I'm writing it down- I agree 100% with Kibort.

 

ive done a lot of tests and the stock filter with the wide and thick airbox has the least restrictive set up.

the air on top of the radiator is cold, and is in the highest pressure zone of intake tract. even though the radiator is hot, the air transient time is short, very short. venting the air box to the rear is good, but tought and not that effective with a stock set up ( all that stuff in there vs a racecar)

 

Mark,

He's talking about Roger's EIS. I'm pretty sure they have demonstrated improved HP with this system.

While the stock system is the result of many years of development by some of the greatest minds at Porsche at the time- anything in a production car is going to be some kind of a compromise of materials or economy of production. It may be that they hit upon the idea of something exactly like the EIS, but the cost of changing the airbox and retooling for a different design may have been shot down.

You have tested many different configurations and air pressure zones. Have you tested the EIS vs. stock setup back-to-back?

Have you tried something like my setup on the dyno or on the track? (when a CAI is more effective, presumably than on the dyno with the hood up anyway).


To everyone:
The OP asked about CAI and instead got told to just leave it alone. There are CAI systems out there and they may provide more HP than stock, so why not just let him know?

 

'Cause we don't know whether his 25 year old car is in 100% working order before he goes about modifying it? A working Hall sensor is the cheapest hp/dollar you can buy for a 928.

 

Oh yes, ive done pressure testing , not only on the dyno, but on the road with sunx sensors everywhere! ive seen HP gains with no changes, so its hard to really nail down where gains come from unless you are doing back to back, on the dyno. what did for example was use a 4" straight pipe, on the MAF, sticking up like a smokestack! it lost 4hp, with a 4" diameter inlet, bell mouthed inlet filter (big efficiency gainer), vs the stock air box, with vents. the stock air box, no mattter the test on the dyno was better. based on flow theory, there is no reason the other designs would work any better than what i tested. certainly im convinced that what i use DYNMAICALY, is the best too, getting cold high pressure air from the windshield area, plus fromt the air tubes, with the tubes being smoother as well.

all these things can be flow tested, on a bench. or, i can put a sensor on it to see which has a greater pressure drop across it at speed. regardless.

the stock design is genius. it is wide, has a tolet bowl inlet to the MAF, and has two large 3" inlet, flowing air across a 2 foot flat , pleated fliter. its a pretty good design. if i was a betting man, i certainly wouldnt bet that any of the designs ive seen are better than stock, especially what i have done to modify the stock box. it is hard to improve on perfection. and adding a couple of more turns and bends doesnt really seem to add flow value to the sytem as is.

remember, ive spent a lot of time on the dyno, testing with the eRAM axial forced air system measuring pressure differnetials and dyno outputs. measuring these changes on the hyway is really telling too.

 

I know you are always right, and never accept anything anyone else has proven.

But we did dyno 4 different cars, back to back, in the amount of time it takes to change the stock intake system with Rogers EIS, each and every car showed an increase of 8-11 hp/tq with it. Which I am sure is higher than your electric supercharger.

 

Oh, great now you've done it, here we going into the whole suck vs. blow abyss...

 

Ok let me chip in... I was thinking of going with the EIS system because it looks nice and my stock system is looking very tired other than the dent in the wallet I still don't see a downside.

 

Mark,

I'm not doubting that you believe your system is right and that you tested it every way you know how. But what I can't believe is that anyone how attempts to base his argument on facts and science would ever use terms like 'perfection' and 'never'. There is ALWAYS a better system that could be designed.

Your design assumes that smooth is better than not smooth but there are very sound reasons (which are kind of non-intuitive) that say that ridges are better than a smooth surface. Golf ***** have dimples for this reason. The air that attaches itself in these dimples acts as small ball bearings to allow the rest of the air layer to flow over it smoothly. So intuitive isn't always right and everything one person imagines doesn't necessarily mean everything available. There is at least one orientation where the MAF causes problems in SC installations but rotating it a few degrees fixes the problem. AFAIK no one has mapped out the path of each air molecule as it goes around all of the bends and done tests to show where all of the eddies are.

I'm just saying that the OP asked about CAI installations and instead gets a list of things he should do to his car, none of which include CAI options.

To the OP:
There are at least two 'systems' available: Roger's EIS which is a true system, and building one on your own which is what I did and several others have done as well.

Good luck with your install and as with every other mod: The best plan is to get it working as well as possible with your stock configuration before upgrading.

 

Ricky Ricky Ricky.....

LEAVE IT STOCK....don't change ANYTHING.....just drive it as is.....save your $$$.....or your dads :>)

 

Uncle Bryan I knew you would say something I can't just leave it stock I'm 16 that's impossible haha

 

Tested car numerous times at the track...
Cold air intake added about 1.5 mph to 2mph and not much in ET in 1/8th mile
plus it looks way better than the stock air box.
Stock air intake on left varied from 76.65 to 77.99 mph with stock intake.
Cold air intake on right varied from 78.52 to 79.12 mph
Cold air intake changed from 3 1/2" elbows to 4" out back and ET was lower to 9.40 and MPH went up to 79.82
Never unhooked the computer either to reset it after the change so it may of added more.
All the years I owned the car it never reach 78mph in the test and usually ran 76.5 to upper 77mph now getting closer to 80mph.
Not that it is fast,just shows what the Cold air intake did and was track tested and definently showed gains in MPH.
Old thread here on how it was built.
https://rennlist.com/forums/928-foru...er-system.html

 

Listen to your DRUNKLE.....I guess I should be concerned that my real nephews call me that.....but then again I thought it up!!!!

Now its time to get your dad to come to the NCRC race weekend April 7-8 at Thunderhill!!!! I need a chance to beat him straight up!!!

 

[quote=IcemanG17;9289066]Listen to your DRUNKLE.....I guess I should be concerned that my real nephews call me that.....but then again I thought it up!!!!

Now its time to get your dad to come to the NCRC race weekend April 7-8 at Thunderhill!!!! I need a chance to beat him straight up!!![/QUOTE
Haha yea sounds like a plan, we gotta talk him into it! He's crumby haha

 

Okay... Repeating here...

You'e got a cold air intake. That's the two tubes that run to the front.

If you want to improve that, or at least make it more interesting and add something, get some 3" brake cooling hose. You need about 5' for the two sides. The brake hose is heat resistant and comes if a variety of styles and colors. Check Summit or Jegs or another mass merchant for this.