Rear Diffuser

[Guest stuart_]

hi all, if i was going to make a rear diffuser, what would be best to make it out of, and what sort of desgin should i be looking to make? i want something that will still get rid off all the dirty air from the engine bay, and cool the diff, but try and make the air go quicker under the car than other the so it pushes the back end of the car down.

 

thanks

 

stuart

[Guest Tim Norman]

I have sheeted the underside of the rear but you can't have the design, it may not be legal

[Joel]

Something like this?

[Guest Tim Norman]

seriously if you want a picture, happy to oblige.

[Guest pencil]

Hi, Scot (scottie686) has made and fitted one might be on his blog site.

 

John

 

P.S. he did fit it after sva but before Jenson!

[Guest stuart_]

hi all, do you think it is something worth while doing? well i would like to keep my slef busy uintil i get a job, but was wondering could i make a card board template and then make a foam buck and then make a fiberglass diffuser, as i would liek to make more things out of fiberglass, as my mini is going to have a few things in fiberglass all homemade.

 

stuart

[speedtripledan]

I’m going to copy / adapt the design of my mate’s s2 exige diffuser, weather it will make any difference on the road at road speeds remains to be seen. Something to do so I don’t have to watch coronation st thou..

[Guest Jabberwocky]

The Brawn F1 is now legal perhaps that is the way forward

[Guest Tim Norman]

If you have it like the Exige make sure there are no sharp edges. I got pulled by the police while I was experimenting with the under tray. They said it would shred someone if I ran over them. When I pointed out that the front of the car was only 3" off the ground and that they would probably be dead by the time they got to the "Shredder". He agreed but still suggested I remove them. The main reason I put the under tray on was to stop the SVA man seeing too much whilst he was under the car.

[Joel]

The main reason I put the under tray on was to stop the SVA man seeing too much whilst he was under the car.

 

I'm going slightly off-topic here, but there's an issue in the new IVA test where by fuel tanks are checked to see if they'd be susceptible to rupture in the event of an accident - I know the 2B tank is very exposed from underneath, for example. So we might all be paneling-in (or diffusing) the underside of our cars soon.

[Guest Jabberwocky]

would paneling in/diffusing under the fuel tank area make much difference to the handling to the car?

[Guest stuart_]

hi, well i have had my head under the mk this afternoon for a few mins, and took so messurements and draw up some rough sketechs on a notepad. right then i am going to make a foam buck and lay some fiber glass up.

 

right a few more question the rear diffuser, how should the 90deg bits hanging down be? larger towards to the front and narrower to the rear, so it acts like a jet turbine. well that one in the center and one each side of that?

 

i will try and draw one up on the coumputer,

 

stuart

[Guest stuart_]

right then please do not take the mick out of my drawing it is a very simple paint drawing which took about 2 mins.

[Guest stuart_]

as well, is it better to make the air channel through the diffuser, such as the end closer to the front have a big open end and tapper smaller? kinda like a jet turbane or is that not a good idea?

 

thanks

 

stuart

[Guest RichardO]

is it better to make the air channel through the diffuser, such as the end closer to the front have a big open end and tapper smaller? kinda like a jet turbane or is that not a good idea?

 

Wouldn't that be the opposite effect?

 

Isn't the idea of a diffuser to slow down the fast moving air underneath the car so that it causes a low pressure area, so that the high pressure of the fast moving air over the top of the car gives more down force.

 

 

 

Rich...