need more front downforce.

[comptechgsr]

on the track i felt that my front end was light at some downhill sweepers @ 90-110mph (long sweepers)...
this was at entry through apex.

at first i thought it was the front tire pressure being too high (nope..dropped it from 40 hot to 36 hot to 34 warm/same thing as 36 hot).

could it just be the angle of the turn?

my dad thought it could be blown shocks, but i had them checked out at the track (by a few other instructors) as well as a shop last night....shocks are fine.


I am running bilstein shocks with h&r 375lb springs front and 550 lb. springs rear.

ALSO
i do not have an underpanel, and one of the bolts that holds the oem lip is off (so the lip sags maybe .75") at one point right under the air dam towards the passenger side.



or is this normal?

it only happened on this one downhill right turn

[dinomite]

Well, any car is going to feel light on a downhill turn, that's just the physics of it. So, yes, it's normal for the car to feel light going downhill.

However, you bring up a good point. This reminds me of the downhill portition of Summit Point, where I too could benefit from downforce. Does anyone know if those lips (Reiger, Infinity) actually do anything?

[comptechgsr]

i was actually looking at those CF splliters/ the ones witht he metal bars that fit the front of the front bumper.

but i dont know anyone that has them.

my old integra gsr did not feel that lightness on that same turn, ~5-10mph slower.
however, i was running front engine/front wheel drive, and i did have canards and a front lip

[Spencer]

Your car is always going to feel light around downhill sweepers.

I had an opportunity to get a RD wing/splitter setup on my car a couple years ago for free, so I did it.

I did some before/after high speed runs. The car isn't as floaty at high speeds (120+). But, I didn't notice any improvements at the track. You are really going to need an aggresive rear wing (ie, large) and splitter setup to actually make a difference.

IMO, aero is probabily the last thing to worry about for a track car. There are just so many other things that can be improved on the car before worrying about areo changes.

Just my 2 cents.

[comptechgsr]

aerodynamics places an important part on traction (especially as speed increases, since lift/downforce increases linearly with it).

hoosiers ain't nothing if they're not being held down (err pilot sports lol)


even if it doesn't give me 2 seconds/lap,
i'd rather feel more stable than floaty and high.

[Steve J.]

Go to most BMW Race shops and they can fab up a racing splitter for you.

How low is your car?

What Rear wing do you have?

[comptechgsr]

already contacted an old-friend/shop to see what he had for canards ---just had generic ones..

as for the splitters..
i've seen a lot the "ltw"-type ones...the ones with the two "steps", one on each side..directly below the foglights w/ an inlet under the air dam-------how good is this?


im looking for something that people have had good experience with (before i purchase it).

also,
for now, the car is also my daily driver...
so i cant use anything too extreme...



as for the rideheight of my car,
the front oem lip is about
+/- 5".

i will measure during my lunch break.

[Steve J.]

If its your daily driver then I'd say don't even bother, b/c on the street it'll be screwedup in no time, and there goes your hard earned money.

[Spencer]

aerodynamics places an important part on traction (especially as speed increases, since lift/downforce increases linearly with it).

hoosiers ain't nothing if they're not being held down (err pilot sports lol)


even if it doesn't give me 2 seconds/lap,
i'd rather feel more stable than floaty and high.

Thanks for the info... but there is alot more that goes into aero than that.

My point is that anything that is going to be going on a street car is not going to much of anything at the speeds you are going at. That is, unless you want to run some huge 3 tier spoiler as high as your roof, and a splitter that is 1" off the ground (i'm sure 95M3racer can give more technical info).

Put your money elsewhere. I've been there/done it and wouldn't have spent a dime on it if the spoiler/splitter were coming out of my pocket.

[comptechgsr]

so i have to drive slower for stability =(

are there mounting brackets or anything,
that i can mount a spoiler and remove it within 30 minutes?

[B.Watts]

so i have to drive slower for stability =(

Or just grow some balls...I'm sure there are plenty of faster M3's that go through there without a front splitter. The amount of downforce you'll make with any of the popular aftermarket splitters is very minimal anyway...especially at your ride height.

[comptechgsr]

i didnt know if this was normal or not, since the instructors (only 1 had a 4 door e36 m3) were not that familiar with the car..
they also agreed that it was abnormally light up front.

i currently have oem balls, but i was wondering where the best place is to order the euro dtm balls.

is that avatar of your car with the big wing?
any larger pics?

I have the balls, it's just that i don't have the $$$ to get a new car like that...like you did when you crashed your car then got wide body.
give me funds and i'll have testicular elefantosis (sp?).

for now, i'll go as hard as 7/10ths on the road course, but that's it.


LOL,
noone responded about the underpanel---you think that's what i need (jtd metal unit or oem) to solve this problem. that and the dtm CF balls

[Steve J.]

That is, unless you want to run some huge 3 tier spoiler as high as your roof, and a splitter that is 1" off the ground (i'm sure 95M3racer can give more technical info).

