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BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > Tracking, Autocrossing, Dragstrip, Driving Techniques > Update - 2012 Track Prep...bring on the rice



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      12-30-2011, 12:30 AM   #23
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Originally Posted by CCase View Post
Interesting project you have here...mind sharing any data and calculations you have done regarding this aero setup producing 500lbs downforce at 100mph? How did you come up with that number?
The conversion of the 150lbs of lift to 500lbs of downforce is simply my goal; sorry if it didn't come across clearly. That is a pretty reasonable number that should be achievable quite easily with this system. If I chose to add an AM Wing and canards this summer, that'll be another ~300lbs in the rear and 70 in the front. Not sure how 'extreme' I want to make it. Like I said in the first post, most of the downforce comes from underneath; so that's where the focus is.

There is a LOT of data to go through so far; as I'm using 20 mounting points for the Manometer. I haven't even begun to put the data together yet. Plus, I really need to do more testing with lower ride height; as it's pretty high at the moment. This type of data acquisition is a ton of work to collect, then do all the math to convert the data into useable info.

In essence,when static- plus dynamic pressure stays constant: The equation is ps1 - ps2 = pd2 - pd1, where pd = Rho * v^2/2.

For 500lbs downforce, it'll require an average of .05psi" pressure differential underneath...which should not be overly ambitious. I'll be working with a local Audi guru, who also happens to be an Aerospace Engineer....so he has a bunch of pretty cool (and crazy expensive) equipment and tools that will be a bit more accurate than my $100 Manometer and old school magnahelic.

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      12-30-2011, 02:25 AM   #24
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Brian,

What custom map do you use? I'm heading to Laguna Seca this weekend. I plan on running 11-25 Aggressive, Stage 0, Map 4. From what I hear, it peaks around 12psi. But, I'm unsure until I load it tomorrow.
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      12-30-2011, 08:56 AM   #25
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Brian,

What custom map do you use? I'm heading to Laguna Seca this weekend. I plan on running 11-25 Aggressive, Stage 0, Map 4. From what I hear, it peaks around 12psi. But, I'm unsure until I load it tomorrow.
Well Laguna is not a super hard track for engines, assuming good suspension, sticky tires and skill so you can keep momentum up, so it will probably be fine on the regular default maps. however, you'll just have to adjust according to the conditions you're seeing.

Personally, I am always on the more conservative side for 20-30 minute track sessions, knowing that 380hp is not going to get significantly faster times or more fun. (when talking about a going to 420hp for a single lap time attack shootout the power comes more relevant)

Not sure where you heard STG 0 is 12psi peak, but that's pretty low. When I did the dyno testing of all different aggressive maps, STG 1 was still at 16psi in the midrange.

12psi with advanced timing and Lower IATs, that's probably around 340hp at 240*, and going down on power as temp rises.
In any case, my conservative suggestion is to use the 7-29 maps, autotuning off, and increase meth by 15pts across the board. I could send you the specific one i wrote, I'd you'd like.

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      12-30-2011, 09:09 AM   #26
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Quote:
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Well Laguna is not a super hard track for engines, so it will probably be fine on the regular default maps. however, you'll just have to adjust according to the conditions you're seeing.

Personally, I am always on the more conservative side for 20-30 minute track sessions, knowing that 380hp is not going to get significantly faster times or more fun. (when talking about a going to 420hp for a single lap time attack shootout the power comes more relevant)

Not sure where you heard STG 0 is 12psi peak, but that's pretty low. When I did the dyno testing of all different aggressive maps, STG 1 was still at 16psi in the midrange.

12psi with advanced timing and Lower IATs, that's probably around 340hp at 240*, and going down on power as temp rises.
In any case, my conservative suggestion is to use the 7-29 maps, autotuning off, and increase meth by 15pts across the board. I could send you the specific one i wrote, I'd you'd like.
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      12-30-2011, 09:52 AM   #27
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Thanks. I have been eyeing up the ER dual core setup for a while too; and actually saw it for the first time about a week after I got the first AR Oil cooler.

