996Outpost.com

It was a beautiful day yesterday in the mid-70's. After looking at some of your bikes in the motorcycle thread, I went outside to push a bike out to go for a ride and glanced over at the cab and... yup, change of plans. I gave her a bath and headed out to the twisties of north San Diego county for a fun few hours. I even did a detour to my old neighborhood to visit my old next door neighbor, which is where I took the photo. But the question of the day for all of you 996 gurus: Why does my naturally aspirated c2 pull harder from 6,200 to 7,200rpm than my turbo does? I'll go ahead and turn the coffee machine on now while you guys diagnose the issue. Thanks.

Ummm... don't have YOUR luxury of owning both cars to compare. And, I'll be straight up here... I don't push the rev on my car to redline. I'm usually shifting at much lower RPM than 6200 and keeping the car happy at about 3000 RPM on average. I learned my lesson with my '03 cab about over rev'n the motor... that is, the dreaded rev limiter - fuel cutoff feature.

You sure this phenomenon is not in your head? In theory, you should have tremendously more boost from the turbo over the NA cab. Maybe it's just the two platforms that are messin' with ya? RWD vs AWD ... open roof vs. closed roof. yada yada yada.

Your turbros are not working?

Hmmm.... leak in your piping?

(Keeping the old tradition of the rookies chiming in first )

NA996, makes most of its power at the top of the RPM band by design; power peaks pretty much at redline. In many ways motor in 996 behaves like a Honda Vtec motor, it loves to rev and makes all of its power at at redline. 996 TT makes it peak power at 6,500 RPM, so power is dropping off after that point.

If I had a guess, it would be that once the car comes on full boost, torque quickly jumps to max and then starts to drop back down, while HP continues to build in a more linear fashion. At about 5250 RPM on the Turbo, torque and HP values intersect; from that point, torque continues to drop while HP continues to build toward redline.

The torque curves I've seen for NA cars tend to be flatter. Since HP is a function of torque and RPM, the "sweet spots" for the butt dyno are in different places. I expect you feel like your Turbo hauls ass right after the turbos spool and then kind of tapers off toward redline; the NA car, even though it makes less power, tricks the butt dyno since the torque doesn't drop off as precipitously...so it feels like it's pulling more consistently as you near redline.

Or I'm making shit up.

The apex of the hp curve is here for teh n/a



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while the apex of the trubo torque-shove is here



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Because there is no 7,200rpm on my turbo. The rev limiter pulls the fun juice at approx 6,600.
Without the appropriate tune mod, only non-turbo folks get to hear the glorious sound of the 996 flat six singing at high revs. And that sound really is just plain beautiful.

I see what you did there.

Bwahahahahahaaa!