rnln

This is a nice air intake set up, right? Would I gain anything if I mod similar setup into my 911? Of course just the right side, and maybe lead it up to the inside of the tea-tray tail, and of course cold condense air is better than engine hot air, but proximately how much different will it give?

JackOlsen

Zero difference, unless your 911 is water-cooled. When the main engine blower is running under full throttle, so much air is sucked into the engine compartment that the temperature difference between the air inside the engine compartment and the air outside approaches zero.

(I've done the measurements.)

scarceller

100% agree, I have a WideBandO2 control system and have recorded intake air temps via the AirFlowMeter's intake air temp sensor and while doing normal street driving the intake air temp = ambient air temp.

The only time I could maybe see this not to be true would be with AC on. Most of the air comes into the engine bay via the deck lid entrance but if AC is on this air must first pass through the AC Cond. which could cause slight heating of the air. I do not have AC system so only a theory.

Don't waste good money on cold air system for these cars.

ked

I think that air intake set-up is a fine approach... along w/ the rest of a 959 drivetrain.

rnln

:lol: ok ok... got it.
I have read related threads many times but still hope it'll make a little different. One of the thread Jack found that soon the car starts moving, fresh air circulate into the spot, but what about those seconds when you start off the line? Will it make any different when accelerate from stand still?
Thanks guys.

JackOlsen

It compromises efficiency to make the engine suck air through a long straw. With water-cooloed cars, that trade-off can be worth it, since there is (more or less) stagnant air in the engine bay. But the blower on the 911 makes it a fundamentally different issue.

Those ducts you see on the 959 are coming from the intercoolers. Cooling intake temps on a turbo are a different game than with a normally-aspirated 911.

I'm not knocking the impulse to improve things. I tested a snorkle type intake and also a box that sectioned off intake air from the rest of the engine compartment. In my experience, neither provided any improvement.

But I can't judge anyone. After all, I'm the guy who tested a front wing.



(For the record, it was a bad idea.)

flatsixnut

God, I can see it now...after pics of this circulate to the civic forum.

old man neri

Actually, now I am really tempted to post it on the honda forum. So very tempted.

ked

Jack; you were on the right track, but a bit compromised... did you try going either higher up or further forward?

JackOlsen

What I wasn't thinking (and that list is long, honestly) was that a wing creates a lower-pressure (and turbulent) zone below and behind it. Theoretically, this meant it was 'pulling up' on the body of the car even as it 'pushed down' on it through the support struts. In fact, at a sustained 100 mph that thing caused a huge amount of fluttering across the length of my lightweight fiberglass hood -- and actually pulled a section of the hood gasket up and out.

No improvement, based on my ride height sensors. However, all the other junk you see there that I was trying did have a repeatable and demonstrable effect.

I didn't try getting it up higher or putting it out further (and lower) in front. Both of those approaches would probably work -- but both would be at least as ugly and a lot more complicated to engineer.

rnln

OMG, are you turning that car into a... monster looking machine? ... In that case, why not make the low bumper lip bigger and sturdier instead of the front hood wing?
Alright, I'll give up the idea of cool air intake.

MUSSBERGER

At first I thought it was like the Jackalope pictures.You have earned my eternal respect by posting that picture. Not too many would have the set to do that.

JackOlsen

That was an aero test day where I went out to try everything but the kitchen sink on a remote stretch of road where I could reliably make two sustained 100 mph runs in opposite directions with my data logger measuring any changes in ride height.

Everything you see there bolts on and off and fits inside the car. By the time I was making the drive home, it looked normal again:

JackOlsen

And rmln, I did end up going with a more aggressive (and simpler) front setup:

Daviboy

Jackolsen kudos to you gorgeous car!!!