Need Advice on Supercharging

[Jakee]

And if you bugger the next one up, I have one as well. You have two trys.

 

[zachow3]

What do you think about using a heat gun to warm and reshape the factory washer reservoir?

Had'nt thought of that. I guess I could try it out on the stock coolant tank and see what happens. Once i get the aftermarket tank mounted I wont need the stock one, so if I destroy it in the process it wont matter.

Good call! Now where did I put that heat gun......

 

[zachow3]

I found this interesting since it applies to my type of supercharger, but I have'nt heard of anyone using one.


Bosch Blow-off Valve for Supercharged Cars



The Problem: Frequent belt failure on belt-driven superchargers.

The Solution: can be as simple as replacing a blow-off valve meant for a Turbo with one properly designed for a supercharged application.

I rarely see this discussed - but I often see this mistake. Pop-off valves for Turbo applications and Blow-Off valves for Superchargers are NOT the same thing, and not interchangeable.

Think of this: you are shifting at or near redline. The blower, at redline, is making maximum boost. Now you lift suddenly off the throttle (to shift, to brake for the corner, whatever) and you slam the throttle body shut. All that boost has no where to go, and runs backwards through the system looking for an escape. The blow-off valve is supposed to be that escape.

A valve for a turbo system will "flutter" - you can hear it if you listen - as it is designed to NOT loose all the back-pressure and keep the turbo spooled-up a little bit. This open-shut-open-shut action in a turbo-type valve pushes the belt-driven Powerdyne sprockets forward-and-back several times a second and the belt takes a beating. These same valves when applied to a gear-driven blower seem to work OK - but its just because the gears can take that kind of abuse where a belt cannot.

A blow-off for a Supercharger is designed differently and will open ONCE and dump the boost like it should on a supercharged system. It is much kinder on belts.

Over years of trial and error (and a LOT of money spent on blow-off valves), I still have not found a better blow-off valve than the one the Bosch engineers designed for boosted applications. Here it is, and at a darn good price too.

One more thing: Test your blow-off valve by making sure it holds vacuum and moves correctly from time-time. They don't last forever!

Cheap insurance, but then again perhaps not necessary for mild boost applications like mine? Just another thought.

I think I need a good kick in the butt. Other then measuring things and dry fittng parts together, I have,nt turned a wrench on the Explorer in a couple weeks. On the other hand I'm not setting a deadline anymore for this build so I'm not pressuring myself. Plus I am behind on the yardwork, so I guess my priorities have shifted somewhat.

I'm with Jakee though, the day I fire up the finished product will be very exciting.

 

[zachow3]

Oh yeah, I found my heat gun so I'll see what kind of damage I can do.

 

[Jakee]

I was set on running a BOV on mine just because of the thought of all that pressure building up on the turbine wheel. That's bad for a turbo, but the recommendation for running a BOV on a turbo is anything over 8-10 LBS. I'm not even running that much pressure but still wanted it.

For a supercharger, I can see the same thing happening. The TB shuts and the pressure finds its way back to the supercharger. I'm sure it's not good to have forces applied from the opposite direction.

 

[zachow3]

I was set on running a BOV on mine just because of the thought of all that pressure building up on the turbine wheel. That's bad for a turbo, but the recommendation for running a BOV on a turbo is anything over 8-10 LBS. I'm not even running that much pressure but still wanted it.

For a supercharger, I can see the same thing happening. The TB shuts and the pressure finds its way back to the supercharger. I'm sure it's not good to have forces applied from the opposite direction.

Yeah, thats why I posted that article. Just from a reliability standpoint, regardless of boost pressure, anything that decreases wear and tear is worth the extra money. And even though it mentions the Bosch, there are less expensive ones out there. I think the Bosch at $72 isnt to bad when you consider what an impeller or bearings etc would cost.

There are several options for my head unit that would beef it up. Stronger belts, better bearings, but my unit is brand new. I dont really want to put anymore money into it right now if I dont have to.

In the future, if I decided to run more boost at least I know there are options out there. Forget Powerdyne, they wont offer me any support. And forget about a warranty.

 

[zachow3]

Here is a pic of the Bosch Compressor Bypass Valve off of Vortech's website.
Said to be good for 6 to 12 PSI.

 

[CDW6212R]

Do they make one for about 8-16psi, or do you step up to a larger size for more boost?

 

[justin146]

Here is a pic of the Bosch Compressor Bypass Valve off of Vortech's website.
Said to be good for 6 to 12 PSI.

You can get these used for about $20-25 on eBay. It is a Saab OEM bypass valve.

 

[justin146]

I was set on running a BOV on mine just because of the thought of all that pressure building up on the turbine wheel. That's bad for a turbo, but the recommendation for running a BOV on a turbo is anything over 8-10 LBS. I'm not even running that much pressure but still wanted it.

For a supercharger, I can see the same thing happening. The TB shuts and the pressure finds its way back to the supercharger. I'm sure it's not good to have forces applied from the opposite direction.

The two times my BOV didnt work because I left it unhooked, I blew intake couplers.

 

[justin146]

Do they make one for about 8-16psi, or do you step up to a larger size for more boost?

I believe it is that the plastic case just cant hold more than 12psi. You can step up to a JGS, Tial, Turbonetics Raptor for higher boost/horsepower applications.

 

[zachow3]

Do they make one for about 8-16psi, or do you step up to a larger size for more boost?

Yes they do.

This is off the Vortech site:
http://www.vortechsuperchargers.com/view.php?f_cat=Air+Components

The standard bypass valve is the one I pictured.
Justin could probably explain this better since I'm not sure what would be required for that kind of boost.

