FlyYellow

Does anyone have any experience with the PowerHaus RamAir Motronic Intake? I spoke to David @ PowerHaus and he claimed that it is 4 HP (Dyno measured) better than a mass air flow meter. To me that was quite a statement! Does anyone have any experience with these units.

Over all I found the performance interesting and it is convincing with the Dyno Results (posted on their website). So I ordered one and I will post my results as well.

See website below for more info:
http://www.powerhaus.com/ram_air_filter.htm

Of course any experiences that you wish to share would be welcome.

Bill Gregory

You can pick up 8 hp by either drilling holes in the intake to let more air in, or installing one of Fabspeeds euro holders that holds the filter on and opens up the filter face.

FlyYellow

I already have the drilled out air box. But that 8hp gain is at the crank. Most people argue that on dyno the drilled out air box scenario doesn't make any difference. This is HP at the rear wheels (dyno tested). Just my 2 cents?

apw964

It may not make any significant power difference, but the induction noise is good

Roland Kunz

Hello

The factory cup version had a removed restrictor pipe and a half drilled aircleanerhousing and the standard airfilter.

However drilling holes into the upper area will ower the power output. The enginebay is under as specific ram effect at higher speeds. Generatet by the rearspoiler the overpressurezone is along the underside from the filterhousing. makink a hole in the upper area will release the traped overpressure but adds more noise with feels faster. As the AC compressor disturbs the effect Porsche changed the setup on the 993.

This effect is not reflectet at a dynorun with the car standing and so all that nice curves proof nothing except that thy gained power while the car is reved up in the parking lot. On the other side the ram effect needs higher speeds and I think at 55 it might show up .

jfkaminsky

Hi Roland-
Do you mean that the factory cup setup offers lower power because its half-drilled, or if you drill any more holes than this you will lower power?

What do you mean by drilling holes in the "upper area." DO you mean anywhere on the top of the air box, or on some region (upper?) of the air box cover. Maybe you could add a sketch of what you are referring to?

Thanks,
Jon

Roland Kunz

Hello

Do you mean that the factory cup setup offers lower power because its half-drilled, or if you drill any more holes than this you will lower power?

I mean that if you drill the holes on the wrong area you make relief holes for the overpressure generatet by the ram effect.

If you drive a Shacker hood on a american muscle it also shows a open section into the driving direction catching the wind but it isn´t drilled up all over.........

What do you mean by drilling holes in the "upper area." DO you mean anywhere on the top of the air box, or on some region (upper?) of the air box cover. Maybe you could add a sketch of what you are referring to?

Was searching for a Cup Filter picture. But didn´t find one yet. The cup filter has only holes on the lower section something like up to the lower 1/4 on the sideways showing case face. Most people drill up the complete case.

Anyway no problem as the rameffect has only benefits at higher speeds while the sound effect hits most people even ideling in the slow speed zone.

I just wantet to show that most off those things are based on more sales orientatet backgrounds then real life parameters.
And a static dynorun isn´t real life.

Grüsse

Adrian

Another statistic to support Roland with his comments on the dyno. I have received from many kind 964 owners dyno results. The HP figures from Porsche are at the crank/flywheel not on the rear wheels. The latest data I received was from somebody who did a few mods to his rather special 964. His flywheel HP output on the dyno was measured at just under 275HP. Measured at the wheels was 78HP less. 78HP lost through the transmission. 28% approx. How much of the 4HP at the crank is ever going to get to the rear wheels. Transmission losses as pointed out by Roland are not linear either. A static dyno run and real dynamics, like traction or lack thereof increase the losses or waste of HP. Most of these improvements in the end just relief your pocket and provide little no improvements. In fact I have three cases where HP was actually lost. All proven on the dyno.
We have no data on the C4 because AWD dynos are hard to find but I am sure the transmission loss is worse.
Personally I apply the 5% rule. If anything offered is 5% or less (12.5HP approx) I would not bother with it.
Ciao,
Adrian
911C4

PS: I have holes in my airbox. The affect in my opinion is not worth discussing. I will say that the sounds with the same drilled airbox are different in my C4 as compared to the C4 this was originally done to. The only main difference being I have the Swiss Exhaust system. Supposed to be quieter but according to those who have driven with me, is deeper and throatier than the US versions.

J richard

There is a guy on the RS America web page selling one of these for $195. I think it's used. Its on the parts for sale tab at www.rsamerica.net. You might check with him and see how it worked.

Hope it's what you're looking for.