adrian928se

Has anyone tried and tested the 928 Specialists Twin air filter inlet system? If so what were the results?

Some impressive claims on the 928GT website, though I can't quite work out why there would be more that a few hp gain at most?

Adrian

FlyingDog

Smooth flow through the MAF is bad. People who remove the screens from their MAFs usually have problems. DR has pressure drop data on a lot of filters and the ones he uses are very efficient.

IIRC, the first user who installed his at SITM posted dyno charts of before and after.

ew928

Wasn't it Doc who installed the first unit?
Ed MD was his user name?
SITM was so long ago I can't remember.

John Speake

I agree with Stirling. The stock airbox is attempting to turn the air through 90 degrees into the mouth of the MAF. Lots of possibilities for turbulance. Louie and others have experimented with some success by reshaping the bottom of the airfilter box to persuade the air into the MAF better.

The MAF requires a laminar airflow, without turbalance.

DR's design looks good. It would be interesting to see what effect, if any, the design has on A/F rattio through the rpm/load range.

tleaf321

Hopefully I'll be able to tell you if there is a noticeable increase in HP. I have the Blackbird intake on order. There's a delay in shipping though. It should have delivered weeks ago.

I really need to have my car dyno'd before and after. Anybody know of a good dyno shop in MD. DC, VA area?

callgeorge

I tried something; cut out paper aspect of air filter; left rectangular rubber edges in place to be able to close airbox straps; used aftermarket cone filter(5inches at base), plumbing 5inch to 4 inch reducer coupler connected to 4inch air intake tubes; this was done on both sides; seat of the pants feel possible horsepower increase; will send photos to anyone who can show/post on thread.

Imo000

Are you sure it wasn't just the extra noise?