The bypass valve will vent the air charge ( I assume you are talking about a supercharger) back to the inlet side of the S/C when the throttle is lifted at high rpm/boost to prevent reverse airflow when the T/B is closed suddenly. Besides preventing possible engine surging do to the compressor trying to stall I read more than once that (especially at high boost) you can end up bending the T/B plate. This also prevents sudden boost loss since the air charge is recirculated to the S/C inlet, and reduces IAT. Turbos would vent this air to atmosphere. Apparently same concept, just a difference in where the excess air goes.

Thats about the best I can explain it. For the amount of boost you are talking about, might require a bypass valve/blow off valve combo. I really havent researched your application enough to give you a concrete answer.

 

[justin146]

Yes they do.

This is off the Vortech site:
http://www.vortechsuperchargers.com/view.php?f_cat=Air+Components

The standard bypass valve is the one I pictured.
Justin could probably explain this better since I'm not sure what would be required for that kind of boost.

The bypass valve will vent the air charge ( I assume you are talking about a supercharger) back to the inlet side of the S/C when the throttle is lifted at high rpm/boost to prevent reverse airflow when the T/B is closed suddenly. Besides preventing possible engine surging do to the compressor trying to stall I read more than once that (especially at high boost) you can end up bending the T/B plate. This also prevents sudden boost loss since the air charge is recirculated to the S/C inlet, and reduces IAT. Turbos would vent this air to atmosphere. Apparently same concept, just a difference in where the excess air goes.

Thats about the best I can explain it. For the amount of boost you are talking about, might require a bypass valve/blow off valve combo. I really havent researched your application enough to give you a concrete answer.

You could vent yours to atmosphere if yout MAF was blowthrough. When the meter is before the supercharger or turbocharger, you have to recirculate it so you aren't blowing off metered air. If the BOV is before the meter(like my truck) venting doesnt hurt anything.

 

[zachow3]

You can get these used for about $20-25 on eBay. It is a Saab OEM bypass valve.

Right now E-bay has a few but they would run about $60 shipped with the BuY It Now, and their used. They are made by Bosch, which is what I was looking for, But for $72 I can get a new one thats guaranteed.

Come to think of it, every part I have purchased for this build is new, or at least never used. That must be why I'm so far over budget.

Now if only I could find a good deal on a used wideband.

 

[zachow3]

You could vent yours to atmosphere if yout MAF was blowthrough. When the meter is before the supercharger or turbocharger, you have to recirculate it so you aren't blowing off metered air. If the BOV is before the meter(like my truck) venting doesnt hurt anything.

I will have to recirculate the air. You know where I can get the fittings for this?

 

[justin146]

Right now E-bay has a few but they would run about $60 shipped with the BuY It Now, and their used. They are made by Bosch, which is what I was looking for, But for $72 I can get a new one thats guaranteed.

Come to think of it, every part I have purchased for this build is new, or at least never used. That must be why I'm so far over budget.

Now if only I could find a good deal on a used wideband.

You can buy a wideband build kit- If you know your way around a soldering iron you can pull it off. Then you add an OEM wideband sensor from a newer Caddy. But if you have it professoinally tuned, you really dont need one. I just wanted mine for security..

 

[zachow3]

You can buy a wideband build kit- If you know your way around a soldering iron you can pull it off. Then you add an OEM wideband sensor from a newer Caddy. But if you have it professoinally tuned, you really dont need one. I just wanted mine for security..

I could do it. Just thinking if I want to. Rocket sent me a schematic for wiring a wideband and MAP sensor to my Livewire. I too would like to have piece of mind.

Professionally tuned? I cant even figure out how to datalog. I have a local shop ready to send me a tune just so I can drive the truck down there and put it on their dyno for the final tune. I wish James could do it, but the cost to get him out here and the tuning, I dont have it in the budget. This shop is quite nice. And the people are friendly and have answered every question I could throw at them. They work on alot of mustangs and when I told them I was looking for a place to tune an old supercharged Explorer. they actually thought that was pretty neat and told me to bring it in when I was ready and they would take care of me.

I like that attitude.

So I read your going dual turbos? With 4" pipes? I wish you luck with trying to fit all that. I,m just doing a short section of 4" intake pipe and I've had to modify it twice so far and it's still fighting me.

 

[zachow3]

You can buy a wideband build kit- If you know your way around a soldering iron you can pull it off. Then you add an OEM wideband sensor from a newer Caddy. But if you have it professoinally tuned, you really dont need one. I just wanted mine for security..

Oh, forgot to ask. Where can I get a wideband build kit? And what year and model Cadillac came with a wideband sensor?

 

[justin146]

I could do it. Just thinking if I want to. Rocket sent me a schematic for wiring a wideband and MAP sensor to my Livewire. I too would like to have piece of mind.

Professionally tuned? I cant even figure out how to datalog. I have a local shop ready to send me a tune just so I can drive the truck down there and put it on their dyno for the final tune. I wish James could do it, but the cost to get him out here and the tuning, I dont have it in the budget. This shop is quite nice. And the people are friendly and have answered every question I could throw at them. They work on alot of mustangs and when I told them I was looking for a place to tune an old supercharged Explorer. they actually thought that was pretty neat and told me to bring it in when I was ready and they would take care of me.

I like that attitude.

So I read your going dual turbos? With 4" pipes? I wish you luck with trying to fit all that. I,m just doing a short section of 4" intake pipe and I've had to modify it twice so far and it's still fighting me.

Why not just put the truck on a trailer and pull it to the dyno? It would keep you from having to do any datalogging and you wouldnt need a wideband- they have a wideband to use with their dyno ( I am sure)

 

[justin146]

Oh, forgot to ask. Where can I get a wideband build kit? And what year and model Cadillac came with a wideband sensor?

I am not sure where people get the kits, but the sensor is from an 05+ Cadillac SRX, CTS..