Bossman
Expert
On high boost setting that is correct. If you go low boost you can let it rev to about 10500.
onrof
Extreme
I have the stage 2 blower... so 10lbs is my low boost. So is 10,500 OK? Was this actually done on a dyno? Does somebody have any sheets I could see? I sure would like to clutch for max at 10lbs and 17lbs.
87gtNOS
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Bossman said:
Idling at 17 is fine...I think cruising at 17 (or close) is fine too. It's when you are under boost it'll go rich....
My car at 4000rpm at cruise is like 16 or so, then upon hammering it it dips to 11.
Vortech powered 5.0L. 442 rwhp. 11 to 1 AF
TurboJamie
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First day out on ours here holy(insert F word here) is this thing fast! Its just stupid at only 5 lbs! I have a WMS wideband on it and basically went off of MPI's box settings for 800-1500' we seem to be about spot on I had to add .5 to the red and thats it. Running a Hartman clutch kit in it seems to be very good clutchs after hard pulls are cool enough to hold you hands on them! I have the AFT @ WOT tuned for 11.5-12.0 works awesome. Idle about 13.0-13.8 mid 13-14. Fuel mileage used 3 liters more then my mach z 1000 in the same ride so not bad for being on the gas steady! Totally awesome and impressed so far I think we need more boost! Turning it 10,200 at 5 psi now might go for 7 with the pulley change!
Now a bit of juicy stuff you all noticed the mention of the mach z 1000 above yes its clutched and runs 122 mph in 2000'.
The apex and mach last weekend pre supercharger the mach would just drive away from it all the time. Now we roll on apex pulls 10+ lenghts instantly and just keeps driving away. I plowed the strip tonight to see what it will MPH but so far its just ridiculous! This is running on 91 octance fuel and never skipped a beat. No TORS probs to speak of as well. So far just lovin it.
Now a bit of juicy stuff you all noticed the mention of the mach z 1000 above yes its clutched and runs 122 mph in 2000'.
The apex and mach last weekend pre supercharger the mach would just drive away from it all the time. Now we roll on apex pulls 10+ lenghts instantly and just keeps driving away. I plowed the strip tonight to see what it will MPH but so far its just ridiculous! This is running on 91 octance fuel and never skipped a beat. No TORS probs to speak of as well. So far just lovin it.
87gtNOS
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Bossman
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onrof I dont know how it will convert with the stage 2 kit. I have a stage 1 and on 10 lbs you should stay at 10000 rpms or lower.
87gtnos with the supercharger you always have boost running even when you are just cuising so wouldnt you have about the same AFR?
87gtnos with the supercharger you always have boost running even when you are just cuising so wouldnt you have about the same AFR?
87gtNOS
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I don't know, is there boost on a snowmobile when cruising?/ My car made 12-13" vacuum at cruise.
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Cruising at 9,000 rpm the supercharger will have roughly 8 psi. You don't want your A/F any leaner than 13 while cruising and top end A/F at the leanest 12.5.
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oh, you guys are referencing the boost form the intercooler. Not after the throttle bodies.
Bossman
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Yes you are correct 87gtnos we are reading the boost in the intercooler.
TurboJamie
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Yeah my gauge bounces around 7 psi at cruise in the intercooler.
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umm, shouldn't boost be measured after the throttle?
Couldn't the boost be refernced off the fuel pressure regualor? Isn't it vacuum controlled?
Couldn't the boost be refernced off the fuel pressure regualor? Isn't it vacuum controlled?
TurboJamie
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I dunno I just do what MPI told me.
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Boost on a S/C is related to RPM and throttle position. What you guys are seeing is boost from running 9000rpm at cruise...this is not boost at all..well maybe close or some.
Boost is a measure of restriction and load. What you are seeing at 8000 or 9000 rpm at cruising, is pressure in the intercooler. Restricted by your 1/2 open throttle.
I do know what I am talking about, had a supercharged Mustang for 5 yrs....but I am not sure how to explain this clearly.
What's on the otherside of the throttle blade? 2" of vacuum?
You see, you can rev the sled up to 9000 rpm with no belt, and hold it at 1/4 throttle and reference the boost off the intercooler. You will see boost...BUT there is no load!! So there really is NO boost.
I am not sure how the fuel is managed on the APEX...but I am sure it must add fuel per pound of boost, therefore, in this 'extreme' scenario, you are adding UNNEEDED fuel.
Again, I understand the sled is seeing more load than a car does at cruising, so it needs more fuel.
Maybe I am missing something here?!!
Boost is a measure of restriction and load. What you are seeing at 8000 or 9000 rpm at cruising, is pressure in the intercooler. Restricted by your 1/2 open throttle.
I do know what I am talking about, had a supercharged Mustang for 5 yrs....but I am not sure how to explain this clearly.
What's on the otherside of the throttle blade? 2" of vacuum?
You see, you can rev the sled up to 9000 rpm with no belt, and hold it at 1/4 throttle and reference the boost off the intercooler. You will see boost...BUT there is no load!! So there really is NO boost.
I am not sure how the fuel is managed on the APEX...but I am sure it must add fuel per pound of boost, therefore, in this 'extreme' scenario, you are adding UNNEEDED fuel.
Again, I understand the sled is seeing more load than a car does at cruising, so it needs more fuel.
Maybe I am missing something here?!!
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I'm not sure you no what your talking about,but even still whats your point? What do you have when throttle is open and the boost gauge says 10 psi, with the belt on by the way the sled doesn't move well without it, and I'm not holding my motor at 9000 with the belt off to see no load no sh*t. Maybe were both missing something here! 
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