RolexNJ

And I'm sure you know this, but that's ST's white car. I actually saw it in person when I was at his race shop. The hood duct and nose panel look very nice too.

lart951

Yep it's ST's car.

streckfu's

I know that and was messing with NZ, Machtig, Turbo944T, aka banned again. NZ has white intercooler pipes and posted something about them reflecting heat. You'll see him on another website.....

lart951

WTH??? NZ951 got banned again.

streckfu's

I guess he snuck on as turbo944T. He even posted in this thread.

RolexNJ

I know you were playing. And yes, everyone and their mother knows its NZ. Duh!

evil 944t

nz banned again. He can't seem to catch a break. Can't he play nice?

RolexNJ

Brother? Right, nice try NZ. Good luck on here, while it lasts!!!

streckfu's

Where did his posts go?

RolexNJ

To the abyss I guess. Anyway, back to the show boys!

streckfu's

Back on topic:

I like how ST kept the spine in the hood after installing the vent.

TRWright

That hood is pretty flimsy as-is. I would be afraid to open/close it without that support.

DanG

Azmi was working on a research project for a hood extractor, he emailed me asking for some help (I didn't have much to offer).

I expect he'll chime back in here soon. While I'm disappointed that the vented nose panel might not have any benefits (or possibly negatve effect), I still realy like their look! What's someone to do? I know! I'll just put on a vented panel and block the vents! Good looks, and no loss in function. Its kindof like a ricer mod, except it would actually be for the benefit of the car.

I'm a genius.

User 41221

I did some flow modeling on a 951 a few years back and found a few interesting things.

1) Putting a vent on the low pressure area (basically, the nose panel area where the vents wind up) upsets the flow characteristics of the stock opening, and creates turbulence in front of the intercooler that reduces flow through the intercooler at most speeds. To alleviate this, you need to split the internal duct so that 60-70% flows through the lower portion and 30% or so flows the through the top. Doing so brings the flow back to roughly what the stock vent provides on its own.

2) The relief vent behind the intercooler is very effective at helping draw air through the intercooler. Doing so with the venturi baffle that I described above WILL increase flow over just the stock intercooler vent, but its not going to be a huge amount.

3) The size of the stock intercooler is a limiting factor in the effectiveness of the nose vent. A better option wouild be to put a bigger intercooler where the AC condenser coil is a skip the nose panel vent. Also, a water sprayer/mister in front of the intercooler would be more effective at reducing temperatures.

4) The flow characteristics of how air is designed to be handled from the factory are very complex, very effective and very interesting. The way air is designed to flow through and under the car helps create downforce at speed and increases cooling for the engine and brakes. The air flow at the front of the car should be considered as a total system and changes in one part of it can have unintended effects on the others. Most of the folks that talk about how great some of these mods are can't quantify the results.

5) Two front end air mods that are very worthwhile are to 1)put a front air splitter on it, as that puts more air through the front of the car (roughly the same effect as if you were driving faster) and 2)brake cooling ducts.

Lastly, this was comparative analysis only, and should not be considered to be the last word in aero and flow dynamics. We made some assumptions mathwise in doing this that may have skewed the results, but it should have had the same on all results we got. Some of you math/engineering majors have much better tools to work with than I did and could probably poke holes in teh methodology we used, but oh well. Take it for what its worth.

Regards,

Dash01

Scott,

Could you please elaborate on your point no. 2 about the relief vent behind the intercooler? On my '86, the IC cooling air gets jammed into the post-radiator air and then presumably drawn out underneath the car, via circuitous route and not-so-good sheetmetal passageway holes just behind the intercooler. It does not seem very well vented, and invites improvement. Your thoughts?

Seems to me, some improved internal fairing/ducting of the flow passages could do a lot to help the cooling air escape. And, cutting some escape slots on the aft vertical edge of the header panel would allow some of that cooling air to be sucked out and over the hood, via the gap between hood and header panel. Being curved and ~12-15" behind the nose, the airflow up and over the front of the car would have accelerated, generating low pressure per Bernoulli to draw the air out through the gap. If the hood can be positioned a bit further aft, this would increase the hood/header panel gap, increasing flow by Venturi principle.

Laust suggested removing the rubber strip at the rear of the engine compartment (in front of the w-wipers and beneath the rear of the hood) to allow the higher pressure air that accumulates at the base of the windshield to flow forward over the engine, then out through this gap or down and out under the car, thereby reducing engine bay temps. somewhat.

And, your comment about having an effective splitter seems right on the money.