M4GTS Track Build

[JRocker3]

Originally Posted by IB M

Cuz then he'd be like every other Porsche/VW guy. Love the uniqueness.

Agreed! This is good stuff.

Plus, if power/dollar was all that mattered we'd all be driving Teslas... this is about The Roundel !!!

Nice build OP !!!

[adc]

Originally Posted by Lienrocs

Because you can get your golf clubs/Costco run/furniture in a GTS and still run with GT3's on a race track.

Not really once you put a rollcage in it, but there are other advantages. No M car oil change costs $600, it will be much more reasonable to maintain over time is my guess.


OP, what size and model tires are you running on those rims?

[Lienrocs]

Originally Posted by adc

Not really once you put a rollcage in it, but there are other advantages. No M car oil change costs $600, it will be much more reasonable to maintain over time is my guess.


OP, what size and model tires are you running on those rims?

I've done literally all of those things in my GTS. Costco run? Easy. Golf clubs? Easy. Furniture? Yeah. I got a few night stands in the trunk no problem.

As far as speed goes, the GTS lapped within a second or so on most tracks, same PRO driver. For us mere mortals lap times would be near as makes no difference between the two.

But it's neither here nor there. OP is building a car. That's the take away. It's a cool car out of the box and OP wants to make it better.

[yjypm]

Congrats on being featured on Bimmerpost front page!
And thanks for letting me have your CCB. Best wishes!

[Brake_Late]

Originally Posted by yyy

Thank you! I can show you the car no problem. Whenever you are in Los Angeles let me know. Our shop will also be opening to the public at the end of this year. We test the car in private at Buttonwillow Raceway sometimes. You are more than welcome to get a ride on track if you would like. If you have any other questions, don't hesitate to ask!

You're super close by in Arcadia so bump.
Lit build out OP

Any calcs on final power to weight
ratio achieved or shifted / change from baseline ?
Interested in your p/w ratio.

Cheers to Ohlins especially ttx


https://www.springrates.com/vehicle/...esc&page=2

[Ghostriderf80]

What do you guys think of the New Porsche Carrera 4s doing the ring 3 seconds faster than the M4 GTS? 100 hp less.

[FormulaMMM]

Originally Posted by Ghostriderf80

What do you guys think of the New Porsche Carrera 4s doing the ring 3 seconds faster than the M4 GTS? 100 hp less.

Keeps me up nights.

But I’m starting a support group with fellow GTS owners, plus 991 GT3 & GT3 RS, Carrera GT, Enzo, Zonda, MP4-12C, Huracan, and 812 Superfast owners to work through it

[jpdchicago]

Originally Posted by FormulaMMM

Keeps me up nights.

But I’m starting a support group with fellow GTS owners, plus 991 GT3 & GT3 RS, Carrera GT, Enzo, Zonda, MP4-12C, Huracan, and 812 Superfast owners to work through it

Good one!

You can add the M3 gts to that list. A snail...

[Ghostriderf80]

Originally Posted by jpdchicago

Good one!

You can add the M3 gts to that list. A snail...

Originally Posted by jpdchicago

Good one!

You can add the M3 gts to that list. A snail...

A snail is certainly one thing. One thing is for sure, some passengers will leave a snail trail. Lol

[AddyK]

Thank you so much for taking time to post this. Just got a M4 manual. Hoping to turn into a weekend track warrior.

Notice you have front and rear end links , but did you put these on factory sways ?


Also why Ohlins over kw cs ?

Also why Fall line over SPL ?

[PARTS@STBMW]

Sick!

[Lienrocs]

Originally Posted by FormulaMMM

Keeps me up nights.

But I’m starting a support group with fellow GTS owners, plus 991 GT3 & GT3 RS, Carrera GT, Enzo, Zonda, MP4-12C, Huracan, and 812 Superfast owners to work through it

Get ready for 997 GT2RS prices to drop like stones. Some sticky tires on the new 992 and those are gonna be obsolete cars. Everybody get ready for it.

[M3SQRD]

Originally Posted by AddyK

Thank you so much for taking time to post this. Just got a M4 manual. Hoping to turn into a weekend track warrior.

Notice you have front and rear end links , but did you put these on factory sways ?


Also why Ohlins over kw cs ?

Also why Fall line over SPL ?

Why don’t you spend a few minutes looking up info on Ohlins TTX 4-way Motorsport dampers? KW CS are street-based dampers so there’s really no meaningful comparison to TTX dampers. KW Motorsport dampers would be the closest thing KW offers but Ohlins TTX are more widely used by top pro teams (from sport car GT classes to F1). FYI, the M4 GT4 comes with Ohlins TTX dampers. He’s currently running Moton Motorsport 3-way dampers which are another high-end race damper and a direct competitor to TTX (3-way) dampers.

