Sami951

Hi,

Quick question: I recently got the IPD Y-pipe + 74mm plenum installed (car is otherwise stock 997.1 turbo). During my brief test drive back home from the workshop I noticed a much more pronounced "swoosh" sound when getting on boost. Wasn't able to properly test how much car would boost but I briefly saw 0.8-0.9 bar, climbing to 1.0 with sport mode enabled..

Is the increase in sound normal, or does it indicate a boost leak somewhere? Car has been in storage for past winter months, so I'm having a bit of a hard time trying to remember how it used to accelerate performance-wise. Didn't feel really "broken", but the increased noise was weird.

Thanks!

best regards, Sami

808c2s

It's normal, as your Y-Pipe is wider now, allowing more flow. My car has the Y-Pipe as well, and the whoosh is more noticeable now, but no loss in boost psi.

USNA12

Did you notice any throttle response or power difference? I was thinking about doing the same eventually.

Tim997S

Excellent..I am installing on my 2009 Turbo this week.....my previous Porsche (2005 S) I used the IPD comp plenum / GT# throttle body..sounded great and ran great...
Current Mods - AWE exhaust / 200 cell cats / Evo motorsport headers / H&R Springs / Rennline comp shifter
Next - IPD Y pipe / Plenum / Tune (Softronics}

Tim997S

All turbo owners....please read !
Installed the Y Pipe / Plenum from IPD yesterday.....fairly simple {2+ hours) - the results are incredible....as I mentioned above I have 2009 TT with AWE exhaust / Evolution Mtrsports headers - the throttle response and power to redline are just nuts
I campaigned a 1967 Shelby GT350 with a 700 HP 380 CI ( clone of a Roush Fenway NASCAR motor) for many years, so I do know power....Greg @ IPD is great !

Sami951

OK, I was able to go for a more spirited test drive finally today. Something's definitely not right, but it might be something else than a boost leak. Car runs very well when going part throttle, however on full throttle there's a noticeable hesitation at approx 3500 rpms - right when it should normally hit the max boost. I'd even say that full throttle felt slightly less powerful than like 80% throttle, because of the hesitation... on the stock instrument readout I saw 0.9 bar max when in normal mode and 1.0 bar when in sport mode. As far as I remember I used to easily hit 1.0 bar off-sport and 1.1 bar in sport mode last year, before the modifications.

Not sure if stuck VTG actuator might cause what I'm experiencing, or if for example it's really flowing such amounts of air that the full-throttle map is not keeping up.. or, maybe it's simply a boost leak. I'll need to read up on this and start troubleshooting. edit: after googling a bit, looks like it might also be spark plugs. Car is getting close to 100k kms which equals 60k miles, which I guess means 2nd time for spark plug change in it's lifetime now.

cstyles

First thing to check is of course whatever you were just playing with. Y pipe and throttle body? Check all connections and hose clamps to ensure they are seated correctly and tight.

Are you tuned? If so, you can disregard the Porsche service interval for spark plugs. You need to change the plugs much more often once you're tuned. Your issue exactly describes a misfire situation. Misfires typically develop right as maximum torque output occurs which is right around 3500 rpm - and this is exactly where people report misfires once plugs go bad. If you have a lot of time / miles on your plugs, maybe the extra airflow from the new y-pipe and TB was what pushed them past their end of life point.

Kevin

Tim did you install the plenum and the tune around the same time?

Datalogging your MAF(kg/hr) Engine load and boost will tell you the output gained or lost with tuning and hardware changes (good or bad>>bad equal boost leaks or other issues)

Sami951

OK, found the culprit! Left side hose from turbo to intercooler was loose, the clip mechanism was somehow mangled and it didn't lock in place. My guess is the shop that tried to fit GT2 intercoolers for me didn't know how to detach the retaining clip and instead tried to pry the hose loose, thus damaging it. But this is of course only speculation.

Fixed it while GT2 intercoolers went in (great many thanks to my friend who basically did all the work while I watched from the side) with a 2nd-hand hose from another car, and everything works 100% perfect now. The noise is also gone - so it really was just a boost leak..