["Puddles the Pontiac"]

i plan to build a twin turbo engine this febuary. my only question is the fuel system. i know i need boost reference regulators and more fuel over all. but do i need a high dollar pump or can i get what i need from two smaller pumps? the aeromotive peice i am looking at is not too cheap, but i have one holley blue. and getting another would be much cheaper. any other fuel system need brought up would be appreciated as wel. thanks to all.

[tininjun67]

injected or carbureted?
Keep in mind that the pump must be able to provide adequate pressure to overcome the boost you're running. 7psi plus 15 boost referenced psi = 22psi. Most carbureted pumps can't provide that. Also, follow your flow reading on your pump at that pressure. The GPH plummets as pressures go up. Don't go cheap on your fuel system. I always go overboard on hose size and pump capacity, that way if I want to step it up, I'm not spending even more money to redo everything.

[455Turbo]

More information would help in answering your question.

Carb or EFI?
What size engine?
How much boost?
What heads are you going to use?
What turbos are you going to use?
How much HP do you want?

My engine is injected and it uses a Weldon 2025A fuel pump.

["Puddles the Pontiac"]

455turbo, i was hoping i could get you out of the wood work...
.060 455
6x-4 heads w/heavy porting. flow unknown untill later this month
2.11 1.77
holley 750hp
looking for about 700-800
twin to4b turbos.
i will be conservative on boost (8-10psi) untill the new crank comes out. also woundering if i have to switch to downleg boosters on the carb. and how you tuned yours. i plan on using an aeromotive return style boost ref. regulator. can i use two tandem holley blues or will i need more? the fuel system is all i am stuck on right now. also, what did you use for your plumbing? thanks.

[PONTIAC DUDE]

Magnaflow 500 with filter.

[v869tr6]

If you want to run a blowthru carb this link will help a lot.
http://www.turbomustangs.com/smf/ind...?topic=51153.0

I purchased a A1000 pump to run with my blowthru turbo setup.

[455Turbo]

My engine needs about 16 psi of boost to make 800 hp. You may need a little more boost with 6X heads but it's a good starting point.

With 16 psi of boost + 7 psi for the carb you'll need 23 psi. (as tininjun already mentioned)

The BSFC for a turbo engine is around .60 lb/hp-hr. This works out to 480 pounds of fuel per hour for 800 hp.

Converting to gallons yields about 85 gallons per hour. (at 23 psi)

The maximum pressure output of a Holley Blue pump is 14 psi. Therefore it won't cut it.

You can follow this link to the smallest Weldon pump I found that will support the HP you're looking for. http://www.weldonracing.com/a2005.html

If you look on the "performance chart" it shows about 87 gallons per hour at 23 psi. I'd recommend buying a bigger pump, that way you can crank the boost up to 22 psi and make 1000hp.

I can't help with carburetor questions, Tom V and PontiacDude probably can.

PontiacDude - Do you mean the MagnaFuel ProStar 500 pump? The information I found says that it free flows 95 gallons per hour. I haven't found any information on its flow rate at 23 psi. Have you used it with 15 psi of boost? If so then it's a pretty good deal.

[GTOGEORGE]

When running a Forced Induction (Turbo, Blower, Etc.) engine I found out bigger is always better (this also goes with fuel lines) ...........................DON'T want to run it lean! I agree with what Pontiac Dude says.

["Puddles the Pontiac"]

thanks guys, that is a frickin wealth of info you all provided. i was going to go the usuall route of aluminum heads for the power, but this way i get to keep my iron heads and make the big numbers for cheaper and keep it on the street. again thanks.

[RobbMc]

The Mallory 250 pump will provide about 140 gph at 23 psi. It comes with the bypass set at about 16 or 18 psi but it can be adjusted to 23 psi. However, I would recommend you use a return style regulator with boost reference and then just block off the bypass at the pump. This will make the pump last a lot longer than if it is forced to run at 23 psi all the time. Using a return regulator with a blocked off return will allow the pressure coming out of the pump to go up and down with boost, taking the load off the pump when not under boost.

[Tom Vaught]

I was talking with the SX fuel pump guys and they are interested in offering a Blow thru fuel system for the Pontiac turbo and supercharger guys. The guy quoted me a couple of pump and regulator combos that would be cheaper than a Weldon but would support 800-1000 hp easily. I talked to them at PRI about the Pontiac guys getting into boosting.

I can post some names in a few days and phone numbers.

Jimmy Keen was sponsored by SX and with 2 pumps (old design) in 1998 was a World Champion making over 1400 hp. Can't be too bad.

Tom V.

[PONTIAC DUDE]

I have been running the ProStar pump for over 6 years, with Nitrous, ProChargers, etc. It has 28lbs to the regulator and have run it with 15/16 lbs of boost at Norwalk and 1300 EGT with a blowthru. Ran 9's with a D1SC!!!!!! in a 3550lb PG car.

["Puddles the Pontiac"]

is there any way to keep the fumes down to a minimum? i have heard it is bad at idle and at low rpm. i would like to take this on power tour, if not that at least to va. beach and iowa.

[PONTIAC DUDE]

Fumes??????????


If the carb is properly reworked. It won't be an issue.

["Puddles the Pontiac"]

i have heard from a few sources that gas fumes are an issue at low rpm with blow through turbos, due to the carb being overly rich, when boost is not present

[Tom Vaught]

You get a CSU prepared or a Tom V prepared Blow thru carb and it will not be overly rich when off boost.

Tom V.

[fast72lemans]

Originally Posted by Puddles the Pontiac

is there any way to keep the fumes down to a minimum? i have heard it is bad at idle and at low rpm. i would like to take this on power tour, if not that at least to va. beach and iowa.

I can tell you from experience....No Fumes at low speeds or idle.

[bad69bird]

As with the Dude, I have a Pro-Star 500 that I run on a Procharger F-2. I ran -12an line from the cell to the pump, -10an line from the pump to the regulator, and (2) -08an lines to the carb. I run a CSU prepped 850 holley and their hat. The "500" will support 1400hp with forced induction and 2000hp NA. I have a friend who has the same set-up in a Chevy (540cid) that sees alot of street time. It run's 8.58 @159.95 with no issues with the pump. The Weldon and Aeromotive pumps can't handle continuous street duty. You'll also need the boost ref. regulator that magna fuel sells to go with the pump/filter combo. I can't remember the part# off the top of my head (I think it's #9833b), but I know that you have to but a "b" on the end of #.That will cost you about $760.00 for the combo, not including the "an fittings for the pump and regulator, which are about another $60. WHAT EVER YOU DO...DON'T TAKE SHORT CUTS ON THE FUEL SYSTEM WITH A BLOW-THRU!!! You'll regret it!

-Brian

PS. Didn't have any problems with fumes at idle with mine or my buddy's blow-thru.

["Puddles the Pontiac"]

i appreciate all the info guys, i really underestimated the fuel system. geeze the money i save going with the turbos instead of heads is being swallowed by the fuel system. i may have to rethink things some.

[bad69bird]

NP. The turbomustang board is an excellent source for you also. There a good bunch of guys who are willing to help you out.

http://www.turbomustangs.com/smf/