[Bumpinjeep]

Originally Posted by ChrisF

Hi all. I have been looking at the F/G gen M2's as a daily driver. Looking for something a bit sharper for daily duties since most of my commute is through the canyons and down PCH. I've had decent seat time in the F87/M2C and never felt the rebound in the rear of the car was excessive. I had also read that the G87 was even more civil for daily duties so i took one for a test drive.

Within the first few minutes on the roads surrounding the dealership, the rear was hyperactive, overly stiff and bouncy. I went into the display and dropped suspension down to comfort and not much difference. Liked a lot about the rest of the car but the rear end was annoying.

There is very little here or in the automotive press about this so wondering if maybe something was wrong with the car? For reference, I'm used to driving stiff cars so that's not it.

Thoughts appreciated.

It sounds like an issue with that particular car. Mine, even lowered in KW HAS, has been perfect. No bouncing, no dartyness, nothing but planted. I've done the M Performance driving school and tracked a G87, the car felt at home on the track with no issues that you described.
I would imagine the car may be on the shipping blocks (happens far too often), tires are over inflated, or there is something wrong with the car.
I would recommend going to either another dealer for a test drive or drive a different G87.

[ajchoi]

Originally Posted by T-Rexx

So 35psi cold?

I've been running 34PSI on all 4 since I made an adjustment from the dealer leaving it at 44-45PSI. I've found it's really balanced at that PSI where like others mentioned 32 felt kind of off, and 34 seemed like a middle ground between the low and high speed recommendations. That said, I set these in a "cold" Vegas setting which was around 85F at the time, so probably closer to a 33PSI in slightly less warm ambient temps. I'll probably redo them soon as it cools down here.

[T-Rexx]

Originally Posted by ajchoi

I've been running 34PSI on all 4 since I made an adjustment from the dealer leaving it at 44-45PSI. I've found it's really balanced at that PSI where like others mentioned 32 felt kind of off, and 34 seemed like a middle ground between the low and high speed recommendations. That said, I set these in a "cold" Vegas setting which was around 85F at the time, so probably closer to a 33PSI in slightly less warm ambient temps. I'll probably redo them soon as it cools down here.

Thanks for the help!

[matty_f]

My F87 always felt a little bouncy to me, but the G87 feels very planted. When I picked my car up the tire pressure was in the 40s.

Let us know your thoughts when you try another.

[BroDoze]

Are we supposed to set our rear tires to 20” in iDrive or the manual/other whatever?

[Ravenseal]

Originally Posted by T-Rexx

So 35psi cold?

Correct.

[///M TOWN]

Originally Posted by Ravenseal

Correct.

I run 1-2 psi less as a general rules in the rear because the front is slightly heavier

So 35 front 34 rear

Or 35 front 33 rear

[JABCAT]

Originally Posted by T-Rexx

Thanks mate!
Embarrassing for a passionate car guy to not know that hahaha.
But also a car guy that would always look down at factory equipment/settings and look to performance aftermarket for something “better”.
Those cars were no M cars though, so maybe I should shift my thinking now

Engineers of sports/performance cars are pretty knowledgeable Unless you're regularly racing (on a track) these things, the factory settings are pretty dialed in. I tend to follow the factory recommendations on my sports cars because they're driven almost exclusively on the street.

Tire pressure recommendations factor in handling, braking, comfort, tire wear, etc. I've got 13,500 mi on my M2 and have found for my driving; 90% higher-speed highway 80-85 mph sustained for hours at a time, around town, and occasional trips along curvy country roads, the door jamb sticker 32 psi all around works best.

Keep in mind if you run higher pressures, you're likely to get faster wear. As someone who owns 4 vehicles, all with very expensive tires, I prefer to give up a little of their max performance for longer tread wear.

[RockCrusher]

Originally Posted by T-Rexx

I always thought (since being a boy racer way back when I knew everything) higher tyre pressure was good for performance, and manufactures only recommend a lower pressure to find a good compromise between performance and comfort.
It would seem I was wrong.
What would the ideal pressure be for performance where comfort is not a consideration (it is an M car after all)

If your car came with sport tires, the manual offers this:

Sport tires General information

The vehicle can be fitted with sport tires, which have been optimized for use on a racetrack in dry conditions.

These so-called track tires are made from an optimized material mixture specially derived from motorsport. In addition, the tire tread is partly reduced to create a larger contact area with the road surface. These adjustments can increase driving dynamics such as steering behavior, precision, or road grip.

More information on wheels and tires:
▷ At an authorized service center or another qualified service center or repair shop.
▷ On the website of the respective tire manufacturer.


Tire pressure specifications

In the tire inflation pressure table
The tire inflation pressure table, refer to page 262, contains all tire inflation pressure specifications for the specified tire sizes at the ambient temperature. The tire inflation pressure values apply to tire sizes approved by the manufacturer of the vehicle for the vehicle type.

To identify the correct tire inflation pressure, please note the following:
▷ Tire sizes of your vehicle.
▷ Maximum speed for driving.

On the control display
The current tire inflation pressure values for the mounted tires can be displayed on the Control Display.

The current tire inflation pressure value is located on each tire.


If your M2 has sport tires fitted -- mine came with Michelin sport tires -- then I refer you to your owners manual and then the tire pressure monitoring system control to arrive at the recommended tire inflation pressures for the tires fitted.

[T-Rexx]

Originally Posted by JABCAT

Engineers of sports/performance cars are pretty knowledgeable Unless you're regularly racing (on a track) these things, the factory settings are pretty dialed in. I tend to follow the factory recommendations on my sports cars because they're driven almost exclusively on the street.

