Vortech Supercharger wastegate idea

[kc95sc400]

Somewhat built 1uzfe V8.

So I'm about to upgrade my little V-9 F trim with a V-2 Si trim. The V-2 moves way more air and is capable of 22 psi (get 12 psi out of the V-9 on a good day). I don't know that my motor is quite capable of holding 22psi.

Thread here : http://www.clublexus.com/forums/buil...ged-sc400.html

I've seen a few domestic guys (Mustang and Vette mostly) use a wastegate on the intake pipe. The purpose of this is to run the smallest pulley possible on the supercharger (based on supercharger and engine max RPM) so that boost is at max desired boost as low in the RPM range as possible but then have the capability to release excess pressure.

Say I want to run 15 psi. I have a 2.62 pulley which will put the V-2 at near peak RPM at my set peak engine RPM of 6800. Lets say it will make 15psi at 4000 rpm and get up to the max 22 psi by 6800 rpm. I will then have the wastegate set to open at 15psi to "vent" the excess pressure.

I also think I can use the wastegate as a bypass / blow off valve as it is a two port wastegate with one port on each side of the diaphragm.

I'm not sure if I will need a way to vent vac / boost in the lines between the VSV / one way check valve and the wastegate. If the boost or vac lines hold vac / boost it might make the valve harder to open / close. will need to do some bench testing.

Attached is a diagram, I'd love some input as I have no experience with wastegates,

Thanks

 

[kc95sc400]

Ok, the PDF file is too large to attach but can be found here : http://www.clublexus.com/forums/8593079-post1.html

 

[H7ERO]

I like your thinking!

I Planning on implementing the same set up very soon iv got all the bits,

It seems pretty well documented on other cars so we just need to get on an do it with the 1uz

Im wondering If mine will fuel ok with increased Psi through the range as opposed to just at peak values, however I have an Safc and vortech super FMU so that should be able to dial it in,

Let me know how yours goes, and I will the same on this thread

 

[H7ERO]

Just read your thread, your set up is very enviable!

your going to be just fine, I would love to hear what power you can put down once its set up, Its a great vortech build.

as for the waste-gate plumbing you just need a boosted pipe to the lower of the wast-gate inputs, think of it as you need some boost to counteract the spring to open the valve in the waste-gate.

the top input can be left open , this input would assist the spring and help keep it closed. you want it to open at set values

you can control the psi value with different springs, mechanically reloading the spring ans bleeding off air going into the vacuum input

The only other point I can see as a problem for both of us is the tiny pulleys we have to use on our set ups mean less surface area for the belt to grip,
its hard to know if its slipping too, I think for your ultimate aims you will probably have to address this somehow, hopefully not for a while tho!

Im on thin rods in mine and just mechanical fueling, but I will be interested to see what power I can make before mine goes bang...

 

[H7ERO]

I dont think it will work to use the waste gate as a bypass valve at the same time unless you can essentially get it to operate at your desired PSI mechanically. with just the spring rate controlling the pressure

Then have the lower input pre-throttle body and the top input from the plenum post throttle body, thus when closed the pressure diferential should open the vale depending on what spring is in there,

I think some bench tests are in order...

 

[kc95sc400]

I dont think it will work to use the waste gate as a bypass valve at the same time unless you can essentially get it to operate at your desired PSI mechanically. with just the spring rate controlling the pressure

Then have the lower input pre-throttle body and the top input from the plenum post throttle body, thus when closed the pressure diferential should open the vale depending on what spring is in there,

I think some bench tests are in order...

The trick is to use a weak spring and 2, computer controlled 3-way vacuum switching valves to control the wastegate.

 

[H7ERO]

Hmm yes a vacum switching valve could work,
but for the cost of computer control you could just run a separate dump valve,

I had a new boost pipe made up with 3 'take offs' so i could run Tripple dump valves

two to dump,

one machined to accept preload adjustment so it could act mechanically as a waste-gate by adjust ting the spring preload ~ maybe by stepper motor