MCast - GT4 Race Conversion

[racerbruce]

Unreal build M-Cast!
The mere mortals (that would be me) are in awe at the tech, time, expertise and $ to create a purpose built race car.

Please continue posts and photos for us.

[RvsBmw]

Originally Posted by M-Cast

It's been ages since I have posted and we have made some updates converting the car over to DCT. Not sure if it's the first S54 DCT conversion in an M Coupe but it fits as it should.

Wowh, nice steps!
Curious if you also placed the engine a little more backward? also which software your planning to use, HTG?

Good luck, looking forward for the next update .

[M-Cast]

Originally Posted by RvsBmw

Wowh, nice steps!
Curious if you also placed the engine a little more backward? also which software your planning to use, HTG?

Good luck, looking forward for the next update .

Yes, the guys at a Seems Legit Garage have been a big help. The HTG box has came a long way and the programming capability expanded. Unfortunately, you cannot move the engine back without switching to a dry sump. The pan does not allow you to pass the front subframe. If all goes well, I am planning to switch my 3.0 car over to the ZF8 transmission for endurance racing.

[M-Cast]

Just added a full air jack system to the car. I should have a lot more pictures in the coming weeks of all the plumbing for the coolant systems, trans cooler, and diff cooler.

[Michael9218]

Damn son, you planning on hiring a Nascar team to pit for you?
Looks sweet!

[Westersund]

Love the build!

I have a suggestion/recommendation regarding the rear FCAB however. The tie rod looks weak (same as the front inner as well) and I highly recommend some kind of reinforcement of the body at the rear pickup point (the inner front as well really). In the X an Y axis (horizontally) the body is fine but in the Z axis (vertically) the body will flex without reinforcing it, eventually the body will fatigue and crack. You're building a race car and the pickup points aren't designed for the kind of abuse you're gonna throw at it.

This is how it was done on my E46 M3 (it's designed by an experienced race chassi engineer who also drives Europes fastest time attack car):

[Vanne]

Cool airjacks mate. Love it. how much weight do they add? not the jacks themselves ofcourse as they weigh hardly anything, being an alu sleeve with a piston, but the reo looks sturdy, thus must weigh a bit?

nice progress

[M-Cast]

A little more eye candy for all you Z4 Lovers. Making more progress as we are waiting on more parts.

[M-Cast]

We did actually come back to it and reinforced the front and rear subframe connecting points in multiple places. I just had an issue on my other car where the front sway bar stripped out of the subframe. That's a nice little setup on the M3.

Originally Posted by Westersund

Love the build!

I have a suggestion/recommendation regarding the rear FCAB however. The tie rod looks weak (same as the front inner as well) and I highly recommend some kind of reinforcement of the body at the rear pickup point (the inner front as well really). In the X an Y axis (horizontally) the body is fine but in the Z axis (vertically) the body will flex without reinforcing it, eventually the body will fatigue and crack. You're building a race car and the pickup points aren't designed for the kind of abuse you're gonna throw at it.

This is how it was done on my E46 M3 (it's designed by an experienced race chassi engineer who also drives Europes fastest time attack car):

[Vanne]

The front swaybar stripping out on these chassis is a very well know issue, easily fixed and not really much of a drama, unless its over looked. I think Westersund is talking about the front/rear fcab attachment if your running the SLR arms. Might wanna have a chat to Micheal about what happened to his, he's since returned to OEM arms. Its definitely a concern mate. It definitely worries me a bit, i guess a few rounds will tell the story.

[M-Cast]

Just got my custom paddle box in for the CM car. ATC did an excellent job and the quality is spot on.

[Westersund]

Originally Posted by Vanne

The front swaybar stripping out on these chassis is a very well know issue, easily fixed and not really much of a drama, unless its over looked. I think Westersund is talking about the front/rear fcab attachment if your running the SLR arms. Might wanna have a chat to Micheal about what happened to his, he's since returned to OEM arms. Its definitely a concern mate. It definitely worries me a bit, i guess a few rounds will tell the story.

You're exactly right! That's why I have connected the x-brace with the rear FCAB so the body won't flex and crack.

[Beedub]

this is by far the best build ive seen for this platform, the quality is different levels.

[M-Cast]

I know it has been a while, but as the Mod car is still progressing, we have been busy with its little brother, the 84 car. We swapped the manual trans for an 8-speed 8hp45 transmission with an HTG Transmission Controller. This was a big update and great learning for the DCT we are putting in the Mod Car. For those interested, I can start another thread explaining the conversion, as it was not that bad and much cheaper than a sequential box.

We are currently swapping out the stage 3 intake for an N54 intake while building the next engine, which will be an N52 with an N53 head and S54 throttle bodies. It will be an exciting update.

