Endurance Build Tips?

[MPACT]

I'd love to get the collective advice of the group on building an E90 for endurance racing. We already have an E36M3 and E46M3 we have run in endurance series and are considering adding an E90M3 DCT.

Based on what I am finding the biggest issues are going to be heat (DCT + oil) and the wheel studs. The wheel stud issues seemed solved now by going to the M14 hubs, I already have the Do88 DCT, Oil, and Radiator plus the Slon pan, but doubting that will be enough for extended runs.

I am wondering if maybe I drop the rev limit to 7500 it might help keep the extra heat out of the engine? Also seems like hood vents are a must. Anything else to keep the engine cool over 14-24HR runs?

For the DCT, thinking of maybe swapping over to the Fall-Line DCT pan and adding a pump + extra cooler, perhaps I can solve the trans issues?

Several team members have run M3 GT4s and Cayman GT4MR so they like the idea of keeping the DCT.

Thanks!

[evilspiritM3]

In for everyone's thoughts on this too. But I have a manual. Looked at doing a larger fuel cell but rules in most places limit fuel fills per stop so maybe not worth it. Figure I can get 1-1:15 hrs out of a tank.

[roastbeef]

you'll be fine with all that. jordan yost did it in his e92. d088 and the slon pan are superior to what he had.
http://www.speedhunters.com/2015/06/...-autosport-m3/

[MPACT]

Originally Posted by roastbeef

you'll be fine with all that. jordan yost did it in his e92. d088 and the slon pan are superior to what he had.
http://www.speedhunters.com/2015/06/...-autosport-m3/

I did see that, he had the MT so not sure about the DCT, which is why I was thinking of going more than just the Slon pan + Do88

[DRLane]

Originally Posted by MPACT

I did see that, he had the MT so not sure about the DCT, which is why I was thinking of going more than just the Slon pan + Do88

Will you run a diff cooler as well?

Consider the Core4 Motorsports hubs with press fit studs. Could do either M12 or the M14s. They supply a bunch endurance teams including an e92 team which might be helpful!

[roastbeef]

Originally Posted by MPACT

I did see that, he had the MT so not sure about the DCT, which is why I was thinking of going more than just the Slon pan + Do88

aah, i see. do you know when and were the endurance races are? if its an annual race held in december like the 25 hours of thunderhill that yost competed in, temps might not be a huge factor... norcal gets pretty cold in december, and 1/2 the race is at night.

[OG Shark]

Originally Posted by MPACT

I'd love to get the collective advice of the group on building an E90 for endurance racing. We already have an E36M3 and E46M3 we have run in endurance series and are considering adding an E90M3 DCT.

Based on what I am finding the biggest issues are going to be heat (DCT + oil) and the wheel studs. The wheel stud issues seemed solved now by going to the M14 hubs, I already have the Do88 DCT, Oil, and Radiator plus the Slon pan, but doubting that will be enough for extended runs.

I am wondering if maybe I drop the rev limit to 7500 it might help keep the extra heat out of the engine? Also seems like hood vents are a must. Anything else to keep the engine cool over 14-24HR runs?

For the DCT, thinking of maybe swapping over to the Fall-Line DCT pan and adding a pump + extra cooler, perhaps I can solve the trans issues?

Several team members have run M3 GT4s and Cayman GT4MR so they like the idea of keeping the DCT.

Thanks!

A project near & dear to my heart right here

Have you still had trans heat issues with the do88 setup? The pans are going to mainly to prevent high g starvation, not really to help with cooling.

To me fuel is the biggest potential roadblock. This piggy likes to drink it & depending on which series you are running your capacity could be pretty low.

What series are you going to run it in?

[tsk94]

^ Agreed. I'd think you want as big of a fuel cell as the rules allow. Lowering the rev limit will help with both temps and fuel economy, which for endurance racing is extremely important and won't hurt lap time very much.

[MPACT]

Originally Posted by OG Shark

A project near & dear to my heart right here

Have you still had trans heat issues with the do88 setup? The pans are going to mainly to prevent high g starvation, not really to help with cooling.

To me fuel is the biggest potential roadblock. This piggy likes to drink it & depending on which series you are running your capacity could be pretty low.

What series are you going to run it in?

I haven't had any issues with current setup but also haven't run longer than 30min with it. We plan to spend 2021 as a shakedown year, so will likely do some 6 hour races on the west coast, a 14-hour ChampCar race (in EC and detuned) all with the point of identifying weak points.

Between us we have won the NASA 25 3 times, but 2x in an S54 E36 and then 1x in a Mustang GT, so not sure that is the target with this car, there are likely better platforms to start with for the 25HR, but we just love the car and are thinking of turning into an enduro workhorse with DCT if possible.

[Richbot]

I know this is sortof elementary enduro stuff, but I wonder if you can get a CAN signal for the shift lights and use those to yell at the drivers to short shift for longer stints and fuel save etc. Not many cars have a built-in shift light already The way these cars are geared, there aren't many tweener corners, it's pretty much just 3rd-4th with the occasional 2nd here and there adn 5th on the occasional straight, so at least de-limiting it a bit might not be too much of a lap-wrecking annoyance. I would want that extra couple hundred rpm available on a PTP basis, but if you're building to a power-to-weight class, might not be such a big penalty since the car makes the last 20hp in the last few hundred rpm too.

Also, for a dedicated enduro car, might look at reconfiguring the radiators up front entirely to duct everything up and out. The stock oil cooler dumps all its air under the car which is not ideal for obvious reasons

edit: I didn't even read your whole post and realized you had suggested delimiting it, yes! The real party piece on this engine is the torque curve from 3500rpm to 7000 rpm is a tabletop, without any turbos, as much as people love to go on about 8000+rpm, the party is almost over at 7500 or so anyway and you're just making noise and heat trying to squeeze out the last 20hp above that, the curve flattens out dramatically above 7k on stock cams

[MPACT]

Originally Posted by evilspiritM3

In for everyone's thoughts on this too. But I have a manual. Looked at doing a larger fuel cell but rules in most places limit fuel fills per stop so maybe not worth it. Figure I can get 1-1:15 hrs out of a tank.

This is something we are looking at too. In our experience it would be great to hit 90min if possible but doubt a stock tank will hit that.

[m13s]

PM me for details. I race an E90M3 and we endurance race an E92M3 that has had both DCT and Manual. No way to get an hour + on a stock tank and some series limit your fuel intake as well so a larger tank is useless. The S65 is thirsty when running at race pace. You stated experience in E36/46M3's the E9XM3's are a much heavier platform. No one mentioned brakes and you will need them as this car eats them like a fat kid does cake.

[dparm]

What did the old DTM E92 M3 race cars use for fuel tanks? Or were they stopping every ~45 minutes anyway?

[MPACT]

Originally Posted by m13s

PM me for details. I race an E90M3 and we endurance race an E92M3 that has had both DCT and Manual. No way to get an hour + on a stock tank and some series limit your fuel intake as well so a larger tank is useless. The S65 is thirsty when running at race pace. You stated experience in E36/46M3's the E9XM3's are a much heavier platform. No one mentioned brakes and you will need them as this car eats them like a fat kid does cake.

Bummer, I'd really hoped to hit the hour mark per stint.

For brakes, we use the AP Essex Radical setup on all our cars and have been generally happy with them.

What do you guys have on your endurance e92?

[e36clubracer]

I would contact Fall-Line, their dct pan has provisions for an extra cooler. It would likely be a custom setup but it’s likely your best bet preserving the dct for extended runs.