I have an '01 996tt Tip, and I've been considering getting an ECU flash, so I've been trying to learn what I can. I recall reading somewhere that for the non-X50 996tt, I should see transient peak boost at 0.8 bar, and sustained boost at 0.6 bar (under load). So I set out to see what my peak boost is by going to manual mode in 4th gear on a 20% upgrade hill and going WOT at 45mph. I saw 1.0 bar for just a moment, then it went down to 0.8 bar until I slowed down (about 80mph). When I did the same thing in 5th gear, I saw 0.8 bar for a brief moment, then it went to 0.6 bar and stayed there. From what I understand, this doesn't seem right (the 1.0 bar).

The car runs fine, no CELs, no strange sounds. I bought it 10/05 as a CPO from a dealer in IL, and I believe it is completely stock (original FR5 spark plugs and stock DV's). It feels a bit "laggy" at low rpms, but I think it might just be the higher gearing of the 5-sp Tip. I don't feel the boost really come on until about 3,500-4,000 rpms.

So ... is this normal? Or does it sound like someting is not quite right, and what might it be? I would appreciate any help. Thanks.

 

any cels? try unhooking your batt. for 15min. then go for a ride. sounds like your in limp mode. you do need to get rid of those old dvs. this happened to me a while ago good luck. unhooked the bat and all is well

 

Steve -- no CELs, and the car runs fine.

 

How many mile's are on the car, just wondering? BTW stock k16 turbo turbo's are suppose to sustain a .6-.7 peak boost, the higher boost you are seeing for a second in the higher gears are because your turbo's are really under heavy load making them work alot harder, its not a true or accurate reading. I would change the DV's if i were you just for the hell of it, see if it is more steady boost wise!

Goodluck, Martin.

 

Martin -- Thanks for the reply. I'm glad to hear that you think the high boost is just a matter of transient high load (and not necessarily an indicator of something else wrong). I remember reading a thread a while back where someone was seeing abnormally high boost levels, and he turned out to have a vacuum hose leak or something like that. But he was hearing a strange "whooshing" sound, and everything seems fine with my car -- no strange sounds. New DVs are on my list of things to get -- I would like to also get an ECU flash after that. I have well below 30k miles, so I'm not due for new plugs yet, but I still have the FR5's and would need to replace them with FR6's before the ECU flash.

 

Hey man, no problem. I mean to me, i do believe you dont have a boost leak issue and its just from the turbo's working hard in a higher gear under load, which isnt a true measure of boost being produced like i said, a true measure would be what you sustain at in 3rd gear or 4th, on about a level surface!

Cant go wrong with the ecu flash and diverter valve's, i feel it is such a necessary upgrade for turbo's, you will love it. And doing fresh plugs is a smart idea, goodluck

 

Get the fr6 Bosch plugs... dont go with the berus they sell at the dealer.
Dvs need to be changed if u upgrade the ecu...
k16s spike like any other turbo... so its not uncommon to see 1 bar spikes.... its what the sustained boost is what counts...
change ur oil every year... not every 30k like they say...

 

Marksi -- Thank you for the advice. I'll make sure to insist on Bosch plugs when the time comes. I'm due for the annual oil change 10/06. I'll stop worrying about it, and just enjoy the drive!

 

So wait wtf, the actual car oil is suppose to be changed every year, not like 3k miles? Damm i cant believe in the manual it says 30k, wow!!

 

May sound stupid, but I just discovered yesterday that the on board computer included a boost indicator ? Wow, new toy.
Was surprised to see how it stays stuck at 0.0 in normal driving conditions. What kind of boost pressure should I see on a X50 at full load ?

 

ah, that did sound stupid!!

0.9 bar

spikes are common and remember the guage that this guy just found is not very accurate anyway.