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Turbo3Iroc
03-29-2007, 01:10 AM
I'd like to know how much horsepower a stock fuel system is good for. Also for grins I'd like to know how much a 1/4" and 3/8" feed line would be good for.

Thanks,
Kelly

Anonymous_User
03-29-2007, 01:57 AM
When you say fuel system, I immediately think stock fuel pump and injectors. If that's the case, without adding extra fuel, maybe 200??

If by fuel system you mean the stock lines, as your post seems to point towards, then as long as your stock lines are in good shape, there is no need to upgrade untill you are making some big numbers.

Man, it's been a while, but seems to me, somewhere it was calculated the stock lines could take you to 400.

Someone correct me if I'm wrong.

Turbo3Iroc
03-29-2007, 02:05 AM
Yea, I'm pretty much only talking about the lines. I already have a 255 Walboro pump.

4cfed
03-29-2007, 02:18 AM
i just read on thedodgegarage stock t2? should be good for 290ish hp.. full system....

turbovanmanČ
03-29-2007, 03:51 AM
Stock fuel lines can supply enough for 500 whp.

Murphy
03-29-2007, 09:26 AM
i just read on thedodgegarage stock t2? should be good for 290ish hp.. full system....

your gonna need bigger than stock injectors for that kind HP

the s 60 kit rated at 300 hp came with +40's

powermaxx
03-29-2007, 09:58 AM
Stock fuel lines can supply enough for 500 whp.

Where did this info come from? I've been concerned with the new Steve M head in place it's making a ton more power :thumb: and had me concerned.

Turbo3Iroc
03-29-2007, 11:06 AM
I'm not doubting but just looking for some poof as in someone making near that power on stock lines or the boring mathematical equation lol.

4cfed
03-29-2007, 12:05 PM
your gonna need bigger than stock injectors for that kind HP

the s 60 kit rated at 300 hp came with +40's


ops my bad!! i was wrong.. it says stock fuel pump is good for 290-300 hp...


sorry for the false info

Directconnection
03-29-2007, 12:37 PM
larry 4cefed4 would know best. I think he MAY have run his 500+whp on stock lines. This is a question I am wanting to know as well....

TurboJerry... have any input on this?

turbovanmanČ
03-29-2007, 01:08 PM
Where did this info come from? I've been concerned with the new Steve M head in place it's making a ton more power :thumb: and had me concerned.


Larry on TD back in the day laid down 500 whp on a basically bone stock RT.



ops my bad!! i was wrong.. it says stock fuel pump is good for 290-300 hp...


sorry for the false info

Your pushing your luck with a stock type fuel pump at that level.

Mario
03-29-2007, 01:47 PM
Larry on TD back in the day laid down 500 whp on a basically bone stock RT.




Your pushing your luck with a stock type fuel pump at that level.

Back in the day, geez, it has been a long time.

Aaron Miller made 407WHP on the stock fuel lines.

Frank
03-29-2007, 01:59 PM
Larry on TD back in the day laid down 500 whp on a basically bone stock RT.



You are missing a big piece of information... he was sucking down mad amounts of alky to supplement his lack of tune and fuel ability. I would recommend upgrading the lines when pushing 400whp for sanity and reliability sake especially when you are dealing with 52lb/hr injectors. Why? Well the pressure at the pump will eventually burn out your pump because between the pressure and the rail and pumping losses thru the lines... well lets just say its more pressure then what the pump was designed for. In addition to that, with stock lines, its harder to quickly bleed off the fuel pressure when your engine changes driving conditions. Something you will also find is that when you do upgrade lines and rails, you may need to increase the priming pulse on your calibration because its harder to build the proper cranking pressure in the fuel system. Or you just key the engine a few extra times.


Frank

85glht
03-29-2007, 06:27 PM
Kelly, for what you are doing, You will be o.k. (stock lines and upgraded fuel pump.)

1FastCSX289
03-29-2007, 07:13 PM
Sorry to highjack here, but its right on topic.

What about the stock rail? How much power will it support? I am aiming for 400 whp this summer with alcohol injection. I have stock lines and stock rail, 72lb/hr injectors, 255 lph pump, and an accufab regulator.

4cfed
03-29-2007, 09:31 PM
Larry on TD back in the day laid down 500 whp on a basically bone stock RT.




Your pushing your luck with a stock type fuel pump at that level.

ill be happy with 250 WHP

Frank
03-30-2007, 07:34 AM
Sorry to highjack here, but its right on topic.

