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      09-15-2017, 11:26 PM   #1
dre99gsx
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Rear wing without front splitter

Anyone here road coarse with just the addition of a rear wing (no front splitter)? How does the z4 coupe feel at top speed and corner entry? Being that are cars are 50/50 weight, I curious if addition of only a rear wing made the car that much lighter up front, or if our front end is already pretty good at downforce in stock form?
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      09-16-2017, 12:47 AM   #2
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It definitely needs front aero to balance it out.
I have run many variations of front and back setups.
...& that's why I ended up designing my own front end; APR splitter alone wasn't enough.
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      09-16-2017, 08:01 AM   #3
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Quote:
Originally Posted by inTgr8r View Post
It definitely needs front aero to balance it out.
I have run many variations of front and back setups.
...& that's why I ended up designing my own front end; APR splitter alone wasn't enough.
yup , i agree. I found adding canards helped front end a little, especially going into turns with speed. Would need slightly bigger ones to be honest but near impossible to find at reasonable price to test fit.

I am running rear varis diffuser and a gts wing in the back along with apr and canards in the front. Pretty good stability and can feel the aero grip. I'd say a slight rear bias but car is pretty stable.

To answer your other question, stock front end and rear have slight lift at speed. There are some threads about how much buried around here somewhere. I found slightly lowering with coil overs helped front end lift. I felt floaty in the front under stock suspension when above 150kph.
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      09-16-2017, 09:22 AM   #4
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Interesting. Obviously I'm trying to avoid going front splitter, mainly for daily driving sake (speed bumps, driveways, etc), and the uncertainty of how much splitter is enough.

Guess you're somewhat referencing this thread:

http://www.m3post.com/forums/showthread.php?p=22089354
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      09-16-2017, 11:25 AM   #5
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With your skills you could make one ala M4 GTS that slides in and out.
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      09-16-2017, 11:29 AM   #6
dre99gsx
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Don't give me anymore ideas!
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      09-16-2017, 03:21 PM   #7
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Just to add my .02 to this discussion.
No road course for me but I have had a chin spoiler/air dam on my non M for 3 years and this year I add the Skyer rear lip spoiler and side skirt extensions. I do experience front end floating at "highway speeds" now that I did not experience before. I can't see the extensions causing front end lift so it has to the the rear lip pushing the rear down.

I wish there was a decent splitter option for the Pre facelift front fascia.
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      09-16-2017, 07:22 PM   #8
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Quote:
Originally Posted by dre99gsx View Post
Interesting. Obviously I'm trying to avoid going front splitter, mainly for daily driving sake (speed bumps, driveways, etc), and the uncertainty of how much splitter is enough.

Guess you're somewhat referencing this thread:

http://www.m3post.com/forums/showthread.php?p=22089354
It's going to push in the corners... no need to go crazy, most racers use Home Depot diy splitters with great results.


Quote:
Originally Posted by dbarton62 View Post
Just to add my .02 to this discussion.
No road course for me but I have had a chin spoiler/air dam on my non M for 3 years and this year I add the Skyer rear lip spoiler and side skirt extensions. I do experience front end floating at "highway speeds" now that I did not experience before. I can't see the extensions causing front end lift so it has to the the rear lip pushing the rear down.

I wish there was a decent splitter option for the Pre facelift front fascia.
Believe or not I actually think the OEM aero bumper is somewhat functional and doesn't upset balance of the car such that you need a rear wing.
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      09-16-2017, 08:14 PM   #9
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Ok. Not an ideal splitter for all intents and purposes, but I just built my own for the heck of it. 1/4" thick lexan, carbon fiber wrapped.




Also, my wing is mounted fairly low, more like a spoiler, and is adjustable. I will see how it does at NJMP in two weeks. This was a FT86 SARD wing (got it for a steal) that I custom mounted with brackets which fit on the edges of the hatch. No holes drilled!




I know there are ways to improve on what I have, and I could have kept going, but I'm not a fan of the large roof-height wing nor long 4" splitters with canards. I'm going for subtle right now.

Also in the works is a custom rear diffuser similar to FancyWide, but integrated with my current rear diffuser. I doubt the diffuser will do much, but I have many holes/pockets underneath the rear which need to be filled.
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      09-16-2017, 10:01 PM   #10
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Quote:
Originally Posted by dre99gsx View Post
Ok. Not an ideal splitter for all intents and purposes, but I just built my own for the heck of it. 1/4" thick lexan, carbon fiber wrapped.




Also, my wing is mounted fairly low, more like a spoiler, and is adjustable. I will see how it does at NJMP in two weeks. This was a FT86 SARD wing (got it for a steal) that I custom mounted with brackets which fit on the edges of the hatch. No holes drilled!




I know there are ways to improve on what I have, and I could have kept going, but I'm not a fan of the large roof-height wing nor long 4" splitters with canards. I'm going for subtle right now.

Also in the works is a custom rear diffuser similar to FancyWide, but integrated with my current rear diffuser. I doubt the diffuser will do much, but I have many holes/pockets underneath the rear which need to be filled.
Very nice work. Which club you running with at NJMP?
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      09-16-2017, 10:02 PM   #11
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Delaware PCA
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      09-16-2017, 11:34 PM   #12
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Originally Posted by dre99gsx View Post
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Nice one of the best clubs.
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      09-17-2017, 09:26 AM   #13
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What just happened. Just a day ago, seemingly casual question was asked. And suddenly out pops a custom front splitter.

Can you post more pics of the your custom wing mount? Specifically directly from the rear, and also the mounting points with the boot raised. I'm shopping for a wing, have a few options in mind but am really holding back due to the need to drill holes.
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      09-17-2017, 10:13 AM   #14
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I work fast With HPDE coming quick, need to have something to experiment with. The splitter is by no means correctly done. It is probably too narrow, and there is no damn to help direct high pressure air around the bumper to the sides.

I was going for this look and 'effect' with just enough rear spoilage to help reduce lift, not necessarily add downforce:



Hopefully the downforce really isn't that much more than before, reducing the need for a proper front spoiler. I'll know by this track session, and have the winter to mull over a more complete design.

I'll get some photos later tonight.
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      09-17-2017, 01:20 PM   #15
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      09-18-2017, 09:41 AM   #16
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Thanks for the pictures!
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      10-16-2017, 02:47 AM   #17
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Very nice. Love the Fab work
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      06-16-2018, 02:46 PM   #18
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I wish I can get one of these wing for mines.
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      06-16-2018, 09:07 PM   #19
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Quote:
Originally Posted by 3002 tii View Post
It's going to push in the corners... no need to go crazy, most racers use Home Depot diy splitters with great results.




Believe or not I actually think the OEM aero bumper is somewhat functional and doesn't upset balance of the car such that you need a rear wing.
This. If anything these cars need more help with grip in the front than the rear.
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      09-01-2018, 06:57 PM   #20
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I hate how the steering wheel feels lighter during turning with throttle.
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