Vortex/Novi equipped

[Pat]

Hi guys,

At what RPM does your Vortec or Novi supercharger begin to make boost?

My Novi S/C, for sometime now, has not made any boost until past 4K RPM. It achieves it's rated 10 Lbs at nearly 6K RPM.

Since this is my first experience with a supercharger I don't have any background to draw on.

A couple of friends who are versed on this subject related to me this evening that the supercharger should be at full boost around 3-4K RPM.

I've replaced the belt and the tensioner is not at limits, however, the S/C does make a lot of "machine noise" when it's cold. Maybe I need a rebuild?

Ducting all seems in order and all hoses are connected as they were when the S/C was first installed.

Pat

[RR|Suki]

Hi guys,

At what RPM does your Vortec or Novi supercharger begin to make boost?

My Novi S/C, for sometime now, has not made any boost until past 4K RPM. It achieves it's rated 10 Lbs at nearly 6K RPM.

Since this is my first experience with a supercharger I don't have any experience to draw on.

A couple of friends who are versed on this subject related to me this evening that the supercharger should be at full boost around 3-4K RPM.

I've replaced the belt and the tensioner is not at limits, however, the S/C does make a lot of "machine noise" when it's cold. Maybe I need a rebuild?

Ducting all seems in order and all hoses are connected as they were when the S/C was first installed.

Pat

A centri doesn't make it's "full boost" as a general matter till you run out of RPM... IE unless you manage to max it out, it will keep making boost as you rev higher. That being said having no boost at all till 4K is a little odd.

[Local Boy]

What size pulley, you running?


ALOHA

[Vortech347]

Whats a Vortex blower? hehehe

On my fox my Vortech S-trim see's 5-psi at 4200rpm, at 6000, 10psi. "Full boost" is as at the peak RPM you turn before you shift

Takes a bit to spin up... They're RPM based so you've gota keep that in mind. Full boost at 3-4k would be with a turbo or positive displacement.

[rayjay]

Hmmm, I want to follow this. I thought SC'ers made boost much sooner. It seems the MM needs help before 4K rpms. Atleast mine does. Once at 4K+ she is screaming.

[RR|Suki]

Hmmm, I want to follow this. I thought SC'ers made boost much sooner. It seems the MM needs help before 4K rpms. Atleast mine does. Once at 4K+ she is screaming.

when you say boost though that's not the way to think about it... it is always pushing air, boost is only a value of how much pressure is being built up in the manifold... once you hit the thing it's pushing air

[Vortech347]

Boost is only a measurement of back pressure. Even if your boost gauge is at 0, its still helping because the car isn't SUCKING in air.

[Pat]

In aiding my understanding, the "boost" Gauge has readings on the left side denoting vacuum and reads about 16 at idle and 10, more or less, driving around town at low loads.

When going to WOT or passing gear the vacuum drops to around zero then builds on the pressure side to about 5 lbs as the car accelerates past 4K. As the RPM's build the pressure climbs to 10 by 6K RPM.

I bring all this up because the car is running slower and slower at the strip. I know my nitrous is working because I can tell when it fires and my times are .5 second faster. Right now this car is a 14.5, up from a 13.3 last year.

The car is not losing traction, my 60 ft times are still in the mid 2's.

I don't know what size pulley. It's the one that came with the kit I believe.

I am not able to find the dyno sheet that was Posted on DR's old forum.

I'm also asking the folks on Modular Fords, they also have a forum on superchargers.

[RR|Suki]

In aiding my understanding, the "boost" Gauge has readings on the left side denoting vacuum and reads about 16 at idle and 10, more or less, driving around town at low loads.

When going to WOT or passing gear the vacuum drops to around zero then builds on the pressure side to about 5 lbs as the car accelerates past 4K. As the RPM's build the pressure climbs to 10 by 6K RPM.

I bring all this up because the car is running slower and slower at the strip. I know my nitrous is working because I can tell when it fires and my times are .5 second faster. Right now this car is a 14.5, up from a 13.3 last year.

The car is not losing traction, my 60 ft times are still in the mid 2's.

I don't know what size pulley. It's the one that came with the kit I believe.

I am not able to find the dyno sheet that was Posted on DR's old forum.

I'm also asking the folks on Modular Fords, they also have a forum on superchargers.

well something isn't right, first off, you should be pulling more like 20inches (vacuum).
However the pressure doesn't seem to be too far off, I dunno about the little novis but mine will hit 5psi hard as soon as I get into it (which is about 3K rpm with my converter) it's hard to tell what it is making under 3K because with the converter the engine is at 3k basically as soon as I hit it from a stop, then about 9-10 at 6Krpm when it shifts (way too low of an rpm in my mind, but that's for a different topic).
I dunno what to say about those times though... I gotta say they are pretty bad which kinda says to me something is pretty off. When I had about 430hp with the 295s I'd hit it off idle and pull a 1.8 60' and my MPH was about 110...

That makes me think... what is your mph?

[Pat]

RR/Suki;

The MPR is low, ranging from 95-97 over several passes, 60 ft = 2.2 average.

Perusing some of the threads on Modular Fords it seems that the boost is not too far off of what other S/C users are experiencing as far as "max" boost Vs RPM (6K), however, the rate of climb is a little slow.

I have a 3500 RPM stall converter and 4:10 gears so I'm at 4K real quick. But no 5 lbs of boost.

Would a compression check be in order?

[RR|Suki]

RR/Suki;

The MPR is low, ranging from 95-97 over several passes, 60 ft = 2.2 average.

Perusing some of the threads on Modular Fords it seems that the boost is not too far off of what other S/C users are experiencing as far as "max" boost Vs RPM (6K), however, the rate of climb is a little slow.

I have a 3500 RPM stall converter and 4:10 gears so I'm at 4K real quick. But no 5 lbs of boost.

Would a compression check be in order?

I would think so man, with that kind of boost out of that blower, even with a bad 60' 97mph is a very very slow MPH and you are hitting it with the juice too? Compression test or get it back on a dyno/to a tuner. Something isn't right, that car should be tearing your face off.

[Pat]

Agree. Looking through my son's took kit, I find a brand new Mac Tools compression test kit. As soon as he get's some free time we will do a compression test.

If that's OK then a trip to a Ford product dyno/tuner in Dallas for some analysis.

Thanks for your help RR/Suki

[SID210SA]

Something has to be off in the begining Pat....my 60 foot times are around 2.1xx and all I have is a tune and JLT. Havent been back the the track since the new tires or exhaust.

[Marauderjack]

Is your blow-off valve fully closed??

[BODYMAN]

Is your blow-off valve fully closed??

well he beat me to it. That would be my 1st question and all plumbing is intact? This is a gimme question but Iam gonna ask you ck'd air filter or clean it lately? I have had 4-diff Vortech Chargers 2-Marauders and 2 Mustangs! From what I have read Pat it sounds like either having a hard time getting the air to the Charger or the Charger is not at 100% effeciency, or plumbing is a miss or as Marauderjack questioned popoff or Bypass is not closing? It sounds like sommething before the intake manifold! How many miles on youre Paxton? a Dyno is gonna youre best shot for getting a idea of What is happening geta good A/F reading