Rear carbon spoiler

[BMWZ4MC]

...I don't think that this would create aero inbalance by lightening the front end of the car because the area of low pressure would extend the whole way under the car and not just at the rear. The Z4C design acts as an aerofoil which creates measurable lift with increase in speed so anything which might reduce this would be good.

Gurney initially found that his eponymous race car modification harmed lap times despite increasing rear traction. It was only by combating the consequent front end lift that he gained the potential advantage from his spoiler. Since the Coupe has a tendency to front end lift at high speed and the rear suspension lends itself to the car squatting under load (whether that be torque through the rear axle or downforce over the rear end), the risk of exacerbating front end lift with a Gurney flap is very real.

 

[exdos]

Gurney initially found that his eponymous race car modification harmed lap times despite increasing rear traction. It was only by combating the consequent front end lift that he gained the potential advantage from his spoiler. Since the Coupe has a tendency to front end lift at high speed and the rear suspension lends itself to the car squatting under load (whether that be torque through the rear axle or downforce over the rear end), the risk of exacerbating front end lift with a Gurney flap is very real.

Change the OEM suspension which defeats front end lift, lower the car a little, and at the same time increase the rake and the job's a good 'un!

 

[BMWZ4MC]

Yes. I have an AC Schnitzer rear roof wing and I fabricated my own rear diffuser (the wing between the tail pipes and the vertical strakes beneath the car). I also have AC Schnitzer front flippers. The car is extremely stable at all speeds.

The silencers on my Z3MC are a pair of OEM silencers which I've gutted (which have provably increased engine performance) and I have also refabricated them so that they have flat undersides which form part of my diffuser under the car.]

Did you drive the car with the rear aero modifications before fitting the flippers? If so was there noticeable front end lift at speed?

One day when I have my Z3MC I'll be consulting with the Exdos school of modification to render the handling a little less twitchy

 

[BMWZ4MC]

Gurney initially found that his eponymous race car modification harmed lap times despite increasing rear traction. It was only by combating the consequent front end lift that he gained the potential advantage from his spoiler. Since the Coupe has a tendency to front end lift at high speed and the rear suspension lends itself to the car squatting under load (whether that be torque through the rear axle or downforce over the rear end), the risk of exacerbating front end lift with a Gurney flap is very real.

Change the OEM suspension which defeats front end lift, lower the car a little, and at the same time increase the rake and the job's a good 'un!

Mine was made stable at speed by fitting Eibachs, whilst understeer is all but gone with these, a strut brace, front 15mm spacers, better tyres, and now maximum attainable negative camber through pulling the camber pins (thanks for the tips 8) )
My test NSL roundabout where driving three quarters of its circumference at 50mph was met with body roll and front end washout can now be taken at 65mph and still accelerating

 

[exdos]

Did you drive the car with the rear aero modifications before fitting the flippers? If so was there noticeable front end lift at speed?

One day when I have my Z3MC I'll be consulting with the Exdos school of modification to render the handling a little less twitchy

My Z3MC was completely OEM when I bought it and I did about 12k miles in it until I started modding it. I did every mod one step at a time and so know exactly what each part does. I have driven the car with both rear roof wing only and front flippers only, and there is more of a difference with the front flippers off than the rear aero off. The front flippers really sharpen the steering and turning. The car has KWV3 (with front coilovers) which virtually eliminates the tendency to squat/lift under acceleration (same as the ACS suspension on my Z4MC), but as the photo of my Z3MC at The Ring shows, the sum of all the parts produces a car with minimal bodyroll, and it feels like I'm wearing the car when I'm driving it.

 

[exdos]

Mine was made stable at speed by fitting Eibachs, whilst understeer is all but gone with these, a strut brace, front 15mm spacers, better tyres, and now maximum attainable negative camber through pulling the camber pins (thanks for the tips 8) )
My test NSL roundabout where driving three quarters of its circumference at 50mph was met with body roll and front end washout can now be taken at 65mph and still accelerating

Excellent!

Everyone needs some test corners. I have a test route where I have measured the corner radii using Google Earth and calculated the speeds at which they can be legally driven at speeds of 1g or more. :wink:

 

[Putter Whore]

All that said, the spoiler does nothing for me I'm afraid. Perhaps it looks better in the flesh.

 

[shawna]

i cant see it doing anything of benefit aerodynamically, if it did anything it would make the front end understeer more....but i doubt its gonna generate anything...im sure some ppl on here have prob worked out aerodynamics of the bumpers on here using bernoullis therom and newtons eleventh law of go faster stripes...

It could act as a Gurney flap, increasing downforce and thence traction at the rear but at the cost of front end lift and increased understeer. As long as you add appropriate modifications to increase front end downforce it could be a good idea, but without this instability at speed would be a concern.

yes sure sure

 

[slick]

Its on a coupe...... as long as no ones hair gets ruffled

 

[3002 tii]

Nice and subtle

 

[littlerascal]

Well I decided to take the plunge and order one so it should be here in a couple of weeks. How hard or easy are these to fit?

 

[Taz]

look forward to the pics

 

[Zed Five]

Well I decided to take the plunge and order one so it should be here in a couple of weeks. How hard or easy are these to fit?

pretty simple, but you need to not be the nervous type. Buy the black adhesive from BMW. Mark where you want it with a few felt tip marks on the tailgate. Have masking tape to hold it in place until the glue dries and have tons of kitchen roll and thinners to wipe away the access glue.

doddle.

 

[3002 tii]

I highly recommend not using the glue they provide, it's very messy to work with. Instead use automotive double sided tape, will make your life 10x easier.

 

[tomscott]

Ye I agree the double sided stuff is easier to work with, and less mess if you want to remove it.

 

[littlerascal]

Where can i buy the tape from?

 

[3002 tii]

any automotive parts store

 

[Cibbers]

Nice and subtle

If I could get hold of one of those diffusers I would have one in a flash

 

[tomscott]

I would too! Sucks BMW have dropped everything worth having for the Z now

 

[Zed Five]

I would too! Sucks BMW have dropped everything worth having for the Z now

And equally, there is sod all for the E89. What happened to clear brake lights, carbon bits and oem spoilers?