Happy New Year

[Westersund]

Please do tell a little about the 8HP swap. During next year I'll be putting a S55 with a 8HP70 in my Z3 Coupe, but I don't know a lot about the actual transmission swap yet. But I understand that they will be the next big thing. Very low cost compared to a sequential gearbox and the service requirements are basically an oil/filter change once in a while and no need the clutch on downshifts. And they cost about 1200$, but you will need a harness and the HTG control module or equivalent also. So in total a third or fourth the cost of a sequential gearbox.

[M-Cast]

Originally Posted by Westersund

Please do tell a little about the 8HP swap. During next year I'll be putting a S55 with a 8HP70 in my Z3 Coupe, but I don't know a lot about the actual transmission swap yet. But I understand that they will be the next big thing. Very low cost compared to a sequential gearbox and the service requirements are basically an oil/filter change once in a while and no need the clutch on downshifts. And they cost about 1200$, but you will need a harness and the HTG control module or equivalent also. So in total a third or fourth the cost of a sequential gearbox.

You can get away with the HP50 unless you want over 600hp. Depending on what your use case is the parts list will be different. Mine is a race setup. The transmissions are cheap, but if you need all the components, it can add up quickly.


The key components are:

• Transmission
• Trans Mount is a custom fab for the Z3
• The driveshaft will have to be fabricated lengthened or cut
• Flex Plate
• Harness and upgraded Metronics
• HTG GCU
• Oil Cooler for the Transmission
• Shifter or Paddles
• Cann Controller

The next thing you will need to look at is the differential setup, Turbos will range from 2.91 to 3.23, and NA cars will be more like 3.46 to 4.10

Once you have all the components together, it is worth getting with Bartek at HTG to set up your initial configuration and tune. This will be worth the time and money.

[Westersund]

Originally Posted by M-Cast

You can get away with the HP50 unless you want over 600hp. Depending on what your use case is the parts list will be different. Mine is a race setup. The transmissions are cheap, but if you need all the components, it can add up quickly.


The key components are:

• Transmission
• Trans Mount is a custom fab for the Z3
• The driveshaft will have to be fabricated lengthened or cut
• Flex Plate
• Harness and upgraded Metronics
• HTG GCU
• Oil Cooler for the Transmission
• Shifter or Paddles
• Cann Controller

The next thing you will need to look at is the differential setup, Turbos will range from 2.91 to 3.23, and NA cars will be more like 3.46 to 4.10

Once you have all the components together, it is worth getting with Bartek at HTG to set up your initial configuration and tune. This will be worth the time and money.

Thank you! That's a good list, that transmission mount and prop shaft will be custom made. The car will be street legal and it have to weigh a certain amount so I'll go with the 8HP70 to add some weight and future proof it, but it will run on stock power in the begining. A complete F8X M rear end will be used, and I have a 3.91 ratio laying around if needed.

With the upgraded mechatronics, do you mean the need to splice/solder the OEM wiring?

The CAN controller is needed to communicate between the ECU and GCU?

[M-Cast]

Originally Posted by Westersund

Thank you! That's a good list, that transmission mount and prop shaft will be custom made. The car will be street legal and it have to weigh a certain amount so I'll go with the 8HP70 to add some weight and future proof it, but it will run on stock power in the begining. A complete F8X M rear end will be used, and I have a 3.91 ratio laying around if needed.

With the upgraded mechatronics, do you mean the need to splice/solder the OEM wiring?

The CAN controller is needed to communicate between the ECU and GCU?

You will want to go with the stock ratio if this is a street car and running turbos. The 3.91 would work with an NA car otherwise your first 2 gears will be to short.

The mechtronics, is a chip replacement which includes the splice and solder of the new harness.

Yes it all works off your CANN 1 channel, the button controller works off CANN 2

You would also want to look at HTG's DCU for the F8X Differential. This give you full control of the diff settings electronically.

[Westersund]

Originally Posted by M-Cast

You will want to go with the stock ratio if this is a street car and running turbos. The 3.91 would work with an NA car otherwise your first 2 gears will be to short.

The mechtronics, is a chip replacement which includes the splice and solder of the new harness.

Yes it all works off your CANN 1 channel, the button controller works off CANN 2

You would also want to look at HTG's DCU for the F8X Differential. This give you full control of the diff settings electronically.

I'll stick to the stock ratio then, and I'll sort the car out a bit before I invest in a DCU controller.

Ah, that's what I thought. This is all new to me and I wanted to get it right.

Seems like the TurboLamik only needs the GCU and a CAN key pad for selecting M, D, N and R. I read a little about HTG's IO CAN controller and it seems like it's optional, but will be beneficial to get the ECU and GCU to work optimally together.

[Vanne]

Nice updates