Heavy Z Posted June 21, 2003 Share Posted June 21, 2003 Do we have enough clearance? http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=42610&item=2419428880 Quote Link to comment Share on other sites More sharing options...
David K Posted June 21, 2003 Share Posted June 21, 2003 Wow wouldnt that setup cause pressure loss? Look at how the turbo blows into the manifold. Dont blow thru setups have to blow down into the carb as a sealed unit so all air is forced into the engine? The setup they are selling looks as if pressure gets too high, air would start blowing out of the carb, instead of in. If im not seeing something, let me know. Its interesting. Quote Link to comment Share on other sites More sharing options...
Datsun660z Posted June 21, 2003 Share Posted June 21, 2003 This is a cool setup. The turbo sucks air fuelmix from the front tube that you see then forces the mix back into the rear tube. I Like Quote Link to comment Share on other sites More sharing options...
David K Posted June 21, 2003 Share Posted June 21, 2003 Ohhhh so now i see how it works. But what about the air/fuel mixture going through the HOT turbo? Isnt that kinda Darwin'ish? Quote Link to comment Share on other sites More sharing options...
QWKDTSN Posted June 21, 2003 Share Posted June 21, 2003 Pretty Sweet! It'll fit! Hell, cut the hood if you've gotta. It'd be worth it Quote Link to comment Share on other sites More sharing options...
dmyntti Posted June 21, 2003 Share Posted June 21, 2003 I am a little confused. How is the exhaust routed through that turbo? It appears you would have to pluck the outlet on the manifold and plumb the exhaust through turbo at the top. Also in the picture it looks like the turbo is pulling air in from the same chamber as it is putting it back into, notice the holes in the floor of the manifold under where the carb. bolts up. I think I am confused about this setup because from what I am seeing it wouldn't work at all. What am I missing? Quote Link to comment Share on other sites More sharing options...
David K Posted June 21, 2003 Share Posted June 21, 2003 Isnt the exhaust supposed to run in and out of the turbo alone to get the propellers to spin? Why does that exhaust manifold still look like it dumps out the bottom and functions the same as....stock? You cant just bolt a turbo to the side of a manifold and expect it to work. Where does the force come from to make it work? Thats some weird shit. Quote Link to comment Share on other sites More sharing options...
spdsk8r Posted June 21, 2003 Share Posted June 21, 2003 I believe the old exhaust outlet now becomes the inlet from the crossover pipe from the left side manifold. To equalize backpressure both sides of exhaust need to feed turbo. Just an uneducated thought. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted June 21, 2003 Share Posted June 21, 2003 I believe the old exhaust outlet now becomes the inlet from the crossover pipe from the left side manifold. To equalize backpressure both sides of exhaust need to feed turbo.Just an uneducated thought. No, you are correct--what was the bottom of the manifold now has the cross-over tube attached to it and exhaust come UP the manifold and ALL exhaust goes UP through the top of the manifold. Kinda neat, eh? I have those manifolds, but I have to get an adapter machined to fit the turbo (Buick turbo 3 bolt flange...) I am thinking about upside down block huggers instead, but that is theory at the moment. I just have not decided. I think a cowl induction hood would be in order to fit under the hood. I like turbo V8 stuff despite some of their dinasaur carb setups. If there is any way to convert a carb setup to efi, it would be worth it to go there... Just my $.02. Davy Quote Link to comment Share on other sites More sharing options...
stony Posted June 21, 2003 Share Posted June 21, 2003 Isnt the exhaust supposed to run in and out of the turbo alone to get the propellers to spin? Why does that exhaust manifold still look like it dumps out the bottom and functions the same as....stock? You cant just bolt a turbo to the side of a manifold and expect it to work. Where does the force come from to make it work? Thats some weird dodo. on the single v8 setup the out on the turbo side is actually where the other side crossover pipe bolts up then both side exhaust feed into the turbo and out the back of the turbo as one pipe, on a twin setup with this manifold you could use this as teh place to bolt on the wastegate. pull thru systems have been around for awhile Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted June 21, 2003 Share Posted June 21, 2003 Twins fit under the car to the left and the right of the oil pan better than above the engine. Placement is reallllly iffy, that's why I decided to put mine under the car. Placement on the driver's side is the issue. The passenger side has some room to move around. Quote Link to comment Share on other sites More sharing options...
