Has anyone made the jump with a PDK car? How much of a lag penalty with the upgrade? Any gotcha's or drivability issues?

I know the DFI motor is fuel limited for max power, but I wouldn't mind a nice increase of power on 93 octane which the larger turbos should offer. Then the headroom will be there once someone figures out the fuel/pdk/rod upgrades necessary.

It will happen. Just a matter of time especially as the .2's come off of warranty.

 

I don't think many have done it. A couple of Champion customers have done the 68mm upgrade but I don't think they post here much. Maybe Tom can chime in.

There are a number of 997.1's with auto transmissions that have done 68's including forum member kenromero and my guess is that they can comment on the additional lag / spool rpm compared with stock turbos.

 

I think the issue is you are at the limit of the PDK with 68's so no one has gone bigger. If there was ever a upgrade to the PDK made available like in the GTR, I would make the jump to a 2010+ in a heartbeat!

 

BBi Autosport has one. They cut it open, installed larger clutches (clutch pack provider's name was not disclosed) and welded it back together.

 

The DFI issue with fuel is a tough nut to crack. I came from the BMW world and they are having the same issues and that platform is from 2007 and no one has been able to really figure it out. A lot of "bandaid" solutions but nothing concrete and definitely nothing in "product form" that could be sold.

My guess is that when someone figures out the trick, they will make a ton of money because there are a few platforms in need of a solution, not just pcars.

-Jose

 

It seems the move to DFI is a pretty remarkable leap compared to traditional efi. Almost like carb to efi. The aftermarket will figure it out though. Just a matter of time.

An OEM supplier losing an OEM contract could be a catalyst or an oem engineer venturing out on his own.

The codes will be broken.

 

My honest advice would be to hold off for the time being. Right now, there isn't a plug and play fueling solution for the added airflow. In terms of lag, it is very minimal as even on the smaller displacement 997.1 you'll see peak torque around 4,000 RPM.

There are a few shops working on a reliable fuel upgrade for the DFI, but until this is available it is hard to justify the price tag versus the performance of a FBO stock turbo car.

 

I appreciate the candidness. Lag is a funny thing that can't be measured solely by rpms/dyno sheets. Back in my Supra days, I had turbos that "only spooled a couple rpm later" than my smaller turbos but the actual time it took for the engine to get to said RPM increased tremendously and the lag was much worse than it looked on paper.

I have a pair of 997.2 VTGs sitting in a box in my house waiting to be upgraded so my car isn't down. I guess I'll hold on to them until someone makes something that's better than factory for my application.

 

Like a few have said...right now the best bang for buck on the PDK cars is definitely stock turbos with a few hardware upgrades, like our GIAC flash/Intercooler/Exhaust pacakge with our proprietary Champion/GIAC tune. There really isn't another hardware or tuner package that has proven to be much competition for what we can do with the PDK turbo cars.

We've done larger 68mm VTG's on a few cars, which has definitely netted slightly higher peak HP but they quickly hit the limit of fueling before you can really take advantage of the additional air flow.

If your car is totally stock now, I can definitely make some suggestions on how to totally transform it for now, until we get the fuel system up and running. Feel free to PM or email.

 

Rigth now the smart move is bolt ons... Exhaust, IPD, IC's and a good solid Tune. Until the aftermarket world figure out the "fuel problem" stick with the stock ones.

 

This.

 

Like other's have said, you could do it but you don't have enough supporting fuel to make it A) safe and B) worthwhile. IF you want to go out on a limb, you could try to have a supplemental fuel system wired in, which would active under high load & allow you to capitalize on bigger turbos/more boost/ignition timing/etc.


Not sure how you'll get it to play nice with the factory ECU, but I'm sure it can be done.

 

It looks like the upgrades are starting to trickle in:

https://www.gmpperformance.com/index...ail&PID=226948

 

Interesting find...
I wonder if that has been tested

 

Nice! Agree with Chris...wonder about testing.