To maximize performance it is important to have a fuel pump which matches the demands of your engine.
If a swap of a boosted engine is done using a supercharger/turbo or one of considerably higher displacement, you may find that the stock Fiero fuel pump won't keep up with the WOT fuel requirements. This problem can surface if you are running nitrous as well. One shortage of fuel here could cost you an expensive engine.
I have located two AC Delco ( Delphi) Corvette 5.7L fuel pumps which are direct fits and will increase the fuel supply at a reasonable cost. The part numbers are EP-236 and EP-376 from the 80's and 90's Corvettes with the 5.7L engines. These can be purchased new on eBay for around $35-$40. They should be able to support well over 300HP perhaps as high as 350. Both these pumps put out 27gph @50 PSI This is almost 1/2 gal per minute of constant fuel flow!!
As an alterantive you can choose to puchase the much higher capacity Walbro and Holley high performance pumps but these cost about $110 and we've read reports that these pumps while putting out a higher fuel flow can be noisey. I've used the Corvette pumps but not the Holleys and Walbros so I'm really not sure of the noise level. However, a stock OEM GM pump is sure to be both reliable, quiet, available and low cost. Let us know what pumps have been used on which swaps with success.

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87GT 3.4 Turbo- 0-60 5.2 seconds -Best
Engine Controls, ECM goodies, Chip
re-programming & odd electronics stuff

EP242 (GM 25116164) with the LT1 for the last 4 years with no problems.

This subject has been brought up before and there are many differing opinions on it. However, the facts speak for themselves.

Flow test data from multiple sources shows that the AC Delco EP376 pump can NOT supply enough fuel flow to meet the demands of even a lightly modded supercharged 3800 engine at pressures approaching or exceeding 60 psi. The stock fuel pressure of a 3800 Series II SC engine @ 10psi of boost is approx 60psi. According to my information on the L32 (3800 Series 3 SC) engine, it's stock fuel pressure spec is 55-60psi. This is already in excess of the flow capabilties of the EP376 pump.

If the pump you are trying to use is an OE-replacement unit designed for a naturally asperated application, then you are taking your engine's life into your own hands. I have suggested before, and will continue to suggest that you use a pump that is rated in BOTH pressure and volume of flow @ pressure it will be seeing in your application. Pumps like the EP376 were designed to supply a 300hp V8 engine with enough fuel flow volume at about 45 psi. Various flow tests of this same pump have shown it incapable of flowing enough volume to support anywhere close to 300 hp at 60psi. In addition, this pump was NEVER DESIGNED for continuous flow duty at this higher pressure.

So what does all this mean? Well it means that you MAY get lucky with an EP376 and never have a problem. I have talked to a few people who have been running EP376's on their 3800 SC engines and haven't had any problems. However, I have talked to at least an equal amount of people who were running EP376's that exhibited lean-out conditions under boost...some resulted in catastrophic piston failures.

The Walbro 255lph (F20000169; item# 834GMHP) pump costs $99.99 w/ install kit (including everything you need to drop it into an 87-88 Fiero fuel tank) over at www.fullthrottlespeed.com . Yes, it is louder than the stock Fiero fuel pump. But 99% of the Fieros out there with this engine in them are never quiet enough (exhaust note) for the "whine" of this fuel pump to become a concern of the person driving the car. Personally, I find it funny what some people are willing put up with concerning noises, vibrations, quarks, etc. with their car; but then they will complain about the whine of the walbro pump. If it is that big of a deal to you, then install some dynomat between the fuel tank and the chassis. That should take care of the noise increase of the walbro pump vs. an AC Delco unit.

I am no longer interested in getting drawn into arguements over this subject so don't bother because this will be my only post (and warning) in this thread. If you don't want to listen to my advice on this subject, that's your choice. Personally, I don't think the chance of going lean while under boost is worth saving a little money and a little noise level that you will probably only notice at idle anyway.

-ryan

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power corrupts. absolute power corrupts absolutely.

Custom Computer Tuning | Engine Conversions | Turbocharging | www.gmtuners.com

Hey Dennis,

For a 3.4 pushrod and the Turbo kit you used to offer. Which fuel pump did you recommend? Bought the kit used, but havent swapped over a different fuel pump yet.

