Thinking about twin-charging w/ remote turbo, Good idea or utter fail?

[TexasAceTA]

Ok, I am a bit out of my league with this one and this is the only place I have found that seems to have people that really know what they are talking about.

Quick rundown of my setup. I have a 2000 Toyota 4runner 4wd with a 5vz 3.4l DOHC engine. Right now it has an eaton MP-62 TRD supercharger on it running about 10.5psi of boost making ~250-260whp if I had to guess. I am using methanol injection as it is and plan to use more with the turbo, I figure around ~2000cc all said and done (need the fuel since the stock injectors are maxed out).

I want more power out of it mainly because I can.

I have pretty much decided on doing a remote mount turbo setup (planning on a 6262 turbo). These trucks have no options for turbo manifolds up front and getting a custom one made will cost more then this whole remote setup.

At first I was just going to remove the supercharger and run the turbo alone but then started thinking about twin-charging it.

I have put a lot of thought into this and I am just not sure if it is a good idea in the long run or not.

First off the 5vz motor I am working with while pretty strong does have a limit of around 400hp on stock internals before the rods become a weak link. I plan to get as close to that as possible and want room to grow later when I build the motor but till this one blows thats about the limit.

The supercharger uses power to make power and as such would put more stress on the motor for a given power output then the turbos.

Next up is the supercharger adding a LOT more heat to the air charge then the turbo and no ability to intercool it after the supercharger on my setup.

These were my reasons for ditching the SC in the first place.

I then got to thinking about the by-pass valve. What if I took control of it and opened it once the turbo is spooled. Would that basically render the supercharger as doing nothing?

My theory (no idea if it is correct, thats why i am here) is the supercharger will not know the turbo is doing anything before it and the by-pass valve should still vent off any extra boost from the supercharger allowing the turbo to produce all the boost.

Thus giving me the fast spool of the supercharger and the top end power of the turbo.

I am sure there are flaws in this plan as I have never done or even seen a twin-charged setup myself and there is remarkably little info on these setups.

Is it practical to open the by-pass valve once the turbo is spooled to stop the supercharger from working? Or will the by-pass valve turn the supercharger into a heat pump?

Should I just nix the supercharger and run the turbo alone?

Is a 6262 (62mm) turbo about right? Any larger would be pretty laggy if the twin-charging doesn't work so I didn't really want to go bigger in case I decided to ditch the supercharger afterall. Without the supercharger I expect the turbo to spool around 3500-3750rpm which is about perfect with my 5500 redline.

I already ordered the turbo but the order won't go through till tomorrow so could use a response quick. Thanks

Call me TA

I carry a gun cause a cop is too heavy.

If guns kill people, then Spoons make people fat.

 

[TexasAceTA]

Well, after doing some more research on the limits of the stock block, It seems that the rod issues are luck of the draw and mainly the earlier year motors that have the problem.

If the rods hold up then the limit of the motor is higher then I first expected. It is still unknown how much power it can handle but it is not as set in stone as I first thought.

My goals have also changed after finding this out from just wanting a fast truck to wanting to take the stock block HP record which near as I can find is around 375-390whp proven HP.

The supercharger will make this a much harder goal to complete for many reasons.

A big one is the turbo I got will want to run ~20-25psi of boost to be "happiest". If i leave the supercharger in place the turbo would be lucky to make 10psi of boost.

Not to mention I keep coming back to the fact that the supercharger belt will simply not hold the power needed to run compound boost without putting a super big pulley on it turning the boost down to ~3psi.

In this case I don't think the supercharger would help enough down low to make the top end losses worth it. Which comes back around to wishing the bypass valve would truly by-pass the supercharger.

I have also decided to do things a little different by adding a better piggyback (AEM FIC) and getting a larger fuel system allowing for a better tune with these new plans. This means more money and I really need the money from the supercharger to pay for this extra stuff.

All said and done the turbo/fuel setup should be good for ~600whp if I am brave enough to turn the boost up high enough for that. The transmission won't hold that though, it is good for around 500whp.

You can Call me TA

I carry a gun cause a cop is too heavy.

If guns kill people, then Spoons make people fat.