tektrans

iTrader: (23)

Interesting. Tape the headlights too.
Does look alot more aerodynamic the way you have it.

Demonicbird00

iTrader: (17)

lately ive been taping the bottom of the lights so that air doesnt get under there as well.

-brandon

JEB99TA

iTrader: (32)

Yeah, I'm gonna' buy some red duct tape to match the color of the car. I have heard NHRA rules discourage the use of duct tape like the NASCAR boys use. Here at the local track, as long as it's color matched, I don't think they care much. I'm gonna' tape up the cracks aroung the headlights, the fog light holes, and prob the front running light slotted holes. It only makes sense it will improve my times.

To get a 1/10th ET and a full 2 MPH faster time Friday night just from removing the rear hood rubber seal and the front lower air dam, well, I'm now a firm believer in better aerodynamics.

For anyone to dispute this gain, I can offer up timeslips. Weather was near identical ... track conditions were almost identically the same ... my 60' time was even a little lower by 6/100 of a second. Not really much to dispute, IMO.

Track opens back up in 2 weeks and I'll post up the times here of any differences the taping makes.

BrianC98Z28

iTrader: (11)

cool man keep us up to date as im currently thinking of any ideas for an extra tenth for minimal money

Demonicbird00

iTrader: (17)

tape up all the holes in the bumper....the "vents" under the DRLs do nothing so you can tape that as well.

my car is still taped...been taped for about a month now.... when i went to the track i forgot to put my front liscense plate cover on so i had to tape that as well..... anc actually that made it alot cleaner in the front then the cover on there.... ill get pics tommorrow if i remember.

good luck, and keep me/us updated

-brandon

JEB99TA

iTrader: (32)

Will do Brandon ... appreciate the tips. Everyone else, thanks for the replies ... can anyone else think of any aerodynamic changes I can make to the car to squeeze 11's out of it without spending a lot of money? I'm already looking for some cheap/used Mickey Thompson ET Street drag radials and a couple of lighter take-off wheels.

Demonicbird00

iTrader: (17)

jeb99ta.....check out my post in the FL section.... ill be in daytona next weekend if youd wanna come check out some kart racing

also did you remove the rear bumper supports?
heres what i did






i put the rear plate on a hinge so that any air that gets up under the rear bumper can escape along w/ the 4 holes on the bumper next tothe plate as well

-brandon

Demonicbird00

iTrader: (17)

oh hell....i just saw your page you should easily be in the 11s w/ heads/cam

whats your timeslip break down? maybe theres just some tweaking to be found in launch/shifting/and rpm shifts

-brandon

JEB99TA

iTrader: (32)

That plate is along the same lines as I have been thinking for months now .... didn't know somebody had actually done it. I like it ... wonder if anyone's thought-of/designed/fabricated a narrow plate like that which would cover the tunnel in the middle of the car, as well. I would just about bet money it would drastically rduce the mount of wind drag under the car. And a cover for the front K-member and motor. That would be very lightweight and should be good for a LOT less drag and maybe some good gains.

Hey, I'll get back on here in a few and discuss my timeslips and the car. It's built for low-mid 11's, but, without skinnies up front and lighter wheel/tire combo in the read, it's still pretty heavy ... has stock brakes/rotors, as well.

JEB99TA

iTrader: (32)

OK, I'm back now ... been the victim of some forced Christmas picture-taking ... LOL!

As for the bumper supports, I'm alwasy paranoid about getting rearened. It happened once when I was rearended at a dead stop and this Honda lpoughe dinto the rearened at 50 mph. If the bumper support hadn't been threre, my cra would have been FUBAR.

I have removed the rear seats and seatbelts and removed the swaybar ... along with the spare tire and normal DD weight reduction stuff. Still have stock rotors/brakes and went back to WS6 17" wheels so they'd be a little lighter than what I had in the 17 x 9.5/17 x 11.00 ZR1's.

SFC's are round BMR's ... should have went with chrome-moly stuff for suspension. Also, the torque arm is pretty heavy (BMR adjustable). Still have stock K-,memebers and upper/lower control arms.

All this said, I have some room to grow (or should I say 'shrink'). Srtange 12-bolt has HD Eaton option, so, it's heavy, as well.

The car still should be faster, but, I don't have a tuning program to play around with the shift points/firmness. I have a better 60' ft in it now that I have learned how to launch the car and I'm ordering the Strano 21mm hollow rear sway bar next week. With MT Street drag radials going back on the car soon, I should be cutting consistent 1.5-1.6 60' times, so, not much to gain on my launches, that I'm not already working on.

Any suggestions definitely are welcome.

