Willow Springs Club Race Report

[scottn2retro]

Hi All -

Results starting to show up on MyLaps.com
July 8 Race:
http://www.mylaps.com/results/newResults.jsp?id=360541

Congratulations to Ralph Warren who, despite 105 degree temps, set a new HP track record of 1:31.477 (old mark was 1:32.4xx)

Some pics from the weekend in this photo album (Photos by Dan Wu):
http://scts.323ci.net/gallery/main.php?g2_itemId=15187&g2_page=7

http://scts.323ci.net/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=15675&g2_serialNumber=2

http://scts.323ci.net/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=15730&g2_serialNumber=2

http://scts.323ci.net/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=15805&g2_serialNumber=2

http://scts.323ci.net/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=15815&g2_

http://scts.323ci.net/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=15870&g2_serialNumber=2

http://scts.323ci.net/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=15895&g2_serialNumber=2

http://scts.323ci.net/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=16020&g2_serialNumber=2

http://scts.323ci.net/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=16107&g2_serialNumber=2

http://scts.323ci.net/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=16117&g2_serialNumber=2

[lemming]

do you think that those ridiculously large spoilers on the OTHER cars helps them any more than your car's ducktail-type spoiler?

just curious. they look ridiculous, but if they help, then i'd have to eat it....

[Nick M3]

do you think that those ridiculously large spoilers on the OTHER cars helps them any more than your car's ducktail-type spoiler?

just curious. they look ridiculous, but if they help, then i'd have to eat it....
Scott's car has no front end aero. If he put in a splitter, he'd probably want more down force in the back.

[scottn2retro]

do you think that those ridiculously large spoilers on the OTHER cars helps them any more than your car's ducktail-type spoiler?

just curious. they look ridiculous, but if they help, then i'd have to eat it....

We've just started putting aero on our car over the last few events. We believe they do work - by creating more grip, it reduces wear on the tires. I'm definitely seeing that. Ralph says he can tell the car is faster with the aero components, but we won't be able to do a track again that we did before until Oct. 21/22 when we go back to PIR. If we pick up a bunch of time, I'll be a believer. More photos in the gallery and I'll have more to come (once they get sent to me).

Nick is right about the rear wing needing to be sized to match up with whatever front splitter you have if you want a balanced car and not too much drag on one end or the other.

http://www.bimmerfest.com/photos/data/3146/medium/Infineon_01_-_01.jpg

[lemming]

this is fascinating.

:devpop:

please keep this thread alive if you have more updates.

does the increased downforce affect (greatly) the car's ability to turn? i guess it depends on entry speed, too, but i'm just trying to imagine the increased downforce and the havoc it could potentially play with the balance of the car with regard to under/oversteer.

[scottn2retro]

this is fascinating.

:devpop:

please keep this thread alive if you have more updates.

does the increased downforce affect (greatly) the car's ability to turn? i guess it depends on entry speed, too, but i'm just trying to imagine the increased downforce and the havoc it could potentially play with the balance of the car with regard to under/oversteer.

Yes, turn in and braking are better.

Right, that's why the size of the rear spoiler must work together with the amount of downforce you create up front. Right now our car is balanced, but for that size rear wing, if we take the bottom plate off the front splitter, the car will understeer.

A lot of what we have is predicated on previous racer's trial and error and we have a real frankenstein setup, but it all works together pretty good: The rear wing was originally on Brad's of Evosports e46 M3 HP car and then it was on Jon Holder's CM e36 widebody until he got his HUGE rear wing. Our front splitter consist of a front lip that was on Carl Lagoni's HP (then CM) e46 M3 and attached under that is an e36 front splitter plate that was on Ralph's old Speed World Challenge 328 made of alumilite sheet.

Pretty amazing - all the pieces are hand me downs. The rear wing is nice - it's CF with CF end plates (that used to be white). We did powder coat the scratched up uprights that used to be white. Also got some nicer attachment hardware. Cost - a few hundred $ (almost all of it the used CF wing)

The front lip was a nice CF piece that was split apart on a driveway and patched up with fiberglass and painted with black rubberized fender liner paint. Cost: some fiberglass and paint.

The front splitter plate was a piece that had been taken off Ralph's old car when it sawed a cone in half at California Speedway - it was really bent up, but I took big C-clamps and kind of straightened the whole thing best I could and painted it flat black. Cost: couple of C clamps and paint.

So the whole setup was a low budget test setup that based on Brad's experience we thought would be in the ballpark as far as grip and balance.

Once it was on the car, dialing it in was fairly simple - the front splitter plate is not adjustable, so it was a matter of dialing in the rear wing angle. We want the lowest rear wing angle (for less drag) that gives us a balanced car.