I'll likely swap out the OEM oil cooler for a better core and see how that goes.
That's also what I did as - similar to you - I still got too high oil temps after installing the AR oil cooler (although this one already dropped the temps somewhat). Right now I'd use the ER sports oil cooler that replaces the stock core with one that is double the size. In my case this has eliminated all oil temperature problems for me.
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I've already got pure distilled with RL's Water Wetter in the radiator; and wouldn't hesitate to buy an aftermarket aluminum radiator...if there was one and it was under $1k. AR had made one, but I don't think they plan on producing it anymore.
You can see what I wrote about the one I got from them in the thread in my signature - I wouldn't really recommend it. They seem to still make them though, but on special order apparently.

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      12-30-2011, 10:28 AM   #28
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Hmm, what meth/water ratio? I'm at 75/25 for track and almost 100% meth for street. My thought process for this is to run a bit less boost and more ignition advance as opposed to more water (a little bit more cooling) and less timing.

Another thing that makes a large difference is the design of the track; more straights vs. twisties. For example, the two popular tracks around me are BIR (4 long straights, one of them being 1.1 miles long, the two 1/4 mile long, etc. and Road America also has many very long straights; and there is absolutely no area for the engine to cool on these tracks.

RA is known for being extremely hard on engines...and BIR as well. No question that that is attributing to the higher heat I'm experiencing. In any case, 265 or even 275 is not concerning; but anything above that is a bit uncomfortable.
I ran a 75/25 meth/water ratio, just like I do on the street. Big Willow is a fast track, but not as long/fast BIR or RA; however, with the meth, the air intake temps are staying cooler when you are actually flooring the car in full boost with the meth flowing 100%.

I'm sure you have done logs and seen other's logs and it's clear that IAT's drop from the beginning of the run, before meth is flowing, to the end where meth is flowing 100%. Obviously the logs are only for a few seconds and I've never seen a 20 minute log to see whether the meth flow can sustain the low IAT's for such a long duration; however, I remember Shiv commented on a thread a while back that it would help to cool oil temps in track use. So maybe he was spot on in this regard?

Since you have a Procede, why don't you contact him and get his opinion, and then track your car on both your 12psi map and also at max boost/power and let us know if there was a difference in temps
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      12-30-2011, 11:28 AM   #29
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That's also what I did as - similar to you - I still got too high oil temps after installing the AR oil cooler (although this one already dropped the temps somewhat). Right now I'd use the ER sports oil cooler that replaces the stock core with one that is double the size. In my case this has eliminated all oil temperature problems for me.
You can see what I wrote about the one I got from them in the thread in my signature - I wouldn't really recommend it. They seem to still make them though, but on special order apparently.

Alpina_B3_Lux
Thanks, I've seen your posts and if it is available this year; I'll likely pull the trigger.
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I ran a 75/25 meth/water ratio, just like I do on the street. Big Willow is a fast track, but not as long/fast BIR or RA; however, with the meth, the air intake temps are staying cooler when you are actually flooring the car in full boost with the meth flowing 100%.

I'm sure you have done logs and seen other's logs and it's clear that IAT's drop from the beginning of the run, before meth is flowing, to the end where meth is flowing 100%. Obviously the logs are only for a few seconds and I've never seen a 20 minute log to see whether the meth flow can sustain the low IAT's for such a long duration; however, I remember Shiv commented on a thread a while back that it would help to cool oil temps in track use. So maybe he was spot on in this regard?

Since you have a Procede, why don't you contact him and get his opinion, and then track your car on both your 12psi map and also at max boost/power and let us know if there was a difference in temps
?? I'm not quite sure what you're saying/asking. Even though IATs stay cool[er] with meth; you are still at WOT for long durations of time; with no real chance for rest or cooldown. It will definitely help oil temps; but it's not the magic cure that will bring temps down to 240. Like I said before; Meth keeps my oil temps at 265 vs. 275-280 on 90* ambient temp days, which is quite impressive..but still in the undesirable range.

For the most part, the powertrain of my car has been relatively untampered with over the past year/10 track events as I was testing other components and needed all-else equal. I did encounter a few 335s and 135s who were first-timers on the track running normal street-map power and overheating (boost cut down to nothing) within 3 laps on a 80* day. One of them was running race gas and 17psi and race gas and he couldn't figure out why his oil temps were at 290 after 8 minute of hard driving, haha.

It's very simple; the more power/psi (regardless of meth), the higher the temps. In my [extensive] track experiences and testing with this engine over the past 2-3 years, I've gotten a bit of data. I'll look for the exact numbers I had in my computer from last year; but I have a good idea of the results.

