I reached out to IPD to see if they wanted some additional data on a somewhat high-powered 997tt in regard to their Y-Pipe performance. I purchased the pipe and decided to do some comparative runs to see how it did.

Initial thoughts:

The y-pipe is a beautiful piece. Its significantly heavier than the stock piece, but mates right up to the OEM location without any difficulty.

The sensor sits on top of the ypipe rather than the side of pipe like the factory location, but there is enough slack in the wire to connect the sensor without problems.

The inside of the ypipe has a nice dimpled design, similar to a golf ball, but not as tight. I am sure someone smarter than I can explain the reasoning, but I feel it's probably something to do with aerodynamics and how the air flows through the pipe.







The bottom runs labeled 1-2 were the first two runs with stock y-pipe. The top runs 1-3 are the runs post-IPD y-pipe.

My torque value was off from the first run on the stock value, but I'll call it 791 since it's about in line with all the other pulls.

Initial gains showed ~22hp / 5tq from the swap.

This was on the same tank of fuel, same dyno, same day. I did do some driving after the y-pipe was on, but since I am running aftermarket EMS, there really isn't any adaptions to take place like the OEM ecu.

I am also running the 82mm Plenum and TB.

The dyno doesn't load like a mustang or street run would, chances are I may gain a bit more if it were load bearing. Your results may vary!

Run conditions:

Stock - 79.13F / 10% Humidity
IPD - 72.45F / 19% Humidity

 

That dyno sheet looks like 5 identical runs to me

 

I'll have the dyno files tomorrow and I can overlay the two runs that show the difference.

It's the comparison between the 913 & 935 runs.

 

To me it looks like the +5 hp is really just that green blip that I've circled in red. It doesn't look like there's any real HP gain..

And the torque gain is almost un-noticable,.. but must be from the tiny deviation in the yellow circle.



So "IF" you have a big-hp engine,.. and already have the 82mm throttle body, and the 82mm plenum,....... then this Y-pipe will remove a dip in the mid-range from roughly 4,800 to 5,300 rpm.

Hmmm,... not sure what that's worth dollar-wise,... but it doesn't seem to have hurt your car's performance any,.. and removing that small dip in the mid-range might be nice.

 

The y-pipe adds power in odd spots, not necessarily peak power. This was mentioned to me from someone who's been messing with several 996/997/991 platforms.

Once I get the actual data files, I can overlay the two runs in question and remove that dip.

Is it worth the money? That's up to the individual. It certainly does look nice

 

I'd also be hesitant to call a 3% delta a measurable improvement...

 

That dyno tho. Holy crap must be such a rush to drive.

 

certainly looks like peak HP has improved from between 2 sessions. i would like to see just two files overlayed tho. nice job man and glad your car is running good !

 

So, you already had the 82mm TB and plenum? And these gains are ONLY with the Y pipe swap?

 

Thanks, dude. Sure is fun! Soon to break 1k.

Yes, y-pipe ONLY

 

Pretty amazing at that power level that it doesn't make much difference. The stock Y-pipe is $220ish from Porsche. It does kind of look like that spike at the end (dyno brake?) is the majority of the extra power.

 

Updated overlay of two runs.

I do not see much of a power difference that the y-pipe can account for.

Run conditions:

Stock - 79.13F / 10% Humidity
IPD - 72.45F / 19% Humidity

 

It's too bad you can't do area under the curve but I agree virtually no difference.

Are the numbers corrected or uncorrected?

 

I had 2 big-name tuners tell me that the Y-pipe actually lost you hp,... unless you had a 700+ hp engine that already had the throttle-body and plenum.

Most say to stay away from all of those parts on engines under 700 WHP.

A couple people did say that the 74mm plenum from IPD "can" help with spool,.. so I picked up a used one of those to try out next Spring.

 

Numbers are corrected using STandard. You can see it annotated in top right of graph. Correction is 1.03.