Ilovechevymusclecars

The car has the 3.4" pulley for the A&A Vortech setup, which corresponds to 10 pounds of boost. I am seeing 10 pounds of boost exactly at redline. If max boost is achieved exactly at redline, does it mean that I don't have a boost leak?

I'm only asking this because after a dyno the shop owner/dyno operator said he thought I might have a boost leak, and my car also appears to be running rich. The car only made 491 rwhp with the 10# pulley, long tube headers and no cats.

LTZ PLY

I believe how much Boost you generate is relative to each set-up an individual has...

What I mean to say is - your compression level, how well your heads flow, your engine size...these things will all determine how much boost you generate with a 3.4" pulley versus the next guy with the same size pulley. And yes, your peak boost should be reached by when you hit your peak RPM.

My NOVI, with a 3.5" pulley made 10 pounds. (I dyno'd 625 w/ this one on.)
With a 3.25" pulley it made 14 pounds.
I'm in the middle of trying to firgure of what it will do with a 3" pulley.

I hope this helps, good luck.

Ilovechevymusclecars

My real question is....if you have a boost leak will you build max boost?

BLOWNBLUEZ06

Not unless you are running twin turbos and your boost leak happens to be the lines running to your waste gates.

narfdanarf

lolz, that is not even remotely true. If in doubt do a boost leak test.

AlwaysInBoost

actually it is. he is talking about losing the boost reference to the WG which would cause it to not open.

I do agree htough that a boost leak test should be the first thing to do. it will eliminate ALL the guess work and tell you EXACTLY whats going on.

valdeztke

narfdanarf

I was laughing at the fact he said it is the only way. You can make max boost and still have a boost leak, if you don't understand that or how it's possible you shouldn't have a FI car.

AlwaysInBoost

BLOWNBLUEZ06

I mis-understood the q. Hitting max boost when losing the boost reference to the WG is causes runaway boost. I think the original question should be " will the boost be lower if there is a boost leak "

madmatt9471

I would say that the tuner might be refering to the fact that he believes with your set-up you should have more BOOST or he is seeing a drop off at a certain point.

Your final outcome should be more than the 491 RWHP so this is why he is supspecting a leak somewhere.

Thanks,Matt

madmatt9471

Regardless of a B@@ST leak or not you will have a MAX B@@ST level but it will be higher when there is no leak present.

Hope this helps.

Search all through your plumbing and look for tears or holes or loose parts or clamps.

Then check your BOV and make sure it is not openning or is staying open while under boost!

Thanks,Matt

Ilovechevymusclecars

I have achieved the max boost that the pulley corresponds to.....can I still have a boost leak? And also, how do I check the functionality of the bov. It is open at idle like it is supposed to.

BLOWNBLUEZ06

There is no set boost level for a supercharger with a given pulley. You just know that with a smaller pulley, turning the supercharger faster the boost will go up. How much boost that is yielded (assuming no boost leaks ) will be determined by the engines resistance to air flow. A stock engine stock exhaust car will yield higher boost with the same given supercharger rpms, vs. a engine with mods. Things that will bring down boost are: ported or better flowing cylinder heads, better flowing exhaust, larger cam with more overlap, larger engine displacement engine, better or ported intake manifold etc.

As for the BOV, you might want to remove it and make sure it's sealed when it has no vacuum on the diaphragm. Make sure the gasket or seal isn't bad too.

BLOWNBLUEZ06

Forgot to mention that if someone with experience with your exact combo is involved, they might know what a specific pulley should yield for boost and they then should also know what kind of power it should make assuming the tuning is proper.

madmatt9471

Yes you could to some degree but if it is relatively near the B@@ST levels expected then you should be good!

The best way is just to make sure that all your plumbing is tight and not have any tears and holes or loose clamps that would allow B@@ST to excape!

Now as far as the By Pass Valve you need to see if under BOOST it closes and stays closed!

So you may need to remove it and put the 10 lbs of pressure into the vac line to see if it closes and does not leak and take your finger and push against the blade to simulate the pressure put on the blade to keep it closed too and push against to try to make it open!

Thanks,Matt

FactoryRaceCar

What heads and cam are you running? Are you using meth? What Vortech headunit is this? Any restrictor plate?

Ilovechevymusclecars

Vortech SQ headunit, no meth, stock size heads and cam, no restrictor plate. Long tube headers and straight pipes into stock mufflers.

Higgs Boson

check under the car. boost will stain your pavement.

Ilovechevymusclecars

I dont get it....