At the long and demanding road courses with an ambient temp of 80*F:
12psi With meth: 200*Water, 265*oil sustainable temps. (Perfectly content, but could be better)
12psi without meth: 205*W, 275*oil sustainable temps (content, but undesirable)
14psi with meth: 205* Water, 275*oil sustainable (content but undesirable)
*14psi without meth/stock oil cooler: ~205* water, 280* oil..not sustainable (very undesirable)
*15psi with meth/stock oil cooler: 205* water, 280* oil stustainable (very undesirable)
**16psi without meth, w/race gas & clown owner: ??water, 280-285* oil after 10 minutes; reduced boost and limp mode (bad)
**17psi without meth, w/race gas & clown owner: ??water, 285 and higher after 10 minutes; reduced boost and limp mode (horrible)

* = Other car 1
**= Other car 2

Whew, long post
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      12-30-2011, 06:48 PM   #30
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?? I'm not quite sure what you're saying/asking. Even though IATs stay cool[er] with meth; you are still at WOT for long durations of time; with no real chance for rest or cooldown. It will definitely help oil temps; but it's not the magic cure that will bring temps down to 240. Like I said before; Meth keeps my oil temps at 265 vs. 275-280 on 90* ambient temp days, which is quite impressive..but still in the undesirable range.

For the most part, the powertrain of my car has been relatively untampered with over the past year/10 track events as I was testing other components and needed all-else equal. I did encounter a few 335s and 135s who were first-timers on the track running normal street-map power and overheating (boost cut down to nothing) within 3 laps on a 80* day. One of them was running race gas and 17psi and race gas and he couldn't figure out why his oil temps were at 290 after 8 minute of hard driving, haha.

It's very simple; the more power/psi (regardless of meth), the higher the temps. In my [extensive] track experiences and testing with this engine over the past 2-3 years, I've gotten a bit of data. I'll look for the exact numbers I had in my computer from last year; but I have a good idea of the results.

At the long and demanding road courses with an ambient temp of 80*F:
12psi With meth: 200*Water, 265*oil sustainable temps. (Perfectly content, but could be better)
12psi without meth: 205*W, 275*oil sustainable temps (content, but undesirable)
14psi with meth: 205* Water, 275*oil sustainable (content but undesirable)
*14psi without meth/stock oil cooler: ~205* water, 280* oil..not sustainable (very undesirable)
*15psi with meth/stock oil cooler: 205* water, 280* oil stustainable (very undesirable)
**16psi without meth, w/race gas & clown owner: ??water, 280-285* oil after 10 minutes; reduced boost and limp mode (bad)
**17psi without meth, w/race gas & clown owner: ??water, 285 and higher after 10 minutes; reduced boost and limp mode (horrible)

* = Other car 1
**= Other car 2

Whew, long post
Well, I was hoping that an increase in power would not necessarily equate to an increase in oil temps, insofar as meth was keeping IAT's low (whether at 350 WHP or 450 WHP). It certainly worked for me, pushing ~ 17psi sustained for 10 minutes with no other cooling mods, and my oil temps stayed rock solid right at 250. Maybe I wasn't pushing the car nearly as hard as you would, as I'm fairly new to this.

Your analysis however has good data to suggest a linear correlation between power output and oil temps while running the 335 all out on a track, even with meth.
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      01-04-2012, 08:29 PM   #31
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damn that's sick Brian -
make me one.

what material are you using?
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      01-04-2012, 08:58 PM   #32
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This is actually really cool, looking forward to more data..

I'm getting my car prepped as I was hit by the track bug.

Just ordered vorshlag camber kit, had kw v2 for two years, and just installed an M3 sway.

Keep it coming
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      01-04-2012, 10:22 PM   #33
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Nice Aero project Brian.

On the cooling front, why haven't we done a PWR radiator group buy already? Any interest in this?
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      01-05-2012, 09:31 AM   #34
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Thanks Guys- This is turning out to be quite fun...I've got this weekend blocked off to do a bunch of data acquisition with my aerospace friend. Luckily he has the equipment to hook up 20 test points at a time that measure wind speed and pressure... which is a HUGE advantage for testing purposes. If I were to have to manually move every a single manometer hose each session that would take wayyy too long.

Front Splitter is made of 3/8" Hi Density Polyethylene (plastic), which will be soft and flexible, yet very very strong.
Side skirts/undertrays/prototype diffuser were all made of 1/8" ABS Plastic. Very strong, decently light.
Final production of the diffuser is a mold/carbon fiber. This includes all the vertical strakes, mounting points, etc. So the entire diffuser is only 3 pieces that is riveted together once installed.

