?? Why dual fuel pumps??

Why? Why not just go with one big fuel pump instead?

To me dual fuel pumps set up is a blow up waiting to happen.

 

care to explain your reasoning?

 

If you have ever seen the stock fuel pump assembly where the fuel pump sits, you will see that there isnt a lot of room to work with. Therefore, you have to customize the assembly to accept another fuel pump. It would be even harder to design it to fit a bigger, LONGER pump because there just isn't enough room in my oppinion. Also, you can control fuel much more precisely and accurately when you have 2 pumps compared to just one. For example, you can setup the car to just run on 1 pump up to a set boost pressure but have the second one kick-in once that boost threshold is passed. Also, about your comment about the pumps blowing up- that logic, to me, doesn't make any sense. Would a very large fuel pump have the same chance of blowing up? Maybe I'm not seeing something, please explain your reasoning behind your statement.

 

Cost and Size. 2 Walbro's would be around $150. Do you want to know how much one fuel pump that can flow 500 lph costs?

You can do 1 Walbro and 1 external fuel pump which is cheap and works very well. 1 giant fuel pump would have to be all custom. At this point in time, the Walbro flows the most out of any stock size FP for the Evo.

 

Well, my logic is this,
if one pump is good for 500whp, and your car making more than that, so you need a second pump to accomodate the excess power (this would be the case for most people that need to run dual fuel pump, right?). What happen if you were driving down the track, using the maximum potential of your can and one of the two pumps die? Wouldn't that result in an instant lean condition and will cause your engine to blow up?

In the case of one pump, the pump die, the car die.

This is just my own logic, please tell me if i'm wrong.

 

Ok, by that reasoning, what if you're driving down the track and your one big pump dies. Guess with is going to cause more of a lean condition...

 

If that the case, your car just shut down and die. No fuel = no combustion = no detonation.

 

Ok.

 

Ive seen peoples pumps fail, and the motor goes with it as a result of the pump failing.

in that logic 2 pumps would actually be safer.

 

Yeah, that's why most EVO tuners suggest upgrading the fuel pump as a safety precaution. If the pump goes, your engine could definitely blow. Also, the fuel pump won't always just die all of a sudden. It might severely lose performance and lose a lot of fuel pressure, but the motor doesnt know that and it causes an extremely lean condition = BOOM.

 

My first reaction was that this thread was gayer than aids. But now I see this guy's point. If one pump starts to go slowly, you'll toss a motor. But if it fails outright, you probably won't. I forget the exact numbers, but I found years ago that somewhere above 20-30% too lean there isn't enough fuel to creat enough heat/pressure to do any real damage. You don't make **** for power in this case, and you know right away something is wrong. But I made some extended pulls in this set of circumstance in the name of science.

So it depends on how they fail.

-One pump: Partial failure, motor's probably done. Complete failure, motor's probably going to live.

-Two pumps: One pump partial failure, motor will probably survive (depends on how much of the second pump you are actually using). One pump total failure, motor's probably done (again, depends on wether or not you were using the second pump at all).

IMO, it's a wash. These pumps don't fail often enough to make me worry about it. The big race pumps on the other hand fail much more frequently despite costing much more. YMMV, but I wouldn't lose any sleep over running two in-tanks.

 

Have any of you ever run out of gas? Under normal conditions, you simply put in more and start the car again. No different if you run out because there's no fuel in the tank, or you run out because your pump stopped.

If you're running two pumps, you may continue to have some fuel from the pump that's not dead (depends on whether your system is set up in parallel or in series) but either way you're not going to get what your motor needs, if you're running hard.

A good failsafe, like the Zietronix with alarms and a trigger for a relay will protect the motor under either circumstance and is a VERY GOOD idea for anyone worried about damaging an expensive motor...

 

So in most cases do the pumps always run at the same time? Do most people use them all the time or just like stated above run a boost dependant switch over?

 

Ever Double Fisted yourself????????

At the bar or at a party??

Everyone else get your mind out of the gutter....