Taubr Unit

iTrader: (32)

I have no rear bumper support and i got rearended by a mid-'80's Ford f250 at 40mph. Didnt crack one piece of body, it pushed in the well in the back and dented my pass. side fender. Didnt break my hatch glass, bumper cover or anything. STILL SUCKED HARDCORE!!!

JEB99TA

iTrader: (32)

Do you know how much the support material actually weighs? The sticky says it weighs 21 lbs ... just wondering how accurate that is.

speed_demon24

iTrader: (6)

JFYI taking out the weather stripping at the base of the hood forces air into the engine bay not out of it since the cowl is a high pressure zone.

brandonppr

iTrader: (9)

I removed my lower air dam and I cut the metal bracket that holds it on off.
It was a pretty big bracket, it runs all the way across the bottom of the radiator. you can see in the pic.

I had no problem cooling. BTW I don't have the front bumper on anymore though.

WarShrike

iTrader: (5)

So why not just fab up a belly pan? I have yet to actually see anybody get truly serious with the bottom side of the F-body. I'd love to see a smooth belly and a true diffuser under the rear.

From what I remember, somebody had tested a belly pan on their car at the track and did see some gains in ET and MPH. Nothing like getting rid of alot of turbulence under the car. I just can't find it on here...

JEB99TA

iTrader: (32)

See results (above) from my earlier post. Just removing the front lower air dam and the weather stripping gave me 1/10th and 2 mph. Not convinced your statement has validity. Can you post your basis of your statement ... maybe a Car & Driver/Road & track/GMHP magazine or wherever you're getting this information?

You may be correct. If so, that means I would have gotten more out of only removing the lower air dam, so, I'll put the weather stripping back in to see if does a little better the next time I go to the track.

Anybody else know of any supporting documentation indicating why the weather-stipping at the base of the hood should not be removed when I go to the dragstrip. I only remove it for the dragstrip and put it back in when I am finished racing.

BTW ... Brandon .... bought some red duct tape to match the color of the car ... :-)

jsmcortina

It is standard aerodynamics that the cowl is a pressurised region.

James

Demonicbird00

iTrader: (17)

well when i was drivig around i had the weather stripping only on 4 of the push pins to see where the weather stripping would be pushed to from the air. it was getting pushed out towards the windshield and not the motor. so that tell me that there was a lot of air movement under the hood that wanted to escape out near the windshield.

also i was wondering about a belly pan as well earlier inthe year. but i couldnt find anything. im going to figure something up and use .30 aluminum since its lite and strong there will def be gains to be made in the 1/4 ET and trap. as well as improved mpg.


-brandon

VIPRETR2

iTrader: (63)

I was thinking about this a little today and remembered John Lingenfelter taking the side mirrors off his LT1 bird for top speed contest back in the day. Has anyone tried this for drag racing? Should be easy enough to take off and tape over the holes. I'm going to try the taped front end, air dam, hood seal, and mirrors in the spring to see if I can bust 130mph with a cam only LS6.

JEB99TA

iTrader: (32)

Yes, however, you are confusing aerodynamics with physics. When there is an upper-level pressurized region of HOT air and cooler air pressure from underneath is pushed upward towards that region of pressure, along that line of intrusion into the pressurized area, there is a force called resistance. Is there not?

Why would it not be better to release that resistance and allow a nice flow of air to dissipate the heat and keep the motor cooler the faster one goes? Remember, my front lower air dam is no longer forcing air directly upward, since it has been removed completely from the car at the dragstrip.

I believe that massive air flow into the engine compartment creates massive much resistance unless it is allowed to escape and take hot air from the engine compartment. You say. 'It is standard aerodynamics that the cowl is a pressurised region'. It also is an aerodynamic fact that the force of air underneath a race car, as opposed to the force of air pushing downward on the top, is much greater (called the Bernoulli Effect). Therefore, when the weather stripping/seal at the base of the hood is removed, there is still a pressurized effect of the outside downward airflow, which only allows a minmized amount of air to escape and thus relieves the prssure, as well, so very little resistance within the engine compartment. And you're keeping the engine cooler, as well ... and we all know that means more power produced. So, we're not speaking about daily driving in the pressurized design of the cowl area of my F-Body. We're talking about racing ... at speeds well above what our cars were designed to anticipate on a daily driving basis.

After I gained 1/10th on my ET and 2 MPH with a lesser 60' time by only removing the lower air dam and the weather stripping at the base of the hood (near-identical weather and track conditions [two days apart]), I proved to myself these two changes made a MAJOR difference. I believe one chnage complimented the other. Maybe it applies differently to some others, however, these are my results and I have the timeslips if you'd like for me to post them. Plus, several others have annotated improvements, as well. This is all IMHO.