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Proper diffuser option for the ///M

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Beedub
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Proper diffuser option for the ///M

Post by Beedub » Sun Sep 17, 2017 1:00 pm

functional Diffuser...

Well it seems theirs a functional rear bolt on diffuser option for our cars... Alot of people have that stuck on upside down piece of tat which for me at least is total sacrilege on such a serious sports car ... This one may be abit aggressive for some but extends out and really should smooth out the air from the rear of the car.... and actually provide some function.

NOTE** - Rpi or similar small silencers are required.

Whats peoples opinion?

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Proper diffuser option for the ///M

Post by john-e89 » Sun Sep 17, 2017 1:16 pm

Complete waste of money on a road car unless you like the look.
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Proper diffuser option for the ///M

Post by Beedub » Sun Sep 17, 2017 1:31 pm

john-e89 wrote: Sun Sep 17, 2017 1:16 pm Complete waste of money on a road car unless you like the look.

Plenty of track users on here.......

Also as a side note.. most of the performance modifications we do to these cars are pretty pointless on a road car..... id wager only certain people would buy the above diffuser HOWEVER, id much rather have a function piece /or None at all than the recent trend of stick-on upside down vortex generator thing which is again imo of course sacrilege on such a performance orientated model.
Last edited by Beedub on Sun Sep 17, 2017 1:43 pm, edited 1 time in total.
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Proper diffuser option for the ///M

Post by john-e89 » Sun Sep 17, 2017 1:43 pm

Beedub wrote: Sun Sep 17, 2017 1:31 pm
john-e89 wrote: Sun Sep 17, 2017 1:16 pm Complete waste of money on a road car unless you like the look.

Plenty of track users on here.......
Indeed, which is why I said road car meaning just road users. You didn't mention track users, but then I didn't take that into consideration either so for a road car a waste of money, for a road and track car who knows without data? Would it really gain anything worth the cost of it for a car used on the roads as well?
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Proper diffuser option for the ///M

Post by Vanne » Sun Sep 17, 2017 4:34 pm

I like it, though that sticker looks bogus, and again, is easy removable. It does have function over form, and I bet it does as advertised.. Byron, there is another option mate, the Varis rear pieces are quite nice too, but at more than 8 times the price of this.if your looking for something that functions, this is a no brainer.
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Proper diffuser option for the ///M

Post by mr wilks » Sun Sep 17, 2017 5:01 pm

Not for me mr B , , you'd be on Barryboys in no time with it :D

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Proper diffuser option for the ///M

Post by Machine monkey » Sun Sep 17, 2017 5:02 pm

For 90% of the people who brought this it was for cosmetic reasons. For the other 10% it's only a cosmetic thing 90% of the time!! Then it might actually work and do something at high high speed on an aurobahn or track.

Saying that I like it have been looking st them. I think I may well make something like it one day. But it dose look like lots of easy to make anodised aluminium bolted together.
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Proper diffuser option for the ///M

Post by Beedub » Sun Sep 17, 2017 6:13 pm

thanks for the discussion on this one peeps, always good to hear what the masses think!
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Proper diffuser option for the ///M

Post by john-e89 » Sun Sep 17, 2017 6:31 pm

Beedub wrote: Sun Sep 17, 2017 6:13 pm thanks for the discussion on this one peeps, always good to hear what the masses think!
Seriously I'm not trying to be controversial but my thoughts are that a Z4M used for road and track wouldn't generate enough cornering speed to make this of any use, as for straight line stability Is there a problem with that in the first place with the said car? Surely you need front aero and under car panels to channel and control air to make it of any use out the back which again you couldn't generate on a fairly stock car.
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Proper diffuser option for the ///M

Post by TomK » Sun Sep 17, 2017 7:08 pm

Beedub wrote: Sun Sep 17, 2017 1:00 pm functional Diffuser...
I just can't see the point really in our country on our roads. I do track my car quite a lot but it is not a dedicated car that get' trailered to the track, if I were to have such a thing I very much doubt I would start with one of these cars. I like the fact I can drive there and back and do other stuff with it. Coupled with the reality that I don't live next door to Spa or some extremely high speed track where that kind of aero grip might be useful, plus the need to balance it with a bloody great splitter on the front if you're going to do it properly, means it's a no for me. Agree those stuck on faux 'diffusers' are absolute cack though, belong on seat leon etc, or most modern turbo hatch stuff it seems, bizarre.
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Proper diffuser option for the ///M

Post by Beedub » Sun Sep 17, 2017 7:56 pm

john-e89 wrote: Sun Sep 17, 2017 6:31 pm
Beedub wrote: Sun Sep 17, 2017 6:13 pm thanks for the discussion on this one peeps, always good to hear what the masses think!
Seriously I'm not trying to be controversial but my thoughts are that a Z4M used for road and track wouldn't generate enough cornering speed to make this of any use, as for straight line stability Is there a problem with that in the first place with the said car? Surely you need front aero and under car panels to channel and control air to make it of any use out the back which again you couldn't generate on a fairly stock car.
nah didn't think that at all... just enjoying everyones opinions :) :)

id hazard guess in a straight line this would probably be very functional, but again , you'd probably have to be going 80mph plus for it to start cleaning the turbulent air ??? i have no idea... In the world of trying to make our z4s the best their it can be.... and seeing many similar type setups for elises Exgie, Vx, .... plus ontop of all that, it looks very cool.....
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Proper diffuser option for the ///M

Post by Steve84N » Sun Sep 17, 2017 9:21 pm

They only work when they're fed smooth air but the underbody is not blanked off.

Their job is not to tidy up turbulence but to create a larger exit than the opening. This creates a pressure difference which creates the downforce.

This is a Cayman to show what I mean:

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Proper diffuser option for the ///M

Post by Mangozac » Sun Sep 17, 2017 9:51 pm

I reckon over the top stuff like that diffuser looks stupid on anything but a dedicated track car. I also question how functional it would be without a lot of other aerodynamic improvements.
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Proper diffuser option for the ///M

Post by BMWZ4MC » Sun Sep 17, 2017 10:35 pm

I like it but it would be a pain 90% of the time and (as said) would function only with other aero mods. I've not considered fitting a splitter or diffuser largerly because they would ground all the time.
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Proper diffuser option for the ///M

Post by RedUn » Tue Sep 19, 2017 8:57 pm

You'd be better off paneling the rest of floor and doing something down the sides I imagine. That would be my stealth route and then if you need more, splitter and diffuser?

One thing to be careful of is keeping the diff cool if you decide to panel...
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