BGB Motorsports

100%. All of the cold start and moving the cars around without a subsequent flogging are contributing to that. The race cars get flogged on a routine basis which cleans out everything.

CAlexio

My impression is that there is no difference at all, just that they happen in a much more muted fashion with the PSE off. Even just so much I was barely touching the gas starts this sequence, completely pointless and artificial.

EDIT: just read above and if BGB says there is a point to the pops and crackles then great, I stand corrected. Still wish I could do without though.

user1029

GT3 Intake Manifold/TB/Plenum swap, Do IT!!

legin

Care to elaborate on why ?

CAlexio

the engine changes in character.. it pulls all the way to redline. it completes the cycle with the headers... very impressive change overall from stock to headers and intake.

legin

That sounds good as Im going with the ipd and cobb for now and maybe pipes next. Im more interested in a zingy top end than the torque low down hence why have done it this way around. I guess I miss the X51 in my 997 a little.

BGB Motorsports

These are all positive mods. I'm a big fan of the X51 manifold because it allows you control of the side intake runners for making low end grunt and then they open up top to become larger intake runners which maintains that flat torque curve and keeps that power curve climbing all the way to the top.

Any larger manifold mated to a bigger 82mm throttle body is going to increase power up top and fix the dip that causes the car to lose 20hp over 7200 RPM.

The X51 in the 997.2 was awesome and the X51 in the 991.1 is even better. Either way, with some better flowing intake and exhaust pipes and a tune, more power is available.

Peter_GT4

Unfortunately, I never had the chance to enjoy the x51 equipped 3.8.

But what the GT4 powertrain lacked as a worthy GT powertrain all
came around with CG headers, IPD Plenum and a tune. No more dips,
freer rev-out, more aggressiveness all over, perfect match now.

When doing my typical country road trip, I found myself often wriging
gears totally out and feeling a little underpowered anyway. Now I often
shift beetween 5.5 and 6.5 upm because of the meatier powerband.
With the option to rev it out when desired without the stock "dead"
feeling on top.



Peter

BGB Motorsports

It's amazing the potential these cars have with the mods. The reports from all of my customers running Stage I (manifolds, tune, filters & intake) are the same; you all agree that the car has "woken up" and now power up top is super linear. Have you driven a car with the lightweight flywheel? Where are you located? If you're ever in Central Florida, stop by.

John@Fabspeed

Experienced an X51 in a 2011 997.2 GTS the other day. It was love at first throttle lol.

In regards to the burble/overrun, my tuner is going to play around with some tuning files to see what effects they have on a 991GTS owned by jbgill6535, with the sole purpose of trying to reduce that sound. Curious to see how things come out but will let you guys know.

Take John up on that offer to experience the lightweight flywheel!

Jimmy-D

Ditto

CarAholic

Curious if anyone out there that has modified there GT4 had a prior 991.1 S. Do the mods make the car feel more like the motor when in the 911, as I miss the pull all the way to redline and the missing torque down low.

Jimmy-D

As stock I find the GT4 to be more alive than the 911-S

jpgunn

I had a 991-S and the GT4 was definitely not as "alive" up top. I did not modify, etc. to try and achieve that. Just sold the GT4 because I figured Porsche would do it themselves eventually.

cox1974

I 'm going to install in the next two weeks the ipd plenum, the 82mm throttle body and the cobb tune... I already have the sport headers and the bmc filters.... I really like to read other opinions about this performance combo