Butt Strut

[dalecan]

After fitting a Butt strut (purchased from Luke, thanks) my initial views are very positive. Took 25 min to fit at a local garage (£20), straight on no problems with clearance.
The car has a much improved turn in on cornering and the back end feels better planted (especially over pothole infested roads in London).
I've had no gound clearance issues, even over speed ramps, which was an early worry. However, I think this may be different with lowered cars (the speed bumbs anyway). Very satisfied with the end result. I think some uprated roll bars next on the list (before Le Mans).

Thanks Luke, very nicely packaged :lol:

[Spooks]

Where exactly does the Butt Strutt fit then if you refer to ground clearance ?

[c_w]

It bolts across the car underneath the exhausts using the subframe pin bolts as location. As it goes below the exhaust and needs some clearance from them it becomes the lowest point of the car in terms of ground clearance.

[exdos]

For a better understanding, here are some photos of the butt strut taken on my car:

This is a view of the butt-strut seen from the front:
http://www.z3mcoupe.com/photopost/data//500/53Ground_clearance_from_the_front.jpg

This is a rear view of the fitting of the but-strut on the Off-side:
http://www.z3mcoupe.com/photopost/data//500/53O:S_mounting.jpg

This is a view of the attachment to the subframe bolt:
http://www.z3mcoupe.com/photopost/data//500/53O-S_mounting_close_up.jpg

There are a few other photos of the butt-strut in-situ in my gallery (page 6 or so)

I've had a butt-strut on my MC for almost 2 years now, and I wouldn't want to remove it.

Although I have lowered my MC by 25mm I've had no ground clearance issues to date.

As can be seen, the butt-strut lies transversely across the car and must add to the car's drag, especially since it has a "squared-off" front profile. I'm presently working on some aerodynamic ideas that might reduce the drag.

[p 5ary]

do you not get any vibration from the exhaust on the butt- strut?

[dalecan]

No vibration, there is about 3 - 5 mm clearance between the butt strut and the exhaust (I have a pro-speed exhaust fitted).

At last, had the opportunity to really test this out on some good roads around the Aldershot / Woking area. Big, big improvement. The only downside is that I started to go a little too fast :twisted:

I think the addition of some beefier roll bars will be an excellent addition.

Exdos, I think one area for drag improvement would be the area around the rear bumber (as viewed from the underside of the car). It's acting as a hugh collecting duct for oncoming air. I think some form of rear diffuser would work.

[exdos]

Exdos, I think one area for drag improvement would be the area around the rear bumper (as viewed from the underside of the car). It's acting as a hugh collecting duct for oncoming air. I think some form of rear diffuser would work.

Dale,

See my recent posting of the Exdos MkII Mod (Rear Aerodynamics) at:
http://www.z3mcoupe.com/forum2/viewtopic.php?t=4033

[dalecan]

Nice thought out design :D

Covers the area I was thinking about. It would be great to have that much time on my hands :lol:

[luke]

Thanks Luke, very nicely packaged :lol:

:lol: :lol: :lol: Glad your enjoying it :P

[Spooks]

Great pics Exdos.

Quite a few recent posts are making me think sod the holiday to a hot sweaty country and buy front & rear strutt braces and uprated Anti-Roll bars........only obstacle is my Fiance !!

Thanks
Ian

[Spooks]

Just thought - to accomodate the butt strutt do the subframe bolts need to be replaced for longer ones or do they still protrude far enough through their locking point ?

[dalecan]

You get special nuts, that replace the original ones, with the butt-strut. Basically a bolt with an internal thread that acts as a nut on the original studs