I meant exactly what I said, the engine internals dont care what you are using to force more air into it.... it only cares what the outcome is. like I said boos is boost. A turbo charger is capable of generating high boost levels... the addition of the supercharger in many cases is to minimize the amount of lag. if you want to generate head lifting boost levels you dont need a dual system to do it.
-dave
Quote:
Originally Posted by NotAnotherHonda
what do you mean? that having a supercharger AND a turbo is gonna put the same amount of stress on the engine as if it had only 1 of them? maybe thats possible, but only if both of the chargers only were running very low boost, 5-8psi at most...still, i dunno
A turbo and supercharger is called a twincharger. How about this one guys...
It is a RB26DETTR - "R" means Supercharged and it is a Nissan (NISMO) built engine. 1500 HP never looked so beautiful.
Troy
an ogura supercharger i think it is. anyways, there's a skyline out there somewhere that has rb26dett with TWO ogura superchargers. also known as positive displacement superchargers. it's kicking 1400 hp. does anyone know what it'll do in the quartermile, im very curious.
So, what if you set up a nearly-lag-free 5 psi turbo and a hefty 20 psi centrifugal sc in series, and you plumbed them sequentially, so that the turbo hid the weak low-end boost of the supercharger?
the method of boosting that you are refering to is called compound forced induction. it can be done but it think unless it is a full race motor it is a waste of time and money, get a properly sized ball bearing turbo and save some money and frustration.
I wonder why we're discussing this... its not like any of you guys will actually do this... and there are plenty of books and information that is more reliable than what you hear on a forum.
I wonder why we're discussing this... its not like any of you guys will actually do this... and there are plenty of books and information that is more reliable than what you hear on a forum.
I already said earlier on in the thread that I would probably never be able to afford it. However, I was just asking out of curiousity and sometimes it is fun to talk about things even if you will never be able to do it. We all talk about skylines but very few of us will ever own one.
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on the oct. 2001 edition of super street there is a then new type r that was boosted with both a super and turbo...it had a 11:1 compression and 20 lbs of boost...thats just crazy
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damn not another honda...well i guess its time to woop some a$$
on the oct. 2001 edition of super street there is a then new type r that was boosted with both a super and turbo...it had a 11:1 compression and 20 lbs of boost...thats just crazy
Thats not long for this world....
Mike
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I wonder why we're discussing this... its not like any of you guys will actually do this... and there are plenty of books and information that is more reliable than what you hear on a forum.
For power production, supercharges suck. Centrifugal superchargers have more lag than most turbos.
New generation turbos don't have much lag.
I was talking with Kenny Tran and he said even the big turbos the racers use have nearly no lag nowdays, in fact the power comes on so quickly, its really hard to find traction.
Compound super/turbocharging is a gimmick and sucks.
Mike
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There can only be one Icy Hot Stunta, Don't Hate.
For power production, supercharges suck. Centrifugal superchargers have more lag than most turbos.
New generation turbos don't have much lag.
I was talking with Kenny Tran and he said even the big turbos the racers use have nearly no lag nowdays, in fact the power comes on so quickly, its really hard to find traction.
Compound super/turbocharging is a gimmick and sucks.
Mike
Actually, superchargers have close to zero lag because they have a mechanical connection to the crankshaft thus RPM and boost are in direct relation. A turbo if built with the correct size, trim, A/R, etc. can have minimal lag but it still has a degree of lag (unless expensive Anti-Lag technology is utilized). A turbo uses gas flow over a fan blade and therefore will always have this hesistation. Newer turbos have greatly improved turbine design with the useage of ball-bearing centers to reduce the friction component. Pro import drag racers like Kenny use semi-auto sequential trannys and a form of anti-lag which allows them to build boost at the line. Twin charging system allows for the great low end response of the supercharger until the larger turbos come into boost and then when the supercharger begins the parasistic loss - where the power produced by the supercharger is mostly consumed by the drag of the belt - the turbos are at mid to full boost.
