I was also told that this is normal before a flash ex. Dynoflash.... the stock ecu will boost 19 then taper off to 16 then build back up and taper off again right before redline..... the Dynoflash will fix that and have a continuous boost throughout the RPM range....

 

Again every car boosts differently. So whoever told u that is wrong. What it will do is build boost peak around 4000 then taper off slowly as you go through the rms then suddenly drop off. Now on the 9's its different.

With the flash it wont let it suddenly drop; it will let it slowly taper off.

 

The V/// tops out at 19psi and tapers down to 16 by redline. w/minor mods such as TBE MBC, BOV, dynoflash you can run 22-23psi safely on pump. 26-27 on full race gas.

 

I just traded in my VIII MR for a IX MR on Monday. I noticed that it boosts to 1.32 bar and holds, while my VIII MR would hit 1.5 bar and taper to 1.3 bar. I hope the dealer can adjust it to do what my old car would do.

 

it depands on but.. usually no more than 20 for the stock turbo for some safty reasons..

 

WTF??????? There is no way your 8 boosted to 1.5 bar stock. And there is no way your 8 holds boost. Stop BSing. No 8 in the world ever holds boost even when tuned correctly even the 9's dont hold boost. The 9 will still taper off very slightly. Every turboed cars boost tapers off at somepoint. No car holds the same amount of boost through the all rpms.

 

The stock rating on the 9 turbo is 20.3.

 

I have a TBE /02 housing/ EBC / Drop In Filer w samco turbo inlet hose / Walbro pump and I run 21-22psi on pump gas ... is that too much? I was also told that with 100oct I can run 25psi . However what confuses me is what is really safe? What can the stock motor handle? I see people boosting 27-30psi all the time with turbo kits (which are bigger turbos) so how is that safe?

If I add I/C piping can I add more boost? ...

 

The stock motor can handle more than the stock turbo can give it - this should not be confusing. The only thing you need to do is run whatever boost is safe for the octane you're using. 21-22psi is fine on 93oct. 25psi is fine on 100oct.

People on big turbos run 27-30psi on race gas or alky.

What the hell would IC piping have to do with how much boost you can run?

 

I was just wondering if freeing up airflow would make it safer to run more boost ...

But what you said above makes sense about it being based on fuel.

Ok another stupid question then. Say Im running pump gas and thats all I want to run. So on pump 21-22psi is cool. Now at 21psi Im making about 306whp on a mustang dyno, why would I want to do a tubo upgrade like I see a lot of people saying "oh I need to upgrade the turbo to hit 400 whp" or what ever? Its wouldnt really make sense right? as I would still be pushing only 21-22psi on the new turbo, so it in effect would just be a big waste of money unless I wanted to add more boost which in turn means the need for higher ocatnge fuel.

 

A larger turbo will flow more air at the same boost levels as the stocker.

 

Really? I thought PSI was the measurement of how much air was going in the motor .... so 20 pounds per square inch would be 20 pounds per square inch on any turbo .... am I way off my rocker?

 

The measurement of how much air is entering the engine would actually be CFMs if I'm not mistaken. Different turbos flow at different CFMs, even at similar PSIs.

Of course I could be completely wrong. Could someone else verify?

 

No, occultworks has it right. 20psi on a 2g DSM t-25 doesn't flow half the air (CFM) of a GT35r at 20psi. Also, bigger turbos can flow higher boost levels more efficiently without blowing hot air, so you can't compare them when determining what boost levels you want to run on pump gas. The stock 16G on our Evo can't run 25psi on pump gas, because it generates too much heat, which causes knock and detonation. A GT35r can run 25psi without even breaking a sweat, so pump gas can be used in most cases.

 

Is it safe to run 21-22 psi on 91 octane long term or is that a no, no.