Put your money elsewhere. I've been there/done it and wouldn't have spent a dime on it if the spoiler/splitter were coming out of my pocket.

Hehe, uhoh, I better read those race car aero books again, maybe apply for a dual major, this ME degree wont be enough I kind of feel likeI should have done Aero,as most formula type engineering will be aerodynamics and composites.

But, he's 100% right. You are better off worrying about your driving skill at DE, and even novices in Club racing, then bothering with small aero aids.

Only thing I can think of to do is bring two bumpers to the track. mine is 6 bolts and the entire front end comes off in about 2 minutes (less with powertools) and just swap on a street setup. Other then that, don't worry about aero, it won't help you enough until you have really mastered the car.

You can get the replica LTW setup, but even that won't do magic, and will run veyr low on the street...plan to have it ripped offor broken in a week.

[comptechgsr]

sounds good guys.
it being my first time at this particular track (first time with this m3 as well)
--have taken my gsr out 2x there

didn't know what to expect.
i posted this not because i'm a pro or anything (can you tell, lol), but because
the instructors pointed it out to me as possibly abnormal.
even the guy with the four door m3.

i'm trying to diagnose what this problem is?
if not the missing underpanel, could it be the spring rates?
i'm having my bushings/etc checked today as well.

please let me know-------maybe frontal downforce was not what i should have sought in the first place.

[Steve J.]

Can you describe what the car was doing again, what exactly it felt lke, what you were doing in the car, etc. Its possible you justhave a hardware problem.

[melmyers12]

when was the last time you checked your alignment settings. Also, Bilstein shocks don't have that much compresion valving, sometimes not the best choice for higher rate springs + a racetrack. I used to run Bilstiens as well, and until I got them re-valved I never knew how awful they were.

[melmyers12]

Can you describe what the car was doing again, what exactly it felt lke, what you were doing in the car, etc. Its possible you justhave a hardware problem.

tru. Do a nut and bolt of the car. I have seen swaybar endlinks come loose, or could be another bolt somewhere. Also, how about the bushings? The stock rear trailing arm bushings are known to suck pretty bad. Your front control arm bushings could also be shot as well.

[comptechgsr]

had the bushings checked.

front CAB's are still fine---no front or rear wobble. My mechanic said that they still have life in them, but to check back within the next few events if the problem is set.

as for the RTABs, had them switched out for newer units (forget the brand, aftermarket and recommended here on the forums) as well as rear shock mounts (bmp) when my shocks/struts and springs were installed.


on the flat and uphill sections of the course, the car was very planted, and turn-out exit was very stable (the car sat very well).

on the downhill (not so sure the degree, but nowhere near as steep as laguna's corkscrew) the front inside wheel seemed to bounce..

the bounce was not like a busted shock, but rather the wheel was maybe lifting a bit/then touching the track, then lifting then touching the track.
i doubt (as well as the others there) that the car was in fact threewheeling, but im sure that the pressure of the inside front wheel was definitely decreasing then increasing.........

I know it's normal for the pressure of the inside wheel to be definitely less than the weight/pressure of the outer turning wheels,

BUT

what's with the oscillation? the up/down of the inner front?
i held the line, and i kept the throttle steady?????

[badmonkey]

What track, where on course?

.

[Steve J.]

If its Bouncing as you say, your shocks are DONE!

Time to upgrade, and if you plan on tracking more often, get something more suited for the track abuse. Maybe revalved Koni SA with some GC coils to corner balance it.

[B.Watts]

I have the balls, it's just that i don't have the $$$ to get a new car like that...like you did when you crashed your car then got wide body.

Neither do I, I race a Miata.

My point is simply that a little splitter isn't going to solve your problem. In fact, adding AERO grip (what minimal amount it may add) is the last place you ever want to add grip when you aren't comfortable in a particular car or at a particular track. AERO grip is the hardest to take advantage of and the most dangerous when you do get out of shape.

What you first described as a lifting problem now sounds a lot more like a suspension problem when you describe the bouncy feeling. BUT, adding the undertray back will certainly limit the amount of lift that occurs on the front of you car and will probably help a bit with cooling as well.

[comptechgsr]

heyyyy,
spec miatas are on point!

it's all about the miata racer discount!

~50% off right!?!

[B.Watts]

~50% off right!?!

Don't think it is that much...and it varies depending on the part. I haven't joined Mazdaspeed yet, as the only parts I've needed have been body parts, and I can source them cheaper from junkyards. Mazda is definitely very supportive of grass roots motorsports though.

The BMW in my avatar belongs to my father. He invites me to co-drive with him on occasion.

[krisko]

The BMW in my avatar belongs to my father. He invites me to co-drive with him on occasion.

BTW, that car has inspired a little design idea I have for mine. I have an Avus Blue, I plan to utilize a red and white checkered flag on the hood like yours and have an American flag waving on the hood, roof, and trunk. Sponsor decals on the sides will be white with a red shadow. Should be done in about 3 weeks, I'll post pics.

[B.Watts]

Cool!