My next steps with this project are:
1) Make the a 3-piece mold of the rear diffuser out of carbon fiber (entire diffuser, mounts and strakes will be made of 3 pieces: 2 sides and one center) This will be a rough version- not worried about making it look super pretty at this point.

2) Lower car to track height (Splitter being 3.65" off the ground) and conduct extensive pressure and airflow testing to determine how much downforce is created where. (This weekend)

3) Build underbody system (splitter, side skirts, underbody, diffuser) for another local E90 335 with dual mufflers...possibly different diffuser design

4) Build underbody system (splitter, side skirts, underbody, diffuser) for another local E92 M3 with dual mufflers

If this all goes well; I might be looking at marketing this to the E9x enthusiasts First I need to get hard facts and figures to show this actually does make a substantial difference.

Cheers!
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      01-05-2012, 02:07 PM   #35
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If this all goes well; I might be looking at marketing this to the E9x enthusiasts First I need to get hard facts and figures to show this actually does make a substantial difference.

Cheers!
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      03-09-2012, 03:32 PM   #36
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Quick update here:

I had the chance to borrow a Stock (lowered) E90 335i last weekend for baseline testing, and it is making this underbody aero system appear to work much better than expected! Not only does this underbody system show [much] lower pressure rear of the transmission, it also shows practically no turbulence compared to the stock E90. I learned quite a few interesting facts about the underbody aero of the E90 and will be making a comprehensive post after this weekend when I complete the testing on my car.

I've posted below simple screenshots of the *summarized* data collection from 90mph (in mexico). I originally anticipated doing all testing at 100mph, but Johnny law is out in full effect, and choosing to run hours at 100mph is just an option where I cannot afford the potential consequences. I do have quite a bit of data from 70mph- 130mph for specific data points, but the sample rate is too low to publish them as conclusive.

In any case, here is the summarized data from the test cases where there were ideal conditions.
-Windspeed 0
-Both E90 Pre-LCI, at same ride height, same wheels, same size tires.
-Stock E90 = Stock exhaust and stock control arms
-Mod E90 = M3 front control arms, stock rear control arms

*This data was taken from 26 data points from the first couple test sessions. I now have over 45 data points on my car for this weekend


Underbody Aero- MDM System Design2 Data2 by MDM Enterprises, on Flickr

Underbody Aero- Stock by MDM Enterprises, on Flickr

Without going into deep deep detail and long explanations of equations, I'll suffice it to say that the Underbody system is producing the following characteristics.
Rear of the Car- Delta of 350lbs of downforce at 90mph
Front of the car- Delta of 300lbs of downforce at 90mph

Cheers,
Brian

Last edited by BrianMN; 03-09-2012 at 04:20 PM.
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      03-16-2012, 03:28 PM   #37
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Without going into deep deep detail and long explanations of equations, I'll suffice it to say that the Underbody system is producing the following characteristics.
Rear of the Car- Delta of 350lbs of downforce at 90mph
Front of the car- Delta of 300lbs of downforce at 90mph

Cheers,
Brian
Really impressive! Thank you for sharing your work, really looking forward to more updates!

P.S. Have you done any evaluation of a rear spoiler or wing, or is it too early to move to that spot?
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      03-17-2012, 01:31 AM   #38
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Interesting, would love to see what data you come up with. As you already mentioned, lowering your car a bit more would seem to benefit as well, but obviously without over-lowering. Also, have you thought about bringing the side fences in a bit? Just throwing ideas out there... is there a lot of turbulence that gets caught up around the wheels and would bringing the fences to the inside edge of the tire create more of a tunnel?
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      03-18-2012, 02:20 AM   #39
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Hey All, just wanted to give a quick update on the diffuser project from the past month or so. I've been working with a couple great resources and also got ahold of a stock E90 335i for baseline testing, so I now have some great data to make educated evaluations of the performance of this system

I have been working with 2 amazingly intelligent resources from the U of M; an Aerodynamicist/Professor and a Physics/Aerodynamics student. They have been very helpful with teaching me more of the intricate testing possibilities and brainstorming solutions to everything. They both have the background knowledge of aerodynamics and also a passion for cars and racing. In addition to the current setup, we're working on more testing of different side skirt placement and even running vortices on the front splitter, which would negate the need for side skirts anyways.

