jeremyb

Walbro - $110
Nippondenso - $230

Which one should i get? I'm going 550cc primary injectors with 1600cc secondaries with upgraded fuel rail and lines. I know both of them are really worth it... but is Nippondenso really worth the extra 120?

ijneb

. What are some of the popular fuel pump upgrades and how do they perform?

PLEASE NOTE, RC ENGINEERING NOW PERFORMS A FUEL PUMP FLOW MEASURING SERVICE. IT HAS BEEN FOUND THAT THE NIPPONDENSO COSMO FUEL PUMP AND THE WALBRO GSS-341 FLOW APPROXIMATELY THE SAME (THE COSMO ACTUALLY FLOWS A BIT MORE). IT WAS ALSO FOUND THAT THE COSMO PUMP HAS A MUCH HIGHER CURRENT DRAW THAN THE WALBRO OR BOSCH PUMPS. BECAUSE OF THIS, I SUSPECT THE POOR PERFORMANCE OF THE COSMO PUMP IN RX-7S MIGHT BE EXPLAINED BY INSUFFICIENT STOCK WIRING (WHICH IS SUFFICIENT FOR THE BOSCH AND WALBRO PUMPS).

SO PLEASE DISREGARD THE FOLLOWING COMMENT THAT THE COSMO FLOWS SIGNIFICANTLY LESS THAN THE WALBRO AND BOSCH, BECAUSE IT APPEARS TO BE INCORRECT. I WILL TRY TO UPDATE THIS WEB PAGE AFTER GATHERING MORE INFORMATION FROM RC ENGINEERING FUEL PUMP TESTS.

I APOLOGIZE FOR ANY INCONVENIENCE THIS MAY HAVE CAUSED.


Pump NameAppx. CostEase of InstallFlow informationAlso Known AsObserved QualityCommentsWalbro GSS-341 255 liter per hour$110-130In-tank, Not exactly drop-inClick for graph
Practically equivalent to Bosch 1 year warranty
Appears somewhat "flimsy"
No recent failures on Big List Bosch 220 liter per hour$180-275In-tank, Not exactly drop-inClick for graph
Practically equivalent to Walbro GSS341Kinsler's big Bosch 300 lb/hr? warranty
Appears pretty durable
No recent failures on Big ListI believe this is the pump M2 sells, M2 doesn't revealNipponDenso Cosmo$190-280In-tank, drop-inClick for graph
Far inferior to Walbro GSS341 or Bosch ? warranty
Appears pretty durable, same as OEM
No recent failures on Big ListIt is believed by many that this is also the pump RP sells
93+ Supra pump flows almost identical amounts

taken from
http://www.newwave.net/~flanham/wlan...l/fuelfaq.html

jeremyb

hmmmmmm... maybpe a poll should have been done instead.

Railgun

I use the walbro and have had no issues what so ever. Running 850/1600s. Lines up to the FW are stock.

oorx7

iTrader: (2)

Is there a max HP that can be had with the walbro? I'm only looking into having about 400 or so.

tolkyr

Where can i buy a walbro for 110$?Any sites available?

potatochobit

iTrader: (1)

i believe walboro does not fit properly and needs some type of modifications?

Railgun

I didn't have to modify anything other than some wiring. I should have done this but I didn't, but use some zip ties to help secure the pump to the bracket.

I'm at 60 psi under boost but it's coming down a bit above 6k. I'm hitting 15 psi on the 35R kit so I'm probably at about 350. If I remember I'm at about 83% duty cycle.

oorx7

iTrader: (2)

83% duty cycle of your pump or injectors? maybe this is another reson I blew my motor, stock fuel system @ 345 rwhp doesn't quite compute.

manatecu

iTrader: (6)

That is interesting. I have a 35R kit and I was running in the high 90's with one walbro. I have since added a second. I have 850's and 1600's. Boost was 15-17psi.

If you are running over 400 I suggest running two.

RX7Wishing

i thought the walboro had some issues running in hi and low mode? Also, some people had issues with running rich at idle with the walboro.

manatecu

iTrader: (6)

I bypassed the high low relay. I only run on high for both pumps. No problems. I control the flow via the fuel regulator (SX 10an). My fuel pressure is always solid.

Railgun

On the injectors.

I didn't even think about bypassing the hi/low relay. I'll do that this winter I suppose among other things but I've had no problems in that regard as well.

Let me look at my logs again. I'm pretty sure that they peaked at not more than 85%.

I'll be upgrading my lines as well as adding a second pump sooner or later. I don't think it can handle 20 psi by itself.

jspecracer7

Are you using the SX regulator as they "Y" or do you have it Y'd before it gets to the first rail? You're using -6 line correct?

wonder1and

I've got one of each of those pumps sitting in my garage... if anyone needs one pm me w/ an offer. both low miles... the walboro only has around 20 mi and the denso about 5k or so.
-R

manatecu

iTrader: (6)

I utilize one pump per rail. I go up through the hard lines and connect to 6an. Run both lines up to the front of the car and connect to the primary and secondary rail. Come out the other side and go directly both sides of the fuel pressure regulator. At the regulator I use 6an to 10an connections. The return coming out the bottom is an 8an back to the tank. At the tank I installed a bulk head fitting and tubing to the bottom of the tank. There are 5 total fuel lines no y's.

wonder1and

Make sure... if you do that replace the line (hose) that would go from the emmissions stuff to the metal hard line. if you don't look at my avitar to see what will happen

manatecu

iTrader: (6)

who said anything about using metal hoses? Those are just extra connections that can fail.

93FD3S

Wonder1and.....I thought you could vent the charcoal canister hose. I have mine venting out the back of the car from the canister. Even Don over at Marvel Speed said it was ok to vent....hmmm

the_glass_man

iTrader: (2)

The Denso flows a bit more and straight plug and play. The Walbro is much cheaper however.

jeremyb

Ok, So the denso flows more and is more of a plug and play. While the Walbro is much much cheaper and is efficient. What are you people talking about when you say running two pumps?. Where do you put the second pump? (Flame me if that question was dumb but... im noob =(

the_glass_man

iTrader: (2)

There's no need for a second pump unless you want to pump out crazy hp 500+ rwhp. So unless you have a huge single and plan to run a ton of boost a single drop in replacement would work fine.

jeremyb

oh ok... im just planning a t78 @ 17 psi. Nothing higher... i hope =). But back to the pump debate... so walbro would be the better spend?

manatecu

iTrader: (6)

When I was running a t04s with 550 and 1600's at 15 lbs I was running on the edge with a Denso. After about a year of wear and tear the pump was not holding up under WOT. I was running stock pressure over the lines.

I decided to split the load with two pumps. Simply worm clamp them together and y the wiring. Add a bulk head fitting and your good to go.

I also now only run on high. The low to high transition caused a weird flux in pressure.

jeremyb

I'm not planning to go over 500 HP. My goal is around 450 or so. So if you're on the edge of a denso... and a denso "supposedly" flows more... then i shouldn't get a walbro and get a denso? I really dont want to run two pumps, especially since i have no idea where the scond pump would go. But if i HAVE to... HAVE HAVE to... then i will...