Not trying to lose you sales but why not just fit the walbro 455 that I and others have fitted. It's designed for over 800bhp engines, fits in the oem housing with very slight modification to the housing. Never had any problems with it being to noisy and it's only just over £100 to buy.
Hi
No problem about sales, always worth discussing.
They are chalk and cheese for a start and for different applications.
The problems with the Walbro conversion is that it isn't that simple to convert the Delphi unit correctly, and I mean correctly, the issue is that the eductor no longer matches the pump output, this is what causes the noise on many installations and also why many suffer from starvation in left handers. Poor conversion is why several have starting problems due to bleed back.
Historically we have converted about 150 of these units including most of the Audi conversions, never had an issue at any time and some are more than 10 years old now.
Last year we re-converted about 5 "Walbro conversions" two from this forum, both would not start without several prime cycles. When correctly converted and fitted with a descent modern turbine pump all the problems cease.
We still do HP conversions on these units, but from now on we will only recommend converting pumps which need a greater output than that available from a new unit.
Units are only converted after a discussion regarding requirements with the owners and select pumps which suppy the required fuel plus a 20-30% margin max.
We stopped using Walbro pumps about 4 years ago BTW as they are way too inneficient, draw too much power and noisy by design.
If you do not have a high power engine then you get fuel heating issues as the Walbro is heavy on power anyway and to keep recirculating 60% of the output round and round again from the pump canister, around the engine bay, through the reg and back to the canister again is a well nown problem, Remember pumps use the fuel as both a coolant and a lubricant so at idle you have 16A heater warming up under 1L of fuel. Not smart.
The other problems with the original unit: -
The eductor does not supply a good feed to refill the canister, even when matched it takes about 15 seconds O.E and about 10 seconds when we convert them with a higher output, this is a design issue and cannot be corrected.
Once the pump is stalled the eductor system stops working completely and you need gravity feed into the canister to start both the main pump and the eductor again, this issue is what causes starvation with the poor Walbro installs.
The canister is also small and only holds just under 200cc.
Add to this, we have seen several damaged units, usually the sender has been strained and gives erratic readings.
The connecter is not great and many have pitting caused by shorting, if you now add the 17A for a Walbro you can see how this may cause further problems later.
The fact that the industry has made this type obsolete but the earlier 5 pin varients are still in use should tell us something?
As mentioned, we still do pumps for up to 600bhp depending upon rail pressure, pumps we use are about 12A
NEW UNIT
This is perfect for all cars without mods and modded cars up to about 400bhp depending upon rail pressure.
The entire unit is new, sender, float the lot. It comes with a full warranty and is quiet.
It refills the (larger) canister in about 6 seconds at full power right down to 4 seconds at idle @45psi rail at higher rail pressures this reduces to 4 seconds at full power (i.e no return from the reg)
It has a canister filter.
If stalled the pump can suck fuel from either the canister (though if the pump is stalled this is probably empty) or the tank directly, so as soon as you come out of the corner the pump will supply engine fuel effectively immediately, and within 6 seconds or less it has a full canister again.
So hopefully it is clear that they are different animals?
For 90% of cars the new unit is perfect and way superior to the original O.E unit in just about every department, it's new and has a full warranty.
For those who have to have a higher output pump then you are stuck with the old O.E unit and all it's compromises but at least it is better than a swirlpot system!
You can do it yourself though you will never get the eductor working correctly without a LOT of reseach testing, it may overheat the fuel unless you know how to sort that as well but as you say it is cheaper.
Not too sure the two members from here were impressed by the cheap price after having to strip the car down for a second time to change the Walbro pump, and then paying us to do it correctly with a modern turbine pump.
Gaz
Edited by Spitfire Engineering, 26 November 2015 - 06:44 PM.
