Question for guys who actually have the the Roush Kit

[IMCHRGD]

I hope i can get an answer from Roush about belt slippage,..... how far can i pulley down before i start seeing some slippage. I havent asked them yet , but soon i will.

 

[brucelinc]

Yes thats correct 12 lbs boost

Is that what you are seeing on a boost gauge in your Mustang?

 

[IMCHRGD]

Is that what you are seeing on a boost gauge in your Mustang?

In my f 150 yes. Havent bought the wife her Mustang yet, im holding off on that

 

[brucelinc]

12lbs for me is too much on 93 octane. I would prefer to stay under 10psi, but this is just strictly my opinion.

Yeah, hard to imagine 12 psi, considering how conservative Roush is with a warrantied kit.

 

[IMCHRGD]

Im hoping after the headder install boost went down some, im shooting for 14 lbs after the e-85 conversion
pullying down of coarse

 

[brucelinc]

In my f 150 yes. Havent bought the wife her Mustang yet, im holding off on that

The stock tuning on an F150 Coyote is different than a Mustang. I wonder if the boost levels are different on F150 kits vs Mustang.

 

[IMCHRGD]

The stock tuning on an F150 Coyote is different than a Mustang. I wonder if the boost levels are different on F150 kits vs Mustang.

yes but the pulleys are the same size right?

 

[Sweitzer]

Some people r reporting the Phase II or the Roush system in general makes 12lbs of boost, but I’m not so sure this is accurate

It seems some guys who own the setup are seeing 10-11lbs which makes me happy if true, if true

I’m curious as to what owners here in the post have seen at redline on the warranty tune and basic factory exhaust (Cats still in place but maybe a car back)

 

[Stymee]

Yes thats correct 12 lbs boost

So you’ve seen 12lbs of boost at redline

 

[Stymee]

Sweitzer, I’m not 100% convinced this is accurate, u truly need some kind of boost box or a vacuum gauge to read boost?

Quite a few guys on other boards have reported 10-11 PSI?

 

[IMCHRGD]

So you’ve seen 12lbs of boost at redline

On the dyno, yes im sure it was up there

i was told that from my tuner

 

[Cory S]

I see 12.5-12.7psi with a 72mm pulley. 11.2-11.5psi with a 75mm. At 7400.

 

[IMCHRGD]

i think 14 lbs is the majic number , lol.

 

[Stymee]

I see 12.5-12.7psi with a 72mm pulley. 11.2-11.5psi with a 75mm. At 7400.

Corys running headers but again he’s revving to 7400 and running a 72mm and seeing 12.5lbs, hell his 75mm made 11.5lbs

No way the 80mm pulley is making 12lbs on a stock engine, yes the restriction will cause boost to rise but take his SMALLER pulley vs 400 more rpm and from what 3 guys posted, their seeing 10-11 out of the 80mm on a stock GT?

 

[Sweitzer]

Yes, more fake news from me.. Not sure why it wouldn't be accurate. It's also what Roush has always published. Can't believe this hasn't been covered in 167 pages yet. Keep the thread alive.

https://www.fordmuscle.com/features...upercharger-boosts-2018-mustang-gt-to-700-hp/