Comparing my 2015 (991) 911 Turbo and 2011 (958) Cayenne Turbo, I noticed there is a difference in peak boost levels. The Cayenne will reach 0.8 bar while the 911 will reach 1.2 bar.

This is likely perfectly normal, but got me thinking if the Cayenne is losing boost. Anyone notice peak boost levels on the Cayenne turbo to see if it's the same?

 

I noticed this even with a tune. It will hit .8 drop off to .6 and then back up when it shifts. I been thinking about getting another shop to tune it and see if I get a little more out of it. I will go out and record a vid and post it.

 

Mine does this without a tune, just intakes and secondary pipes.. Pegs the boost gauge while rolling into the throttle at mid rpm, will hold it to around 4500 then drops to .6 then picks back up on the shift and drops again.


I thought tuned CTTs always pegged the gauge over and held it to virtually redline?

 

I have a 2014 CTT, tuned by GIAC and get 1.1 bar at full acceleration.

 

This is the norm and the reason I was thinking about getting a different tune. I also never received the durametric cable that was supposed to come with the flash.

 

I have the GIAC tune on my Cayenne Turbo along with 82mm IPD intake and the E81 82mm Turbo S Intake manifold and 82mm Throttle body like Kent has on his Cayenne. I also have Fabspeed's secondary cat bypass pipes and exhaust so my Cayenne Turbo runs REALLY well!

With all of these mods my vehicle still only hits a max of 1.1bar of boost and will hold that boost pressure only to about 5400rpm or so. This is entirely due to the stock Mitsubishi 18T compressor wheels just being to small to hold that much boost to redline with the 4.8L of displacement.

This is one of the main reasons that I am trying to find out from RAKLAW what the boost pressure levels are for the 2016 Turbo S for comparison. The new setup where the turbo is integrated into the manifold might offer better flow on the exhaust side which may allow the stock 18T to hold boost a few RPM longer. Hopefully RAKLAW will eventually finish his break in miles soon............

Jeff

 

At WOT my 955 with Softronic tune runs up to 13+psi and hangs there pretty well. If I roll into it instead of going WOT it will sometimes run up to 14.5psi or better then settle back at around 13.

That's according to my P3 gauge with boost taken off the diverter valve vacuum line.

And to answer the original poster a stock Cayenne will only boost to about .8bar. Perfectly normal unless it's tuned or modded.

 

GIAC tune. It peaks at 17-15 psi and tapers to 10 at redline.

 

I'm assuming everyone has checked diverter valves for leakage or upgraded them.

 

Yes, I have Agency Power diverter valves on my Cayenne Turbo.

 

+1..

 

10psi is normal stock boost. 16psi with a tune. What mods are you talking about? The ECU controls the boost level. Only a tune will increase the boost.

 

I'm talking about a Softronic tune. I also have secondary delete pipes and a slightly more open exhaust. I've not seen 16psi yet although like I mentioned it will get up around 15psi if I roll into the throttle. WOT from pretty much any speed and it settles right around 13psi or so.

 

you said tuned or modified. Like i said, only a tune will increase the boost. Boost is controlled by the ecu, NOT by other mods.

 

GIAC 17-18psi.