It is a really nice system if built correctly and is especially useful for the RB above with the two rather large KKK Blitz turbos.
If anyone is interested check out the books by Corky Bell titled Maximum Boost: Designing, Testing, and Installing Turbocharger Systems and Supercharged! Design, Testing, and Installation of Supercharger Systems. Both are tremendous information sources and will give you ALL of the basics in both areas of forced induction.
Troy
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1992 S13 240SX SE Fastback KA24DE 5 spd - Type X Aero & Seibon Carbon Hood & Hatch -soon GT28RS
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Still trying to import a 1988 R31 Skyline GTS-R w/ RB20DET-R - only 800 produced (legal under show/display regs)
Last edited by KA24Tech : Feb 13th, 2004 at 06:15 PM.
Actually, superchargers have close to zero lag because they have a mechanical connection to the crankshaft thus RPM and boost are in direct relation. A turbo if built with the correct size, trim, A/R, etc. can have minimal lag but it still has a degree of lag (unless expensive Anti-Lag technology is utilized). A turbo uses gas flow over a fan blade and therefore will always have this hesistation. Newer turbos have greatly improved turbine design with the useage of ball-bearing centers to reduce the friction component. Pro import drag racers like Kenny use semi-auto sequential trannys and a form of anti-lag which allows them to build boost at the line. Twin charging system allows for the great low end response of the supercharger until the larger turbos come into boost and then when the supercharger begins the parasistic loss - where the power produced by the supercharger is mostly consumed by the drag of the belt - the turbos are at mid to full boost.
It is a really nice system if built correctly and is especially useful for the RB above with the two rather large KKK Blitz turbos.
If anyone is interested check out the books by Corky Bell titled Maximum Boost: Designing, Testing, and Installing Turbocharger Systems and Supercharged! Design, Testing, and Installation of Supercharger Systems. Both are tremendous information sources and will give you ALL of the basics in both areas of forced induction.
Troy
Centrifugal superchargers have plenty of lag because they are not positve displacment. The boost to rpm of a centrifugal is very non linear. Look at the power curve of any centrifugal system. It has less area under the curve than a turbo. It has less low end power as well.
Kenny does not use a semi auto sequntial tranny. He is currently running a stock tranny with a tilton twin disc carbon clutch. He has experemented with dog shifter gearsets for the stock transmission.
Twin charging sucks with two inefficent roots blowers.
A roots blower with boost at low rpm marginaly helps power because the engines VE is so low at that rpm anyway. You are increasing the density of a very small charge.
Mike
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There can only be one Icy Hot Stunta, Don't Hate.
For power production, supercharges suck. Centrifugal superchargers have more lag than most turbos.
New generation turbos don't have much lag.
I was talking with Kenny Tran and he said even the big turbos the racers use have nearly no lag nowdays, in fact the power comes on so quickly, its really hard to find traction.
Compound super/turbocharging is a gimmick and sucks.
Mike
Yeah, the more I think about it and after reading the NPM board about not using the Greddy TT kit, I figure just buying one, good turbocharger should be good enough. Here's another stupid question for you, , what does a blowoff valve do? Is the purpose to release built up pressure from the turbo charger when you let off the gas and the pressure is high? Also, is a blowoff valve necessary when you add a turbo or beneficial at all? Or is it just something you can add if you want? Sorry for the dumb questions but like I said, I'm new to the engine stuff, .
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If anyone is interested check out the books by Corky Bell titled Maximum Boost: Designing, Testing, and Installing Turbocharger Systems and Supercharged! Design, Testing, and Installation of Supercharger Systems. Both are tremendous information sources and will give you ALL of the basics in both areas of forced induction.
Troy
Cool, thanks for the tip! I'll check em out.
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, what does a blowoff valve do? Is the purpose to release built up pressure from the turbo charger when you let off the gas and the pressure is high? Also, is a blowoff valve necessary when you add a turbo or beneficial at all? Or is it just something you can add if you want? Sorry for the dumb questions but like I said, I'm new to the engine stuff, 
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