Pulley swap without tune? Only 1psi more.

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I have a 2018 stage 2 whipple car. Kooks without kitties and 3in back to the axles. I had it dyno tuned and i bought a size smaller blower pulley for 1lb more boost. Can the computer adapt for that or is it a mandatory tune thing? My tuner is not available at the this time as he is off for medical.

If it matters whipple states i should be at 11lbs but with the exhaust work done im at 9.5-10psi

 

Jackson1320

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you can run more boost. it will adjust. whipple says you should be a 11psi with the stock exhaust. but it doesn't matter anyway. the tune will make adjustments for more or less boost
 

Andy13186

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Depends if you are at the limits of your fuel system probably.
 
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Depends if you are at the limits of your fuel system probably.
Plenty of fuel left. I even added a BAP after the fact as a little extra. The intention was to go e85 but he wont do a flex fuel tune or multiple fuel type tunes i can change on the fly. So i have the pulley, 80lb injectors and the BAP on hand currently.
 


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Certain parts of the tune adapt and others don’t. It just depends on what your knock margin is and how much risk you’re willing to take.

The increase in air flow is easily handled if you have the fuel system capacity.

The main issue in my view is that the Whipple cal doesn’t lower the timing command as you raise boost. I guess the theory is that the knock sensors will retard the timing which makes sense if you don’t think about it too much. The knock sensors have to sense knock before they can prevent knock, so I personally don’t like running that way. I don’t know who your tuner is or if they improved the timing control as a function of boost. You could log it and see if you’re picking up knock on the 3.875 pulley (and I don’t mean simply verify it’s adding timing).

Personally, I run mine from 9 (4”) to 15 (3.375”) psi boost on 93 and the timing floats up and down to match it. I’ve also spent hundreds of hours honing the timing curves and I don’t know that the “pros” have done that for their customers.
 
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Certain parts of the tune adapt and others don’t. It just depends on what your knock margin is and how much risk you’re willing to take.

The increase in air flow is easily handled if you have the fuel system capacity.

The main issue in my view is that the Whipple cal doesn’t lower the timing command as you raise boost. I guess the theory is that the knock sensors will retard the timing which makes sense if you don’t think about it too much. The knock sensors have to sense knock before they can prevent knock, so I personally don’t like running that way. I don’t know who your tuner is or if they improved the timing control as a function of boost. You could log it and see if you’re picking up knock on the 3.875 pulley (and I don’t mean simply verify it’s adding timing).

Personally, I run mine from 9 (4”) to 15 (3.375”) psi boost on 93 and the timing floats up and down to match it. I’ve also spent hundreds of hours honing the timing curves and I don’t know that the “pros” have done that for their customers.
Im not on the whipple tune. I know on the dyno with winter 93 i pulled 4 degrees after 4500 rpm. That is also before i went full 3" to the axle
 

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Im not on the whipple tune.
I know that but Whipple isn’t the only tuner that uses the same timing regardless of boost. Without knowing that, I can not vouch for the safety of making boost changes.
 
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I know that but Whipple isn’t the only tuner that uses the same timing regardless of boost. Without knowing that, I can not vouch for the safety of making boost changes.
Fair enough.
 

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Out of curiosity, what overall timing are you hitting on the 3.875?
 
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Out of curiosity, what overall timing are you hitting on the 3.875?
Hmm. Good question, drawing a blank at the moment. Would have to check. If i recall right like 24ish at idle and 14ish wide open.

I did get a quick reply from the tuner. He said it would be best to tweak the tune by pulling 1 degree out but i could get away with the pulley swap with the wide band o2's and 4 knock sensors the gen3 coyotes have.
 

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Decent 93 with a 3.75-3.85 will usually allow 16-17° at 10-11psi. If you’re only at 14° above 5500, you have some window of improvement there.

For reference only.
 

Jackson1320

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Certain parts of the tune adapt and others don’t. It just depends on what your knock margin is and how much risk you’re willing to take.

The increase in air flow is easily handled if you have the fuel system capacity.

The main issue in my view is that the Whipple cal doesn’t lower the timing command as you raise boost. I guess the theory is that the knock sensors will retard the timing which makes sense if you don’t think about it too much. The knock sensors have to sense knock before they can prevent knock, so I personally don’t like running that way. I don’t know who your tuner is or if they improved the timing control as a function of boost. You could log it and see if you’re picking up knock on the 3.875 pulley (and I don’t mean simply verify it’s adding timing).

Personally, I run mine from 9 (4”) to 15 (3.375”) psi boost on 93 and the timing floats up and down to match it. I’ve also spent hundreds of hours honing the timing curves and I don’t know that the “pros” have done that for their customers.
i Guarantee that the big-name tuners don't do this for every customer. you and i both know that bro
 

 
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