AC DELCO # EP376 / EP-376

GM PART # 25163464

I just got one from a forum member; it is brand new and it came with a new whole assembly, filter etc...I only paid $50 for it. And it is for a 96 Corvette, hopefully it will be Ok for my N* with nitrous.
BTW those you listed are made in China, and I have nothing against it, in fact I will like to know if they are reliable or not since you never know in the future I might need another one.

Thanks,
JG

i have a walbro 255 in my tank ans its really loud annoying.... since it is like a foot away form your body......

next time i drop the tank i think im goin to wrap the pump in fuel safe rubber to help absorb the whine.

quote Originally posted by 2feido: i have a walbro 255 in my tank and its really loud annoying.... since it is like a foot away form your body...... next time i drop the tank i think im goin to wrap the pump in fuel safe rubber to help absorb the whine.

Excessive noise is my main reason for not using the Walbro. A number of people have told me that they are REALLY LOUD. While I do not wish to disagree with darkhorizon on the necessity of using the 255, there is some test data on Loydes FastFieros website that appears to provide evidence that the Corvette pump will feed a stock or mildly modified 3800SC. One guy says OK the other says no way .
. While I can understand that more is always better than less, the GM pump with an output of 27 gph @ 50psi ( they will go higher) doesn't sound like a wimpy pump. Now I would agree if we cam and port the engine later on, the Walbro pump becomes necessary. If you read this Loyde would you give us your opinion and provide the basis for the test data shown on your website.

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87GT 3.4 Turbo- 0-60 5.2 seconds -Best
Engine Controls, ECM goodies, Chip
re-programming & odd electronics stuff

I would ONLY use the corvette pump in n/a applications, as I know for a fact that the S/C motor sucks serious amounts of gas at the upper RPM's and maintaining fuel pressure up there is very very very important, which ALL over the counter GM pumps are not designed to do.

The 3800 is very unique due to the fact they run insanely high fuel pressure, actually the highest fuel pressure of any "normal" MPFI car made (63PSI at WOT). The general idea of stock GM fuel pumps is similar to a roots blower, its not really designed to "compress" fuel, it just packs it into the line, and hopes for the best.

quote Originally posted by darkhorizon: I would ONLY use the corvette pump in n/a applications, as I know for a fact that the S/C motor sucks serious amounts of gas at the upper RPM's and maintaining fuel pressure up there is very very very important, which ALL over the counter GM pumps are not designed to do. The 3800 is very unique due to the fact they run insanely high fuel pressure, actually the highest fuel pressure of any "normal" MPFI car made (63PSI at WOT). The general idea of stock GM fuel pumps is similar to a roots blower, its not really designed to "compress" fuel, it just packs it into the line, and hopes for the best.

You make a very convincing argument for going with the Walbro pump. Perhaps we can wrap that pump to quiet it down a bit. With that pump you would also need to scrap the pulsator as it would probably blow it apart. You've got me thinking about doing it the safe way.

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87GT 3.4 Turbo- 0-60 5.2 seconds -Best
Engine Controls, ECM goodies, Chip
re-programming & odd electronics stuff

Does it HAVE to be an in-tank pump? If the noise is that bad, why not get a remote mount pump and extend the pick-up to the bottom of the tank? They do have kits for that. I'd save up the cash for the right pump to save me an engine. Even if it means putting the pump in the engine compartment somewhere. I have thought about it, but I don't have the engine for something that drastic... Yet.

quote Originally posted by AquaHusky: Does it HAVE to be an in-tank pump? If the noise is that bad, why not get a remote mount pump and extend the pick-up to the bottom of the tank? They do have kits for that. I'd save up the cash for the right pump to save me an engine. Even if it means putting the pump in the engine compartment somewhere. I have thought about it, but I don't have the engine for something that drastic... Yet.

We've thought about that but don't want to make the installation more piecemeal than necessary. We prefer to use genuine GM parts whenever possible. There are many parts out there made in China that are of questionable quality (including some HP speed parts) and just our luck that we would end up with one of these and smoke a brand new 3800SC. Getting back to the debate, Loyde Roscoe on his website (FastFieros) claims to have installed over 25 Corvette EP 376 fuel pumps in 3800SC swaps without a single tuning or performance issue. Loyde goes on to show data that the Corvette pump can put out 80PSI and support 325 HP. On the other hand Ryan ( darkhorizon) cautions against using an AC delco pump on a 3800sc installation.
The safe bet for the 3800SC is undoubtedly the Walbro pump. You certainly can't go wrong with more fuel capacity than less. Pehaps if installed properly with a rubber sheath and isolated on the right mounts, the noise should be tolerable.