What about the stock rail? How much power will it support? I am aiming for 400 whp this summer with alcohol injection. I have stock lines and stock rail, 72lb/hr injectors, 255 lph pump, and an accufab regulator.

I think the rails, especially on a two piece are better then we give them credit for, however I dont think so on the lines. I would just be careful and move your EGT probe aroudn to get a good feel of balance across the car.


Frank

1FastCSX289
03-30-2007, 08:14 AM
I think the rails, especially on a two piece are better then we give them credit for, however I dont think so on the lines. I would just be careful and move your EGT probe aroudn to get a good feel of balance across the car.
Frank


Ive got two spots for the probe....one on the #1 and the other on the #4. I may just get two probes, than all I have to do is unplug one and plug in the other inside the car. Ill keep an eye on it and turn up the boost slowly. Thanks.

Turbo3Iroc
03-30-2007, 01:54 PM
I have EGT also and I know for what I am doing the stock lines are sufficient. It's just come up in conversation so that is why I asked. I'd still like to know how much horsepower a 5/16 line has the ability to support.

Come on Frank, I know you can do it! :thumb:

shadow88
03-30-2007, 07:18 PM
I'd like to play the role of Devil's Advocate about the fuel line diameter.

Let's say you've stepped up the feed line from the pump outlet in the tank all the way to the fuel rail. Inside the pump is a 5/16" fuel line and the inlet to the rail is also 5/16ths. So where's the advantage?

You stepped it up from 5/16th just to step it back down again. There's only so much fuel the 5/16ths line in the tank can possibly flow. I understand the reason for making a 5/16ths return line to help lower fuel pressure below 30 psi (ish)

Directconnection
03-30-2007, 08:38 PM
Let's say you've stepped up the feed line from the pump outlet in the tank all the way to the fuel rail. Inside the pump is a 5/16" fuel line and the inlet to the rail is also 5/16ths. So where's the advantage?

You stepped it up from 5/16th just to step it back down again. There's only so much fuel the 5/16ths line in the tank can possibly flow.

If you have a 3" mandrel exhaust from the SV back.... but for some odd reason, you like the looks of that 1-7/8" exhaust tip. This setup would still flow considerably more than a complete mandrel bent 1-7/8" exhaust.

Why go 3" when all you have is a 2-1/2" SV?

Not totally correct, but still major gains to be had.

Now... the fuel line size and stock fuel rail capability topic. 5digits was not a believer in the old hollowed out fuel rail trick. I am sure he'd be against the billet rails as well.

Is the old tale of needing a large ID billet rail just that? The stock rail has an internal mechanism to keep flow consitant and dampen pulses.

turbovanmanČ
04-02-2007, 03:12 AM
Now... the fuel line size and stock fuel rail capability topic. 5digits was not a believer in the old hollowed out fuel rail trick. I am sure he'd be against the billet rails as well.

Is the old tale of needing a large ID billet rail just that? The stock rail has an internal mechanism to keep flow consitant and dampen pulses.

I cut one apart and can offer this, the tube inside definately blocks flow. I have seen other fuel rails apart and there totally hollow inside. I honestly believe taking it out or using a billet fuel rail is the way to go. I ran my 2 piece without the internals and no injector balance issues. Theres so much pressure and volume inside the rail that to have balance issues, you'd have to be running out of fuel.

Ondonti
04-02-2007, 07:09 AM
If you have a 3" mandrel exhaust from the SV back.... but for some odd reason, you like the looks of that 1-7/8" exhaust tip. This setup would still flow considerably more than a complete mandrel bent 1-7/8" exhaust.

Why go 3" when all you have is a 2-1/2" SV?

Not totally correct, but still major gains to be had.

Now... the fuel line size and stock fuel rail capability topic. 5digits was not a believer in the old hollowed out fuel rail trick. I am sure he'd be against the billet rails as well.

Is the old tale of needing a large ID billet rail just that? The stock rail has an internal mechanism to keep flow consitant and dampen pulses.

So we could say that just upgrading the line after the sending unit would be sufficient to extend the limits of the fuel system significantly?

Anonymous_User
04-02-2007, 08:14 AM
I am willing to test this all out.

I have a fuel tank with a stock pump in it out of a vehicle. I have a stock set of fuel lines out of a vehicle.

If I hook up the stock fuel lines to the stock fuel pump and measure the amount of time it takes to pump 5 gallons of gas, we have a baseline.

