zerotosixzero

I bought my first corvette. 01 z06 came with a magnacharger installed
Guy I bought it from didn't know much about it.
Non ic Maggie. I'm assuming stock pullies so 5 lbs of boost region. No boost gauge in car. Have one on the way.
I was suspect of the cars claimed 460 whp when I ran it along side my buddies 03 stock pulley cobra. I thought it was going to be a massacre. Because this car barely pulled on my 01z28 with just full exhaust.
My vette pulled on him. But not like it should have. So I went home and took a good long look at this thing
1. The bypass valve was doing absolutely nothing. After a good hard search session. I got the bypass working. And thought to my self oh yeah now it's game over!..... No.. car feels like a stock c5 z06. The charger makes all the whining noises it should. I turned the pulley by hand. Seemed fine. Took the front off looked inside. Rotors are turning. But the bypass is closed at idle and opens under throttle. Is this normal. Shouldnt it be the other way around?

My questions are
1 can the bypass valve not be setup right and opening and closing opposite of what it should.
2 can all of my pulley combinations be wrong that I'm not turning the blower fast enough to build boost.
3 the pulleys have nothing stamped into them to identify size. How do I identify the pulley sizes.
4 I've seen reference to a thing called a magnavolt. I haven't seen this anywhere on the car so I believe the fuel system is still 100% stock except for the injectors that come with the setup... Do I absolutely need a boost pump setup?
Thanks

NITRO UK

Hi
If you have a booster pump fitted it should have a vacuum hose going to it , so have a good look at the top of the blower manifold maybe near the rear pulleys to see if you have any vac lines , if you do, see if you can trace them to where there going.

Magnuson usually tell you to install the booster pump near battery area, ease of install I suppose.

To know what pulleys you have , just measure across them 9 o`clock
3 o`clock , your rears will probably be stock size , front around 3.4"
but that is the one people change so could be different.

Might be worth checking that bypass valve again , should be closed with no vac .

T/body off should be able to see bypass plate ,push on linkage see what the plate is doing.

zerotosixzero

OK when the car is at rest not running. The valve is closed.
I start the car and create vacuum in the line that feeds the valve and it remains In the same position
When I push the throttle the valve moves. When it moves the valve is opening. My understanding is that that butterfly should be closing

Also the car doesn't run or drive any different if the bypass is disconnected or hooked up. I've manually set it in the open position and drove it. And the closed position and drove it. There is no discernable difference in performance

Steve@RSD

The Bypass valve is open until vacumn is reduced, like hard acceleration or WOT. At idle the valve should be open, building Zero pressure. Without a boost gauge trouble shooting may be tough. If the valve closes at idle the vacumn pot that opens the bypass may be ruptured, either way, you should be getting boost, unless your valve is operating backwards....
If your LS6 does not fry the tires when you depress the gas pedal all the way in first gear, something is wrong!

zerotosixzero

the car does light the tires up pretty well, i had a talk with the guys at mag. my valve is resting against the stop at idle and when not running. and he said thats wrong.
when i start my car, should the valve move from a rested position of no vacuum to a open position with vacuum, and as vacuum is reduced during acceleration this valve should close
i disconnected the bypass all together, when its at rest with vacuum the diaphragm is up, then when i throttle up, it seems to pull it down, the rod action is going down not up like it seems it should.
if i had 6-7 grand to blow id toss that maggie in the swap and start over with a centri.

Steve@RSD

If you scrapped your Maggie you would miss out on alot of fun! No centri can give you the same seat of the pants kick like a PD blower, until you get to the big gear driven ones. You will get yours sorted out and soon learn why the Centri guys just wished they could get the same 60' times.
Take a picture of your diaphram and Bypass valve linkage and post it up as a refresser for me. I have a TVS unit and I think it may be a little different.

Steve

NITRO UK

Can you connect and test the valve with a non car vacuum source ie multi vac tool , or vacuum cleaner with a made up reducer tube .

Just to see if the linkage rod actually moves in the correct direction with vac and holds it ,and without vac .

ZOOM in a tad ,is your linkage orientated like this .

NITRO UK

Steve , good on ya bud

bit covered with crap

zerotosixzero

Well I think I got it figured out.
My valve is oriented the same as in the first picture. I'm not 100 percent sure but there was a electric vacuum switch attached the the master cylinder. The line from the bypass valve was going to this. And then into another vacuum operated device. It round and located on the firewall behind the washer fluid tank

zerotosixzero

Pics

zerotosixzero

Nitro is that a non Intercooled model?
that one is so much prettier than mine.

NITRO UK

Hi
Not sure what all that stuff is lol ,get rid for now ,try and keep it simple.

Yeah that is a non intercooled mp112 ,had that on a 01 coupe few years back .

Was a lot of polishing

zerotosixzero

After looking at your picture I see that you are using a different vacuum port than I am.
I am using the one next to the fuel rail
Should I be using the same port? What's the other port for. Boost gauge?

NITRO UK

That could cause all sorts of problems .

That port see`s vacuum and pressure , YEAH USE THE SMALL PIPE COMING OUT THE SIDE OF THE SNOUT.

That port has vac , open up the throttle and that port`s vac goes down , it will not see psi cos its above the blower.

The other port near the rear pulleys is vac / boost , cos it`s below the blower , so not sure but think you are sucking and blowing up that hose to the bypass valve

Anyways bud be interested to hear what it goes like with a very short hose to the snout barb .

zerotosixzero

Thanks nitro I appreciate the help. And all those who responded. The car runs drives and idles way better. I cut my bypass line down it was over 3 feet long. Now its about 6 inches pre blower. Still waiting on my boost gauge to see how much boost im really making.
How much boost did You push your maggie up too?

NITRO UK

Sounds good .

I just ran the mp112 as out the box 5 ish lbs boost.

Working on a TVS2300 at the mo 12 lbs ish .

Lots of info out there for the mp112.

silver408z

If you the blower was installed wrong and you get it straightened out that's good. I would also have your tune checked to make sure your timing and fuel is good.

BLOWNBLUEZ06@RKT Performance

If something so trivial was wrong with your car, I wouldn't hesitate to dig in and make sure everything else is right. Most cars that I tune come to me with issues that need straightening out before I'm able to tune. I'm amazed at how much power is lost from the smallest issues. Where do you live? There are many reputable shops to take the car and there are many that you might want to avoid. Let us know and we might be able to make a recommendation.
If you're a 100% do-it-yourselfer, you can go over everything yourself.

zerotosixzero

im near greenbay wi. as far as close reputable shops... im not sure.. there is a shop in greeybay called beyond redline, i haven't heard anything good or bad specifically.

speed inc is about 4.5 hours away

in the past the car was tuned by lsx performance dyno tuning in tx.
im pretty sure someone had their hands on the car since then tho.
i have cleaned up a lot of the sketchy vacuum lines, it seems to run better.

if i can get it sorted out id like to spray a little meth and maybe change some pulleys. nothing to radical id just really like to be at the 500.

NITRO UK

Hi

Did you get a magnuson installation instruction manual with your car ?

Would help you with knowing your whole install is correct .

Magnuson do a pdf but I had a look , seems the only one I can find is for the tvs2300 .

That has different connection points for vac lines so don't go there

May be one of the guys here could point you in the right direction with the right pdf , or I can scan mine and post all 40 odd pages

Oh and your already thinking about mods , think you`ll fit right in .