T_MaX

I like the idea and can't wait to see what your end product looks like!

Tony

You have a TC in the cross over?
I ask as im looking at putting some in my I/C system to see what temp drops and increases i get across the system.
HE IN vs OUT
IC IN vs OUT

again..perhaps overkill and nerdy stuff, but i like seeing what happens and why.
Keep up the good work.

pappy92651

Hello Tony,

I have been placing sensors on the Porsche designated locations in the engine bay. L2 is the water temp sensor to the LH. It seems to be a good place to obtain readings that the LH will act on.

Vlocity

Here's a pic of my 3 inch insulated air intake tubes, insulated modified airbox and insulated Maf.

Regards,


Ken

pappy92651

Hello Ken,

Your pictures did not post (or do you have a link?). You are on the right track. I'm doing something very similar. In fact many people are doing something quite similar and on track cars. I mentioned the Speed Channel Acura RSX project in a previous post. Dyno numbers and track times show continuous improvement on that car.

Rob,

You win the big prize. Where do I send the check.

The car runs very well when the measured L2 temperature is between 175 and 185 degrees F (water temp). This works out to be 150 to 160 F on top of the intake manifold, air temp at the aux fan switch. I have a 65C (150F) fan trip point with a thermistor. The fans cycle on at air temps over 150F at the aux fan switch location. The temp drops back down to 145 F after about 3 minutes, fans go off, and L2 water temp stays in the 175 to 185 F range. Heat from the radiator no longer enters the air tubes at low speed or while stopped. The result is nice, crisp, wheel spinning throttle response because the air box temperatures stay near ambient (everything is insulated). The diverter is out of the car, may it rest in peace. There is more testing to be done.

Many will question the battery drain issue. On my car the fans never run for more than 5 minutes with they key out regardless of temperature. Power to the main bus times out (Porsche design) so no issue with dead batteries unless your sitting around with the key on and engine off (why?). Will fan life suffer? Yes, but this would be no different than driving with the AC on all the time. So the fans are on, similar to having the AC on, but with periods of off time.

I took the hood off and ran hoses from the air box to the bell mouths at the nose. 100 MPH: I got a whole 1.7 PSI at the air box (not fully sealed). Fully sealed I got 2.1 PSI. I cannot feel a difference at low speed. At 100 MPH I cannot feel a difference. My opinion: Not worth the effort for a street car and you would need a custom hood to make room for the tubes to go over the radiator. If you start changing geometries to create an air passage under the hood you create pressure drops. Louie has already done a lot of this research so now our notes match (see picture).

I'm going to try to get the car on the dyno tomorrow.

Opinion for now: On a street car it is not worth the time to add scoops, ducts, or diverters. You can accomplish a lot more by reducing water and air temperatures in and around the engine.

blau928

Steve,

Thanks for confirming what I have suspected for quite some time. I'll be in touch to ask you about part numbers et al. on the aux fan switch and its wiring..

Keep up the great contribution to the forum

Adam C

So you've removed the diverter, then?

pappy92651

Hello Adam,

Yes, it's gone. The car runs just as well or perhaps even better without it. When it is installed The water temp changes much more, from 1/3 (cruising) to just under 2/3 (stopped). With the thermistor in place I'm running at 1/2 to just under 2/3 under all conditions. The LH seems to like this narrow range.

Adam C

Off topic but do you have a good shot of your rear wing? Looks interesting.

pappy92651

Let me know if you need more detail by emailing me directly at stephous@att.net (picture atached).

Adam C

That must have been you I saw in Dana Point a week or so ago! You were driving down dana harbor drive, on the island side of the harbor, and I was coming towards you - i think I waved. i was the black 928.

If it wasn't you someone is driving around with the same wing.

I love it - how much?

pappy92651

See my PM.

rob rossitto

glad it worked better than my last great idea of crushing a beer can on my head(like the beer commercial)...(ps don't try it, it hurts)...

airbox should be here any day, can't wait to see if it works or if it's just another $125 paperweight to go w/my "collection"...

IIRC, the 11" 1300cfm spals only use about 19 amps vs the 24amps of the stock fans, so longer run times might not be such a big deal, at least compared to a monster stereo...

what was the ambient temp during your tests? it's been pretty cool up here lately and that could impact results rather significantly... (ie density altitude, etc)

pappy92651

Hello Rob,

Send me a link for the 1300 CFM spals. I would like to check those out since I can tell that another fan is nearing EOL. Not bad for 115K miles. A 21% electrical power reduction would be welcome.

The ambient during my tests has been 67F. That's why I want to do a bit more testing. I'm thinking that there will be a threshold where nothing helps, and the car will bog off the line once you get into 100F ambient conditions. Delta t closes in on the unsuspecting LH and no there's no place to go but lean.

SharkSkin

FWIW, my single 2300CFM SPAL uses about 17 amps(measured, 19 amps(rated). http://www.spal-usa.com/pdfs/16Fans.pdf