I was just curious what the normal boost pressure was on a stock non X model 996 turbo? Normally I see .7 or .8 for a second or two, but today I saw 1.0 for about a second or two.

The car seems totally fine, and I had to drive it for another 60 miles after that doing a couple hard pulls. Oil pressure was fine the whole time, no lights or anything abnormal, just never seen 1 bar and was wondering if it's normal, okay if it doesn't do it all the time, or something that should be looked into. The weather today is a beautiful 55* with hardly any humidity and blue skies.

I'm not too worried about it since, like I said, the car seems fine and the computer didn't throw lights, I was just curious.

Thanks.

 

0.7 is the normal limit. Based on environmental conditions you can see 0.8. The 1 bar you saw was probably a spike. Tuned cars usually peak at 1.1. As long as you're always running 91+...

Don't worry about it

 

Sweet, thanks.

And I always run at least 90 in it if that's all there is, but here in Boise we can get 91. I'm going to start carrying around a couple bottles of octane booster just in case.

 

My family has a place in Sun Valley, and it pains me to fill with 91 when we have 92 here in washington. Hah

Usually octane booster won't get much more than a single octane- but it can't hurt!

 

Hmmmm. 1.0 is a heck of a spike. I would leak test. Octane boosters are snake oil IMHO.

 

Boost leak almost for sure

tighten all clamps you can see and if you still get it, leak test.

 

If a car leaks boost...the gauge would read less no?

 

no, because of the leak the blow off / diverter valves and waste gates will not operate correctly when required and you get a pressure increase or spikes at the boost pressure sensor located before the throttle body.

 

that is at least how i understand the boost leak issue.

i have had ur issues and the easiest and cheapest fix is to tighten every hose clamp you can find before and after the turbos.

if that doesnt work, leak test, but i'd say it will work.

 

Take in to account as elevation increases the need for higher octane diminishes. Hence higher octane fuels are not available. A spike is an intermittent and very brief moment of high pressure and should not be taken as what the turbos are actually pushing into the motor. Spikes are generally not repeatable and will often occur just before making a shift at a high RPM.

Pulling a grade such as in a canyon will allow you to watch your boost build up to a maximum in each gear and determine what is normal for your car. Boost will occur at a lower RPM and throttle settings as the load increases. You will often see boost at freeway speeds at very low throttle settings if going up a slight grade.

 

probably a spike... and or some issue with DVs...

 

Like I said it happened once at the beginning of the drive, which went on for almost 60 miles where several harder pulls were made and it didn't go above .7 or .8. I realize that as things heat up they expand which could close any leak up, but I immediately did a couple pulls after I saw the 1.0 and it didn't happen again. Also, I had already driven 12 miles at 65 mph, so everything was warm and up to temp. I'm thinking fluke, but I WILL keep an eye on it. I almost always take a peak at my boost pressure when doing pulls.


The elevation of where I started is 2998 ASL and where I ended up is 2600ASL. Yes, I actually know the altitudes of where I live. Where this happened it was probably right at 3k ASL...not that it matters for the boost issue, though.

 

what do stock cars boost to running an exhaust only (no software) say like Fabspeed w/ 100 cell cats ?

 

Stock K16s or stock K24s?

 

hey OEM how you go with this issue ??