Boeing 717

Yea, if you mod it you won't be able to sell it for $280,000 dollars in a year. Based on the asking prices I've seen lately.

MeanMachine

I am not going to sell it for the next 25 years.

niche

I'd just get a modded 996tt and keep the 3.6 stock.

MeanMachine

I purchased it modified.

Metal Guru

Almost nothing on the stock K27-7200. At .9 bar, the compressor is on the edge of being choked. Once you cross the line, you are pumping very hot air into the engine. You won't feel anything and you risk melting a piston, or worse.
Get a K27-K29 hybrid if you want to boost more.

MeanMachine

Great, when you mean boost more whats that precisely longer boost time or more boost. Should I get a 1 bar spring with that?

DK964T

I went with a bigger Garrett GT35 turbo with upgraded compressor. Huge tial waste gate. All new everything, custom fabbed plumbing. Added an extra 2200 injector that sprays right into the intake. All new injectors, fuel lines, plugs etc. greddy boost controller. Lightweight flywheel and new heavy duty clutch among many other upgrades. It's pushing around 550 to the crank on high boost. I mix 104 octane with 91 pump when on high boost just for extra assurance. Exhaust temp is nice and cool all the time. Custom tune with full boost coming on around 2900-3000k rpm. The system built can handle a lot more power but I went with a conservative tune for longevity. Once I build the motor and new gaskets I will be turning it up. I wanted a system in which I could always go up on power without having to go back to upgrade something. The system is built to handle a lot more power than I'm pushing. It's still a beast to drive. I raced my buddy with a 2012 mustang Shelby gt 500 (550hp) from a rolling 30 start on the highway and absolutely smoked him. There was no catching up either. Needless to say he wants a Porsche now.

I wouldn't mod a 3.6 but if you want that much power be prepared to drop some cash!

MeanMachine

I sent Rarly8 to know if the current oem turbo can be modified to K27/K29 hyrid, In the site it lists that but I was asking if its still possible today. Getting that and a 1 bar boost spring is more feasible than getting a new turbo all together.

997 tt/rs

Guys, this topic is old but I would like to sort out some issues regarding the 964 turbo 3.3 tuning.

I understand that you can start with a sports exhaust, i.e. you can remove the muffler and also install a 100CPSI catalyst.
Will the above modification be felt by the driver?


I understand that the next stage may be a spring in westgate to 0.9 bar?
I expect that all of the above will already be noticeable to the driver and it will probably add up to 30-35 additional horses, I mean these European horses

the next step is probably shorter exhaust manifolds?

the next stage is the modification of the turbo, i.e. sharp as a knife turbine wheel and light compressor wheel with more effective geometry.
after installing such a turbo, is it necessary to tune something? fuel, ignition? or it will work?

the next stage are the camshafts from the naturally aspirated version and then the head studs, kit for 3.8 liters, etc.

thanks for help
K

Metal Guru

Depends on your goals.
What you will feel from exhaust changes will be the boost hitting at a lower rpm, mostly. Turning up the boost to .9 bar won't get you anything you can feel for the reason that I stated above. The K27-7200 stock turbo is at it's limit.
Want more torque? An K27/K29 hybrid turbo or a Garrett is good, but you will need to add fuel as you add mass flow.
Want more than that? Cams. Still need more? More displacement and EFI, possibly doing a full rebuild along the way.
As fun as a 600 hp Turbo sounds, you better be a good driver or you'll hurt or possibly kill yourself.
Then there's your prospective resale market that has to be considered as most of us will move on at some point.
My opinion is that bolt-ons and cams can make a car that's fun to drive and can be reversed when it's time. 425 hp in a car weighing 3200 lb is a hoot.
Anything beyond that and you better like wrenching and tuning and have the intellect to not blow your engine up.

Megatron-UK

Decat and header replacement makes a noticeable difference to the feel of the car - boost is on sooner and stronger than with the stock headers and cat fitted. I don't know the exact numbers, but it's a substantial difference in feel to the standard exhaust system. The standard system has too much additional pipework and bends in it - removal of those and shortening the length from the exhaust ports to turbo inlet definitely makes a big difference, if not to outright power, then to the way it is delivered. With boost coming in earlier and stronger than the standard car, you will find that you have a much more useable band of power and torque than the factory setup. If you are in any doubt over it changing the power characteristics away from the 'nothing, nothing, boost!' feel that (I think?) we all love about these cars, then don't be - it just means that the feeling lasts a little longer, and you have anywhere from 500-1000rpm more of it to enjoy.

I don't think the final silencer contributes much to any performance gains or losses. It would be the last thing I would change in the exhaust system.

997 tt/rs

won't such a hybrid 27/29 increase the lag?

Im thinking about mod that will reduce lag.

we all know that oem is old style turbo, barings, compressor wheel...

what if I install a modified Turbo with light weight more efficient compressor?? what will be max boost pressure running the oem spring ?

thanks

Scott Dunavant

I'm going lightweight and changing the gearing is massive. I did this 23 years ago on a Bare 94 speedster. The car about killed me with those sling shot gears.

Metal Guru

The K27 hot side is the same as stock so no it really doesn't.
It's one thing to go to headers and a sport muffler, but it's a kick in the butt to get a bigger compressor. Worlds of difference.
Besides, if you have no lag, you have no turbo

997 tt/rs

Paul in principle, if the compressor is bigger, the lag is bigger and there is no meaning that the turbine is the same. The question is, how much is the compressor wheel bigger? Who knows what dimensions inside / outside the compressor in oem turbo is?