[mutunekk]

Hi guys,

I have a M2 competition with the following braking setup: the 2NH calipers, ferodo ds1.11 pads, girodisc rotors and running RBF 660 fluid.

I have been doing a lot of track days and overall, I have amazing braking throughout the session (pedal is perfect) but to improve my times I am looking for a way to get the car to stop faster.

There are several times I need to slow down from 150mph to 75mph in 75m or less. Now I know Porche GT3s are monsters, but they can do the same braking in half the distance, allowing them to enter faster and exit cleaner.

No matter how much i push my current setup i just can't get the car to stop in a shorter distance.

So, my questions:
1. Are there any mods I can do to my setup to improve braking distance on these cars?
2. vs the 2NH setup will big brake kits help (excluding the weight drop)?

[MrLizzzard]

A bbk will definitely help - motorsport application type brakes tend to make a big difference, the pads you have are good, the other thing to consider is whether you are at the limit of the ABS or if there is some more to go if you had stickier tyres.

[NISFAN]

What G are you pulling?

[5.M0NSTER]

I think to definitively answer your question we would need to see some data. Brake pressures, ABS intervention, gradient of apply and release of brake pedal, speed, etc.

Do you trail brake in the corners? I found that on some faster corners I end up braking later than I normally would, and then I have to maintain some brake pressure towards the apex, so the car stays on track. But it also helps rotate the car, so I gain a little by braking later, then trail braking helps rotate the car, so I can get on the power a bit earlier. So double benefit.

[kpaso]

You haven't mentioned tires yet, which are the #1 way to reduce braking distance with your setup. What tires are you running?

[OG Shark]

Braking is a function of grip. Increase grip, increase braking efficiency. Weight reduction, aero, stickier tires, etc. - those kind of things will give you the most benefit. With a BBK you are looking to gain in fade resistance and unsprung weight. Once you overwhelm the grip threshold with either you will still get into ABS. I am a big fan of BBKs and the benefits they provide - but the main benefit will typically not be stopping distance unless you had a really crappy setup before.

And certainly braking technique and suspension setup are huge as well.

[SEAT TIME RULES]

Originally Posted by kpaso

You haven't mentioned tires yet, which are the #1 way to reduce braking distance with your setup. What tires are you running?

BINGO! Rolling Friction/Mechanical Grip are the biggest contributors to shorter stopping distances.

So yes Tires, Tires, Tires!

[detroitm2]

Someone mentioned earlier, are you trail braking? You didn't really give too much detail on your approach or experience, so we don't have much to work with. But you can brake much later if you carry some of your braking into the Apex of the turn. It's a bit more advanced technique, and takes some getting use to vs. the standard brake in a straight line, release on turn in, power into Apex.

[richard in NC]

I'll second what others have said. BBKs are great but its the tires that really make the difference in stopping distance.

Also technique, confidence, and experience help a lot.

For a beginner on track, always brake in a straight line. Give yourself the margin of error, IE brake early so if things go wrong, you have a safety margin to get the car stopped. It sounds like you are at this point.

Note you need to adjust the seat so that you can comfortably mash the brake pedal to the floor without fully straightening your knee. IE get closer than you think.

Next pick a braking zone where you can practice braking harder and learn where ABS kicks in. Learn to brake as hard as you can, without activating ABS. This is threshold braking. Get on it quick and hard, but not slamming the pedal like a panic stop. Now learn to release the brake smoothly and quickly as you enter a corner. Now you can begin to brake later and closer to the turn. Now that you have confidence to slow as much as needed for corner entry.

Once you have mastered that, you can try trail braking, IE a slight brake pressure is left, as you start turning the wheel.

It can take many sessions and possibly years to build up to that. But that's a lot of the difference of the other guys.

[NISFAN]

Originally Posted by richard in NC

I'll second what others have said. BBKs are great but its the tires that really make the difference in stopping distance.

Also technique, confidence, and experience help a lot.

For a beginner on track, always brake in a straight line. Give yourself the margin of error, IE brake early so if things go wrong, you have a safety margin to get the car stopped. It sounds like you are at this point.

Note you need to adjust the seat so that you can comfortably mash the brake pedal to the floor without fully straightening your knee. IE get closer than you think.

Next pick a braking zone where you can practice braking harder and learn where ABS kicks in. Learn to brake as hard as you can, without activating ABS. This is threshold braking. Get on it quick and hard, but not slamming the pedal like a panic stop. Now learn to release the brake smoothly and quickly as you enter a corner. Now you can begin to brake later and closer to the turn. Now that you have confidence to slow as much as needed for corner entry.

Once you have mastered that, you can try trail braking, IE a slight brake pressure is left, as you start turning the wheel.

It can take many sessions and possibly years to build up to that. But that's a lot of the difference of the other guys.

He must be a pro driver in a pro racing car with full downforce and quali slicks. His figures suggest he is braking at an average rate of 2.3G.

Those GT3 braking at 4.6g should be entering F1 races.