[TEGRITY]

Originally Posted by Vedha

[IMG][/IMG]
This is my humble build.[IMG][/IMG]
Apart from the visual mods. The car is alpine stage 2+ tuned with downpipes and kline catback exhaust. Fall line bearings,H&R sway bar,ap racing competition brake kit,kw clubsport coilovers,Recaro pole position, rear seat Alcantara close out,apex wheels and a few more that doesn't strike at the moment. GTS hood and front spoiler with splitter are on the way.

is that an Indian plate? mate, its not humble in any form or shape. my indian friends have told me it's not easy to even own the top German brands over there and look at you.

[Bloodykotex]

Ayyeeeee !! We should go for another drive soon !

[Docall]

What did you mount the harness to? Did you weld in plates for rings?

[ogarrden]

Lovely build

[RandyC54]

Pat has a ways to go

[BMW9]

Any updates? Beautiful build.

[YMS]

Merry Christmas and Happy New Year everyone! Apologies for so few updates recently. We have been very busy moving YMS into our new 6000 sq ft facility in Whittier CA.

We have been contemplating building the car into a street class time attack car, a track day car, or a Pikes Peak car. We were at the SEMA and PRI show pulling together some partners to get a better feel for which direction we should take the car. It looks like we are going to end up doing a little bit of everything!

Our ex Formula 1 engineer Ricardo came over from France for a week to get his hands on the car and we planned the build quite extensively. The focal point in the next months will be stripping weight and optimizing the suspension. We have been in contact with BMW Motorsport to get an understanding of how the suspension in the M4 articulates. In order to engineer the car at a high level, we need the suspension coordinates which are extremely difficult to measure ourselves due to the M4's asymmetrical multi link suspension. Once we have the coordinates, we'll have a better idea of if we need to redesign the geometry.

We spoke with Dallara, the biggest formula car manufacture in the world about making a carbon body and aerodynamic parts for the BMW M4. As you can imagine, having Dallara make anything is not cheap! This would depend on if we could do a small production run of track day special M4s. Please refer to this post: https://f80.bimmerpost.com/forums/sh....php?t=1681460.

The car will be getting stripped down in early January so we can weld in a roll cage and cut out pieces of the frame that we don't need. We originally planned to do our own twist test but according to BMW M, the M4 takes 40,000NM per degree of twist. That is incredibly stiff for a car without a roll cage. To put it into perspective, a Formula 1 Monocoque takes about 36,000NM per degree of twist. When Ricardo was technical director at Nissan from 1996 to 2012, they found that the optimal stiffness of a racecar is 40,000NM per degree of twist. If you look closely at modern OEM racecars including the M4GT4, there are minimal gussets between the frame and the roll cage because the cars are already massively stiff. All of this means the M4 can have sections of the frame removed after we put in the roll cage.

One of our customers commissioned us to build his A90 Supra into a caged track day car so will be caging both cars at the same time.

Please let me know if you guys are interested in more in depth technical detail. We are creating a youtube channel to document the M4 and our customer builds. The first video will be linked here as soon as its up. Give us a follow on Instagram @ymotorsport to follow the build more closely.

[bracer]

What is your target weight? With added power the M3/M4 can be a very fast platform, but at 3600lbs it's never going to be a 911, not to mention the CdA.

[YMS]

Originally Posted by blackey

What is your target weight? With added power the M3/M4 can be a very fast platform, but at 3600lbs it's never going to be a 911, not to mention the CdA.

Our realistic target weight is 3300lbs without the driver for our first iteration.

I agree that more power does help but the F8X cars are not lacking in power. To put it into perspective, any F8X car with an engine tune is making more hp than a FIA GT3 racecar. I used to race GT3 cars with a manufacture backed team and I can tell you there were plenty of scenarios where turning down the power was actually helping us go faster. Another issue you run into is overheating DOT tires with too much power especially on 100 tread wear and below. The operating window for soft DOT tires are much narrower than a slick due to the tread removing stability from the rubber. You could attempt to modulate the throttle coming out of corners to avoid wheel spin but the throttle mapping on most street cars are not linear enough and you just end up losing time. Finally, the most important factor you should consider is if your brakes can take the power increase. You are now approaching corners at higher speeds meaning more brake pressure and longer braking zones. I always advise to consider all factors before making power increases as it may not always benefit you.

The F8X is not a 911 but 911 is also not a F8X. Both cars have their strength and weaknesses but I think it's important to not dwell on the weaknesses of the F8X, instead focusing on exploiting the most from its strengths.