So you WERE able to get those guys to get rid of your ESP all together? ... I missed that thread during my holiday trip.

Congrats bro!

 

Wow! With a wing that big your car must be making like 450-500 hp! At least I hope it does.

 

It was stupid easy for them (if it works)... They just hooked-up the computer and turned it off through the MB software... Of course it activated ABS / BAS / ESP lights on the dashboard, but I don't worry about that... I'm not actually sure that it is permanently disabled until I get on the track again and put the car into a situation where it would activate... I ran some spins in their parking lot and it didn't kick on!!!

And the answer to Woody's next question... It does not limit rev at 5K during driving conditions... I don't know about dyno, nor did they... Testing, Testing, Testing.... That's why I haven't mentioned it... Until I know that it is actually KAPUT !!!

 

I know you're kidding and I'm going to be nice since you're new... I'm sure the engineers at Lotus would like to hear your opinions about developing rear aero wings for cars like their Elise and Exige which put out less than 200 hp and are nearly competitive with Corvette Z06's.

You should also look a some other spec class racers that put between 150 - 250 hp to the wheel... It has much to do about HP / Weight Ratio... I'm running a HP/W ratio that is 22% more than the OEM vehicle.

If you would like to play on a road track sometime, you might want to join the National Auto Sport Association (NASA) and come join us during some events, here is the website. There are regions in your area and you will quickly learn quite a few things. And hopefully appreciate the art and mechanics of the sport.
http://www.nasaproracing.com

 

UH Yeah...this is a race car...anyone with aesthetic comments need to reserve those for street cars...they don't apply here.

 

It's getting there, slowly but surely...

 

Sorry MMZ & Woody, for the earlier posts... I'm not happy about this wing at all... It's going to take me a few laps around the track to appreciate the effectiveness vs the butt ugly looks... I was a bit over reactionary because I think it looks stupid...

Thanks for coming to my support SENNA... You made me go back a re-read my previous posts and they sounded awful...

Sorry guys, I'm stressing... Having to leave my home for 6 months and getting the car ready to run in a different region of the country on tracks that I have never raced before... Not to mention leaving my darling wife for half the year...

My apologies...

 

No worries D!

Personally, I like race cars, where wings, spoilers, and body shapes have meaning and purpose. If, in the process of optimizing their performance, you can also make the vehicle attractive...well then you get to satisfy your particular aesthetic sensibilities, but little else. The XF is a beauty...you haven't detracted from that at all. And please don't worry about it either. GO FAST! Allez Derek...your doing great!

Woody, one thing you've mentioned above (and previously I think) regarding airflow in the underbody. Specifically that it was given serious consideration. In addition to that, would it not also be worth considering the movement of air around the front end and along the sides as well. Looking at DTM/BTCC cars, another thing worth considering...since we're spending Dereks budget, is some fairings around the wheel wheels to push air from building up in wells? The front end slides straight back on the standard XF...would it not help to push some air away from the wells?

See:
http://www.btccpages.com/photodispla...&picture=pack2

Also: note the venting for the wells here:
http://www.btccpages.com/photodispla...cture=collard1

Probably too much to consider for this year in the end...just thinkin out loud.

Just to show the beauty and beast relationship...2006 Renault f1 from the rear...

 

No worries Derek... Nuthin but luv for yah brutha.

 

Gee thanks, you sound like my wife...

 

Be sure to give us her contact info when you leave. That way we can give her someone to yell at and kick around. She can vent her "what has he done this time" and be in a better mood when you're able to visit with her.

We can help her spend your budget too.

 

HDDP, did you ever end up setting the wing's inclination?

Based on the parameters you've given, the boundary layer separation should cause a stall (zero downforce) condition at around 10 degrees declination. This boundary layer separation can be reduce by inducing vortices before the air reaches the spoiler.

In any case, I'm interested to hear what ended up coming out of this, and what declination you ended up using.

 

This is the first question I've had regarding the "wing" And if you want the detailed answer, it will take awhile and I probably won't finish it in one post... If you want the short answer, it depends on the track... I have found the range from 11 to 9.5 degrees... I learned that 11 degrees is too much at speeds over 125 mph because it creates too much drag and downforce on the rear and seems to lifts the front end... Here's a perfect example, where you can see the front end lifting and the rear end plastered to the pavement... This was with 11 degrees and speed somewhere around 125...





So let me start by saying it wouldn't be on the car if it was a daily driver because it looks like some pimped-out ricer IMHO... But, it started as an experiment to see if I could keep the rear-end stuck to the ground enough to prevent the traction control from kicking-in during high speed corners...(this was before the TC was disabled) I was taught to "power slide" thru corners and keep the car just on the edge of spinning by throttle control, but the invasive ESP on the Crossfire would just cut the throttle and apply braking pressure the minute it sensed rear wheel slip...

I'll have to finish this later....

 

The only way the car is going to be able to accelerate air is by changing the direction of the velocity vector...it's not going to be able to increase its magnitude.

 

I'm glad you guys brought this post up again because I have been studying this photo for a few months, especially now that the modified SRT6 engine is going into it and I will be running this track (California Motor Speedway) again during the 2008 season, but now with about 150 more HP...

If memory serves me, I was only able to hit 135 on the front straight with the NA engine and I believe this photo was taken during that speed... Notice how the front-end is lifted and the rear-end is squatting nice and tight ? This tells me that the front aero is really bad, and instead of sucking the front down, it is lifting it a high speeds...