Definitely want one!

 

they do look cool and allow for more air flow than the OEM system.

we had to go to a larger injector on my old boat, so I can only assume it allows more air. but if it's a stock motor, I'd guess it's not going to give as much of a gain compared to a blown or larger displacement motor that really needs more than the OEM system can deliver.

smog guys kinda freak out a bit w/them out here. I think a pair of black canisters for filter housings might tone it down enough to avoid unnecessary smog **** attention, could be an option.

mine never gets hot, unless the motor is off after a run. as mark K. noted, too much air rushing through there to warm up much. I suppose one could wrap the whole thing with insulating tape just for fun, but I doubt it would make much diff beyond looking like the michelin man was there.....

 

Or how about one large filter with a filter box with a nice bell mouthed inlet??? Oh wait, the stock one is like that! The stock stuff is pretty amazing. As I mentioned a few times, i put on a large bell mouthed opening, almost one of the most efficient inlets possible, and lost 5hp . The filter and inlet were sticking way out of the hood, for the test. It showed me that the stock inlet, with the large filter above it, was more efficient. Its quite a good design.

It would be a good option to get some really nice DR tubes feeding the stock air box. Venting to the firewall is certainly a better way to reduce pressure drops as well, but difficult to do on stock 928s.

The design is interesting, perfect when removing the air box. It would be even more interesting to compare flow of both the stock and backbird systems. (on a flow bench)

mk

 

Shhhh..... That will most likely be the "Standard Version" a one piece molded cone and canister made out of military grade composite :-)

 

good because I want mine black when this product line goes live in June.

 

If that part doesn't happen by then I will send you a free can of Krylon Semi-flat Black :-)

 

surely to flow more air you'd have to increase the size of the actual intake point?

 

In a nutshell, it's all about smoothing the air flow from beginning to end. The smoother the airflow, the easier (and faster) it can get in and the more you can flow.

 

I understand that the system would do this, it looks fantastic. And I thoroughly believe the dyno results.

Just can't get past the fact that surely both this and the standard system is punished by intake mouths that are each pretty damn small?

 

Another SHHHH... :-)

Once you get a company to start molding parts for you, strange things start to happen.

 

Er... what? Hmm... oh really?

Dan
'91 928GT S/C 475hp/460lb.ft

 

Nice. Another can of Cholo-Vato Boy Graffiti Black to add to my collection at home here

 

first of all, you should see the pressure drop when you seal up the intake system , normally. the pressure drop (vacuum) rises by almost .5"Hg.

so, this means the stock system has leaks under WOT, of unfiltered air. the problem is that air is very hot, coming from the engine bay, so it might be a wash.

the inlets are wide and narrow, but their area is not much different than the 3" diameter of the tubes. the venturi is a neck down in the stock system and if they are used and the tubes are sealed, there is a known restriction there.

As DR says, its all about smoothing air flow to the main 3.5" inlet of the MAF.
a Bell mouth or as DR has in the form of the two-into-one inlet, are very good ways to keep laminar flow and reduce pressure drops to the main inlet, which is the 3.5" diameter MAF. there is no real reason why the filters inline would have any reason of reducing turbulence, as the air after such a filter, still has to make a 90 degree turn , as with the stock air box as well. probably much better than the ribs of the stock tubes though. air also needs guide vains to make turns efficiently, other wise, turns will create some turbulence. the stock set up has this kind of turbulence, but the flat filter will tend to straighten and smooth flow out of it. This can be seen at any KN flat filter demo with smoke or even the boucing floaty *****.

Ive seen 5hp gains by using the eRAM electric blowers, not in pressure mode, but in some kind of flow enhancing mode. I suspect that the gains we saw were mainly due to enhancing flow through the filter by having a positive pressure source at the rear of the air box. ??? kind of black art stuff at that point. much more clear are the effects of the eRAM on sealed intake tubes on smaller engines with less HP (240rwhp max).

what is a clear indication on the dyno runs are gains up top. if the gains are top to bottom, usually something else is going on with the run, because the system is fixed, and flow will show higher or lower gains at the higher flow rates. The "Pipes" actually become effectively smaller with higher air flow, thus amplifying the effects of the pressure drops across the system.

Remember, the speed of the air doesnt change at the inlet. that is fixed by its diameter and engine speed and displacement. what does change is the pressure drop across the system.

mk

 

Yes, its about making more efficient, the intake track. smoothing air flow will reduce pressure drops. as we see in head work, sometimes smalller ports will move more air and have less of a pressure drop.
remember, not "faster", as the speed of the air wont change, but its density will based on pressure drops across the entire system.

easier= less pressure drop
more flow= more mass flow, in the form of density.

mk

QUOTE=DR;6347834]In a nutshell, it's all about smoothing the air flow from beginning to end. The smoother the airflow, the easier (and faster) it can get in and the more you can flow.[/QUOTE]

 

Here are a few dyno runs of cars that had intake changes.

1st dyno chart : Blackbird- noticed the end to end gain. Im sure there could be gains over the stock filter, but I need to know more about the test. Stock air box? sealed? KN? oiled ?

Then, here are several eRAM dyno runs. Some we would do back to back dyno runs with the only change being the eRAM on or off. Notice how the gains are only at the top region. One of the dyno runs were on a the part euro 4.7 and we had the eRAMs (2 of them) . they showed gains up top, and then the same gains, even with the back of the air box open. (no positive pressure) that was interesting, proving the point that DR made about smoothing or optimizing flow for gains. (reducing pressure drops to increase mass flow) Even the last dyno run where its on a Honda. no gains down low, but gains up top in the RPM.

the point is, I always want to do more tests or want to know more when the gains are overall. I can post several dyno runs where you get this disparity of curves with no changes made. The one think i liked about the L-jet cars is the runs were so darn consistant. Look at the one below at devek days. the two runs with little change on the eRAM runs are mirror images of eachother. (they were odd numbered runs. meaning, run... make change then run.... make change back..... run again. The LH systems seem to have a few more variables run to run.