wow i read mostly every post on this thread and found some very usefull information thanks everybody for school'in me
I just visited ElPolacko's shop, Industrial Chassis today. The guy's knowledge of engineering/fabricating is downright impressive. He has an intercooled, twin turbo'ed motor in a '65 unibody F100. The setup blew my mind: http://www.myrideisme.com/Garage/Industrial_Chassis/632/960/
I have a 1980 Turbo TA 301 with the draw through set-up. I think that RacerRick is correct in saying that a bypass valve would be of some benefit.....since every time my car makes a WOT shift the engine pings due to build up of pressure in the intake (caused by engine RPM drop). The waste gate control does not quick enough to handle the spike. I would like to see some photos of the bypass valve setup that he has to see if this could be done on our cars.
that would be cool! i had a turbo 194 cu in chevy in my wagon. i just used the stock manifolds, an integral wastgate, and a stock 1-barrel carb. i was pretty surprised with how much it helped performance. you could seriously set it up in a weekend if you had a welder and some 2'' pipe.
A draw through is fairly easy to set up. Here is a pic of my son's set up on a 225 slant six with a draw thru turbo. Notice at the bottom is the waste gate.
check all this out. a thread i have been relying on for some time now. ha http://www.jalopyjournal.com/forum/showthread.php?t=462637&highlight=close+tolerance+250&page=3
Well, I'm gonna pull this 7 year old thread off the shelf and dust it off, cause I need some information. In a draw thru turbo system, since the carb is always in vacuum, what changes need to be made with jetting? On the flip side, if you box in your carb to use it as a blow thru setup, what carb mods are required? Sent from my Pixel using Tapatalk
I believe that in a draw-though, all you need to do is size the carb and jetting big enough for the target power level. In a blow-though with a carb box, you need to use solid floats (foam plastic) as the pressure can collapse brass floats. Generally speaking, a blow-though system will have better throttle response.
The carb bowl vent needs to be sealed from the boost. And a fuel pressure regulator that can rise the pressure above boost pressure.
Knocking the dust off this threads once AGAIN! I'm inspired to put a ebay t35 turbo on a inline6 250 chev. I've built a draw thru carburetor set up. (Holley 500 2barrel) at this time it cold starts fantasticly easy. My main issue that i'm having is after I give it a quick rev, Giving it a chance to spool the turbo up, When I quickly release The throttle and let it go back to idle, it will die out quickly. It's very easy to restart. If I slowly nurture it to go back to an idling state (after a rev), it will run on its own easily. So I know it's not a initial carburetor problem. I'm assuming what's happening is The spooling turbo Is making a intense draft on a Carburetor with closed throttle blades.... Thereby causing a excessively rich mixture at that moment. So my idea/theory is to Install a bov/pressure relief immediately after the turbo, And dump it into the intake tube under the carburetor (before the compressor). Admittedly My goal isn't to relieve pressure as in a blow through application... Actually my goal is mostly to release some of the heavy suction/ Vacuum draw under the carburetor .... diminishing the carb signal enough to keep it from that brief intensity of rich A/F. Has anyone ever tried this before? Will my theory prove accurate? What y'all think?
What mods where done to carb, Did you Extend the bowl vents tubes High & along roof of carb hat , vent tubes about 10 inches or longer towards pass front of carb bowls . Still under pressure But out of air stream / turbulence flow . Also some hat direct air better smother then others as if inters carb under boost ,
I sold supercharger kits a few years back for Jeep 4.0 I6's. It used the Eaton M90 G4 blower. The G4 has an integrated bypass valve. It was MPI with the throttle plate upstream of the blower (kind of the same as draw through), when vacuum is present between the compressor and throttle body, the bypass opens and diverts air to the downstream side (around the compressor). You end up with off boost performance pretty much identical to stock. Boost shuts the bypass and everything goes through the compressor. At the time, there was no easy way to program the FI for boost. I used a supplemental system and 2 150 lb/hr injectors in the inlet of the blower (after the throttle body). Nice thing about draw through is the fuel's latent heat of vaporization cools things off a bunch. No intercooler needed. I'm working on a carbureted draw through project now, and I am thinking about using a bypass. Plumbed between the carb and compressor at one end and between the compressor and engine on the other. Looking around I found these (they are clones and available at places like Temu or AliExpress too). Cheap as shit ($40), I might try one. https://www.walmart.com/ip/Supercha...5?wmlspartner=wlpa&selectedSellerId=101557880 Worth a look. Mike
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