Pulley


3

33Bravo

GT Owner
Mark II Lifetime
Nov 3, 2006
688
Minneapolis, MN
I hope this is not a dumb question.

I have a Kenne Bell SC snout. In digging around the stuff that came with my FGT – it appears the pulley installed is the small (2.5”) pulley. The paperwork that came with the KB Flash tuner suggests the car is tuned for 91 octane. I’ve been running 93 octane. (Would rather run 91 with out ethanol if I could)

My car has the Ford long tube headers, and Ford racing “muffler” – so WOT its pretty loud… so I was wondering if you can hear knocking with so much exhaust noise? Car runs great – and does not “feel” like its knocking.

I’ve done searches and there is a ton of information on pulleys, tunes, octane, etc…

THanks all
 
I think it is a good question. Do you literally have the 2.5" pulley installed on the KB?? I think that is the smallest (highest boost) pulley that was available with the kit - which intially included 5 pulleys. If you have the 2.5" installed I think you may be running a LOT of boost. I would really recommend putting the car on a dyno where you can check not only boost levels but you can validate the air/fuel ratios to insure your car is safe.

I do think that with the exhaust system that you have it may be very hard to detect pinging.
 
The GT does have a slight advantage for picking up audible knock with the motor right behind your head, that being said I would also recommend as Kendall states to dyno the car and datalog everything necessary to see the full scope of what's occurring.
 
And I should have added - if the a/f's from the dyno run aren't right (or if you don't know if they're right), hook up with Torrie, above. Torrie has tuned a gazillion GT's and he'd be your go-to guy to get a tune in the car that works.
 
nota4re said:
And I should have added - if the a/f's from the dyno run aren't right (or if you don't know if they're right), hook up with Torrie, above. Torrie has tuned a gazillion GT's and he'd be your go-to guy to get a tune in the car that works.
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:agree:
 
And,

He has tuners on sale!!!! LOL

Larry
 
nota4re said:
I think it is a good question. Do you literally have the 2.5" pulley installed on the KB?? I think that is the smallest (highest boost) pulley that was available with the kit - which intially included 5 pulleys. If you have the 2.5" installed I think you may be running a LOT of boost. I would really recommend putting the car on a dyno where you can check not only boost levels but you can validate the air/fuel ratios to insure your car is safe.

I do think that with the exhaust system that you have it may be very hard to detect pinging.
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Yes - I think its the smallest pulley (I have the other 4 on my desk here). The boost gauge is pegged (though it only gets up to 15)...

The car is a *ton* of fun to drive (ok the goodyears are a handful) - but this is the way it was setup when I bought it. Putting a larger pulley back on just seems like a step backwards?
 
You need to switch to the Bridgestones too. :thumbsup You won't regret it when you hook up better.

I don't think the guys are suggesting going down in pulley size, just getting the right tune for your needs and fuel availability.
 
The factory boost gauge is inferred and does not have the ability to show pressure beyond 15 PSI. So actual manifold pressure is (most likely) higher than this based on the pulley size.
 
With that small of a pulley you may be topping out your MAF and would need a Mafia as well as a new tune.
 
2112 said:
You need to switch to the Bridgestones too. :thumbsup You won't regret it when you hook up better.

I don't think the guys are suggesting going down in pulley size, just getting the right tune for your needs and fuel availability.
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Definitely going to switch to Bridgestones... Thanks! Will be nice to put this power to use beyond spinning tires!

Anyone recommend a good dyno / tuner in the Minneapolis area?
 
BlackICE said:
With that small of a pulley you may be topping out your MAF and would need a Mafia as well as a new tune.
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MAF Mafia. So much to learn
 
MAF = mass air flow. It is a sensor that measure the mass of air your engine is consuming. The FGT sensor outputs a voltage from 0 to 12v, but the ECU can only read a max of 5v. What the Mafia does is scale the MAF voltage so that it fits within the limitations of the ECU. A custom tune is needed when using a Mafia.

At around 16+ PSI of boost the MAF is approaching the 5v maximum. When this happens the fuel delivered is topped out and your engine could run lean. Some "hack" tuners will just make the last few cell for the fuel table overly rich to compensate. This will work, but isn't ideal, since the engine will be overly rich during some points of operation.
 
Makes total sense.

My girl is shut down for the season (Minneapolis). Looking forward to spring. Totally acknowledge tire situation...

My new (new to me) car seems to be well set up. Previous owner seemed to put "right parts" in... (throttle body, sct tune, headers, exhaust and KB snout/pulley). Lots of power - seems "about right". Don't want to be dumb - but leaving this "as is" - really seams as close to perfect as I could hope for?
 
Yeah, no one wants to see you go backwards in HP - but just encouraging you to double check that you are safe with the current set-up. A couple of pulls on the dyno while datalogging will tell you that. Consider Torrie to be your tuning expert. I think you can have 17-18psi of boost with the pulley that you have. It IS possible to have a tune that will accomodate this boost with 91 octane as long as you are conservative with the timing that's in the tune. This much boost and a lot of timing could be a combination that may over time not be a good situation for the motor.
 
Have th eKB snout and she makes great power...

Briggstones Last I checked I wanted some but nobody could say what sizes work best. So my tire guy just said when your forum buds know what works let me know and we'll get the shoes ready..

So Forum buddies anyone know what size and model tires...no racing ...I just street drive it.
 
Raceman, shame on you for not doing a search. Thyere are several threads here about the Bridgestones. For the front, order the Porsche N1's and the Enzos for the rear. The tread pattern is the same. Sizes are in the thread.
 
33Bravo said:
Previous owner seemed to put "right parts" in... (throttle body, sct tune, headers, exhaust and KB snout/pulley). Lots of power - seems "about right". Don't want to be dumb - but leaving this "as is" - really seams as close to perfect as I could hope for?
Click to expand...

I don't see a Bumper Delete in that list. :biggrin
 
I know but the thread is so long with a lot of size variations. I was hoping a if you have stock set up the closest and best choice is..... So I did not have to think on my own....When I think on my own I get dizzy....

Ok I'll do the work. Thanks Frank.
fjpikul said:
Raceman, shame on you for not doing a search. Thyere are several threads here about the Bridgestones. For the front, order the Porsche N1's and the Enzos for the rear. The tread pattern is the same. Sizes are in the thread.
Click to expand...
 
fwiw, my 2.7" pulley/tune makes 14.8 psi max boost.
 
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