The flow increase without the restriction of the bypass valve causes the current increase. Think of the bypass valve as a mechanical current limiter. Once the pump hits the mechanical flow limit, it won't draw any more current. Without that mechanical limitation, though, the pump can flow more fuel and thus pulls more current. I'm pretty sure the electric motor and pump geometry are the same. The bypass valve is internal and can't be removed, unfortunately.
Ti Automotive (Walbro) 274 vs 285 vs 295
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The flow increase without the restriction of the bypass valve causes the current increase. Think of the bypass valve as a mechanical current limiter. Once the pump hits the mechanical flow limit, it won't draw any more current. Without that mechanical limitation, though, the pump can flow more fuel and thus pulls more current. I'm pretty sure the electric motor and pump geometry are the same. The bypass valve is internal and can't be removed, unfortunately.
I think you got that backwards. The less restriction resulted in less amps. Look at the results they posted. Higher flow and less amps.
I've ordered the 295 to test as well to make things easier
![F90000295_Graph[1].png](https://www.spoolstreet.com/attachments/f90000295_graph-1-png.33643/ "F90000295_Graph[1].png")
I've got the 295 coming this week and will be adding an inline 8an check valve but I'll try without it too to see if it throws any errors with out it
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The speedflow check valve flows more than the pump output thats why I'm using the 8an version and even if you want more you can use the 10an version with reducers on each end.
These valves will not cause any restriction, test it on the flow bench if you like.
I don't run out of flow with a single bucket less 450 so using a 535/295 with a oversized check valve will not cause issues for me.
I'll be testing without for now to test if it throws any errors and only introduce the valve if it does.
I'll be testing the hydramat on my bucket less 450 first and see how it copes around corners at 1.1g according to the g meter on both left and right turns as that's the biggest question.
These valves will not cause any restriction, test it on the flow bench if you like.
I don't run out of flow with a single bucket less 450 so using a 535/295 with a oversized check valve will not cause issues for me.
I'll be testing without for now to test if it throws any errors and only introduce the valve if it does.
I'll be testing the hydramat on my bucket less 450 first and see how it copes around corners at 1.1g according to the g meter on both left and right turns as that's the biggest question.
That's why I'll be trying it and less load on the stock ekp3.
Still waiting on pump to arrive.
Still waiting on pump to arrive.
So do you think the 295 is an uncorked 274 or a variation of the 285 like radium? Perhaps you'll find out.
Most likely a derestricted 285, the less restriction, less load on the motor, less amps being used to drive it.
I'll do a visual inspection first as I'll have both pumps side by side on the work bench this week sometime.
No one had any stock even though listed as in stock on their websites, so I had to order it in.
Frustrated as Christmas is around the corner so i have to get all the parts i want to try in now so I can play with them over the break.
I'll do a visual inspection first as I'll have both pumps side by side on the work bench this week sometime.
No one had any stock even though listed as in stock on their websites, so I had to order it in.
Frustrated as Christmas is around the corner so i have to get all the parts i want to try in now so I can play with them over the break.
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Well the pump finally arrived but still waiting on the adapter fittings.
Things move slowly when dealing with the postal system.
Still waiting on the hydramat to arrive.
Things move slowly when dealing with the postal system.
Still waiting on the hydramat to arrive.
So I tested the 10an speedflow check valve today on the 450 and the pressure is holding way better than pump alone and this thing flows
some serious volume and will never restrict the pump or two or three if needed.
Pressure stays up way longer and much higher after shutting down, I even went as far as disconnecting the fuel line
before the valve so there is no pressure between the valve and fuel pump, it held over 30 psi after 10 min.
Starting the car with the 295 after priming will never be a problem and should not throw any codes unless there is something wrong with the pump itself
whilst using the check valve.
I was going to try it with out the valve but I decided to throw one in as it was the right thing to do to keep everything like factory intended
and not cause possible issues down the road.
I will try and install the pump over the next few days to test it out whilst I wait for the hydramat and fittings to arrive.
some serious volume and will never restrict the pump or two or three if needed.
Pressure stays up way longer and much higher after shutting down, I even went as far as disconnecting the fuel line
before the valve so there is no pressure between the valve and fuel pump, it held over 30 psi after 10 min.
Starting the car with the 295 after priming will never be a problem and should not throw any codes unless there is something wrong with the pump itself
whilst using the check valve.
I was going to try it with out the valve but I decided to throw one in as it was the right thing to do to keep everything like factory intended
and not cause possible issues down the road.
I will try and install the pump over the next few days to test it out whilst I wait for the hydramat and fittings to arrive.
The spring loaded nature of the check valve itself must have a measurable impeding effect on the flow capability? Does walbro just use insanely restrictive check valves or something? I hope someone does a before and after check valve flow bench. I'd also like to see a walbro 450(274) split open.
linky, not sure what model this is but it should be a 450
i still have a 450 (F90000267) laying around, now i regret cutting the neck off, i should have drilled through the restrictor all the way and see how it runs
The spring is so light it doesn't take much to move it.
I haven't got access to a flow bench but judging by the spring the loss would be negligible.
I do have a dead 450 if you want to play with it.
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Id just like to see a cross section or visualization of the check valve restriction.
Looks like proper testing will be delayed as Holley is out of stock till the 27 of December of the 11x11 hydramat.
I think the delivery is going to be delayed well into mid to late January so I just might do the install with standard mat for now and see how that goes.
I think the delivery is going to be delayed well into mid to late January so I just might do the install with standard mat for now and see how that goes.
one thing that popped into my mind with your planned setup
you might need something to turn off one of the pumps if one side of the tank runs completely dry...
or connect the hydramats like a X pipe configuration...
