I know the 340 wouldnt be able to keep up with the 72's. I don't know, i will try to see how much will have to come out of my pocket and decide that way. I will never go to a bigger turbo, this is bigger than i wanted anyhow. I will probably go smaller if anything.
??? for people trapping 130+ in street cars. (Fuel related)
- Thread starter LUZ_2_A6
- Start date
jeeze Neal, I thought anybody that ran 10.3x HAD to have a FelPro!
But I knew you didn't (hey, I'm old....)......you have an even better advantage, knowing your way around chips...now if we can just get Nick's car going, maybe he'll bring it to Vegas!
maybe I'll put some 72's and Red's double in and see how much damage I can do there this year....I AM bringing my trailer!
But I knew you didn't (hey, I'm old....)......you have an even better advantage, knowing your way around chips...now if we can just get Nick's car going, maybe he'll bring it to Vegas!
maybe I'll put some 72's and Red's double in and see how much damage I can do there this year....I AM bringing my trailer!
ChrisCairns
Senior Member
- Joined
- May 24, 2001
I ran 138.61 mph with Red's double pumper from a stock tank into a stock fuel line then into a BGC fuel rail, out the fuel rail adjustable reg back into the stock return line.
I was at 88% duty cycle on 83 lb injectors. I thought at the time I was "gittin' close" so I converted to a better fuel system.
Now with the Weldon pump, reg and -10/-8 lines I only see 80% duty cycle.
Chris
I was at 88% duty cycle on 83 lb injectors. I thought at the time I was "gittin' close" so I converted to a better fuel system.
Now with the Weldon pump, reg and -10/-8 lines I only see 80% duty cycle.
Chris
Did you see any changes in performance from one fuel system to another? And from the other post, thx for the lesson on carbs and vol vs pres. Didn't know any of that maybe that's why I couldn't get into the 7's. Keep in mind at a point volume goes down as pres goes up or stays the same. So even if you still have a 1 to 1 ramp on fuel you could still run out of fuel with good pres.
Ok Woody, how can you say that volume can't go down as pres goes up. You put your finger over the end of a hose with a constant amount of water coming out it will take longer to fill a 1 gallon jug with your finger over the hose than without it. But preasure is higher. Right?
ChrisCairns
Senior Member
- Joined
- May 24, 2001
No...not from that single change. But as I said...I thought I was getting close to running out of fuel, and judging from the duty cycle change that thought was right.
Had I run out of fuel I'm sure the ole engine would have let me know.
Chris
Cool , Thx for the info. So in your opinion you were getting to the limits of the fuel system you had. That was the point I was trying to make. I never said reds pumps wouldn't get you there, just not much further. So in your case you wouldn't push your old system much past 135-138 and feel safe. I would just go big up front and not have to do it twice. THX again
750H.P.V6
Brutal 6 Racing
- Joined
- Sep 4, 2001
Volume and pressure
Clean 86,
I'm going to take a shot at this and see if this makes sense. Pressure is the evidence of Volume through a restriction. Follow me on this and I'll illustrate my point.
If you have a stock motor with stock oil pump your oil pressure will be X. If you take the same motor and put on a high volume pump the Pressure will increase. The restriction (oil clearance)remains the same.
Since our fuel system has a return line any additional fuel not used by the motor goes thru the regulator and back to the tank. If you have enough delivery to maintain the proper delta P (differential pressure)across the injector you're fine. At this point additional volume is a safety margin.
Velocity and pressure are inversely proportional not volume and pressure.
Neal
Clean 86,
I'm going to take a shot at this and see if this makes sense. Pressure is the evidence of Volume through a restriction. Follow me on this and I'll illustrate my point.
If you have a stock motor with stock oil pump your oil pressure will be X. If you take the same motor and put on a high volume pump the Pressure will increase. The restriction (oil clearance)remains the same.
Since our fuel system has a return line any additional fuel not used by the motor goes thru the regulator and back to the tank. If you have enough delivery to maintain the proper delta P (differential pressure)across the injector you're fine. At this point additional volume is a safety margin.
Velocity and pressure are inversely proportional not volume and pressure.
Neal
ChrisCairns
Senior Member
- Joined
- May 24, 2001
Some years back I remember (wow, a first) reading an article in either the GSXtra or The Source by I think Red Armstrong in which he was quoted as saying,
When pressure increases, volume decreases
and when volume increases pressure decreases.
