Chipping a 911

[dsnow]

I have been seeing advertisements about software upgrades for your car through the trade rags. Do these upgrades work and give horse power or do you need to add headers, pipe etc to realize anything and do they keep the cars reliability in check?

Just wondering.

2002 C4S coupe, manual

Thanks

soutahc4s

[Chuck Jones]

This has been a hotly debated subject from the standpoint of a single modification like a chip, or plenum, or CAI, or whether it takes a number of these modifications acting in concert to give you noticeable performance enhancements.

I have installed just about all of them....and in truth, had I to do it over agin, I'd have saved the money and put it towards a twin turbo rather than trying to pick up 10-20 horses here and there trying to make it faster than it is. The manufacturers throw out all sorts of horsepower numbers....but there are very few of us on these forums who have gone thru the trouble or expense of actually putting our cars on dynos before and/or after. Most (not all) of the feedback you'll get on this hightly subjctive at best....descriptions like "it feels faster"....or "I noticed an increase". Some folks will swear that it makes a difference....others will wonder if the thousand or more dollars you'll spend chasing these elusive horses is really worth it.

Do a search on mod words like Plenum, Cool Air Intake, Flash performance, headers etc...and you'll get all the reading material you can imagine.

[wross996TT]

My guess is Chuck is right...of course in a turbo it's a different story...but who mods their car anyway?

[Lee Quave]

I’m somewhat surprised that there isn’t definitive proof one way or the other. Can’t these mods be scientifically analyzed to determine if they will add performance?

[Loren]

I’m somewhat surprised that there isn’t definitive proof one way or the other. Can’t these mods be scientifically analyzed to determine if they will add performance?

See my Blog here.

[Chuck Jones]

The only product recently that I've seen anything akin to "proof" is some of the info coming back on the Plenum....but even that was the result of only several runs and nothing like the process described by Loren in his blog. There are also a couple of folks who have run the Plenum on their GTek looking at the before and after times. One fellow went from around 5.6 down to 4.7 in the 0-60 run....with a tiptronic no less. Best times I could get were in the 5.6 area....but I didnt do a very aggressive launch on my failing clutch....(no...I'm not sniveling or making excuses)....just don't see a reason to fry a clutch to drop .2 or .3 seconds.....I gave that up after highschool and after my dad quit buying tires for me. Oh yeah....I dropped the clutch out of his car too and it was fixed under warranty....naturally I came home with a bewildered...."dunno what happened" look.

[Izzy]

I agree with Loren's blog but would change one thing. Use statistical power tests to determine the number of runs needed to establish "proof". Based it on the differences between runs, instrument linerarity and accuracy, error terms, etc etc. You enginerd geeks like me out there know what I mean?

On the other side, since I painted my track wheels red, I have another 28.37 HP. Krylon states that on the paint can.

NBL, Izzy :drive:

[lIRATIl]

My guess is Chuck is right...of course in a turbo it's a different story...but who mods their car anyway?

:clapping: :lol: :lol:

[phillipj]

You got 28.37 H.P? From the red paint? I better put on another coat :clapping: