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Fuel regulator setup for triple Webers


Therambleman

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Hi all,
I have searched multiple forums and groups and can't find a straight answer. Any help appreciated. 

I have triple 45s on an l28 (77 260z 2+2) Want to put a fuel regulator with a bypass in the bay to hopefully reduce fuel smell in cabin, remove deadhead setup on the carbs, and stop fuel pump overworking.

From what I've read – I need 3-4PSI for Weber 45s. For the life of me, I can find a fuel regulator that has a bypass and also runs under 4psi and is less than $400 and in the US only!! All the Holley ones are 4.5-9psi. Can you actually crank those down to below 4psi? Or is there another regulator somewhere – or am I dreaming?

Apologies if I'm missing something obvious or if this has been covered elsewhere – have spent hours searching!

Cheers

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There are 3 holes, 1 input, 2 output.  I use one output to Weber’s the other attached to a pressure gauge.  You could possibly use the second as a return line.  Not sure if the smaller diameter of the return line would create enough of a pressure differential to feed the carbies.


Alternatively, have the return line from the end of the Weber’s if you so choose??

Edited by Roady
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51 minutes ago, Therambleman said:

Thanks for the reply - yeah I’m wondering if there’s a regulator like that - but operates at that low psi AND also has a return. Perhaps it’s not a thing?? 

I used to run this reg with the factory fuel rail, reg in line before the carbs, one feed into carb one and the other feed into carb three with all three carbs linked together and the factory Return line back to the tank.

seemed to work fine but you might be able to fine a proper bypass reg at that low a pressure but I haven’t seen one. 

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@Roady @RLY240 thanks guys! 2 good options.

Roady – I was trying to allow the fuel pump to pump its heart out to not over stress it but maybe I'm being overly cautious.So if I just have the non bypass regulator plumped in after the webers, the pressure in the webers should be perfect, and when thay are not sucking fuel it just runs through and back to the tank. Not sure why it's been so hard for me to wrap my head around this!

Either way – I'll keep looking for a low pressure regulator with a return and reply to this thread if I find one.

Rly - I had not thought of that, I think you've cracked it. That setup would mean less stress on fuel pump, consistent pressure at webers and a has a return. Noice.

 

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Quote:  The factory fuel rail has the return built into it.
 

yes this. The factory hard line has a restrictor in the return line. If you don’t use a bypass reg you need to put it before the carbs in the circuit as you have in your diagram  

Roger  

 

Edited by RLY240
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9 hours ago, Therambleman said:

My brother uses one of these in his IDA 13B RX7. They work well but your pump MUST supply fuel to it at a lowish pressure, they get overwhelmed if the supply pressure is over 10psi.

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11 hours ago, Agno said:

My brother uses one of these in his IDA 13B RX7. They work well but your pump MUST supply fuel to it at a lowish pressure, they get overwhelmed if the supply pressure is over 10psi.

Thanks – roger that. I'll figure out what my pump puts out first. I found another one that is low pressure and has a return but it was about $500 and in the US. Noooope :-/

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