No doubt that DR isn't making much or if anything it just the system hasn't been ready yet but looks to be soon spring 2010?and was curious of what some guys were running and also would like something where you can change different filters to see what flows best.DR's setup is very cool looking!

 

If you like I have a HUGE box of all the different filters/housings I tried over a few years time...you are more than welcome to use those and go through the same time consuming and expensive testing and dynos of all of them(again)... that I have already done :-)

To be honest it will make me feel better mentally to know there is at least one more person who is a glutton for punishment of time(and money) concerning this design!

It would also be interesting to see if you come to the same conclusion as I did :-)

BTW, thanks for thinking the setup is cool looking, luckily after a lot of trial and error it works as good as it looks!

 

Time to perfect and time to construct justifies the price IMHO. I like it and as soon as I get properly running again, time to start saving for it.

 

DR, if you're kit does come out in the spring will it be polished aluminum also or more of the composite black material?On going thru the testing it would be easier to say what you have tried and what you haven't tried but would like to try in filters:-) lol

 

copies may look similar, but may or may not match DR's performance baseline...

those they all will look damn cool.

 

FUSE69 did one. LINK


DR is right... slim-to-nil to package out 2 of those K&N filters under a stock 928 hood.

The BMC filter that FUSE69 used is a good choice. Though it would only work for the 87-later models with the more compact intake and fuel rail arrangement.

Oh yea, and 2 of those BMC filters will set you back $400.

DR's price is excellent considering many things. The development costs to prove a product does more than just look good are substantial. Quality of the product is supberb (seen it with my own eyes). Looks OE... and looks sweet!

Only problem I see is he has none to sell... yet. I'm sure it just a matter of time.

Here's my design for a system packaged to work with the 84-86 Euro/ROW, 85-86 US and 87-later ALL. May be easily adapted to the early cars too. Problem is I have no development scrap. Anyone care to donate?

 

That would be a nice setup.

 

I for one think Dave's BlackBird is the best and have been patiently waiting my turn in the production queue. The "Bling Factor" is worth the $700 on its own. To design and develop a system like this takes time and lots of money. The non-recurring costs alone would make your eyes water.
The return on investment is sometimes a pill that is hard to swallow with low volume parts.

 

Anyone ever try a screen with larger holes for the MAF?

 

Nice words Roger and truer words cannot be spoken about this subject!

Knowing what goes into the R&D of trying to come up with quality custom parts for our 928s and then making enough to sell to other 928ers is not for the faint of heart.

I know DR and Jeannie have put a lot of themselves into their product lines, sometimes at a detriment to their regular parts business, since investments in the R&D for these custom parts are not returned quickly and you are carrying the load for many years. That's why I believe it's very important to support vendors like them and others, I'll exclude ourselves for the moment, who go through the trouble and expense to make parts to keep our 928s going. Porsche surely isn't and if they were most could not afford their custom parts if they did.

Stepping off my soap box,

 

just remove it for the best gains. screens are terrible for air flow. in fact, a screen on the Harrier Jump Jet, in early designs, prevented it from even taking off. It is not needed if you have a filtering system securely attached.
Keep in mind, the Holbert car went from 290rwh to 335rwhp with the only changes being: headers, venting the air box, no MAF screen, KN, and a fuel regulator (and the fuel was not that bad on the original test)

Dave knows, I always raz him about the design, because Ive done quite a bit of testing myself. Probably even more than he has with different air intake configurations. Never a 2 into 1 feed to the MAF though. It could have some resonance or flow characteristics that are unique to its design and help provide some extra ponies.

The stock system is very good. One of the tests I did, disregarding the hood and physical limitations for room was a series of tests of special 3.5" diameter cone filters that had an internal bell mouthed inlet. It stood up in the air like a smoke stack with the hood open. I was expecting some big gains, but that never happened. there was a loss of 3hp, and it was pretty uniform, and was regained when the stock system was replaced.

I would be really interested in seeing the performance differnce on the stroker any difference on the S4 stock, would be magnified on the larger flow engines. Ive done some flow bench testing of different configurations, however, it didnt include our stock system. (which woud be easy to test).
As a note, it is interesting to see the flow difference between open pipes, bell mouthed inlets and cone filtered inlets. the open straight pipe of 3.5" diameter, flows less than 3" if it has a filter or bell mouth inlet.

When this thing goes into production, I hope to do some dyno testing to see how it works out on the larger engines as well.

mk

 

Screens do add some resistance, which may or may not matter depending on air flow and size of the pipe. But the important thing is that the resistance, however slight, does make the air velocity across the pipe much more uniform. Which the MAF needs, since it is only sampling a small central area.

For a race car this doesn't matter since the throttle-plate only has two positions. But for a street car which spends most of its time with small throttle-openings I think the screen is important. Without uniform airflow the MAF cannot accurately measure airflow and the fueling will not be correct.

Sure, but headers (and no cats) probably account for all of that. K&N filters aren't worth anything and fiddling with fuel pressure is just a substitute for proper Sharktuning.

I bet if you put the screens back in and got Louie to tune the car you could match our 345rwhp!
(I know, that was before the stroker, just pulling your chain! )

Cheers, Jim

 

The scrfeens dooffer some flow restricion, but also fulfill a necessary function, as Jim mentions, to keep a laminar airflow across the sensor assembly in the MAF.

The important thing it, where is the most significant restriction in the intake system ? I am sure it is not the MAF.

Has anyone ever dyno'd with and without screens and measured any difference ? I doubt it....

 

From what the ad said on screen with larger holes it helped out so the car wouldn't surge.
When they vented the air box are you talking of drilling holes in it like on dirt bikes where they ad the little filters in the sides after they are drilled out.

With air coming in from both sides wonder how a divider would do down the center.On the dyno DR's should a good increase in HP.The real test is taking the car down the drag strip as with the ram air the system may ad more HP while in motion thats one thing the dyno can't show.


Could run the stock air box just cut the whole filter out and use the outter gasket area for a seal and run inline filters could then see how good the stock air box is.
Has anyone tried that?Have you tested the stock air box without a filter to see if any difference?

 

actually, my car does an excellent job of meterng fuel. most of which is really the O2 sensor's job. the filter itself, does a pretty good job of smoothing flow. most ALL race cars do not have screens. I wonder how much HP they cost. not worth it for me to test, but someone, someday will. they are MURDER on air flow. put a MAF on a flow bench , with and without screens and see the difference.

the KNs were worth 5-7hp, and it was pretty distintive. the real reason you or most have not seen gains is due to why? can you guess. Ill tell you . The air box leaks. as you get more restriction as far as paper filters, more air bypasses the air box entirely. sealed up with a proper pressure and fit, Ive measured, near .5" Hg vacuum change! thats huge. IM sure someone can do that dyno test, but if they do, i hope they seal up the air box for a valid test

I dont think headers are worth 35hp, but im sure much of it was the header, pipes, and slight tune up and the screens. (and maybe even the coding plug with the proper setting. .