2 simple mods - increase the horses
 

I have carried out 2 simple mods this weekend

1. K&N induction kit (cone filter)
2. S/S sports pre silencer (straight through)

what difference does it make?

1. The induction kit took 30 mins to fit. I had previously drilled large holes in my air box and took off the snorkel to give that induction roar.
The noise is really no greater until you hit 5,000 rpm then all hell breaks loose.

2. The pre silencer took about 2 hours to fit. A deep throaty rumble at idle and slightly louder at high revs - but not deafening.

I should have taken her out after each mod to get a better feel for where the power has come from.

The result

definitely more power - you get used to your own cars power and this felt like somebody elses! I did not get the more noise, more power syndrome because there is not that much more!
from 2,000 rpm up to 6,750 (courtesy of SW chip) you can tell there is more power

How 'bout some photos of this changes?

M Oosthuizen
'80 911 SC

Hi Jacob,

I think you'll find that any power increases are due to the exhaust changes. There's loads of discussion on here about whether K&N filters improve things or are worse than stock!

Cheers,

Tim.

Hi Jacob, is your car Euro spec or US spec (did it have a cat?). Mine's US spec & I was thinking about a chip change. Did you notice much difference with the SW chip?

Nathan

Nathan,

My car is Euro Spec non cat.

The chip made a noticable difference and was well worth it (have you seen the exchange rate at the moment?)

it's a cheap mod that gives alot of power.

There are discussions in the archives about K+N filters actually being bad for the engine - they may not filter the air well enough.

I replaced my cat with a test pipe yesterday and my "seat-o-the-pants-meter" notices a difference. Redline seems to come much quicker now.

That filter did nothing to increase performance. The change in performance would have come from the Pre- muff.

Jeff

I guess that changing a pre silencer (non cat) for a sports pre silencer may be good for a few bhp but not many. changing a cat converter for a sports pre silencer may be good for about 10-15 bhp.

When you add a K&N cone filter after changing the exhaust and adding a Steve Wong chip I think this would make more of a difference compared to the first mod you may undertake.

Jacob, I've always hated the fact my car turned out to be US spec, so I'll do anything to get a bit of power back (I recently did a top end rebuild but the funds wouldn't stretch to a new set of high comp Euro pistons when mine were otherwise fine). If your ever in the Bradford (Haworth) area I'd be interested in seeing how a Euro 3.2 compares with mine. I've just drilled my airbox and love the sound ;)

I think anyone with a Porsche with a Cat has to look at that as the bottle neck for the flow in the system. Adding stuff before and after just wont help all that much. There are plenty of strong opinions about the use of K&N's most dislike them. But most of those folks are cat car owners so getting any results out of a K&N is slim. There are those that will tell all of the scientific proof of how they K&N will not filter as well as a paper filter and will ruin your engine. And still some will say it it flows no better than stock. Some folks even have the gall to tell you thier car sounds better and feels faster.

I can tell you this, the air box and air filter on most of the later (82 on) P-cars is not the bottleneck in the flow of your motor.

Nathan,

I live just the other side of Leeds. I could arrange to meet you somewhere in the middle sometime soon - always good to meet fellow porsche lovers.

Jacob