Here is a quick pic of how the car is sitting at the moment (without the side skirts). Since the last thread I’ve made the splitter larger and thicker, which required adding supports rods, lowered the car significantly and used even taller side skirts.

M3 Wheels 1 (1024x683) by MDM Enterprises, on Flickr

So much of this data I'm posting up might not be understandable at first glance, but try to imagine this simply as a comparison between Mark's car (stock) vs. my car (underbody system). The data I have below is showing pressure differentials at different speeds for both cars. The [lower] pressure differential is what either pulls the car to the ground, where the high pressure [underneath] pushes it up from the ground. This is a very simple, to-the-point method of testing differences in pressure. Similarly, turbulence (quick fluctuations in pressure) is very good to measure as that can both create. Sure, there are much more sophisticated, accurate and complete ways to test the system (especially the flow separation and air speeds of the rear diffuser). This testing can get extremely involved and can be more unreliable due to variances in external conditions. Regardless, the goal for my testing is to get objective data related to the overall pressure differentials of the underneath side of my ricecar, and simply testing pressures of ~40 data points with multiple magnahelics and a manometer is much more than adequate for my goals

Without further ado, here is the data from the past couple weeks:

Stock- 85mph

Stock E90- T1 85mph by MDM Enterprises, on Flickr


Underbody T1- 85mph

Underbody-T1 85mph by MDM Enterprises, on Flickr


Underbody T2- 70mph

Underbody- T2 70mph by MDM Enterprises, on Flickr


Underbody T2- 100mph

Underbody T2- 100mph by MDM Enterprises, on Flickr


Underbody T2- 140mph- Anticipated

Underbody- T2 140mph by MDM Enterprises, on Flickr


In summary, the downforce of this underbody system compared to stock are:
70mph- Delta of apx. 302lbs
85mph- Delta of apx. 473lbs
100mph- Delta of apx. 543lbs
140mph- Delta of apx. 746lbs

These numbers are calculated based on the average pressure in front of the front axle multiplied by the square inches of the ‘meat’ area in that same area, and similarly based on the center and rear section.

Any questions, comments, insults or jokes are welcomed. I am aware of how silly this is, and I am reminded of it multiple times a week when random teenagers ask me “Dude, that’s a sweet body kit, where’d you get it?!”
Cheers,
Brian


Random pics:

Testing Diff1 by MDM Enterprises, on Flickr

Diffuser CAD 1 by MDM Enterprises, on Flickr

Diffuser CAD 2 by MDM Enterprises, on Flickr

M3 Wheels4 (1024x683) by MDM Enterprises, on Flickr
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      03-18-2012, 03:23 AM   #40
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Really impressive! Thank you for sharing your work, really looking forward to more updates!

P.S. Have you done any evaluation of a rear spoiler or wing, or is it too early to move to that spot?
Thanks!

I am definitley considering a wing. However wings, similar to canards and adjusting the front air dam, should be used to fine tune your aero system, and not be relied upon to provide significant downforce. It is somewhat similar to a sway bar being a fine tuning device after a complete suspension..you want to have the entire 'meat' of the system setup properly, then use the tuning tools to optimize front/back downforce balance. Contrary to popular thought, the large majority of downforce comes from underneath the car, from a properly designed underbody aero system. To put it into perspective- some ALMS/rolex cars can easily acheive 1000 lbs from their underbody system, whereas a normal 68" APR, BW or AM wing will only produce ~200-300lbs on a "normal" AoA...and even only 400lbs at their stall point.

Also- the problem with a wing is that in order for it to produce significant downforce, it will create a LARGE amount of drag. With a 335i on a road course, we do not have the power to balance out the additional drag induced by a wing.

So essentially, the wing/canards are the last thing you need, and only if you need to fine tune the system.
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      03-18-2012, 03:33 AM   #41
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Interesting, would love to see what data you come up with. As you already mentioned, lowering your car a bit more would seem to benefit as well, but obviously without over-lowering. Also, have you thought about bringing the side fences in a bit? Just throwing ideas out there... is there a lot of turbulence that gets caught up around the wheels and would bringing the fences to the inside edge of the tire create more of a tunnel?
Yep, lowering the car helps a LOT. Even on a stock car, lowering down 1.5" or more can definitely reduce the lift and drag.

