Pully swap

jwoods3

New Member
Jul 1, 2007
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Chicago
After switching the pulley to a 2.81 is a tune required immediately? If so, does anyone know the air/fuel ratio needed so I can at least drive it for a few weeks before having it professionally tuned?
 
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After switching the pulley to a 2.81 is a tune required immediately? If so, does anyone know the air/fuel ratio needed so I can at least drive it for a few weeks before having it professionally tuned?

Any time you change your blower speed you should get the car on a dyno. Some people like the mail order tunes but I am not a big fan of them. The replacement cost of our engines it a bit too high to gamble with. You can drive the car for ever as long as you never press the go pedal far enough to enter boost. Can you do that? I never was able. That pedal is too tempting.
 
Yeah, I wouldn't be doing any WOT blasts down the inerstate till you got it back onto the rollers and had the computer properly calibrated. The forged components are forgiving, but only to a point. And it would be a shame to smoke such an expensive engine because you couldn't keep your right foot out of the oil pan in the mean time. ;)
 
These cars absolutely need some adjustments made once an upper or lower pulley is installed. IMHO a mail order tune should be considered temporary until the car can be custom tuned properly (safely) on a dyno, or to validate the state of the mail order tune.

I would never, ever, run a pullied car on the bone stock tune. You're just asking for trouble.

U.M.
 
Does anyone have the tune for me to put in? I have the tuner and hopefully could put those numbers in until I get to the tuner (1 week later) after doing the swap. If that's a no-go, I assume it is incredibly easy to swap and could probably do it at the tuner, with the puller.
 
Does anyone have the tune for me to put in? I have the tuner and hopefully could put those numbers in until I get to the tuner (1 week later) after doing the swap. If that's a no-go, I assume it is incredibly easy to swap and could probably do it at the tuner, with the puller.
I wouldn't rely on someone elses tune if I were you. All of these cars respond differently and when it comes to cramming additional airflow into the engine, you want to make sure it's spot on when you get on it. Iwould just wait til the day or so before you're heading to the tuner to do the pulley swap and once its done, take it easy (keep your foot out of it) on the way there. You're going to need a puller to get the old pulley off, since the M112 uses press on pulleys (unlike the M90 that uses a keyway), so it may not be quite as easy as you think.
 
I wouldn't rely on someone elses tune if I were you. All of these cars respond differently and when it comes to cramming additional airflow into the engine, you want to make sure it's spot on when you get on it. Iwould just wait til the day or so before you're heading to the tuner to do the pulley swap and once its done, take it easy (keep your foot out of it) on the way there. You're going to need a puller to get the old pulley off, since the M112 uses press on pulleys (unlike the M90 that uses a keyway), so it may not be quite as easy as you think.

Ok, I will do that then. Thanks!

Jayson
 
A regular pulley puller will not suffice either. You'll need one specifically designed for removing the snout pulley off of the M112. You may want to call your local tuner and see if they have one you can use/borrow because they are not cheap.

U.M.