aero tech- wings, lips, diffusers, canards, etc.

[roastbeef]

Hopefully this can be done without too much money...

[Redd]

Wow. Nice! Full slicks!

[macdude357]

Originally Posted by roastbeef

Hopefully this can be done without too much money...

Define "too much money"

[roastbeef]

Originally Posted by macdude357

Define "too much money"

Aka more than monthly "income" or whatever.

[dogbone]

Originally Posted by roastbeef

Hopefully this can be done without too much money...

Gawd....it must be the biggest pain in the ass the world to work under that car.....

[jakob66]

Making an effective diffuser on the E92 M3 is a big deal as the rear exhaust and the untertray needs to be flat and the diffuser exit angle/profile needs to be done right. Can't be done with OEM rear exhaust. As important are the side shields to protect the negative pressure. Those side walls have to go all the way to the front axle.
Such system works ONLY if you have the front end sealed with a large splitter.
The car is now so low that trailer loading needs special care and running on a dyno requires to take it off. Engine cooling needs special attention, same for differential.
We tested this setup a lot (and I mean a lot) with active rear axle mounted travel indicators and this design works quite well. So well that I had to increase spring rates in the rear to not run on bump stops.
The result is an insane grip on all fast corners at VIR and RA, see my lap times.
The diffuser can be taken off with quick releases and within 15min.
Here are some teaser pictures -and as mentioned before- it will be for sale very soon, please be patient with me.
The last picture shows an early version.
Enjoy!

[dogbone]

Originally Posted by jakob66

....and this design works quite well. So well that I had to increase spring rates in the rear to not run on bump stops. The result is an insane grip on all fast corners at VIR and RA....

I'm curious---does having a big wing plus the monster diffuser in the rear result in a lot of understeer on high speed rounders? How did you balance so much rear downforce in the front? A GT4 splitter [that I see listed in your sig] is not a lot of front aero. Anything else going on up there?

[jakob66]

Originally Posted by dogbone

I'm curious---does having a big wing plus the monster diffuser in the rear result in a lot of understeer on high speed rounders? How did you balance so much rear downforce in the front? A GT4 splitter [that I see listed in your sig] is not a lot of front aero. Anything else going on up there?

Yes, I bolted a 2' front splitter extension plate underneath the existing GT4 splitter and added some winglets.
The picture below is an old version, the latest version is 4" longer!

[roastbeef]

Wow, thank you for sharing!

[roastbeef]

Originally Posted by dogbone

I'm curious---does having a big wing plus the monster diffuser in the rear result in a lot of understeer on high speed rounders? How did you balance so much rear downforce in the front? A GT4 splitter [that I see listed in your sig] is not a lot of front aero. Anything else going on up there?

maybe someone more experienced than me can correct me if i'm wrong in my assumption- but it sounds like these flat bottom cars or advanced diffusers don't create downforce in a way like a rear wing does. the way people talk about them, they seem to suck the car down, rather than press it down from the back. and seemingly does it while reducing drag. other than clearance issues this seems like there are no downsides to these diffusers.

[warp10]

Originally Posted by jakob66

Making an effective diffuser on the E92 M3 is a big deal as the rear exhaust and the untertray needs to be flat and the diffuser exit angle/profile needs to be done right. Can't be done with OEM rear exhaust. As important are the side shields to protect the negative pressure. Those side walls have to go all the way to the front axle.
Such system works ONLY if you have the front end sealed with a large splitter.
The car is now so low that trailer loading needs special care and running on a dyno requires to take it off. Engine cooling needs special attention, same for differential.
We tested this setup a lot (and I mean a lot) with active rear axle mounted travel indicators and this design works quite well. So well that I had to increase spring rates in the rear to not run on bump stops.
The result is an insane grip on all fast corners at VIR and RA, see my lap times.
The diffuser can be taken off with quick releases and within 15min.
Here are some teaser pictures -and as mentioned before- it will be for sale very soon, please be patient with me.
The last picture shows an early version.
Enjoy!

Attachment 1554942

Attachment 1554943

Attachment 1554944

Question. Are you selling this one custom piece or are you planning on making multiple for people to purchase? Either way nice piece.

