I'm looking to transition to road racing next spring from autocross. I also hit the drag strip once to twice a year. I'm convinced a splitter will help high-speed driving.

I like the APR splitter for looks (somewhat) and the fact that it replaces some undertray (that I've not run for a LONG time). APR also has a IX front bumper with the splitter integrated. My '03 has a lot of nicks, etc. on the front bumper and at least needs a repaint anyway (she used to be a daily driver).

I want to install a brake ducting kit and would rather do that once I have my front bumper, etc. sorted out.

So, a number of questions:

1) Is either the VIII or IX front bumper more aerodynamic than the other?
2) Are there "adjustable" splitters on the market to adjust downforce and/or would such a thing even be necessary/feasible?
3) Is there a compelling reason NOT to go with the APR?
4) Assuming APR's the solution and IX front more inherently aerodynamic, would there be a negative to going with the integrated IX/APR splitter front?
5) Does the ducting for the VIII or IX actually perform any positive function for aero or brake cooling (or anything else)?

I would like to hear from those who have some experience/expertise in this area, specifically as regards high-speed driving.

THANKS!

 

First of all - excellent choice; you won't be dissapointed! Let me know if you want to know what groups to run with in the area. Maintenance is priority #1 for anything on the track imo!

Brake cooling ducts definitely make a difference. They keep temps down which will lead to more consitent braking and extend the life of your pads! There are kits from AMS & Forge out there. A lot of people seem to skip this and think they need a BBK (Big Brake Kit) right away.

I'd put a lot of time/effort into your braking system if you're going to be at speed on a roadcourse. If it's a trackcar - go with some SS (Stainless Steel) lines, cooling ducts, upgraded fluid like Motul and obviously pads. Think about some upgraded front rotors down the like as well.

 

Thanks, boomn29. I wasn't very clear what ducting I meant, I guess. There are CF ducting pieces that mount over both the VIII and IX bumpers. I was wondering if THEY perform any real function or are just there to look good.

SS lines and fluid are in-hand. The AMS brake ducting kit is the one I'm looking to purchase!

 

I agree, other places first. I don't think going all aero first is were time/money should be to start with.

I have an 8 also. Aero wise: front lower lip on my bumper, vortex generator, and wicker bill on the wing. See speeds of 130s to low 140s at Grattan.

Front:
http://i85.photobucket.com/albums/k6...o/DSCF0027.jpg

Wicker:
http://i85.photobucket.com/albums/k6...o/IMAG0014.jpg

PS - PM KingKyle from Hot Lap Motorsports - he has a killer deal going on his BDCK.

Ducts:
http://i85.photobucket.com/albums/k6..._CRkxL-L-7.jpg
http://i85.photobucket.com/albums/k6...o/EvoonGLI.jpg
http://i85.photobucket.com/albums/k6...o/DSCF0620.jpg

With the stock FMIC you can tuck the duct vent holes nicely under the endtank elbows. I need to reduct mine since going to the AMS FMIC.

 

"If you cant stand on the splitter, its worthless"

 

the carbon fiber ducts are there strictly for show, they actually add weight (not enough to really change much)....hot lap motorsports has an awesome brake duct kit for alot less then others, a splitter is a good idea, the APR GT front bumper (looks like the 9 with a lip) is also a good idea, but before you get carbon ducts that serve a cosmetic purpose only, id get sum canards but you need to figure out which bumper you will use b4 you do that....again someone else said it already, aerodynamics isnt the most important place to start

 

It was my understanding that many of the folks on this forum have scrapped the stock undertray stating that in a low pressure zone it won't do anything. Same is said for the stock mitsu brake scoops.

I'm not even lowered much and I'm scratching my front SE lip on tracks with elevation changes. I'm not sure a splitter would last very long on my car.

I'm not sure what kind of speed is needed for those canards and splitters to really do "usable" work but I would think it would need to be fairly high. I'm sure they help with braking from high speeds but is it really something to focus on?

My main concern would be brakes and tires. At my level I put 99% of my slush fund into those two resources and completely skip over areo.

I would like to run a brake ducting kit but on a 9 with larger FMIC there's really no place to put the scoop without stealing airflow from the oil cooler.

 

The APR splitter works much better on the 9 bumper. I have an 8 and the ends of the bumper go down and it pull the splitter up. I used a Carbing aluminum undertray and mated it to the APR splitter and leveled it. Next step will be to use a strip of aluminum to hang down against the splitter. Save yourself the pain and get the 9 bumper which will allow the splitter to be level without a gap.

 

The APR products I used worked well at speed. I have a APR splitter, Carbing undertray, APR canards, 200 wing, and rear diffuser along with a vortex generator. I could run my car in 5th gear hitting the rev limiter at 155 mph through the tunnel turn at Pocono International during a NASA race this summer.

 

depending on how much you care about the name of the products on your car, apr is way overpriced imo.. For front aero the best way to spend your money is on a cwest knock of front, and then a large sheet of alumilite. There's some quality replicas out there that will hold up and the cwest has a few things going for it that others don't. Such as a added/intigrated large lip, also it's flat on the bottom so mounting a piece of flat abs, alumilite, ply wood is real easy. Just get a a piece of cardboard for your templet and your good. From there that should be more then enough front aero until you seal up the rear and add a huge wing. Whatever you do, stay clear of the SE lip on a IX as it adds complications to properly adding a splitter.

 

Thanks for all the experience and input, everyone!

Please, keep it coming!

 

I posted this in another post.

I have the APR IX Bumper with the integrated splitter from on my VIII. The delivered quality was garbage and needed days of prepwork to even it out. The groove separating the splitter section and the upper part wasn't even present on the driver side. The glass process they used left hundreds of tiny bubble holes that had to be filled and sanded. It had numerous stress cracks and the grill they use isn't a grill. It's literally chicken wire. Since it's FRP and not urethane, the body shop had to use an infinite amount of flex in the paint and primer to keep it from cracking. I wasn't happy honestly and even called APR and asked them if they were serious.


In hindsight, I would have got a pre-painted factory urethane IX front end and put a splitter on it. My friend was an underwriter at the shop so I didn't pay for most of the labor, but it came out to 17 hours labor, just to prep and paint it, at 105 an hour.

I replaced it because my wife hit a tire in the road the first day I got the car. After the work they put into it, it does look good now, but no thanks to APR. I may have the original photos I sent to APR when I complained about it but it was a while ago, so I'd have to hunt them down.



Not a fan of APR btw, just if you missed anything.

/brox

 

probably because your suspension is too soft and the body roll causes the lip to go lower then it would if you were on a stiffer setup. I doubt there's a track with sudden enough of an elevation change to make cars scrape.

 

^ Well.... even Z06s scrape. Also the SE lip hangs much lower than the normal GSR lip.

None the less.... areo should wait till after mega tire and brakes work is complete.

 

Dupe