[scottn2retro]

Note the 3rd car in the pic below (go to my gallery to see large size). It's an e46 M3. He essentially has the same front lip as we do, but without the splitter plate, notice how much smaller his rear spoiler is than the other 2 e46 M3s.

Our front lip originally came off the 2nd car in the pic, but he has a whole new front bumper setup now with intergrated lip/splitter.

http://www.bimmerfest.com/photos/data/3146/medium/Laguna_Seca_1.jpg

http://static.flickr.com/109/253905909_f1b38a0e3b.jpg?v=0

Our rear wing used to be on this car, but look at the monster he's got on the back of that thing now (check out the width in the 2nd pic)

http://static.flickr.com/115/253906206_f5687fcf2f.jpg?v=0

http://static.flickr.com/98/252979750_05da545118.jpg?v=0

[lemming]

holy cow. those spoilers are monstrous.

it's really cool to read about how you're tweaking the car. what are the ground rules for aero? if any. and is there a minimum weight to adhere to because it's BMW club racing?

[Nick M3]

If you guys decide you want to sell at some point... :eeps:

[clyde]

Those are little sissy girl wings.

This is a real wing.

http://teamwtf.org/gallery/albums/album646/prof06_sm_019.sized.jpg

The best part was when the car broke the throttle cable for the second time at the Finale. Vic was able to get the car turned enough that the wing acted as a sail and pushed him off the course. FWIW, Tunnell's wing is almost as big.

[scottn2retro]

holy cow. those spoilers are monstrous.

it's really cool to read about how you're tweaking the car. what are the ground rules for aero? if any. and is there a minimum weight to adhere to because it's BMW club racing?

For stock and prepared classes, we have minimum weights, but stock class can only do stock aero components.

There are rules regarding the aero components in the BMW Club Racing rules. I think rear spoiler is free provided it is: not wider than the car, not higher than the roof and not further back than 2 inches or so beyond the rear bumper. Front splitter can not be more than something like 4 inches in front of the car.

[scottn2retro]

Those are little sissy girl wings.

This is a real wing.

http://teamwtf.org/gallery/albums/album646/prof06_sm_019.sized.jpg

The best part was when the car broke the throttle cable for the second time at the Finale. Vic was able to get the car turned enough that the wing acted as a sail and pushed him off the course. FWIW, Tunnell's wing is almost as big.

Amazing - I think that wing might actually be illegal in BMW Club Racing. Might not be practical for road racing, but amazing to see what they're doing in SCCA Solo now.

[Nick M3]

It's WAY illegal in CR due top width.

And I suspect that it would drag limit a supermod car to around 90MPH. :)

OTOH, I bet it does nice things for those cars in "high speed" transitions.

[scottn2retro]

It's WAY illegal in CR due top width.

And I suspect that it would drag limit a supermod car to around 90MPH. :)

OTOH, I bet it does nice things for those cars in "high speed" transitions.

It looks higher than the roof line as well. From that angle, can't tell how far behind the rear bumper it goes.

[Nick M3]

It looks higher than the roof line as well. From that angle, can't tell how far behind the rear bumper it goes.
Less than 18" - it's mod legal there.

[clyde]

Aero has become an issue in the two "Street Modified" classes in the past year. Sias showed up with a big wing (smaller than the one in the pic) at Nationals last year. This year, a number of the big guns have started exploring it, and there are some major rule change proposals on the table for next year. Wing sizes, locations, total area, etc. Same for splitters and how far back the undertray part can run, how they're attached, and so on. It's very much a hot topic. The biggest suprise has been that areo is as effective as it seems to be at autox speeds.

[lemming]

Aero has become an issue in the two "Street Modified" classes in the past year. Sias showed up with a big wing (smaller than the one in the pic) at Nationals last year. This year, a number of the big guns have started exploring it, and there are some major rule change proposals on the table for next year. Wing sizes, locations, total area, etc. Same for splitters and how far back the undertray part can run, how they're attached, and so on. It's very much a hot topic. The biggest suprise has been that areo is as effective as it seems to be at autox speeds.

i'm pretty dumb. but i'll freely admit that.

so i was naively surprised that aero pays off so much for even BMW club racing. i didn't think aero played that much of a role except at sustained 100mph+ speeds. so i was surprised there. i mean, it does make sense, sort of but if i was a betting guy, i'd have said that aero doesn't make a huge difference in club racing speeds. WRONG-O.

i guess i'm even more surprised if aero makes all that much of a difference in auto-X.