Tire pressure recommendations factor in handling, braking, comfort, tire wear, etc. I've got 13,500 mi on my M2 and have found for my driving; 90% higher-speed highway 80-85 mph sustained for hours at a time, around town, and occasional trips along curvy country roads, the door jamb sticker 32 psi all around works best.

Keep in mind if you run higher pressures, you're likely to get faster wear. As someone who owns 4 vehicles, all with very expensive tires, I prefer to give up a little of their max performance for longer tread wear.

You make a good case in that I am not going to notice a tenth of a second faster on the street, but I will most certainly notice the cost of 4 pilot sport 4S’s

[T-Rexx]

Originally Posted by RockCrusher

If your car came with sport tires, the manual offers this:

Sport tires General information



The vehicle can be fitted with sport tires, which have been optimized for use on a racetrack in dry conditions.



These so-called track tires are made from an optimized material mixture specially derived from motorsport. In addition, the tire tread is partly reduced to create a larger contact area with the road surface. These adjustments can increase driving dynamics such as steering behavior, precision, or road grip.



More information on wheels and tires:

▷ At an authorized service center or another qualified service center or repair shop.

▷ On the website of the respective tire manufacturer.





Tire pressure specifications



In the tire inflation pressure table

The tire inflation pressure table, refer to page 262, contains all tire inflation pressure specifications for the specified tire sizes at the ambient temperature. The tire inflation pressure values apply to tire sizes approved by the manufacturer of the vehicle for the vehicle type.



To identify the correct tire inflation pressure, please note the following:

▷ Tire sizes of your vehicle.

▷ Maximum speed for driving.



On the control display

The current tire inflation pressure values for the mounted tires can be displayed on the Control Display.



The current tire inflation pressure value is located on each tire.



If your M2 has sport tires fitted — mine came with Michelin sport tires — then I refer you to your owners manual and then the tire pressure monitoring system control to arrive [...]

Thanks mate, I will be sure to look that up when my car arrives in late December!

[aerobod]

The “Sports Tyres” for the M2 should be the optional Michelin Pilot Cup 2 tyres (not available as factory fit for all markets), the Pilot Sport 4 S tyres overheat after a couple of hard track laps and are not in a tyre class that is track optimized.

[ajchoi]

Originally Posted by T-Rexx

You make a good case in that I am not going to notice a tenth of a second faster on the street, but I will most certainly notice the cost of 4 pilot sport 4S’s

I ended up with the Yoko’s and am convinced they’re worse so maybe I should just burn them off lmao

[T-Rexx]

Originally Posted by ajchoi

I ended up with the Yoko’s and am convinced they’re worse so maybe I should just burn them off lmao

I am hearing that a lot, if not most of the 25’s are now coming with Yoko’s.

So not a good tyre?

[ednir98]

Originally Posted by T-Rexx

I am hearing that a lot, if not most of the 25’s are now coming with Yoko’s.

Here's a tire poll I ran. The numbers are closer than you think. https://www.bimmerpost.com/forums/sh....php?t=2136618

[ajchoi]

Originally Posted by ednir98

Here's a tire poll I ran. The numbers are closer than you think. https://www.bimmerpost.com/forums/sh....php?t=2136618

I thought you meant it was a poll on the quality of Yokos vs Michelins and was about to start a debate haha

[ednir98]

Originally Posted by ajchoi

I thought you meant it was a poll on the quality of Yokos vs Michelins and was about to start a debate haha

Whoops, I should clarify lmao. Yeah just data on who's getting what, not performance. There are some helpful notes in the thread regarding performance though.

[Ravenseal]

Originally Posted by ///M TOWN

I run 1-2 psi less as a general rules in the rear because the front is slightly heavier

So 35 front 34 rear

Or 35 front 33 rear

You're slightly reducing the front contact patch, thus front-end/turn in grip by doing that, but yes. It's a valid tweak to make on a FR car depending on the driving characteristics you want.

[///M TOWN]

Originally Posted by Ravenseal

You're slightly reducing the front contact patch, thus front-end/turn in grip by doing that, but yes. It's a valid tweak to make on a FR car depending on the driving characteristics you want.

I like the steering to feel slightly edgy

I like to feel the turn in a little more from my Honda Accord of Michelin’s the Pilot Sport 4S tires I’m currently running

[///M TOWN]

Originally Posted by T-Rexx

I am hearing that a lot, if not most of the 25’s are now coming with Yoko’s.

So not a good tyre?

If I ended up with Yokohama’s, I’d pull those off and sell them in a fucking heartbeat after installing Michelin’s

The last thing I want is teriyaki sauce on my Brotz and Sauerkraut…

[aerobod]

Originally Posted by ///M TOWN

I like the steering to feel slightly edgy

I like to feel the turn in a little more from my Honda Accord of Michelin’s the Pilot Sport 4S tires I’m currently running

Front toe-out will make it more lively in changing direction. Even a bit of rear toe-out could be tried, but instability is a possibility in that case, has to be done carefully. I haven’t done front and rear toe-out on the M2 yet, but run 0.40 degrees front and 0.54 degrees rear total toe-out on the Caterham, giving really responsive turn-in on track.

[T-Rexx]

Originally Posted by ///M TOWN

If I ended up with Yokohama’s, I’d pull those off and sell them in a fucking heartbeat after installing Michelin’s

The last thing I want is teriyaki sauce on my Brotz and Sauerkraut…

Hahahahaha