I will then remove the stock fuel lines and hook up an equal length of 3/8" fuel lines. Then repeat the measurement of how long it takes to pump 5 gallons of gas.

Of course, each test will consist of 3-5 measurements in order to get an average.

Both test will have the stock size line inside the tank as well as the metal piece that actually exits the tank.

Does anyone have anything to add to this before I begin?

Won't be today, but before the week is over.

**Hopefully the pump in that tank is operational**

Turbo3Iroc
04-02-2007, 10:33 AM
I don't know if a stock pump will max out the flow on even the 5/16" line. The pump would most deffinately be maxed with 3/8" line.

shadow88
04-02-2007, 10:32 PM
I am willing to test this all out.

I have a fuel tank with a stock pump in it out of a vehicle. I have a stock set of fuel lines out of a vehicle.

If I hook up the stock fuel lines to the stock fuel pump and measure the amount of time it takes to pump 5 gallons of gas, we have a baseline.

I will then remove the stock fuel lines and hook up an equal length of 3/8" fuel lines. Then repeat the measurement of how long it takes to pump 5 gallons of gas.

Of course, each test will consist of 3-5 measurements in order to get an average.

Both test will have the stock size line inside the tank as well as the metal piece that actually exits the tank.

Does anyone have anything to add to this before I begin?

Won't be today, but before the week is over.

**Hopefully the pump in that tank is operational**

A few things to consider.
1st, I love the idea!
2nd safety, be carefull.
3rd, steady power from the battery to the pump. A good battery charger should help that.
4th, you may want to do less than 5 gallons. Perhaps more like volume per minute.
5th, the pressure you run the fuel at (if any at all)
I think it's a great idea you should totally do it.

Anonymous_User
04-03-2007, 03:46 AM
The idea is to simply allow the pump to move the fuel from the tank to a gas can. No fuel rail or pressure regulator.

Safety? Psshh.. OK, I won't smoke while I do it. =)

Steady power - good idea. I'll run power from a car battery with the car running. Best way to simulate what the pump would normally see.

shadow88
04-05-2007, 07:03 PM
I'm all for it and would love to see the results. So now you have plans for the weekend?

Anonymous_User
04-05-2007, 07:27 PM
Yes, I'll do this this weekend.

I'll have to bend up some 3/8 hard line to at least come close to the bends in the stock line in order to make it as close a comparison as possible.

shadow88
04-05-2007, 07:35 PM
Something that might make the exact volume more, well, exact is a ball valve on the end of the line to ensure a shut off and on is right when you want it. I'm very impressed you're going through the hassle of bending to match the 3/8" line. Although I think I know what the results will be, I'll keep quiet until you're done.

Most of all, be carefull.

Directconnection
04-05-2007, 07:38 PM
I am willing to test this all out.

I have a fuel tank with a stock pump in it out of a vehicle. I have a stock set of fuel lines out of a vehicle.

If I hook up the stock fuel lines to the stock fuel pump and measure the amount of time it takes to pump 5 gallons of gas, we have a baseline.

I will then remove the stock fuel lines and hook up an equal length of 3/8" fuel lines. Then repeat the measurement of how long it takes to pump 5 gallons of gas.

Of course, each test will consist of 3-5 measurements in order to get an average.

Both test will have the stock size line inside the tank as well as the metal piece that actually exits the tank.

Does anyone have anything to add to this before I begin?

Won't be today, but before the week is over.

**Hopefully the pump in that tank is operational**

This will be a good test in the tune of the Gus method (rip)

One thing.... the larger lines needs to have the exact same bends and radius' to replicate the same flow losses. Maybe a simple test is to stretch out a 10ft long 5/16" and test, and then a straight 3/8" after. Or leave them still coiled.

Anonymous_User
04-05-2007, 08:44 PM
Im fairly experience in bending - part of being an electrician for years - but if I can't get it pretty darn close, I will use straight lines.

Anonymous_User
04-07-2007, 07:24 PM
Well, looks like it's gonna be NEXT weekend. :(

I went and picked up 20' of 3/8" ID tubing. Dug out my tubing tools and the largest bender I have is for 3/8" OD. Drove all over town looking for a 1/2" OD bender and no one has them. I'm gonna order one over the net I guess.

Soon as it gets here, I'll begin testing.

Anybody want to donate a 255lph or chip in on one for a second set of tests?

