Back at the track, 750 brake review

[acspecialists]

Well I made it to the Ridge again. It started a little cooler because of the smoke but warmed up as the day wore on. It got up to 89deg but I did not blow a radiator. Last week it was 98deg and I blew the upper hose right off of the water pump. It is still hard to believe that the engine survived to fight another day, kudo to BMW. I have found the limit of the cooling system and if I go out on hot days again I may have to do some mods. If I have the heater on full bore the cooling system can barely keep up. It's fine when the car is going fast but when I hit the brakes for the corner the temp shoots up. Once I smash the gas the temp comes back down to normal. It may be the engine speed but I am down shifting so the revs are still 3k or higher. I looked at a Zionsville but other than being all aluminum it's the same size and has the same lame fittings. I plan on pulling the grilles and auxiliary fan to improve airflow and see how that goes?

So this is my first full run with the 750 brakes. Hawk HPS pads and cross drilled rotors. First and foremost they did not fade. When I was coming into turn 11 which is about 100mph down to about 30mph they never let me down. The antilock would pulse once or twice and the rear was unloaded and wiggled all over the place. To be honest the 750 brakes with the HPS pads are about the same as the 740 brakes with the cool carbon blue pads. After I burn up the HPS pads I will stick in some cool carbon blues or maybe try something else. So there is an improvement but you can get the same effect from better pads. O and BTY the HPS pads make noise on the street.

So as I stated above the anti lock was engaging in heavy brake so I'm at the limit of the tires. With a 98 and 89 deg days the tires are almost melting off of the car. I might get one more day out of the conti's once they are gone I think I may go to a straight track tire. I already have a set of track rims so the next step is track tires. I'll just have to haul them in the back and put them on when I get there. If you watch the video I can hit 1g with a little offset so I think that's pretty good. I'm braking pretty late and doing all the down shifting. Once I hit the apex and smash the gas I let the car upshift. As usual the other track participants are impressed how fast I can get my living room around the track. Lots of GT3's and GT4's. I think the fastest cars were the track prepped Acura NSX and the Dodge Viper GTS.

Next up for upgrades will be the H&R lowering springs and a 3.15 differential. I suspect that the springs will help with body roll and the differential will get me higher straight speeds. We'll see what happens? I took the last video from the drivers rear window based on a members suggestion. I think the view is a little better because you can see me turning the wheel. If you watch closely you can see the seat move when I hit the brakes. Again kill the audio, someday I'll figure out a way to kill it or overlay it with a good song like Radar Love. The fastest lap from each session,

https://www.youtube.com/watch?v=FvwjnIeSj08

https://www.youtube.com/watch?v=1rhWWZ71Q-Q

https://www.youtube.com/watch?v=9OX7CpsmJ_0

I took my wife out on the first session and set the fastest lap right up until the end of the day. I was taking it easy and still went fast. the instructors always say smooth is fast.

[purplecty]

Most people report that the 750 brake performance is the same as the 740 and it's mainly about the appearance of the bigger rotor and dual piston caliper...

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[asianvenom]

Man that's pretty smooth driving, on stock suspension too...I'm suprised you havent install 3.15 already, they are dirt cheap from wrecking year.

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[acspecialists]

I've had the diff for almost a year now. I want to do the springs, KMAC bushings and the diff all at the same time. Just need to get the car in the air and get it done. I try to do one mod in between track days to keep track of changes in the car. Brake pads, calipers and tires are easy. I also have a 4.6 TB and plan on a 4" MAF with a tune from Dima. For now I don't need more power I need more traction. After I get the car all done I think I'm going to bite the bullet and get a 08' M5. I'll have rod bearings to worry about but I'll also have a 500hp v10.

[purplecty]

Do you mean the 4.8 N62 TB? I was thinking of doing that mod as well with the 4" MAF... Would you be using the 4" MAF that can be sourced on ebay? I heard those get super hot from the engine heat...

I only see a 3.5

https://rover.ebay.com/rover/0/0/0?m...2F262002401700

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[acspecialists]

Yup, you got it. It takes some searching but there are 4" MAF's on ebay. I already have a Dinan CAI so all I need is some 4" hose to connect it all together.

[asianvenom]

3.15 rear end is noticable upgrade especially coming from 2.90? dudmd tune also wakes up the car, though I have done on my 740, I haven't done it on my 750. E60 for tracks? Why not E46? It's going to be cheaper run on the tracks, meaning it lighter and wouldn't eat up tires/brakes and suspension parts so fast.

Edit: Sorry mis-read your title thinking its a 750il. But yeah dudmd and 3.15 was one of my best mods, I had for 740. Mine is on h&r race springs with bilstein b6, it's better, but its still a cruiser, and you feel the weights of the boat. That's why I'm suprise you're so fast and smooth with it.

[Jamos]

3.15 would make a big difference for sure!

I was looking at a 3.46 or something couple years ago, would have significantly changed the car. But I do too much hwy to justify and stick with my stock 3.15 (95 baby.... We win mechanically!)

[asianvenom]

I would definitely go with 3.46 if there's an easy option like the 3.15

I constantly drive in "sport mode" which in 740il it drops a gear, basically driving 4th gear on the freeway even with 3.15 rear

[acspecialists]

The 3.15 is an easy direct bolt up. A 3.46 takes quite a bit more work. As it is now I also drive in sport mode unless I'm above 60mph with the cruise on. Low revs can overload the engine when you stomp on it. I'm at 162k on the OD and she's still running like a dream. If I still have the car I will do the guides over the winter. I need to get my AMX back together first.

[sigzagg]

Lowering springs will for sure improve the feel of the car. I had original shocks and springs on my e38 drift car and the car was all over the place like a boat 😁 but when i changed to coilovers it was actually quite smooth in the corners

[acspecialists]

The H&R springs are going in with new strut arms and the rear diff. After another spin at the track I'll be looking for better tires and sway bars.