Performance is everything... And if I can't get more HP without spending stupid $$$ I gotta take turns 20 mph faster than a car with 100 more HP to stay competitive...

After removing more than 400 lbs of weight from the car before the start of this season, the Eibach springs and Koni dampers that originally lowered the car 1.2" from OEM (3,100 lbs) lifted the car back to the original height (or more) with a 2" gap in the wheel well (2,640 lbs) with full tank and driver...

Since I run road racing courses, I decided to drop the car as low as possible without having tire rub from the Hankook 225/18 fronts and 275/18 rears and having to modify the suspension too much... In doing so, we cut the spring perches and relocated (re-welded) them 1.25" higher than OEM placement and eliminated the perch pad... This dropped the car 2"... Then we had custom spacers built that widened the track on the front by 24mm and the rear by 40mm... We then had to roll the fenders to make clearance for the tires...

I'll post before and after photos later this week... The car now measures 4" at the running board and handles like a slot car and looks terrific laying so low to the ground...

 

Can't wait to see the photos.

 

Nice can't wait to see it too... A+++

 

With all the suspension mods you've been doing, you need to get some lateral-g numbers. I'll bet you're over 1 g now on a 300' skidpad.

 

How did you roll your fenders? did you use the Chicane fender jimmy, or a really good body man? I want to mount a set of WIDE Porsche rims, but haven't
sat down to do the research yet, and the front rims are just scrawny compared to the stock rear rims.

 

We used the roller... Pinched the tabs in first, then had a nice afternoon of rolling back-and-forth to get the fender to fit the wheels/tire on full down compression... I widened the rear track by 3" and the front track by 2" with spacers that were welded to the hat, which is a cheesy way for a car that runs road courses (IMO), but it was cheaper than extending the axel... It's a work in progress and this will be the first weekend I have it on the track with these changes... We also cut the top spring perches away from the uni-body and re-welded them 1" up from the OEM placement... The perch pads are now the one dot (1mm) The camber is completely out of whack, probably -4 rear and -3 front... Like I said, it's a work in progress, but if I didn't have to race this weekend, I wouldn't put the car on the track if I didn't have to try to save my regional position with NASA...

 

One of the things to think about is going to a flat bottom on the car, flat bottom cars create tremendous amounts of downforce, the downforce that you need to take that corner quicker. I have added some links that may stimulate some experimenting.

http://www.mulsannescorner.com/wingendplates.html
http://www.mulsannescorner.com/diffuser.htm
http://www.mulsannescorner.com/techarticle2.html
http://www.mulsannescorner.com/vortexlift.html

Happy racing!

- EJ

 

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AMGLover,

With HDDP having the car 2" lower to the ground at this point is probably increasing his downforce numbers already as the air is being forced over and around the car instead of being allowed to slip under it.

Also, with the monster wing he has in the rear, higher speed corners are not as much of an issue. It's the slower portions of the track that are the problem. Most of these slower corners will not benefit as much from the aerodynamic modifications in the articles you have pointed him to. Most of the techniques shown are mainly for purpose built cars, not OEM cars that have been race prepped.

I'm not saying they aren't things to look at, but I think he will get more benefit from time spent tuning that suspension and wing at this point and getting those dialed in. Then he can start doing little aerodynamic modifications to the underside to smooth the airflow under there as well as maybe a splitter on the front to help guide the air around the nose even better.

Good Luck HDDP!

 

Good info, thanks... Believe it or not, I had considered a full belly pan, but the stupid rules will ding me for modification points that will take me up one class. So, obviously they see the benefit as well... I'm doing this tap dance with mod points to stay in TTD.

 

the crossfire is much better aerodynamically than that overpowered brick the Evo, there is no reason to install a turbulator on your XF.

 

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come on HDDP, post pictures of your flared fenders, stop with the **** tease!