Aerodynamic mods for e30's

[tomislav]

Hi people,

Me and a friend who both have e30's are trying to dream up ingenius ways of keeping our cars stuck to the track better at high speed and wondered if anyone had tried and tested anything.

I dont mean by way of big gay wings on the boot, we're thinking more along the lines of air ducting, rear diffusers, underbody panels, etc etc.

Anyone thats done anything i'd love to see it.

Thanks

[JungleGus]

E30 + Aerodynamics...well...

I've looked into this previously and while I am NO expert I did have a few ideas.

- Hefty front splitter (remember, it needs to be strongly bonded to the car)
- Roof spoiler to direct air over rear wing (major air dead zone is at the bottom of the rear windscreen, hence the M3's raked rear screen)
- Gurney flap on the rear wing (not sure about aero but Mtech1 wing + gurney flap could look cool - which is the main thing, really =)

They also wouldn't look TOO outrageous, which is also nice

[Quaser]

I noticed a considerable difference once I fitted my AC Schnitzer splitter on my touring over 100mph - I had more traction on the front

[Speedtouch]

All you need do is fold back the door mirrors and fold the back seat down; these well-known tips are good for an extra 5-9.5 bhp @ 5,750 rpm.

[tomislav]

Like your idea speedtouch lol.

Quaser, front end grip is not the issue here, i mean overall finding a way to channel the air better along the whole car, just a front splitter probably wont cut it.

Gus, the roof spoiler idea i like, i've seen it on a few scoobys and time attack cars to bring air down on to the boot lid, that may well be worth a few kgs of downforce.

Really want to hear from anyone using underbody panels and/or rear diffusers.

[swindler]

tilt the sunroof

One really easy minor mod is to add the Sport Evo wing seals that smooth the airflow over the edge of the bonnet, and refoam the grills.

[maggspower]

A proper front splitter, coupled with a flat floor, made with aluminium sheet carbon or the exotic material of your choice. The under side rear would then need to be sloped up, a prefacelift shell would be better for this as the rear wings tips are further off the floor. With this set up you are begining to enter the realms of ground effect, and getting sucked down onto the tarmac.

Alterativly you could put a big skirt around the whole car, cut the rear floor out and mount a big MF fan in there, sucking air in to the cabin, kind of like a hover craft, but in reverse. There may be the odd down side to this, but I cant think of any off the top of my head

[tomislav]

A proper front splitter, coupled with a flat floor, made with aluminium sheet carbon or the exotic material of your choice. The under side rear would then need to be sloped up, a prefacelift shell would be better for this as the rear wings tips are further off the floor. With this set up you are begining to enter the realms of ground effect, and getting sucked down onto the tarmac.

This is the sort of thing we're looking at but its trying to work out the best way to do it.

Spare wheel wells can be removed so facelift or not it wont really matter, i'd just really want to find someone thats done it before, see how they cope with getting round the exhaust, suspension etc.

[rix313]

tilt the sunroof

Haha

[JungleGus]

look at picking up a copy of this:

[DanThe]

I plonked one of these on the back, I think it works, dont seem to be locking the rears up as much

[tomislav]

Slight issue tho dan, although i have a saloon now, ians is a touring so its the underbody mods that want looking at.

Gus, i'll check that book out

[Willeh]

It looks like I need some schooling on aerodynamics as I really don't understand what the benefits are of a roof spoiler. Surely all it would do is increase the low pressure area behind the car and create more drag? I have a fair understanding of automotive aerodynamics, and can not see any way that a spoiler would b more advantageous than vortex generators, or even noting there at all?

[hongkongfuey]

The z1 has complete underbody panel. Don't defusers work well too? Could go for porsche whale tail spoiler

[oldroydsr4]

I work at jaguar land rover and had a discussion with one of the aerodynamicist's , the advice he gave me was.

1- front splitter - circa 75mm extending front of vehicle.
2- full flat bottom
3- deflectors at the trailing edge of the fuel tank to prevent the underbody air from hitting the trailing arms
4- fixed rear diffuser that runs to the rear bumper preventing air fom getting caught between the spare wheel we'll and back panel + creating downforce. 7 degrees is apparently a good angle ( guessing the spare wheel we'll would probably require removing to fit a diffuser)
5- I have a touring so rear spoiler will be limited to the tech 2 one I have carefully wrapped up.

These can all be done without drastically changing the look of an e30, I will be doing all of the above on my touring (if it ever gets finished).

[rix313]

The only way you could do a flat floor that doesn't cost a fortune on an E30 is to use plywood however the extra weight would be a large negative. Plus you need to be able to remove them to do maintenance so probably not worth doing. We run full carbon flat floors on the GT3 cars but every GT car I've ever worked on with them is just a pig to get the lined up. some fabrication would have to go into making mounting points etc.

The other thing with a splitter is bigger isn't always better. When Prodrive were developing the GT4 aero kit they found that an 80mm splitter caused more problems than it solved and it was in fact better with a 60mm splitter. Our SLS one is reasonably large but the 911 and 458 GT3's have almost non existent front splitters.

The other thing is if the car is low (which inevitably it will be) you'll need a couple of spares as they don't last long!