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87GT 3.4 Turbo- 0-60 5.2 seconds -Best
Engine Controls, ECM goodies, Chip
re-programming & odd electronics stuff

[This message has been edited by Dennis LaGrua (edited 03-22-2007).]

quote Originally posted by AquaHusky: Does it HAVE to be an in-tank pump? If the noise is that bad, why not get a remote mount pump and extend the pick-up to the bottom of the tank? They do have kits for that. I'd save up the cash for the right pump to save me an engine. Even if it means putting the pump in the engine compartment somewhere. I have thought about it, but I don't have the engine for something that drastic... Yet.

High pressure pumps are lousy at priming themselves. On my front engine application, where I don't have a swirl pot in the tank, I use a conventional high volume low pressure Holley to pump to an external swirl pot which supplies the high pressure pump. If you tried it with just the HP pump, it might work, but if it wasn't below the tank and it ever failed to prime - (going around corners with a low tank) you can burn them out by running them dry.

I have a higher volume pump in my turbo Fiero - so long ago I don't recall exactly which one - I think it was specified for a V8 Camaro or some such, and it is definitely needed as the stock pump would not supply enough fuel.

what hp number will the 255 support ? if i was looking at the 550+ range will this support my fule needs?

So if you have an 86SE, with a highly modified 3800sc, which pump would you use? If a walbro, what part number? Darth gave the part number for the 87-88, but will it work in an 86se?

http://apeusa.com/ has Walbro 255lph High Pressure pumps that are pretty quiet compared to some if heard its a drop in kit for GM vehicles check that out for the 3800 just click the walbro logo on the main page and its the first one on the top. it says $108 but its $113 when you checkout.

quote Originally posted by vallen11: So if you have an 86SE, with a highly modified 3800sc, which pump would you use? If a walbro, what part number? Darth gave the part number for the 87-88, but will it work in an 86se?

It will work in the earlier years (I have one in my 84). You just have to use the adapter since the earlier year pump used a different plug than the 87/88s

www.treperformance.com

They sell china made stuff, cheap, and works GREAT, I love mine, and its quiet enough I cant hear it over my really quiet exhaust.

Wouldn't the pump from a 3.8 turbo grand national be best?

I had an 89 Turbo Trans Am pump in my car.
This weekend I upgraded to a Walbro 340M, the Walbro is actually quieter then the Turbo Trans Am pump was.

I need to chime in here and ask a ?, Iam doing a lambo kit, the guy that built some of it used a external f.p. mounted just under where the battery was located. Since I am not dropping my tank which walbro/corvette f.p. can I use in the same location. 98 s.c. gtp pretty much stock other than a 3.4 pully (I think)


Thanks RUNDLC

quote Originally posted by darkhorizon: www.treperformance.com They sell china made stuff, cheap, and works GREAT, I love mine, and its quiet enough I cant hear it over my really quiet exhaust.

Is this the pump you are using?

TRE-340C 255 LPH Fuel Pump fits these cars:
1985-2002 Chevrolet Camaro and Corvette, Pontiac Firebird and TransAm
1984-1987 Buick Grand National and T-type
1985-1992 GM All Models
1991-1993 GMC Syclone and Typhoon

Thanks
Nolan

[This message has been edited by Sourmug (edited 05-19-2007).]

I've not seen anything in the 20 posts to this thread (and yes, I have read them all) that refers to the FUEL LINE DIAMETER needed for a 3800SC engine swap, whether that engine is highly modified or not.

Aside from the fuel pump issue which has been discussed at length here, wouldn't one also want to increase the Fiero's fuel line diameter after a 3800SC installation?

If not, is that because the horsepower increase attainable with a 3800SC is inadequate to warrant an increase in the Fiero's fuel line diameter?