[jakob66]

Originally Posted by roastbeef

maybe someone more experienced than me can correct me if i'm wrong in my assumption- but it sounds like these flat bottom cars or advanced diffusers don't create downforce in a way like a rear wing does. the way people talk about them, they seem to suck the car down, rather than press it down from the back. and seemingly does it while reducing drag. other than clearance issues this seems like there are no downsides to these diffusers.

yes, diffusers don't add drag (at least underbody styles), they are actually drag reducing as less air flow and its turbulence cost less energy..
However, my car is no way DD anymore and even on the race track like RA I can barely make it to the track down the ramp w/o scratching the diffuser coming from the paddock.
And the problem is that I can't reduce the air dam height as it makes the diffuser ineffective (tried that).

[jakob66]

Originally Posted by warp10

Question. Are you selling this one custom piece or are you planning on making multiple for people to purchase? Either way nice piece.

We will sell through a known vendor on this forum.
Stay tuned.

[warp10]

Originally Posted by jakob66

We will sell through a known vendor on this forum.
Stay tuned.

[dogbone]

Originally Posted by jakob66

Yes, I bolted a 2' front splitter extension plate underneath the existing GT4 splitter and added some winglets.
The picture below is an old version, the latest version is 4" longer!

And the front aero was able to balance out the rear to a fairly neutral state?

Anyway, it all looks very cool. I would love to see that car at Buttonwillow. Would love to see what it's capable of. How much does the car weigh---no fuel, no driver?

[jakob66]

Originally Posted by dogbone

And the front aero was able to balance out the rear to a fairly neutral state?

Anyway, it all looks very cool. I would love to see that car at Buttonwillow. Would love to see what it's capable of. How much does the car weigh---no fuel, no driver?

car drives very balanced.
weight is 3375 w/o driver and 1/2 tank.

[shad0wfax]

So front splitter and wing stay mounted. Flat bottom stays mounted. Rear diffuser quick releases. Can side sills also quick release?

What exhausts do work, or does it require custo, bent tube?

[jakob66]

Originally Posted by shad0wfax

So front splitter and wing stay mounted. Flat bottom stays mounted. Rear diffuser quick releases. Can side sills also quick release?

What exhausts do work, or does it require custo, bent tube?

Front splitter extension is quick release, flat bottom comes out with 4 nuts and 4 quick release (only OEM bolt locations were utilized).
I made a custom exhaust (I basically used OEM rear axle exhaust and cut main chamber off and extended tubing). Car is loud but sound is -combined with DCT and rev matching- totally addictive...

[ThunderMoose]

Originally Posted by jakob66

Front splitter extension is quick release, flat bottom comes out with 4 nuts and 4 quick release (only OEM bolt locations were utilized).
I made a custom exhaust (I basically used OEM rear axle exhaust and cut main chamber off and extended tubing). Car is loud but sound is -combined with DCT and rev matching- totally addictive...

Jens - any plans to build something for E46 M3?

I'll offer up my car as prototype .

Denis

[jakob66]

Originally Posted by ThunderMoose

Jens - any plans to build something for E46 M3?

I'll offer up my car as prototype .

Denis

Denis
great idea and thanks for offering your car! However, we're working very hard right now to fully production develop and industrial engineer the parts we will offer for the E9xM3 chassis. Once done we can talk again.
Thank you!

[ThunderMoose]

Originally Posted by jakob66

Denis
great idea and thanks for offering your car! However, we're working very hard right now to fully production develop and industrial engineer the parts we will offer for the E9xM3 chassis. Once done we can talk again.
Thank you!

Very good. There really is no good diffuser on market for E46. Bimmerworld makes one but it is really to eliminate the parachute of the current exhaust and diffuser.

[///Mobbin]

Originally Posted by jakob66

Denis
great idea and thanks for offering your car! However, we're working very hard right now to fully production develop and industrial engineer the parts we will offer for the E9xM3 chassis. Once done we can talk again.
Thank you!

Hoping your half-cage is part of this effort!