Toyota Supras had a small turbo feeding a larger turbo from the factory. Not technically a turbo feeding a supercharger, but same basic idea
Not unusual at all - a number of production vehicles have used the system. In the 1990's Nissan produced a version of their supermini Micra/March that was supercharged using an Aisin AMR500 and a turbocharger.
On the V6 with the single 72mm and M90 blower set up the supercharger gave instant throttle response then the turbo spooled up and took over. Otherwise that 72 on a V6 would have been in at least second gear before it made boost. It was a cool set up.
Is´nt it a bit redundant these days? I thought turbo "lag" was a thing of the past anyway, since the technology has improved so much?
The true definition of "lag" is the time it takes for the turbine wheel to react to the inflow of exhaust pressure. Modern turbos have pretty lightweight wheels on them so lag is pretty minimal. Again as I stated before, boost threshold is mistaken as lag. Having a high boost threshold, meaning your system doesn't "spool up" before 3 or 4K RPM isn't all bad. It just means you're gonna make a shit load of power in the upper RPM range!
Just to get your head around the boost threshold thing, Relate it to a very loose converter or a cam with some serious overlap. Both instances are going to require a bit of RPM before they start operating in the range they are designed for. The upside of the high boost threshold is that in the lower operating ranges your engine will behave as if it were a normal NA engine. Given that most turbo systems use cam profiles that are very idle friendly and generally quite mild in idle, you get a Jeckel and Hyde personality out of your ride!
That is probably the prettiest Hand Grenade I've ever seen... Not if, but when... Now someone needs to put one on a Boss Hoss to make it even more crazy!!! LOL
JUST PUT THIS THING ON AND CALL IT A DAY! <a target='_blank' href='http://img294.imageshack.us/i/camaro1hn0.jpg/'><img src='http://img294.imageshack.us/img294/6411/camaro1hn0.th.jpg' border='0'/></a> Don't need no stinking turbos with one of these!!
Those look likeT4s, probably around 60mm judging by the carb inlet adapter. They would have been pretty common in that time period. Hard to tell from a picture though. The Enderle scoops butterflies would have to be blocked from the back. This guys work is too smart to overlook something like that. If you look, the throttles and chokes are hooked up on both carbs as well as the blower hat. He also has the injection on the blower hat hooked up. Given that draw through turbo systems don't do well with boost referencing, and I'm not seeing any plumbing for it, he may be using the carbs as the idle and cruising range and the FI for the boost enrichment.
As I said earlier I have built quite a few of these, and helped others to build them too. A turbo + blower works far better than either just a turbo or blower by itself. And you do not need to run very high boost with this system. Turbos suffer from a limited power band and the high turbine exhaust back pressure makes them far more prone to detonation. A positive displacement supercharger will always have a falling volumetric efficiency with increasing rpm. Combine the two, and you get the advantages of both, without having the disadvantages of either. Once you have driven a twincharged car, you will never be happy with anything else. They are so smooth and unbelievably torquey down low, with amazing top end power only a turbo can produce. Nothing else is quite like one of these to drive.
I read the articles when Dobbertin's cars came out and yes, the hat is blocked off behind the butterflys, and yes, this thing did run and make lots of power. His even wilder J-2000 made lots of power too with a twin blower and two turbos.
I have a problem with this statement unless by "as fast as you want to go", you mean fast enough to win....
I don't agree. I have had 10 different turbos in all different shapes and sizes. I want the biggest, fastest spooling turbo with the least stall speed I can get. To say you want a slow spooling turbo to give you better driving charicteristics is nuts. I ran high 10's with 1.52 60' times with a quick spooling turbo.Drove the car 8 hours to the track and got 21mpg. It drove like any other grandma car out there when not under boost. It takes some load to get under boost wheter it has a large exhaust housing or small so why would anyone want a turbo that takes the time to make a sandwich to spool? In the case of the twin charged car he had a 72 turbo which is quite large for a V6 engine...unless you run a lot of stall. So to run it throgh the blower seems a great way to build boost quickly without running a ton of stall speed. Especially in the FWD GP configuration where there aren't a bunch of high stall options out there.
Yup. The blower creates much more exhaust flow when you open the throttle, and the turbo packs dense air into the blower. They help each other, and the result is a far lower boost threshold and much reduced spool time. In fact, a twincharged car can use a stock torque converter, high stall converter is the very last thing you need with twincharging. With a stick shift, you drive it off the line. Fully let out the clutch, then nail the throttle at low rpm in first gear. It will instantly break traction anyway.
Here is one I helped build in Australia. Only 184CID and 9 psi.http://www.youtube.com/watch?v=yzRpz9c-t_o
I dont travel much at all but, I want to travel to australia for the summernats soooooooooo badly!!!! There is some unbelievable machines down there. I've been researching australian hot rodding sense i was about 10 years old. one day ill get there in person, if i could just afford the plane ticket!!!!!!
First off, I did not state I wanted a slow spooling turbo. The fact of the matter is a turbo capable of making 1K HP is not going to produce enough air flow to support the 1K HP level without RPM or a large displacement engine. Or you can use a blower to make the engine flow more air making a larger turbo more useful on a engine that would otherwise be to small in CFM. If you want to carry and pay for the extra gear to have instant boost well, that's the wonderful thing about free will and choice, aint' it. I disagree slightly with your assessment about large or small exhaust housings. There are a few more variables to consider when choosing an exhaust housing, like cam profiles and exhaust restrictions. Yes, both need load to spool up, hence my statement in the previous post. But smaller housings with with a low restrictions may just spool up off idle but will choke up and limit your ability to make any more power at the top end of your operating range. This guy runs some big turbos, no blowers, and through a boost builder program in his EFI, seems to be able to spool and get shit done just fine. And it has some killer street manners too!
Did you see these guys? 200 cubes and only a turbo running 8's! You can hear him coming up on the boost threshold while he does his burnout, awesome!
I misunderstood you. I thought you were saying if you got a big turbo that took longer to build boost you would get better street manners. In a full race set up I agree big turbo and have enough stall/cubes to spin it. On the street if you have a car that already has a SC then adding a turbo makes a nice way to cheat cubes and stall. I would not add a supercharger to my GN it does quite well on it's own. If I was going to build a V8 set up I would go with a turbo only set up. whi knows maybe I'll put twins on my 53? The twincharge is a nice way to cheat but if you don't have a supercharger already I sure wouldn't spend the money to twincharge.
I am in the 'long process' of building a twin turbo supercharged small block Camaro. It is an interesting project to say the least.
Sorry I must be on the wrong site. I thought I was on the HAMB but it seems to be Popular Street Roddin'!
it is entirely possible. world war two fighters and bombers such as the B-17, B-24, P-38, and P-47 all featured a massive turbo feeling through an intercooler, through the the carb and into the supercharger. the fighters used a water/methanol injector when the boost reached 60-75" manifold pressure. the Wright R-3350 turbo compound engine had 3 turbos on the engine, a supercharger and another turbo could be added under the nacelle. the B-29 used twin turbo, intercoolers and supercharger. alcohol would be your fuel of choice. just an opinion, for what its worth ps. am building a flathead ford v-8 with a turbo and supercharger as a fun project.
It is an old idea, but very few did it in Hot Rods from what I read about. So, what is old is new again .. sort of. Hopefully it goes half as fast as it looks.
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