supercharged turbo

[SUPERVAN]

I've heard of people doing this on supercharged 3.8 GM motors. They put on a bigger SC pully to make it more efficient like 7 psi and have a turbo setup to but. The neat thing about it is it actually multiplys the intake pressure. if your running 7.5 psi(about 1.5 bar) and another 7.5psi through the SC your actually going to get about 18.5 psi, not 15 like you might expect. I've also hear people are trying it on Cobalt SS and like powered cars. The one 3.8 example I've heard of ran a nice air to air IC after the turbo and then had an aftermarket water to air underneath the supercharger. Pretty cool thinking if ya ask me.

EDIT: I should also mention that VW has a twin charged 1.4 liter motor in europe that put out something like 174 hp and gets 48mpg, but that switches from one to the other at a set rpm. Google "Twin charged Golf GT"

[Garret]

Quote:

Originally Posted by The Pope SCC has had them win the ultimate street car challenge they have, the yellow MR2 had a blower on the V6 and a turbo. Then there is there red project car. Mod mag has a compunded twin turbo Focus in it. Compounding is great but twin turbos is way too much boost for gas.

FYI that yellow MR2 only was Supercharged not turboed

[The Pope]

Quote:

Originally Posted by Garret FYI that yellow MR2 only was Supercharged not turboed

FYI I was talking about the red project car not the guy who won there contest

[Garret]

Well should've been more clear :P

[turbo minivan]

im designing somthing similar for my van. a belt driven blower and a .63 turbo. my question is, with a cal., 3 bar MAP, and +40% injectors, will it run and stay running propperly under regular driving with little throttle. i wonder because as i understand it, your stock computer reads and acts on fuel ratios at low and half throttle but at WOT the O2 sensor takes over to supply the right ratio, so.... if im only 1/4 on the gas, the new computer is making the A/F adjustments, and im under a couple PSI of boost (from the blower) are things gona be alright? ive been told to never let my boost max unless im at full throttle, cause the computer (stock computer im running right now) wont read as accuratly as the O2 will at WOT. now this is my worry with the stock computer, will the cal im putting in act difforently?
sorry, kinda a loaded question.

[SUPERVAN]

Quote:

Originally Posted by turbo minivan as i understand it, your stock computer reads and acts on fuel ratios at low and half throttle but at WOT the O2 sensor takes over to supply the right ratio, so.

Your stock (and performance computers) use your 02 sensor at anything less than WOT. When you hit WOT it then ignores your 02 and just goes strait off of MAP sensor readings and uses calculated tables reguarding your boost levels and rpm. Your stock computer is maped for any level of boost below 2bar (14.7psi) at any rpm. so if you hit 14 psi with a mitsu and 3 in exhaust at 2000rpm, which is VERY easy to do your computer will handle it. A supercharger doesn't have the lag associated with a turbo but usually doesn't make boost at idle either, so you shouldn't have trouble with aftermarket or stock computer for that matter. Someone correct me if I'm wrong though. Its been awhile since I've thought about how the computer works in these situations.

[turbo minivan]

sweet, thats all i wanted to know! thanks!

[turbo minivan]

ok, i see or im guessing your all talking about doing this with a roots type blower like a wipple, with all this talk of one power adder feeding the other.
why bother with this kind of set up?, ive built a blower much like a paxton design. (a belt driven turbo in essence, mines not built from a turbo,but same idea) the turbo and blower will be totaly seperate units working seperatly, just blowing into the same intercooler, then into the throttle body. this way theres no confusion (i dont think...yet) with whats slowing down what.
right?........ opinions please

[SUPERVAN]

Quote:

Originally Posted by turbo minivan ok, i see or im guessing your all talking about doing this with a roots type blower like a wipple, with all this talk of one power adder feeding the other. why bother with this kind of set up?, ive built a blower much like a paxton design. (a belt driven turbo in essence, mines not built from a turbo,but same idea) the turbo and blower will be totaly seperate units working seperatly, just blowing into the same intercooler, then into the throttle body. this way theres no confusion (i dont think...yet) with whats slowing down what. right?........ opinions please

nothing is really slowing down anything if you do it right. It actually may make things work better. People who are doing it are running a turbo into a supercharger. This way there is no lag associated with running a good hi flowing turbo and you can run a bigger turbo than you normally would because you have less lag. there is also the fact that you can run 2 intercooling systems here. One normal air to air after the turbo than an air to water after the supercharger. I've also heard with some people on the SC 3.8 get bigger SC pullys so they actually become less of a drag on the motor and get more of their boost out of the turbo. Sorta like picking which system you want to work harder for you. And the best part yet is the compounded boost levels. Kinda hard to explain but I posted it earlier in the thread. Interesting thing happens when you put 7psi from a turbo into 7psi from a SC you don't get 14 psi you'd get closer to 18. My above post shows the math to get that number so I'd rather not go through it again unless someone asks.

[turbo minivan]

i still think it would be WAY more efficient to be running a paxton type blower and turbo rather than a roots type and turbo. i guess ill be the one to let you know, when im done. =)

[shelby1.5turbo]

nissan called it a super turbo beleive it or not and my design that is in the works operates like an A,C compressor when the turbo hits 11 psi the super charger will cut lots of work trying to get it to work kind of like the blower from the movie car mad max drove that was cool considering it was not a dodge

[turbo minivan]

i think ive figured a way to get the blower to "ween off" as the turbo starts getting up there in boost with higher RPMs... ill mount a throttle body on the intake side of the blower (paxton style remember) and rig it to a waste gate can with restrictors that will start to "shut down" the blower when the turbo begins to take over. so at 4000 rpm im not making 40 PSI or somthing crazy with both power adders working full tilt. the blower will do its thing off the line till the turbo can spool, then the blowers intake will be "closed off" letting the turbo go as if the blower wasnt there.

[turbo minivan]

Quote:

Originally Posted by shelby1.5turbo nissan called it a super turbo beleive it or not and my design that is in the works operates like an A,C compressor when the turbo hits 11 psi the super charger will cut lots of work trying to get it to work kind of like the blower from the movie car mad max drove that was cool considering it was not a dodge

this is another good idea! basicly a mechanical version of what i am going to attempt pneumaticly.

[The Pope]

Quote:

Originally Posted by turbo minivan i still think it would be WAY more efficient to be running a paxton type blower and turbo rather than a roots type and turbo. i guess ill be the one to let you know, when im done. =)

LMAO, the reason to run a blower with a turbo is to GET BOOST OFF THE LINE. You run a paxton and it'll get going after the turbo not before it. The roots type gives boost right now to spool a huge turbo. Centrificals are great for V8s, they come on real slow and soft so you make allot less torque and hook up way better. A turbo hits real soon and blows the tires away. A roots will make you move air off idle, then they fall down on top. Thats why you run a turbo with a blower.

[shelby1.5turbo]

only problem with mine is fabbing the pulley and brack assembly would want to mount it to the a/c bracket all mounts and pulleys done by dodge like to try and convert some how the a/c compressor and mount it to the intake manifold and run an electro magnegtic clutch to engage and disengage when i want to figure about 3500 rpm when the turbo comes into play