I didn't understand why it would do this so I asked on the list. The answer I was given was because the fuel pump is a negative displacement pump.
Anyone else remember this??
Chris
When pressure increases, volume decreases
and when volume increases pressure decreases.
I didn't understand why it would do this so I asked on the list. The answer I was given was because the fuel pump is a negative displacement pump.
Anyone else remember this??
Chris
Well you can think of it this way too. The electrical power into the system will net a given amount of power out. In electrical terms the power is equal to the product of the voltage X the current. Raise one and the other must decrease to maintain a given power level. Most of us are probably happy with all that. At the pump output the pressure is analogous to voltage, and the volume to current. Raise pressure and the volume number must go down to maintain a given amount of "power" available at the output. And vice versa.
TurboTR
TurboTR
qwknuf6 jr
100% street car
- Joined
- Mar 6, 2002
This is in relation to the fuel pump !
Conversly inj's flow more at higher presure and less at lower (volume )
And you must remember that a portion of the fuel being delivered via the rail is going back to the tank as it isn't being used anyway. As such, the decreased volume from the pump isn't such a big deal.
Numeric example: If the fuel pump is providing 100 units of fuel at 65psi@the rail and the injectors are only feeding 60 units, then 40 units are going back to the tank.
Raise the rail pressure such that the fuel pump is now providing 90 units at 70psi @ the rail. Now the injectors are feeding 65 units of fuel, but you still have (90-65) 25 units going back to the tank.
In this hypothetical example you were able to get 5 more units of fuel into the powerplant without any parts changes. Does this make sense to anyone?
qwknuf6 jr
100% street car
- Joined
- Mar 6, 2002
Yes ...Yes ....
You can increase fuel delivery thru presure but it puts a strain on the fuel pump .
As long as the pump can maintan volume @ a given presure your Pump system is ok ,a good way to chk pump delivery is to adj the fuel presure to say 60 psi static and run 15-18 lbs boost , if the presure(75-78 psi) maintains thru 3rd gear at WOT then it good condition
You can increase fuel delivery thru presure but it puts a strain on the fuel pump .
As long as the pump can maintan volume @ a given presure your Pump system is ok ,a good way to chk pump delivery is to adj the fuel presure to say 60 psi static and run 15-18 lbs boost , if the presure(75-78 psi) maintains thru 3rd gear at WOT then it good condition
First of all I want to say this thread is great. Everyone is getting their opinion in and no one is getting there a$$ flamed. As to my first post , just my opinion, You can run 135ish with many pumps, and different fuel system combo's. What I was getting at is that MOST won't take you far past. When you get to the point of a 340 not cutting it or whatever pump, line , sock, inj, you may be using. When you are moving up from a single intank pump. My opinion is to do it one last time , big lines, big pump, big rails, and a data logger go a long way. And you really shouldn't have to ever change it again. I have bought the same part in a bigger version many times to keep up with my HP habit and wish someone had told me to just spend the money once and be done with it. You can take a 1500hp fuel system and tune it back for a high 12 sec car and drive it around where ever. I just don't think there is such a thing as to much fuel supply. How many people do you guy's know who have hurt a motor due to fuel,or lack of it. WHY CHANCE IT? When i get back to the point of needing more fuel I am going to buy what I know will take me as far as 10.5 Tire will go. Not a system that is adequate for the ET / mph I wan't to run at the time. Thx again guy's
No opinion of mine is necessary, but I will give my personal results. In 2000, my car (3600# with me) ran a then-best of 141.9 mph with a stock tank, Red doublepumper, 83#, stock lines (perhaps even a little more kinked at the front bends from preparation prior to chroming), stock rail. In late 2001, I decided to lose weight, including substituting a cell for the tank. Because of that, and with an eye to the future (?), I took the opportunity to upgrade the fuel system (braided lines, big pump, injectors). When I removed the tank, I found that the pump baffling had come loose . I have not noticed any obvious change with the new fuel system as I didn't really have what I'd call obvious fuel-related trouble before anyway.
Art
. I have not noticed any obvious change with the new fuel system as I didn't really have what I'd call obvious fuel-related trouble before anyway.Art
Nice runs!! Well I never said I knew everything. Just some. I have little exp going real fast with these cars. But have gone 8.86 at 186 single turbo 331 inch mustang. These cars amaze me every day. Just for kicks and giggles what kind of engine managemant system were you using and what was your AF and duity cycle if you remember, Im sure it's been a while. Just woundering. THX
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