Mattie Num Nums

Hey guys. I road race my daily quite often and I my rear likes to slide quite a bit. What options do we have for a rear spoiler that will get the car planted down a bit?

Werks

You really only have 2 options imho. You have the stock ZR1 full length racing spoiler and then you have the Katech rear spoiler. The Katech spoiler is part of their aero kit which includes side skirts (those are similar to the stock ones) and a larger front splitter with undertray and integrated brake cooling ducts. This set up is wind tunnel tested/developed and is imho probably the most effective aero set up for our cars without going to a not so street friendly full race splitter and true rear wing. The catch with aero though is balance, so if you do the rear you should do the front at the same time.

Here is some info on the stuff:

Rear Spoiler:
http://store.katechengines.com/c6-ca...iler-p182.aspx

Front Splitter w/ Undertray & Brake Ducts
http://store.katechengines.com/carbo...-kit-p212.aspx

Here is the wind tunnel testing data:
http://www.katechengines.com/street_...a%20report.pdf

As you can see the Katech rear spoiler increased downforce by 291% versus the stock Z06 spoiler.

If you decide that you are interested in going this route I have both of the above that were on my car for about 9 months and are in near perfect condition. My car is morphing into more of a race car so I went with a rear wing and race front splitter so those are hanging in the garage. I have not really given any thought yet to selling them or even pricing them but if you or anyone else is interested feel free to PM me an offer.

jbsblownc5

Sorry to jump on your thread, but he has a C5. I have a C5 and a C6. I kinda like the Katech spoiler for my C5, could it possibly be adapted?

troyguitar

^ OP is running a C5 though

What about your sponsor "Couture Aero", can they make aero parts for you?

spazegun2213

why not buy an actual wing from Fulcrum, Kognition, etc and get something fabbed up that lets you remove it for street use? I'm sure you could get all of that for ~2K ish, and have actual downforce at speed.

That being said, I'd change my alignment/suspension before I poured money into aero bits.

Werks

Oops, sorry about that the Katech parts are C6Z/GS/ZR1 only. For C5 you are probably looking at some type of wing which will probably be in the $1.5-$2k range on the low end to roughly $5k on the high end. Like spaze said I'd look into just about everything else including alignment before going that route on a C5 because you are going to run into all kind of complications with cooling when you try to balance the wing with a front splitter.

outsideline

Blainefabrication.com
I have one on mine

racerns

I know the OP has C5, but since you brought it up do you or anyone know the difference between the Katech and ZR1 full length?

Olitho

There are probably some chassis changes that should be considered if are only looking to correct oversteer. There are camber and toe settings that will have impact on handling. Your sway bars, shocks and diffs will make a difference as well. Ride height and rake can make a difference, too.

Don't forget tires and wheels. The width of the wheels and tires coupled with the heat cycles, age of the tire and tire pressures will all impact grip.

Some of the oversteer could be driver inputs as well.

I also forgot to mention corner balancing the car....

Other than for cosmetic reason, aero is probably the last modification you should be considering for true performance set-up. If your car oversteers now without a wing, you will still have that underlying problem after the wing, especially on slower tighter corners... which brings me the question at what point in the turn is the car oversteering? Is it corner entry, mid-corner or upon powering out of the turn? Does it do that in slow turns or fast turns?

I am not the best chassis set-up guy on this forum, but those are some questions that must be considered and answered.

Werks

I don't know the numbers but I'm sure it is pretty considerable as the Katech spoiler is significantly taller than the zr1. I'm guessing 2-3x as tall.

Mattie Num Nums

I have about 5 different options from my sponsor but I just wanted to get some input.

My car has been set up by West End Alignment one of the best in the business. Now my tires are garbage and I know this very well however with the HP I am putting down I am starting to think this may be a good idea somewhere down the road. Would getting something simple like an APR style wing do me any good? If so my sponsor has those options.

topmover

If you don't want to go with a full wing for the C5 I would highly recommend the Blaine Product. I love how it works on my C5 and it was recommended to me by another member here. Both our cars have run some serious times at Summit Point and VIR with it.


Anyone looking for a C6 Katech spoiler and splitter with undertray used(less brake ducts) I have a set for sale($750)

racerns

Hey Joe I might be interested. Is the Katech front splitter any different than the ZR1 front splitter and can the undertray be used with the ZR1 splitter? Also, are the ones you have CF or the fiberglass?

topmover

The splitter is FG and is the same size as a CF ZR1 splittler so far as I know. It has 2400 track miles on it and never been damaged however it is kinda sand blasted if you know what I mean. The spoiler is CF and in excellent shape. If you send me a PM I can send you a couple of photos.

The items are in the Hampton Roads area so if interested you'd be able to check them out.

racerns

PM sent.

Olitho

I know West End Alignment well. Both Darin and his son Chris are true professionals when setting up a chassis. They can make recommendations, but ultimately they count on the driver to come back with feedback to make additional chassis changes to suit the car, the tires, the track, etc. Chassis set-up, especially in the beginning, is not a set-it and forget-it task. You make changes, go to the track, test, make more changes based upon the results and repeat.

If you want a wing there is nothing wrong with that. You just need to know that you must focus on the chassis first. Get that right in conjunction with the wing/spoiler and you will have the best your car can handle.

Oli

0Anthony @ LGMotorsports

Forgive me...but I think this has only be touched on a lightly with the thread.

You said the rear likes to slide out on you....but where and when?

Is it a high speed slide that the car does this, or low speed? Mid corner? Corner exit? What kind of corners does it do it in?

If it is a low speed corner exit as you apply throttle down..a spoiler or wing really isn't going to help this issue. If you are having the issue at say 100 mph through a high speed sweeper...then a rear wing would be more in line with what you should look at. At the same point...need to make sure the front is going to be balanced out with that too. Most of the time Corvettes have had a far harder time getting the front down and sticking at speed than the rear.

Olitho

Well said....

Katech_Zach

That's about right depending on where you measure it.

5280Racer

Try these guys!

http://www.ajhartmanracing.com/ajhr-wings-no-uprights/