bcdavis

I think it's an equal tradeoff.

If you just take the top off the airbox, you have very little restriction.
You get a lot better airflow. The downside, is that it is hot air.

If you duct air from the front of the car, with the stock setup,
you get cold air, but that air has to travel a long distance through
twists and turns. So you get some restriction of flow.

I think it's a tradeoff.

And none of these mods gets you huge gains.

jeff jackson

Jim...you can put your hand "behind my radiator"..if you want to, but I'd prefer not to. Why are you guys always ready to "the sky is falling" to any thing that you have not personally tried, or isn't necessarily a "must do"...by a clear concensus of this forum. I have no reason to doubt Mark Ks suggestion off the top of my head...(and if indeed you are correct, that Rich has just allowed an air intake souce from the "hottest place in the ngine compartment" (which I seriously doubt)...how do you know this is detrimental to anything at all ??? Rich has said...his idle speed mysteriously "picked-up"...by a 100 rpm or so. No big deal, but he also said..the sound is noticeably different, and he likes it. It IS his car...and if HE chooses to follow Mark Ks advice...on HIS airbox, and post HIS findings...what is wrong with that ??? I personally have grown "tired" of the "if these guys think its wrong, it must be wrong" mentality of the concensus here. For gods sake...in 2 weeks, if he regrets the decision, he can get a brand new air box lid (from at least 1 of the big 3) for a buck and a quarter or so...and case closed. I don't think Mark K. was, or IS trying to tell anyone, what they ought to do with THEIR car..just offering a bit of first hand knowledge of what he personally uses on his car. And I don't see anyone here telling him what a bone head he is for doing it...

GlenL

Cripes, guys...

I made a open top air cleaner and tested in on the dyno:

5 more HP with the tube setup.

I tried it at the track, too:

No noticible performance improvement.

BUT, I may go back to it because it sounds good, looks cool and is fun. I swap filters at the track anyways. Once you're doing 50, 60, 140 the underhood air isn't overly hot and it shouldn't hurt performance.

Here's the thread and pics:
https://rennlist.com/forums/928-forum/146484-race-air-cleaner-top-project-2-a.html

ErnestSw

OOPS!! We're getting into religion here. Jeff, you go right ahead and worship whatever diety floats yer boat.

H2

Thie is nothing new to the 968/944 guys. All you need is a holesaw and an adapter kit ($5 four holes). Don't know if it improves the preformance but it does sound nice...just another sucking sound to some.

HH

RDS928S

Ok if it makes everybody happy I just went outside and taped over the holes.
Now the car wont start-Damm.
Ernest I need some religion bro.

Rich

Jim bailey - 928 International

Erich I agree the heat off the exhaust manifolds which are far far hotter than the radiator will tend to rise and collect under the hood. Nearly all the racers cut down the top of the firewall and try to get high pressure air off the windshield cowl area since the heater box is long gone and they block off the rest to avoid the heated air off the engine.

PorKen

In summer, you can remove the rubber hood seal along the back of the firewall. (Rainy and cold = steamy windows inside)

jeff jackson

No religion involved Ernest... And I prefer to keep it that way. I certainly do what I want to do with my car. Has nothing to do with religion... Mark K...or anyone else, for that matter. I do find it disconcerting though...that Mark makes this comment/suggestion...and someone posts they tried it...and liked it...out of the wood work all hell breaks loose about what a stupid move it was. Well...whatever. If Rich ends up regretting the choice, I'm sure he knows the way to the telephone, and he can make it alright very easily. One vendor... I know of...( on the east side of the country), has it...and brand new too." If" he thinks its worth the investment, for the "best house, in a cheap neighborhood"...But, it is his choice....my point is, dissing someone, for posting a "mod" they did, on recommendation of a known and respected racer, and member of this community...is just wrong.

ErnestSw

Jeff,
You have a valid point and I apologize if I offended you. I couldn't resist pulling your chain, The devil made me do it!

RDS928S

Ok -so does this mean we are all friends again

I guess I should'nt post the pics of my drilled out muffler.


Rich

jeff jackson

OK...I'm sorry for venting . It isn't a big deal to me one way or the other...I just want to feel uninhibited, about posting this or that most likely "hair-brained" idea I might have (once and a while I have an idea)...without fear of a group crucifixion for thinking out loud...(Oh god Ernest...I see what you meant now)...Peace and love to you all...

ROG100

If I trepan corresponding holes in the hood and cover them with a scoop will that give forced cool air.
Maybe thats the answer.
There's no religion under my hood!

heinrich

Dude Porken would strip the enamel off his teeth to save a few ounces ... Did you know he believes unleaded is better because it's lighter without the lead?

heinrich

Oh I think those overheated pistons are PRAYING for mercy Rog