This conversation has come up more than once (on here as well as other forums). Instead of trying to discuss it with non-owners, which causes speculation, rumors, etc... I figured I'd ask the people who push their Turbo PDK or Turbo S.

What is the maximum HP/TQ on the stock PDK transmission?

 

sorry to respond as a non owner, but I believe champion states that it's around 560awhp at the max, but 540 with a reasonable margin of error.

https://www.6speedonline.com/forums/...eply&p=2806330

hope that helps, sorry to respond as a non-owner, but I am just quoting a vendor.

 

Hey Jasper,

I think the jury is still out on an exact number.

It really depends a lot on your driving style. Do you frequently do hard launches from stand still? With or without launch control?

CMS did quote a figure of 540/560/580 or some such but that was when the car was very new to them and had not seen extended use/abuse.

I think that the figure would decline dramatically with extended use. It would be closer to 480/500 torque. This is from my own impression/feeling with my own car.

The problem with upgrading the gearbox is two fold. Champion did very well to document all the complexities involved.

Yet for all the work Champion put into the gearbox, they addressed only one of the two problems, the clutches. They upgraded the clutch materials and they added a big aluminum oil tank cover for better cooling. This should in theory go a long way towards getting the clutches to hold.

However, the next big (read insurmountable) obstacle lies in the gears themselves.

As you know, there are two shafts in the PDK unit and they are not of equal size. The larger thicker one holds the first, third and fifth gears and is/should be quite sturdy. The smaller shaft holds the second, fourth and sixths gears. the gears themselves on the smaller shaft are also smaller than the gears on the first shaft, and therein lies the problem. (BTW, in this respect, the GTR is much easier to upgrade. A friend just upgraded his trany, gears and clutches, to hold +1000 whp/tq !)

I know of at least one tuner that has gone through the same exercise that CMS went through for upgrading the clutches, etc... and started testing the car with bigger power packages only to abandon the entire exercise because they destroyed these smaller gears completely and ruined the whole gearbox.

They then felt that the added handling capacity of the gearbox with upgraded clutches only is very minor (relatively) before the gears begin to break (with extended use or with abuse). This led them to believe that the cost of upgrading the clutches is not justified given the minor gains before the gears are threatened so they completely abandoned their effort.

In short, and from several tuners I spoke with, short of redesigning the gearbox, it will never be able to hold serious power, and redesigning is, for all intents and purposes, practically impossible/unfeasible.

 

i can't put a number but to get the most out of your PDK without any problems, ( exhaust, filter and ECU)

 

Thanks for the responses!

k_ddsl - these numbers are very close to what I heard was the current limit (600whp). But your summary/explanation is excellent. Makes perfect sense to me.

 

Karim, that was an excellent explanation.

The incredible iron (in my eyes) is the vast speculation about how a weaker consumer grade engine would be the limitation of the new turbo when in fact it appears to be PDK. And since the vast majority of new turbos sold were PDK, a (relatively) limited number of 6 speed turbos are around to really test the limits of the new engine.

bob

 

Bob,

The new DFI engine is not as sturdy as the Metzger. That's fact.
In OEM trim, it will live on and on no problem. But for tuning, it can't hold the same bolt on mods and +700whp without going into the internals.
However, internals can be upgraded, the tranny simply can't. You'll run out of tranny options much before you run out of engine upgrade options.
So for the 997.2tt 6speed owners, they can go far in modding with upgraded internals, but for the PDK owners, no such luck. Best you can hope for is upgraded VTGs after champion release their PDK upgrade, if that.

That's why I think I am fast approaching a radical decision!

 

I also think that CMS mentioned a fueling problem with the DFI motor.

 

What radical descion is that K-ddsl, I guess you are selling the car...for a GTRS4...!

 

Going to trade in for a 6spd car ?

 

I don't think anyone has drilled as deep as we have into the development of the PDK gearbox as well as the 3.8L TT DFi motor. Rather then re-type it all. Check out these threads. They should answer most of your questions:

https://www.6speedonline.com/forums/...t-updated.html

https://www.6speedonline.com/forums/...ch-update.html

https://www.6speedonline.com/forums/...-research.html

However, I'll do my best to summarize:

-- The PDK is limited at the mid-500 hp/tq level (to be safe)
-- The factory fuel system is not capable of supporting power levels much beyond that anyway.
-- The engine internals (according to our testing) are also significantly weaker then their predecessors. (rods specifically)


At this point, we've found a clutch material that seems to be holding good power, however we're unable to test the upper limits of that power capability of it without completion of our upgraded fuel system and reinforced engine internals.

 

what's "good power?"

 

"Good power" is about 620hp at the wheels, slightly less tq, around 600.

 

Tom - Thanks! I've actually followed those threads... But I haven't been keeping up, and I didn't know where to start looking (trying searching for "HP PDK" lol!).

I appreciate the summary...

 

Tom:

Count me in .

PG