BobsZTwins Posted June 21, 2003 Share Posted June 21, 2003 This is the Scarab Stage II 425 hp setup. I have one on my 260Z. Does it come with the boost control, bypass, crossover and downpipe? The downpipe for the Scarab only fits in the Scarab engine position and would need modifying to fit in the JTR position. Any gaskets come with it? Let me know if you need pics or info. BOB'S 2FORTZ '72 240 L28 3XWEBERS '74 260 TURBO 350 Quote Link to comment Share on other sites More sharing options...
zgeezer Posted June 22, 2003 Share Posted June 22, 2003 I see these every now and again on street rods. The turbo is fed from the passenger side exhaust crossing under the motor and up into the passenger side header and then out the turbo exhause scroll. The intake takes a little thought. The intake manifold is divided into a pressure side (the bottom) and a non-pressure side (the top). During light throttle or any other time the turbo is not building pressure the bottom side draws fuel mixture directly from the carb through those slots you see on the floor of the carb "plenum". Those slots have flat metal strips that stay open as long as there is no pressure difference between the two chambers. When the turbo begins to build pressure on the bottom these strips are forced up and seal the top portion thereby routing fuel from the carb into the compressor and then back into the bottom as pressure. Hot air Buick Regals were similar except they lacked the valving to allow a carb to provide fuel directly to the ports w/o going through the compressor side of the turbo. The idea as to provide drivability and throttle response when the turbo wasn't spooled up. This setup was usually sized for around 5-6# boost. Newer technology might be a TB FI such as a Holley Projection in place of the carb. gw Quote Link to comment Share on other sites More sharing options...
BobsZTwins Posted June 24, 2003 Share Posted June 24, 2003 You're right about the operation of the unit but boost isn't limited to 5-6 psi, I've seen 15 on mine (cool humid day with retard at 6 degrees) and routinely hit 13 psi. It's just at high boost you tend to get a jolt when you back off unless you push the clutch in at the same time. Quote Link to comment Share on other sites More sharing options...
Heavy Z Posted June 24, 2003 Author Share Posted June 24, 2003 Well, "ZBoy82" bought it so maybe it's going on a Z after all. Quote Link to comment Share on other sites More sharing options...
Guest gtmattz Posted June 24, 2003 Share Posted June 24, 2003 I dont like the idea of pulling air fuel mixture through a HOT turbo, isnt that just asking for an under hood explosion?? I can just see huge chunks of turbo shrapneling out like a bomb went off : Quote Link to comment Share on other sites More sharing options...
David K Posted June 24, 2003 Share Posted June 24, 2003 I dont like the idea of pulling air fuel mixture through a HOT turbo, isnt that just asking for an under hood explosion?? I can just see huge chunks of turbo shrapneling out like a bomb went off : Thats what i was thinking, but nobody cared to comment on it so i guess its just a tried and true method. Oh well. Quote Link to comment Share on other sites More sharing options...
Guest gtmattz Posted June 24, 2003 Share Posted June 24, 2003 I dont like it, I wouldnt feel safe driving a car with that setup lol Quote Link to comment Share on other sites More sharing options...
BobsZTwins Posted June 29, 2003 Share Posted June 29, 2003 Actually, the mixture going into the turbo is pretty cool, having just been atomized in the carb. So the mixture isn't as hot as you'd expect. This isn't the case with EFI units where the air is compressed (heated) first. That's why an intercooler is needed to both reduce heat (potential for detonation) and to increase the air density. I also have the MSD boost retard system to dial back the spark advance as psi & temp rises. When Scarab was selling these engines they were advertised at 425hp @ 10psi. I've seen +/- 15psi and I can tell you it's a neck snapper. After I get my valve stem seals replaced I plan to dyno the unit to see just what it's putting out. Quote Link to comment Share on other sites More sharing options...
David K Posted June 29, 2003 Share Posted June 29, 2003 Hi Bob, Your explination makes 100% sense now, thank you. It sounds like a pretty efficant setup and im liking it. Would you mind posting some pics of your Scarab? Quote Link to comment Share on other sites More sharing options...
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