I'm looking for a way to vent my front fenders. The air trapped by the fenders produce lift on the track. I'm looking for some universal side fender vents. Louvers over the top of the fender are best, but I don't have the money to fabricate that project. Please let me know if you have any recommendations.

 

Z3 fender vents like all the *gulp* ricers use would work.

 

I used to have a 1979 Z 28 with some fender vents. They were the same in '78 and '79, and I think revised in 1980 with a smoother appearance.

 

Do a search for "vent my hood". There's not much upper surface area on our fenders. What you want to do is vent the hood. This thread has some ideas.

 

Here are the Z28 vents:

 

buy the unversal louvers, and put them where you want them and cut out underneath, wouldn't that work?

 

I'd be more inclined to find a front air dam that not only creates more downforce but also diverts air around and away from the wheel wells to prevent that air air pressure buildup and lift.

 

I have an APR carbon fiber front splitter and canards for front downforce. The car does have flares and there is no way of preventing air from spilling into the fender at high speeds.

I've considered trying the universal vents, but I'm worried about the cheese/rice boy factor.

The air in the engine compartment is being vented through cuts into the top firewall which lead to the stock vents in front of the windshield. The compartment where the stock windshield wiper and motor used to sit. Better engine compartment venting will be coming later, for now I'm looking at the wheel wells.

 

Is that your car in the Avatar? If so, then you can definitely benefit from louvers. They're so effective at reducing lift, that they're required in the ALMS classes.
Since your car's a widebody, you have enough real estate to justify some louvers. You'll have to check your dimensions, but try HRP: http://www.hrpworld.com/index.cfm?fo...action=product

If class rules allow you to vent the hood, do that too. Be careful, though, with allowing your underhood area to communicate with the high pressure zone at the base of the windshield. The new Dodge Viper has a good setup of vents. A friend of mine who had an earlier version without the vents added them, and noticed much lower engine temps and better turn-in on the track.

 

speed holes. i got a gun or a drill

 

Thanks for the info, I will check out the site. That is my car in the avatar, it's not a super wide body but still wide enough to where I can benefit from venting the fenders.

I have sealed ducting going to my radiator but nothing aft. I want to eventually run some ducting from the radiator that will vent through the hood. I'm also considering making an underbody tray for the car eventually. The car has great suspension, drivetrain, and engine setup. Now I'm focusing on the aero. I allready have some aero mods, but there is allways more that can be done.

 

NOOOOOOO!!!! There's your damn problem... the vents just in front of the windshield are in a extreemly high pressure area. In fact you're forcing more air under your hood. That is going to force huge amounts of un wanted air under the hood and under the car causing lift. Search through my posts in the last few months and I have posted some amazing links and info on air flow and testing on FB's, and any car for that matter. Some guy vented his hood and i posted good info in that thread.

p.s. beautiful car. I drooled all over it at 7stock!

 

Somewhere I used to have the airflow diagram for the FB. It's quite similar to the FC one and Hyper4mance2k is correct, the area at the base of the windshield is a high pressure area. That's how fresh air is forced into the cabin.

If you're thinking about ducting the airflow from the radiator, you might look into how Steve84GS did his with his hood vent. His was for his intercooler, but the same idea can be applied to the radiator. That would remove the waste heat of the radiator from the engine bay.

For venting the fender wells, louvered vents at the top of the fenders like the prototype ALMS cars might be your best option since you have wider front fenders. That is a low pressure area and will pull the pressure build up out of the wheel wells.

 

I would like to run ducting that would vent out close to middle of the hood. I cut the holes in the firewall because it looked like the air was pushing up on the back of my hood at high speeds. I figured, why not just cut a couple of holes to let it vent. I realize that the windshield creates a high pressure but I didn't know it affected the stock vents that much. I will have to fabricate something this winter.

I agree on the fender louvers, It's going to suck trying to fabricate louvers that flow with the contours of the fender. After I vent the hood and fenders, it will be time for an under body tray. I would like to run 1:26's at willow springs next year.

Wish I could have been at sevenstock, Guy from Tripoint took the car down for me. I will make it next year though.

 

couldnt he add a "lip" at the opening of his firewall cuts to create a low pressure area?

 

For the hood vent, you want it in the first 1/3 of the hood. By the time you get to the middle it begins to become pressurized again, iirc. I wish I could remember where I ran across the 1st gen air flow diagram, it's been in the past year or so.

I've seen some raise the the rear of the hood about an inch on lock pins for engine bay venting. Not sure how effective that may or maynot be.

 

All car pressure maps are very similar. Although the external pressure may begin to go positive near the middle of the hood, the internal pressure (under the hood) is high enough that there's still benefit further back. What you're looking for is a positive delta between the two. Look at the viper hood -- it underwent a whole lot of development in a very expensive wind tunnel by some very smart people. I go back to that one because it's basically a racecar (so it wasn't burdened with all the normal OEM customer compromises) that was designed by folks that had the resources to do it right.

 

Hey SCott check this site out... they have Carbon Fiber Louvers that you could fiber glass into your fenders...

http://www.racerpartswholesale.com/c...ing_And_Sheets

 

The Pan Speed RX-7 that lapped Tsukuba in Time Attack has front fender louvers... It set some record but I think it was broken that same day by a GT-R R34... I don't think it's Boy Racer or Rice to louver the fenders.... Z3 or what ever those add on vents are called that IMO is RIcer...

Also the tuning company Border, made their Toyota MR2 with front fender louvers.

In this Mazda Ad check out the ALMS car that they are unloading from a trailer... it's got louvers...

http://www.youtube.com/watch?v=C_goFIeOWPw

 

Well the Pan Speed FD RX-7 picture from 7Tune.com didn't work so here is one from... uhg... import tuner... The 7tune.com picture looked way better and you could really see the louvers well.

 

John,
Those louvers would be perfect. That pan speed 7 looks hooked up.

My main issue is finding louvers that will be contoured properly for my fenders. Most louvered fenders are fabricated that way from the start. I think I will need to have some custom made for my fenders.

 

I think I will need to lean my radiator forward for this project. The first 1/3 of the hood would be nice. We'll see how much room I have to work with. Even if the vent isn't perfectly located, it should still work well with some duct work.

 

I agree, hopefully I can complete a couple of these projects by February. I think I could pick up close to a second a lap at Willow Springs if I can vent the hood and fenders.

I've also heard that a smooth under body tray combined with a rear diffuser will reduce drag and decrease under car lift. I can't do the underbody tray until I vent the hood though.

 

Yes, leaning the radiator top forward makes hood ducting much easier. It can also allow you to install a taller 2nd gen radiator.

 

you could make a plate that bolts in for track use
where the front gaurd bolts at the bottom on the sill panel, where the jacking point is theres 2 bolts
you just need to space the bottom of the gaurd out, using the plate
openeing the gap between the front fender and the door, and producing a vent!!!
if you undo bolts and pull fender out you will see what i mean!!!!
oh remove the small bridge brace bolts halfway up inside fender/door gap
similar to my pics...
I was going to do this but i needed to go even wider to fit my wheels,
so i spliced 2 panels together
also raising your bonnet catch slightly and/or driving with the bonnet popped but secondary catched
allows the air trapped like a parachute underneath your bonnet to escape
at near 200kmh the bonnet actually floats when free
most japanese cars have washers stacked at the rear of the bonnet to vent trapped air for this reason