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Posted by: trekkor Aug 3 2004, 12:00 AM

I'm setting up a custom rubber flex dam off an LE F/G dam.

I want the clearance to be the ABSOLUTE minimum.

How much room should I allow?

Can't limbo under my dam.

Flexy T

Posted by: Brad Roberts Aug 3 2004, 12:02 AM

Enough so cooling air passes under the car....

Leave at least 2 inches.


B

Posted by: trekkor Aug 3 2004, 12:07 AM

Thanks, Brad . Thats exactly the amount I had in mind.

Posted by: McMark Aug 3 2004, 12:08 AM

I was right about the cooling air.

Posted by: Brad Roberts Aug 3 2004, 12:11 AM

Rob Way's car tends to overheat..... so dose Darren Dowds..... everyone who runs the flexdam.



B

Posted by: trekkor Aug 3 2004, 12:15 AM

I cleaned my oil cooler, so now I'm good to go...Bro!

Coolious Teaser

Posted by: Joe Ricard Aug 3 2004, 06:05 AM

Air must run underneath the car why? Is there some sort of scavenging effect pulling air out of the engine? HMMMM now I think I may have been killing myself when I drove the car home with that really low "cow catcher dam" I could get my toe under it in running shoes. Sure made the car stick to the road.

Posted by: McMark Aug 3 2004, 08:30 AM

There is a certain amount of oil cooling that goes on when the oil is at the bottom of the engine. There's a reason Porsche added the two "air flaps" on the front lip of the engine bay in 1973. Those two guys stir up the air to create turbulence and get more air up around the engine and cool it.

Posted by: Joe Ricard Aug 3 2004, 08:45 AM

DAng now I will have to re-evaluate the idea I was mulling over in my head. I wanted to make an under belly pan like 928 and some later 911 cars. Thought of louvers to let engine air escape. and now thinking NACA ducts to get some air blowing past the bottom of the motor.

I want the pan to go from the front edge of the fire wall to at least the engine mount bar.

Posted by: maf914 Aug 3 2004, 11:51 AM

There are a lot of opinions about the two flaps Porsche added. I don't think they are there to create turbulence, but are there to direct the airlow from the floor pan down and away from the areas under the cylinders and heads, creating a low pressure area that lets the pressurized cooling air from the cooling fan and shroud exit from the cylinders and heads more easily. The fact that they didn't use a single flap across the engine bay makes me wonder if they wanted some airflow across the finned bottom of the sump. I don't know how much cooling occurs at the sump. It seems it would be relatively small.

I've also wondered about the effects front spoilers have on 914 cooling. I still think someone needs to get a 914 into a full scale rolling road wind tunnel and test out all of our theories!

Posted by: maf914 Aug 3 2004, 11:55 AM

Joe, The belly pan sounds interesting. You may have already seen these but check the project cars gallery at Patrick Motorsports. Some of them appear to have full pans at the rear.

http://www.patrickmotorsports.com/cgi-bin/main?action=gallery

I remember reading about the 956/962 cars in the 80's. During qualifying the teams used to block off the louvers that exhausted engine heat into the underbody venturi's to increase downforce. They could only do this for a few laps before the temps would rise too much.

Posted by: synthesisdv Aug 3 2004, 11:55 AM

As soon as a team decides to run one in NASCAR, otherwise its all trial and error.

dr

Posted by: SirAndy Aug 3 2004, 11:58 AM

ok, here's another one ...

how about two air-scoops under the car, right next to the "flaps" that direct fresh cold air UP and directly into the intake?

that should work nicely, right?
Andy

Posted by: synthesisdv Aug 3 2004, 12:02 PM

it will also scoop up every rock and pile of dirt that gets too close, better not go off.

dr

Posted by: maf914 Aug 3 2004, 12:07 PM

In the winter that would be cool, but in the summer the air temperature at the suface of the road is what... 130-140 degrees?

Well, maybe not in California, but it gets hot as a mofo in Georgia.

Posted by: SirAndy Aug 3 2004, 12:14 PM

of course with a good air-filter in line, you could build it in a way that rocks etc. just bounce off the air-filter and fall back down.


now that is a good point ...


still thinking
Andy

Posted by: SpecialK Aug 3 2004, 12:37 PM

If you wanted some more cooling air going to the engine compartment, I think I'd go with side scoops (NACA) right behind the doors, and duct them through the fender wells into the engine compartment. Hell, you could even flex pipe it right to the fan inlet. Debris would be kept to a minimum even with the occasional "off-road" excursion.

I'm working on ducting my "Old school Trans-Am front fender vents" (mounted backwards a few inches behind the doors) to each of the Webers. I still need to figure out a system (bicycle brake cables?) to open/close them in conjunction with the heater flapper valves. I figure if it's too cold for me, it's too cold for the carbs by my calculations [1970 Baja Bug+Holley Bugspray Carb+New Mexico in December=Ice Maker].

Posted by: Joe Ricard Aug 3 2004, 07:31 PM

Cold air = more horse power. just don't run the big plastic spacer inbetween the head and manifold. should keep carb from freezing. oh hell what do I know I live in Mississippi, I'm half hammered and it's my birthday.

Need bigger piece of aluminum sheet to span the area I want to cover. I like think bending the trailing edge down a bit should create a void in the air stream to allow heat engine cooling air to be sucked out and expelled.

Posted by: Andyrew Aug 3 2004, 08:12 PM

Honestly, I hate the flexidam... I took off the flexible part, and Boy do I like it!

Too bad I need some air flow with the radiator.. 916 comin my way...

Andrew

Word to all those with flexidams..

Posted by: Air_Cooled_Nut Aug 3 2004, 09:10 PM

[QUOTE=maf914,Aug 3 2004, 09:55 AM] [QUOTE=Joe Ricard,Aug 3 2004, 06:45 AM]
Joe, The belly pan sounds interesting. You may have already seen these but check the project cars gallery at Patrick Motorsports. Some of them appear to have full pans at the rear.

http://www.patrickmotorsports.com/cgi-bin/main?action=gallery

I remember reading about the 956/962 cars in the 80's. During qualifying the teams used to block off the louvers that exhausted engine heat into the underbody venturi's to increase downforce. They could only do this for a few laps before the temps would rise too much. [/QUOTE]
That web site shur has some pretty pictures...

Have no idea what that DME thang is they're touting but I found this picture the most informative:

Now I know the orientation and position of that part I need to [eventually] replace, where the swing arm mounts (is that the console?). It's nice to have a picture of what something should look like.

Posted by: Rob Ways Aug 3 2004, 10:27 PM

So that's why you were trying so hard to bust my flexdam by nailing all those cones Damn near worked.

Posted by: Brad Roberts Aug 3 2004, 10:29 PM

If you guy's would use more cones... I would have been successful :finger2:


B