative camber needed up front and not really any needed in the rear.
Seems to me that you were a bit under inflated on all tires but for the passenger front...
usually temps should be either even or ascending in one direction but your center is always colder than the sides....

what PSI did you run...? PASS FR is about perfect... the rest to me are under inflated... would add 2psi but for pass front and check temps again next time
Also Pyrometer is the best for taking the temps as it will automatically average the readings...like this https://www.longacreracing.com/produ...21&prodid=7295

Last edited by pikcachu; 09-27-2021 at 11:41 PM..
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      09-28-2021, 06:37 AM   #10
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Quote:
Originally Posted by pikcachu View Post
Quote:
Originally Posted by beachBmmr View Post
Ran 4 sessions today optimizing for pressures, and looking at temps.


Took Temps with an infrared thermometer directly off track.

The track I run on (Eagles Canyon) is hard left turns mostly, so passenger side gets a beating. This was after a long session on track with a cool down lap, and is surface temps, so they drop relatively quickly.

Out Cen Ins Ins Cen Out
DRV FR 149 146 156 PASS FR 159 168 174
DRV RE 136 133 148 PASS RE 155 149 157

What this tells me, is there is some additional negative camber needed up front and not really any needed in the rear.
Seems to me that you were a bit under inflated on all tires but for the passenger front...
usually temps should be either even or ascending in one direction but your center is always colder than the sides....

what PSI did you run...? PASS FR is about perfect... the rest to me are under inflated... would add 2psi but for pass front and check temps again next time
Also Pyrometer is the best for taking the temps as it will automatically average the readings...like this https://www.longacreracing.com/produ...38;prodid=7295
I was really trying to dial in pressure. Was using the track connect app with the cup2 connects adjusting mid run. I did 5 sessions tweaking pressure and watching temps

My fastest run had these temps which showed more uniform across tread

Out Cen Ins. Ins Cen Out
DRV FR 150 150 150 PASS FR 170 162 162
DRV RE 147 142 140 PASS RE 146 152 152

This was my hot pressure/temps - app wanted 32-33 psi hot and it worked. Tires were noticeably quieter and grippier at a 32@180 around track

After letting the car sit, these were the ambient pressures

Ambient Pressures:
27@97 26@91
27@82 28@88
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      09-28-2021, 02:27 PM   #11
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Quote:
Originally Posted by beachBmmr View Post
Quote:
Originally Posted by pikcachu View Post
Quote:
Originally Posted by beachBmmr View Post
Ran 4 sessions today optimizing for pressures, and looking at temps.


Took Temps with an infrared thermometer directly off track.

The track I run on (Eagles Canyon) is hard left turns mostly, so passenger side gets a beating. This was after a long session on track with a cool down lap, and is surface temps, so they drop relatively quickly.

Out Cen Ins Ins Cen Out
DRV FR 149 146 156 PASS FR 159 168 174
DRV RE 136 133 148 PASS RE 155 149 157

What this tells me, is there is some additional negative camber needed up front and not really any needed in the rear.
Seems to me that you were a bit under inflated on all tires but for the passenger front...
usually temps should be either even or ascending in one direction but your center is always colder than the sides....

what PSI did you run...? PASS FR is about perfect... the rest to me are under inflated... would add 2psi but for pass front and check temps again next time
Also Pyrometer is the best for taking the temps as it will automatically average the readings...like this https://www.longacreracing.com/produ...38;prodid=7295
I was really trying to dial in pressure. Was using the track connect app with the cup2 connects adjusting mid run. I did 5 sessions tweaking pressure and watching temps

My fastest run had these temps which showed more uniform across tread

Out Cen Ins. Ins Cen Out
DRV FR 150 150 150 PASS FR 170 162 162
DRV RE 147 142 140 PASS RE 146 152 152

This was my hot pressure/temps - app wanted 32-33 psi hot and it worked. Tires were noticeably quieter and grippier at a 32@180 around track

After letting the car sit, these were the ambient pressures

Ambient Pressures:
27@97 26@91
27@82 28@88
Those latest temps look spot on
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      09-29-2021, 11:11 AM   #12
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I've been running at 36-38 hot on the PS4S Star tires. I wonder if I should experiment with lower pressure. No noticeable understeer with my intermediate driving skills.
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