:dunno:

[scottn2retro]

i'm pretty dumb. but i'll freely admit that.

so i was naively surprised that aero pays off so much for even BMW club racing. i didn't think aero played that much of a role except at sustained 100mph+ speeds. so i was surprised there. i mean, it does make sense, sort of but if i was a betting guy, i'd have said that aero doesn't make a huge difference in club racing speeds. WRONG-O.

i guess i'm even more surprised if aero makes all that much of a difference in auto-X.

:dunno:

It's a function of velocity and surface area (or cross sectional area). Since the speeds are lower in AutoX, they'll need bigger pieces to get the same effect (see the size of that SIAS wing) - but at lower speeds, maybe they don't need as much effect. But if you too big, then you can start getting into weight trade-offs.

But Aero components are an improvement to a car - not the critical elements (not at our speeds, even in club racing). We already had a fast car - the aero components maybe make us a little quicker. Once we do PIR again, maybe I can be a little more quantitative with that assessment.

But at Willow Springs for example, maybe we shave 1 second off a lap - from 1:30 to 1:29. Not huge percentage wise (less than 2%), but with people chasing you, one second in real estate on the track per lap is huge.

[scottn2retro]

Less than 18" - it's mod legal there.

Club Racing Mod class bumpers can go that far back - are you sure (seems like a lot)? I would look at Holder's car (the white with red trim e36 wide body) - I think they tried to build that to the extent of Club Racing rules (almost up to roof height, almost as wide as the fender flares and I would imagine they went back about as far as they could).

Edit: I just re-looked at his pic and his may be darn near that far back!

[lemming]

It's a function of velocity and surface area (or cross sectional area). Since the speeds are lower in AutoX, they'll need bigger pieces to get the same effect (see the size of that SIAS wing) - but at lower speeds, maybe they don't need as much effect. But if you too big, then you can start getting into weight trade-offs.

But Aero components are an improvement to a car - not the critical elements (not at our speeds, even in club racing). We already had a fast car - the aero components maybe make us a little quicker. Once we do PIR again, maybe I can be a little more quantitative with that assessment.

But at Willow Springs for example, maybe we shave 1 second off a lap - from 1:30 to 1:29. Not huge percentage wise (less than 2%), but with people chasing you, one second in real estate on the track per lap is huge.

you don't have to convince me. 1 second per lap is huge in any sort of racing, especially if the laptimes are only 1.5minutes!

[scottn2retro]

you don't have to convince me. 1 second per lap is huge in any sort of racing, especially if the laptimes are only 1.5minutes!

Yep, but it's not some amazing thing like aero components making us 10% faster or something crazy like that.

But in something as competitive as SCCA Solo, if you can shave another .01 second off a run, that could be the difference.

[Nick M3]

Yep, but it's not some amazing thing like aero components making us 10% faster or something crazy like that.

But in something as competitive as SCCA Solo, if you can shave another .01 second off a run, that could be the difference.
The big thing is that I hear they have to make fewer handling compromises...

The huge wing keeps the rear planted at speed, allowing them to set the tail up pretty loose for low speed stuff. And you can bet that a wing that huge is having a VERY real effect at 60MPH.

[scottn2retro]

The big thing is that I hear they have to make fewer handling compromises...

The huge wing keeps the rear planted at speed, allowing them to set the tail up pretty loose for low speed stuff. And you can bet that a wing that huge is having a VERY real effect at 60MPH.

We haven't made huge setting changes in shocks or springs due to the aero components - but we run a fairly softly sprung car. But with the Aero components we are running the same springs as before and maybe one or 2 clicks different on the shocks.

Tire wear from the tires not sliding around and heating up is much better (I watched in horror as Ralph 4 wheel drifted our car through turn 10 at Thunderhill - scared me, but no big deal to him - but not good for tires). And I would imagine on a high speed sweeper like turn 8 at Willow Springs (130+ mph), a lot more comfort/margin for the driver (another place where the back end would try to slide out). Would imagine that adds a few more mph to that section.

[Nick M3]

I was referring to the autox guys - you can't tweak a race car in the way that you can tweak an autox car.

I *really* need to start working on aero for the race car at some point. I'd like to do a little less sliding around out there.

[scottn2retro]

Well, we ran at PIR again, but with aero this time.

Even with the SMG problems (we only upshifted once per lap, going 3 to 4 on the oval), we were able to shave over a second (1:07.xxx) from our track record of 1:08.xxx in March.

[FC]

Well, we ran at PIR again, but with aero this time.

Even with the SMG problems (we only upshifted once per lap, going 3 to 4 on the oval), we were able to shave over a second (1:07.xxx) from our track record of 1:08.xxx in March.

Wow, that's great!