Directconnection
04-07-2007, 09:33 PM
You don't need a stinking bender. I used a small machinist vice I made back in college and I clamped a 12mm deep socket into the jaws which have perpidicular vees for holding round stock. Use the socket to bend the tubing, but SLIDE the tubing while adding pressure for the radius. The slide and bend technique I found prevents the crappy stretching of the tube and which reduces the ID. Slide and bend little by little... don't make the bend all in one shot, or even 3-4.... use slow strokes. I replicated those crappy
1-1/2 foot sections that go on the trailing arms with crazy bends left/right and up and down.

Directconnection
04-07-2007, 09:34 PM
Ooops... forgot we are talking larger FUEL lines with simple bends... my bad.

TurboJerry
04-07-2007, 09:49 PM
larry 4cefed4 would know best. I think he MAY have run his 500+whp on stock lines. This is a question I am wanting to know as well....

TurboJerry... have any input on this?

All I can say is that I ran 72 pph injectors on a stock 2 piece intake/fuel rail/fuel system. The stock Bosch pump had really high pressure, but no volume. The stock Walbro did 300 hp, and a 255 hp walbro did over 400 hp. I had then changed to a Mallory regulator and welded fittings to a broken 2 piece rail, put it on and got it running, but never got to see if it really helped from there. I used to test pumps by seeing how much fuel got pumped into a measured container in 10 seconds. Then it's just simple math to figure the HP level for that flow. I never used alcohol injection, or any other gismos because I didn't want a lot of *business* going on under the hood. Steve Menegon can agree with this as he has a similar setup as me...... And since the subject car is an R/T, I recommend going back to the '89-'90 Walbro pump. The big plastic tube setup has a 1/4" orifice for fuel to go through, and that's not enough.

Anonymous_User
04-07-2007, 10:02 PM
Well, about bending - I could probably come close by bending by hand, but I figure if I'm going to all this trouble I might as well do a good job and use the lines I build on my car.

And I don't use those crappy cheap-o benders either. I have a set of benders that are more expensive but bend very nice, just that they don't do 1/2" O.D. tubing. My old employer had a 1/2" O.D. bender that I could use anytime so I never purchased one myself. Now I don't have access to it, so I'm going to get one myself.

Turbo3Iroc
04-08-2007, 11:22 AM
Good post TurboJerry, I already have an 89 style tank and Waboro 255 pump in the car. The SRT pump mod to fit in the later tanks came right after I did this. I am assuming you made the 400 hp on stock lines but I just want to clarify that.

Kelly

Directconnection
04-08-2007, 03:18 PM
So, the '91+ Walbros have a 1/4" orifice that limits volume on a high HP setup and the walbro for the SRT4 doesn't and can be modded to work for the '91+ tanks?

Jerry... if the 1/4" orifice is a major restriction in the '91+ walbro, wouldn't the innards of the stock rail be doing the same?

Also, you ran the 400+ on stock lines according to your comment of stock "setup" correct?

Lastly, not to put you on the spot, but could you post the equation for hp potential based on fuel flow?

TurboJerry
04-08-2007, 10:01 PM
So, the '91+ Walbros have a 1/4" orifice that limits volume on a high HP setup and the walbro for the SRT4 doesn't and can be modded to work for the '91+ tanks?

Jerry... if the 1/4" orifice is a major restriction in the '91+ walbro, wouldn't the innards of the stock rail be doing the same?

Also, you ran the 400+ on stock lines according to your comment of stock "setup" correct?

Lastly, not to put you on the spot, but could you post the equation for hp potential based on fuel flow?

I never messed with the SRT-4 Walbro. I used the '89-'90 255 because it's a 5/16" all the way through. It's the housing for the pump that has the 1/4" orifice tube through it on the '91+ cars.

The stock fuel rail is 5/16" all the way, but has really sharp bends. (but not a problem)

Yes, I was able to get 400+ hp on a stock setup with a 255 hp walbro.

The equation is a trade secret, and I can't post it hehehe......

They are: (HP) =lb/hr (fuel) / BSFC. If we assume BSFC of .5, then HP = 2 * lb/hr. if we round the weight of a gallon of fuel to 6 pounds HP = 12 * gal/hr.
So with a 190 lph pump it looks like this. 36 * 12 = 432. 36 GPH, 12 is the .5 BSFC and 6 lbs per gallon of fuel, and 432 horsepower...... And the 36 GPH, if you divide that by 60 minutes, you get 1.6 gallons per minute, and then divide by 60 seconds, you get .03 gallons per second. I hope you know there I'm going with this.......