Ok, so I finally finished the install of the supercharger and went for a dyno tune.
I have a really ****ty disappointed problem....I get no boost!!!!!! Help!!!!!
Its a Rotrex C30-94 with a 95 mm pulley
Charger has no belt slip
The Bosch diverter valve is not defective
We check for any leaks in the piping and couldnt find any
I only was able to get about 5 lbs of boost at max rpms in third gear for a brief second. After boost guage goes to zero i sometimes get 1psi but then i have to come off the throttle because Im redlining. i dont understand, I did the so much research and had a solid plan for this project only to be disappointed. See attached pics, and please help out...thanks.....Rock


This dyno result is just a fluke when the car hit boost briefly.

Well if it is running ok then there is probably not a vacuum leak that would be a boost leak under load. Since you have seen 5lbs of boost then your supercharger is probably not undersized by to much. Were are you measuring boost? Make sure it is after the throttle body. One of the stock vacuum ports should work well. Make sure that you have a pcv valve on the pcv line from the throttle actuator also. That will not be a big leak but put pressure in your crankcase. My bet is the bypass valve still.

Whipple,
I tee'd off the vacuum from the brake booster hose after the throttle since it was the largest diameter hose. I then ran that to a vacuum distribution block and from there in this order the other vacuums are connected. From left to righ


t,
1 vacuum input from tee
2 output to a em f/if
3 to Bosch diverter valve
4 to boost guage.
Please explain the pcv stuff as I don't understand.
At first I had the diverter valve back wards but then I corrected it and it didn't make a difference. I also did the test to make sure it works fine and it passed (I guess)
When I floor the car and rpms are maxed out I get maybe

1 or 2 PS I but I don't feel anything because by then I have to et go of throttle. This was in third gear I sometimesget a check engine of misfire in 345&6(?)

Should I get a new bypass or change to different brand?
Thanks

PCV is positive crankcase ventilation, and in your picture you have breathers on the valve cover, so that shouldn't be an issue.

Are you sure the gauge is just not bad?

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try run it without the bypass valve to see if it help
or check the boost immediately after the SC (before the IC)

At the shop they connected another gauge tee'd off the bypass vacuum and were getting the same readings.
My next move is to bypass the ic all together and mock up some piping directly into the intake over the engine with bypass valve teed off into it.
Is this recommended?
I actually did clamp the bypass hose and had the same results along with the charger surge after the throttle closed. I don't want to continue that and destroy the charger.

If you got a big charge surge after letting off the throttle then I would think that you do not have a leak pre-throttle plate. You could do some light throttle and then pinch off the bypass to create pressure in the pre throttle piping and check for leaks that way.
I was reading your description of the vacuum block and I think that you might just be getting bad readings as a possibility. Try just connecting to the intake plenum at one of the normal vacuum nipples on the lower aluminum part of the intake. There are two in front.
Also on the pcv. There is a second pcv hose from the mounting bracket for a/c. It goes to the intake and a restrictor that is built in to the intake manifold. It then goes to the intake manifold next to the throttle. Hose with an elbow. You need to put a one way check valve or commonly known as pcv valve here. Otherwise you will push boost into the crankcase. You will not build a lot of pressure because the top is vented but it will be a boost leak and will be creating additional lower crankcase pressure and flow through the engine.
For the misfires. If you are dumping boost after reading with the air mass sensor you will be really rich. This will also tell you if you are dealing with a leak or just not enough boost.

Also did you tap the booster line before the check valve in the line. I do not remember were the check valve is on that model. I do not see it in the picture.

Thanks for that explanation whipple and everyone else.
Ok so i tee'd the vacuum from the brake booster line before the check valve. So I will install a check valve in that main line that I teed off.
I noticed on the back of the throttle there is a vacuum line that is elbowed onto it, i guess tjis is what u were referring too I will also install a pcv valve on that and that should eliminate the boost leake if everything else is well correct?
Are the two crank case breather filters ok there?
Thanks
Rock.

have you checked that the rotation of your super charger suits the rotation of your engine as some super chargers are available in counter rotation? you can always take all the ic pipes off turn the engine and check it blows at you!

Yes the charger is confirmed turning in the right direction and is is coming out the right way

i installed the pcv valve in the hose you suggested and now the choked when i accelerated and air fuel is reading off the charts. any other suggestions?

Just throwing ideas out there but can you confirm that your throttle opens fully? I'm assuming that you are still using the stock electronic throttle actuator. If it isn't opening fully then it may be why you're reading low boost in the manifold.

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The throttle foes open all the way. Do u think I heed another tune now that air is not escaping?