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dual tbi with blower?
Posted: Sun Jan 25, 2009 8:36 am
by 57chevy
Im gathering all my parts to set up my small block chevy with a 8-71 blower. I want to use a GM TBI unit, but I don't think that I can get enough air flow from a single unit. I was thinking about dual TBI s. There's very little written in these forums about that. This will be a street driven vehicle so it needs to be drivable at part throttle and idle well. Anyone know if this is a do-able setup?
Re: dual tbi with blower?
Posted: Mon Jan 26, 2009 6:45 am
by Matt Cramer
I know you're not the first one to have done this, though I'm not entirely sure on the results people have had. It doesn't seem like it would be all that different from a dual quad setup when it comes to linkage, and with a blower you could probably get away with using just one IAC valve too.
Re: dual tbi with blower?
Posted: Mon Jan 26, 2009 7:43 pm
by 57chevy
Thats what I thought too. I wish there was a little more written about this setup tho...
Re: dual tbi with blower?
Posted: Tue Jan 27, 2009 9:16 am
by Arrowhead
Well I don't know what the specs are on the engine your putting together, but an 8-71 seems pretty big for a SBC. I'm not real familiar with hte GM TBI, how many injectors are there? Do you know what the TBI's are rated for flow? (Fuel and air?) What are you using for injectors? Why not just go with a bug catcher and put the injectors on the bug catcher or on a spacer plate? What kind of horse power are you looking to get?
Re: dual tbi with blower?
Posted: Wed Jan 28, 2009 4:36 pm
by 57chevy
The 8-71 is pretty big, but It'll be turning relatively slow so not to overboost. There are plenty of TBI's from small block chevys at reasonable prices on Ebay, thats why I'm considering them. Each TBI has 2 injectors, not sure the flow of them or the TBIs off the top of my head, but I remember reading that a single unit would only support around 250 HP give or take. My small block would like to put out double that. What do you mean by a bug catcher?
Re: dual tbi with blower?
Posted: Thu Jan 29, 2009 6:40 am
by Matt Cramer
A bug catcher? One of these.
The TBI units are definitely a bit on the restrictive side; they seem to start to become a restriction around 4000 RPM on a stock 350.
Re: dual tbi with blower?
Posted: Thu Jan 29, 2009 6:41 am
by 57chevy
OK, I now know what you mean by bug catcher. Would those big butterflies give you usable part throttle performance for around town driving? I kinda thought that setup was more for WOT applications only.