Lets talk downforce

[JasonC]

How about the mtech2 front lip? Would it be better to run insted of the "is" lip?

[Jparkr]

yeah I figured as much


I am going to go out on a limb and GUESS that a stock e30 really does not produce a lot of downforce on the rear end.... Well at least not enough to matter one way or another anyways.... IMHO

i understand its kinda a silly topic and i was expecting flameing but it is serious too lol

The only thing is everyone else will be in a stock bodied E30, so anything even if its as little as this, it will be some type of advantage. we are going to be researching alot. this question is for a more technical track then the others. it is also very frusterating that everything has to be a OEM nonM part, but it kinda adds to the challenge

[atomic]

to me the blunt front end on a e30 and the degree of rake on the windshield, that to me, it just does not look like the air could possibly create alot of downforce on the rear spoiler no matter which one is used. It appears that the air would skip mostly over the trunk area and not touch the flat surfaces creating alot of downforce there.... IMHO but what do I know

[Jparkr]

How about the mtech2 front lip? Would it be better to run insted of the "is" lip?

thats true but i though the Mtech 2 didnt have a lip; it was a solid valence as far as i know. it would be better yet, it is expensive and this will be a full contact race car. also in our experience we havent experienced enough understeer in or local tracks to worry about front downforce yet.

[Jparkr]

to me the blunt front end on a e30 and the degree of rake on the windshield, that to me, it just does not look like the air could possibly create alot of downforce on the rear spoiler no matter which one is used. It appears that the air would skip mostly over the trunk area and not touch the flat surfaces creating alot of downforce there.... IMHO but what do I know

in a straightline your absolutly right, it wouldnt matter and less downforce means more speed, but there are many corners on our local tracks where just alittle bit more downforce is a big deal, so thats what were planning for. im not trying to be a dick to you if thats what you think for some reason, im just looking for opinions and maybe some analysis to help you support it

[atomic]

I know your not being a dick and I am just pointing out what looks obvious to me but as I stated I really didnt know much in this area... I would be interested in knowing more for the hell of it though....

[golde30]

uhh, you gonna be driving over 120mph much?

[backtrail69]

I highly doubt that the m-tech 1 really creates all that much downforce. I would be lead to believe that it decreases your drag, just like the stock is lip. I honestly felt that my 325is with is lip, splitter, m-tech 1 spoiler and some good tires was very stable at 125+, but I wasn't trying to turn much at all.

[PiercedE30]

Just from an observatory stand point here.
Drive a car with no rear spoiler (iS), watch the fuel usage. Then throw a spoiler (iS) and watch the fuel usage. There is a difference. From what I understand, limited, it helps create a better vortex around the rear end and creates a "pillow" of air (think about how water flies around the rear of the car when driving in the rain) and allows air to move around/above/below to move a little more smooth. So on that point, I believe that an MTech 1, since the iS spoiler is a smaller version of it, will give you a slightly better aero advantage.
Hell, for the front why not run an i lip with an iS lip stacked up. It would lower the iS lip for a little more of an advantage, or one would believe.
Just random thoughts about it.

edit:backtrail beat me to it.
edit again: you may even want to think about throwing a set of iS sideskirts on to help the aero on the sides.

[atomic]

http://forum.bmwe30.net/cgi-bin/datacgi/database.cgi?file=articles&report=view&ID=00080&Section=03

Aerodynamics

Most aerodynamic kits on the aftermarket are strictly for styling and actually hurt the drag coefficient and downforce. The E30 is not one of the lowest drag cars around, nor does it have exceptional high-speed aerodynamic stability. If you drive on the racetrack, or drive regularly at speeds over 160 km/h (100 MPH) or so, you should only consider spoilers and wings made by BMW or reputable German tuners like Alpina. You would best leave the car alone otherwise. If you never drive at these speeds, you can buy what you like, as aerodynamics have little significant effect on handling and stability at lower speeds.


Alan Rich


just a little somthing I found on the net but it might prove useful

[mode]

Hint: study an m3


The C pillar is stretched back further, and the rear window is longer, the trunk is raised and a huge wing is on the raised trunk.

That is the ticket for downforce

For the front I would go with an I lip, then a stacked IS lip

[Jparkr]

lots of good info! thanks for the honest inputs but the point for this question is cornering. if we were going topspeed or 1/4 then we would have very little downforce.
if we ever end up racing laguna seca or other high speed tracks we will need all the front force we could get to get away from the understeer.
the issues with the tracks ive seen are oversteer so thats why im attempting to keep the rear alittle more secure. :-)

[Teaguer]

E36 LTW wing FTW !!

[PiercedE30]

E36 LTW wing FTW !!

E30/nonM part numbers.

Honestly, to make the rear more planted, here is what I would do.
Get TechII rear wing and put either a gurney flap on it, or a wicker bill (???). And possibly remove the lower "spoiler" section so that it is just the upper wing.
What are you doing about under car aero? Maybe get a big ass piece of ABS and smooth out the underside some.

[gobuffs]

the issues with the tracks ive seen are oversteer so thats why im attempting to keep the rear alittle more secure. :-)

Seriously? You are looking at aero to fix an oversteer problem? Have you looked at changing your suspension settings to fix oversteer? How about a good alignment?