[Maynard]

Get an instructor to ride w/ you, or get/review datalogs. Highly doubtful that P cars are halving your brake distance if you are optimally braking. They are lighter, but not that much so. As long as you can hit ABS, your brakes are more than adequate. And since you are asking this (and asking here) it would be a mistake to go up to stickier tires - they will just mask driving errors, and allow the mistakes to occur at higher speeds (remember that impact force is the square of the speed, so small increases can bite hard).

[Megator]

As others have said tires and experience make a huge difference. P GT cars are usually on some pretty amazing rubber from the factory so its not surprising they can brake later and carry more speed into a corner.

Corner speed also makes a difference, if you need to brake from 200->100 instead of 200->120 to make the corner you need to start braking sooner.

This is my brake pedal trace, as you can see the pressures peak at a pretty consistant level but there are higher peaks. I can therefore probably hit the brakes a little harder and shorter than I do now to shorten my braking distance. I should also work on making my ramp up and down a little smoother.

That being said I am usually over 1G on braking and I think my tires are capable of +/- 1.2G. Sadly the Gs were not properly recorded to overlay the brake traces for a comparison.

[M2guru]

For comparison, I had Goodyear eagle f1 super car 3r's at 1.26 g's (275/35 18) under braking and 1.2 consistently.

[Peter_VIE]

With BBK, slicks, modded chassis a M2 can outperform a cup Porsche in braking, to keep pace in acceleration still some horses too few.

[Megator]

Originally Posted by Peter_VIE

With BBK, slicks, modded chassis a M2 can outperform a cup Porsche in braking, to keep pace in acceleration still some horses too few.

Have you got a link to the specs of your car? are those seats Recaro Pole positions or PP ABE ?

[Peter_VIE]

Originally Posted by Megator

Have you got a link to the specs of your car? are those seats Recaro Pole positions or PP ABE ?

The car is posted here:

https://f87.bimmerpost.com/forums/sh....php?t=1441972

but not up-to-date, as it is now beeing built to a track only race car, will be ready in about 4 weeks.

The seats were Recaro Pole Position

[Karmic Man]

Assuming you are already on semis…then get the widest tyre you can fit on the front axle, which may mean u need wider rims

M2C is already front heavy and under heavy braking with all that weight transfer over the front you need to turn it into ur advantage by using the widest fronts possible

The next step then is to reduce the weight of the car

After that is aero but is way advance for a driver n owner to play with as a hobby so better leave it alone

[Megator]

Originally Posted by Peter_VIE

The car is posted here:

https://f87.bimmerpost.com/forums/sh....php?t=1441972

but not up-to-date, as it is now beeing built to a track only race car, will be ready in about 4 weeks.

The seats were Recaro Pole Position

Nice also lol on the Porsche missing thier braking point. Car is looking very good! Want to do something similar eventually.

[5.M0NSTER]

Originally Posted by Megator

Nice also lol on the Porsche missing thier braking point. Car is looking very good! Want to do something similar eventually.

Haha, the CS driver was trying to Verstappen you

That guy needs a driver mod

[Megator]

Originally Posted by 5.M0NSTER

Haha, the CS driver was trying to Verstappen you

That guy needs a driver mod

Funny thing is that he could have had me round the outside on the left hander after the sharp right hander if he hadn't overcooked it.

No point bys here in NL and I understand how frustrating it is to be stuck behind someone. I didnt think he would be ahead of me on that corner and I knew he would get me in the sweeper hence why I stayed on the inside. Only saw him in my inside mirror once I got to the apex haha.

TT Circuit Assen is pretty great in that it has tons of run off as its really a motorcycle track.

[5.M0NSTER]

Originally Posted by Megator

Funny thing is that he could have had me round the outside on the left hander after the sharp right hander if he hadn't overcooked it.

No point bys here in NL and I understand how frustrating it is to be stuck behind someone. I didnt think he would be ahead of me on that corner and I knew he would get me in the sweeper hence why I stayed on the inside. Only saw him in my inside mirror once I got to the apex haha.

TT Circuit Assen is pretty great in that it has tons of run off as its really a motorcycle track.

It looks pretty cool from your videos. I wish I had a chance to experience it. Stupid Covid. I missed out on my last chance at Spa earlier this month due to the restrictions, but at least I was able to get almost 3s under my target lap time at the Ring. So now I can return to US knowing I conquered the Green Hell.

[Megator]

Originally Posted by 5.M0NSTER

It looks pretty cool from your videos. I wish I had a chance to experience it. Stupid Covid. I missed out on my last chance at Spa earlier this month due to the restrictions, but at least I was able to get almost 3s under my target lap time at the Ring. So now I can return to US knowing I conquered the Green Hell.

Congrats! so you dipped under the 8 min mark


Yeah thats a real shame you didn't get to try some other tracks around here. Never driven the ring but I dont think it gives the same impression as a GP worthy track.

Hopefully doing Zolder next week. If you cross the border for less than 24h there is no quarantine (don't ask about the logic in that...).