i have custom y pipe n intakes. maybe thats the reason im able to hold the boost all the way to redline?

 

sorry to resurrect this old thread, but I have a few questions for all you knowledgeable guys around the world regarding the 991 TTS...


How do you know if the Overboost fuction is actually working? if you floor it in sport mode and hold it to near redline, then press the sport plus button, should you feel a surge and see the psi boost and torque gauges increase too??


similar to the OP, I rarely see any psi boost readings over 14/15psi regardless of whether im in sp or sp+. I don't seem to feel any differnet whatsoever when in sp+ mode. surely this can't be right?


has anyone else felt the same?


I know I'm long overdue a tune, but perhaps there is a functionality issue that I should get Porsche to fix before I slap on a piggy or flash...


even my kids think it feels slow now! WTF?!


any tests ideas I can do to check the 'S' part of my TT is working properly would be greatly appreciated...


thanks in anticipation.

 

MAP is absolute pressure i.e. measured pressure in the manifold so to get boost you subtract 14.7. Course this is with a custom tune but boost hits 21-22 at the peaks. Probably look different without the tune but I haven't measured it that way.

 

Hi mate did you ever get to be bottom of this as we are experiencing same symptoms on a 991.1 tts

Car feels dead

Just about hits 1.0 bar/15 psi max 16 psi which is rare in sports plus

Can't really tell any difference in sports plus apart from the aggressive gearbox lol

Spoke to Sam and he's recommended doing a manual boost leak check but I can't seem to get my head around to making a boost leak tester so until that's done its bugging me

Also no warning or engine management light on etc

Obviously can go down the tune route but want to know if it's running normal as standard as to be honest it's been a bit disappointing with all the hype around these cars being super fast etc

 

I get this as well with a TTS I just bought. It reaches 1.1 (sometimes 1.2) for a brief time and then drops off to 0.9 or 1.0. I've tried to find a video on YouTube showing the boost gauge during acceleration but haven't found a good one yet.

Someone here must know if a stock car should be able to keep 1.2 bar/17 psi all the way to red line?

 

I've had this discussion on the forum back a year ago and the some guys swore that it pegs 17 psi all the way in every gear and other say it varies. My car hits 17 and drops off to 15 or 16 until shift and then back to 17 psi. What makes this even weirder is it sometimes stays at 17. Never understood why because I'm tuned and should be running over 17 psi consistently.

 

Only decent video I've been able to find showing the boost pressure gauge action is as follows


(From 1min30 onwards)

My car definitely doesn't do anything what that car is doing in the video

CPiGuy I think from my understanding the standard gauge only reads upto 17psi so to see the real boost pressure you'll have to hook up a software etc

 

Yes, I'm aware that the gauge caps at 17 psi, which I would expect my car to hold through out the rpm range, but it doesn't and never has.

 

Depends on air conditions and temperature. These cars will reach their targets which often does not require the full boost the car is capable of.

 

So in a cooler environment the car will run with lower boost since it can achieve it's claimed power anyway?

 

It all depends on the tune and package. The stock turbochargers are small so turned up they do tend to taper off. We add hardware and tuning techniques to minimize this as much as possible until adding a turbo upgrade that can handle the flow.

 

My car is still 100% stock. I am planning on tuning it later but I want to make sure it's working as intended before any changes are made.

 

I am sure it's fine if stock. A good test is to compare normal with sport+ so you can see and verify her touching 17

 

Oebb that's exactly what I am trying to do make sure it's running 100% on its stock form before modding it

At the moment car isn't exciting enough unless it's not running full power which I need to verify

Sam has suggested I do a boost leak check and another tuner said get a vbox and check the 100-200kmph to give an indication if it's running spot on or not

So looks like I've got some work to do lol

I don't mind as like doing the work meself and it's always a learning curve