Funny you mention bringing in the side skirts- as that is currently the plan for next weekend In addition to trying that, I'm also going to build 'fences' on the edge of the exhaust/driveshaft tunnel, with it coming to a V around the rear of the engine. That way, hopefully the incoming air will flow around the tunnel as opposed to going through it and creating turbulence in that specific area.

The rear subfram area of the stock E90 has a LOT of turbulence. I wouldn't say that it is a shocking/unexpected amount, but it certainly is undesirable. At 80mph, we were seeing average fluctuations of .2-.3 inh2o everywhere from the rear bumper 1 foot in front of the rear subframe. I had data points up in the control arm 'pockets' of the stock E90 and saw multiple spikes up to .5 due to overpasses and large bumps. On my car there is practically zero turbulence on the diffuser

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      03-18-2012, 04:23 AM   #42
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Yep, lowering the car helps a LOT. Even on a stock car, lowering down 1.5" or more can definitely reduce the lift and drag.

Funny you mention bringing in the side skirts- as that is currently the plan for next weekend In addition to trying that, I'm also going to build 'fences' on the edge of the exhaust/driveshaft tunnel, with it coming to a V around the rear of the engine. That way, hopefully the incoming air will flow around the tunnel as opposed to going through it and creating turbulence in that specific area.

The rear subfram area of the stock E90 has a LOT of turbulence. I wouldn't say that it is a shocking/unexpected amount, but it certainly is undesirable. At 80mph, we were seeing average fluctuations of .2-.3 inh2o everywhere from the rear bumper 1 foot in front of the rear subframe. I had data points up in the control arm 'pockets' of the stock E90 and saw multiple spikes up to .5 due to overpasses and large bumps. On my car there is practically zero turbulence on the diffuser
Interesting data. Have you checked out any of the E9x race cars to see what sorts of aero setups they have? Although many of them may be limited due to class rules and regulations, it might be worth taking a look and checking out specific setups BMW race teams have done.

Do cars see a lot of turbulence around the wheel area? Maybe that "V" can extend towards front of the rear wheels to push that turbulent air out from under the chassis - although I wonder what effect that has when it just "comes out" from the side. I'd suspect some turbulence rather than just having it shoot out the rear where you have the diffuser that can more effectively direct the flow.

Cool project, definitely one of a kind and will follow this just for curiosity's sake.
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      03-18-2012, 10:56 AM   #43
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Interesting data. Have you checked out any of the E9x race cars to see what sorts of aero setups they have? Although many of them may be limited due to class rules and regulations, it might be worth taking a look and checking out specific setups BMW race teams have done.

Do cars see a lot of turbulence around the wheel area? Maybe that "V" can extend towards front of the rear wheels to push that turbulent air out from under the chassis - although I wonder what effect that has when it just "comes out" from the side. I'd suspect some turbulence rather than just having it shoot out the rear where you have the diffuser that can more effectively direct the flow.

Cool project, definitely one of a kind and will follow this just for curiosity's sake.
Of course I've done a ton of research on full body racecars the benefit the m3s have (as described in the first post) is that they can be completely sealed, because the engine does not need the additional cooling benefits. (plus, the alms cars have sealed tunnels that take the air from the kidney grills, through the radiator then through the interior of the car then out the back. Pretty nuts.

I think you might be confusing Turbulence with high pressure. The reason I would "like" to fence off the exhaust tunnel is primarily to promote the uninfluenced air speed on the sides of the tunnel, and the smaller reason is to not let that that turbulence effect anything outside of the tunnel. The tunnel doesn't really create significant turbulence (and turbulence is normally the 2nd priority anyways) rather it is the expanding area and the flow separation that might be introduced, which would slow down the air under the car. Regarding turbulence vs high pressure- directing the air out the side of the car- that wouldn't really make sense, as it is a low pressure area compared to high pressure outside. In all reality though- the data is showing things are working incredibly well. I definitely don't NEED to change anything at this point


The wheelwell area (on the side of the car) is a high pressure zone, which is very undesirable. There are a couple ways to fix that- fender Vents and canards. I might go try canards for fun, but essentially the high pressure from the wheelwells is just something I have to deal with, since there is not a simple, practical way to remedy it.

Last edited by BrianMN; 03-18-2012 at 11:13 AM.
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      03-30-2012, 04:39 PM   #44
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what material did you use to make the underbody and splitter?
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