Incidentally, my question above is NOT some silly slam against the 3800 SC engine swap. It's merely a question that presumably should be asked in regard to ANY engine swap for the Fiero --- not just the 3800SC engine swap, namely: What engine swaps, if any, warrant an increase in the Fiero's fuel line diameter?

quote Originally posted by Dennis LaGrua: EP-236 and EP-376 Both these pumps put out 27gph @50 PSI This is almost 1/2 gal per minute of constant fuel flow!!

i used the 89 turbo t/a pump in mine, ac delco ep-261. heres some info i found on the web showing this pump to produce 38gph@50psi
seems to be a much better choice over the previous pumps mentioned if you plan to use delcos
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The AC Delco book shows a slight difference between the 3.
The following table lists part #, operating pressure and operating flow
part # PSI GPH volts
EP261 50 38 12
EP270 50 37 12
EP381 51 41 13.5

The EP261 is for the 89 Turbo TA. The EP270 has been superceeded by the EP381. The Sy/Ty applications say to use 270 or 381
------------------------------

Would one of these fuel pumps from the 5.7 be a good replacement for even a stock 2.8. Both my cars have almost 200,000 miles on them and I am considering changing out the fuel pumps before I get stranded somewhere. Would one of these be a good idea.

quote Originally posted by project34: I've not seen anything in the 20 posts to this thread (and yes, I have read them all) that refers to the FUEL LINE DIAMETER needed for a 3800SC engine swap, whether that engine is highly modified or not. Aside from the fuel pump issue which has been discussed at length here, wouldn't one also want to increase the Fiero's fuel line diameter after a 3800SC installation? If not, is that because the horsepower increase attainable with a 3800SC is inadequate to warrant an increase in the Fiero's fuel line diameter? Incidentally, my question above is NOT some silly slam against the 3800 SC engine swap. It's merely a question that presumably should be asked in regard to ANY engine swap for the Fiero --- not just the 3800SC engine swap, namely: What engine swaps, if any, warrant an increase in the Fiero's fuel line diameter?

The fuel pump has a fixed output line size. It would seem to follow that you just match the supply line to the pump. The question would be does the higher capacity pumps have a larger output line? (hole, fitting, whatever you call it )

quote Originally posted by Darth Fiero: The Walbro 255lph (F20000169; item# 834GMHP) pump costs $99.99 w/ install kit (including everything you need to drop it into an 87-88 Fiero fuel tank) over at www.fullthrottlespeed.com .

this pump btw is the pump of choice of the syclone typhoon guys running in the 11's @ approx 600hp
the guys in the 10's and lower use external pumps and special tanks etc.

the tuners recommend it and the builders build with it... and @ $125 US (+-) its a no brainer
here is one part you dont want to cheap out on to save $25 and ruin an engine
yes its a little noiser but using a foam sleeve and isolating the tank as much as possible will help.
the stock syclone pump is rock solid to just over 300 hp but thats it...

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87 Fiero GT 5sp with Vortec L35 4300 Turbocharged V6
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Syclone intake manifold and engine management with Moates adapter and chip burner
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quote Originally posted by Hudini: The fuel pump has a fixed output line size. It would seem to follow that you just match the supply line to the pump.

For a truly high-horsepower engine transplant into a Fiero, would you not also want a correspondingly larger increase in the Fiero's fuel line diameter?

quote Originally posted by project34: I've not seen anything in the 20 posts to this thread (and yes, I have read them all) that refers to the FUEL LINE DIAMETER needed for a 3800SC engine swap, whether that engine is highly modified or not. Aside from the fuel pump issue which has been discussed at length here, wouldn't one also want to increase the Fiero's fuel line diameter after a 3800SC installation? If not, is that because the horsepower increase attainable with a 3800SC is inadequate to warrant an increase in the Fiero's fuel line diameter? Incidentally, my question above is NOT some silly slam against the 3800 SC engine swap. It's merely a question that presumably should be asked in regard to ANY engine swap for the Fiero --- not just the 3800SC engine swap, namely: What engine swaps, if any, warrant an increase in the Fiero's fuel line diameter?

The stock 3800SC fuel supply rail is 3/8" in diameter so anything larger than this in the supply system won't be of any help. I believe that the stock fuel rail has been used in applications to over 400HP so with the right fuel pump things should work fine. I am running #6 AN braided SS hose to it and feel that it will be sufficient. I would get too concerned here.

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87GT 3.4 Turbo- 0-60 5.2 seconds
2006 3800SC Series III swap in progress
Engine Controls, PCM goodies,
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" I'M ON THE LOOSE WITHOUT THE JUICE "

quote Originally posted by Dennis LaGrua: The stock 3800SC fuel supply rail is 3/8" in diameter so anything larger than this in the supply system won't be of any help.

That makes sense.

Is the fuel line diameter of a stock Fiero also 3/8ths inch?

IIRC, it is 3/8" with a 5/16" return line.