Moparchat - Home of MOPAR enthusiasts worldwide!



Go Back   Moparchat - Home of MOPAR enthusiasts worldwide! > Technical Forums > Performance Talk

Click here to search for Mopar cars and parts for sale.


Reply
 
Thread Tools Display Modes
  #1  
Old 01-01-2007, 09:10 PM
ITHURTZ ITHURTZ is offline
Inactive User
 
Join Date: Oct 2006
Location: Chicagoland northern
Posts: 54
Default 140gph for 600+hp?

My dads ordering a
http://store.summitracing.com/partde...0&autoview=sku

For his 70 challenger. the tired 440 is being replaced with the 496ci 626 hp mopar engine which will have a tunnel ram and dual holley double pumpers on top (600-650cfm each). Now I know 140gph on a FI setup is weak, but how will a dual carbed engine handle this rate?

Also on a side note, what would be the best PSI rate to run to feed this engine and those carbs? Thanks
Reply With Quote
  #2  
Old 01-02-2007, 01:23 AM
JLM440 JLM440 is offline
Inactive User
 
Join Date: Sep 2006
Location: Branson, Mo
Posts: 96
Default

Quote:
Originally Posted by ITHURTZ View Post
My dads ordering a
http://store.summitracing.com/partde...0&autoview=sku

For his 70 challenger. the tired 440 is being replaced with the 496ci 626 hp mopar engine which will have a tunnel ram and dual holley double pumpers on top (600-650cfm each). Now I know 140gph on a FI setup is weak, but how will a dual carbed engine handle this rate?

Also on a side note, what would be the best PSI rate to run to feed this engine and those carbs? Thanks
140 should be fine, i ran a blue with 530-540 hp, thats a VG price for that kit, i just ordered one of jegs billet pumps, when i ran my Weiand T/R & 2 600 holleys on my 451, it used less fuel then an 850 PF. I ran 7 to 7.1/2 psi.
Reply With Quote
  #3  
Old 01-02-2007, 07:56 AM
DartGT66 DartGT66 is offline
Inactive User
 
Join Date: Sep 1999
Location: vantaa,finland
Posts: 4,622
Default

Did you happen to notice, that the kit is in backorder?
But 140 gph is enough, I used a 140 gph mallory pump in my BB car that was dynoed at 780 hp. Typically, in a decent engine, the engines brake specific fuel consumption per produced horsepower in an hour is under 0.5 lbs. In my engine it was 0.39 at peak power, and total fuel flow 290 lb/hr. It's about 46 gallons per hour.
Reply With Quote
  #4  
Old 01-02-2007, 11:28 PM
ITHURTZ ITHURTZ is offline
Inactive User
 
Join Date: Oct 2006
Location: Chicagoland northern
Posts: 54
Default

Ya we know its on backorder, thus why I am asking now so we can cancel if it wont work. But it seems like it will work, thanks!
Reply With Quote
  #5  
Old 01-04-2007, 12:16 PM
70Barracuda's Avatar
70Barracuda 70Barracuda is offline
Inactive User
 
Join Date: Jan 2001
Location: Beaverton, Oregon US
Age: 62
Posts: 625
Default

If the car is gonna go down the 1/4 you will need more than that. Alot more.

IMO

http://4secondsflat.com/fuelpumps.html
Reply With Quote
  #6  
Old 01-05-2007, 03:55 AM
DartGT66 DartGT66 is offline
Inactive User
 
Join Date: Sep 1999
Location: vantaa,finland
Posts: 4,622
Default

My car does not need more than that, not in the 1/4 mile or anywhere else. And you should see the size of my fuel lines They are nowhere near the "requirements" by sources like BG, but still I've never had any problems running mid 9's in a 3000+ lbs street car. Of course it's better to have more fuel capacity than to have too little, but those recommendations are usually total over kill.
Reply With Quote
  #7  
Old 01-05-2007, 01:56 PM
72Challenger 72Challenger is offline
Inactive User
 
Join Date: Nov 2000
Location: Mission Viejo CA USA
Posts: 2,538
Default

I'll go you one better, DartGT66. Those recommendations are made to optimize performance. Not the performance of your car, the performance of the income statement of the company making the recommendation!
Reply With Quote
  #8  
Old 01-05-2007, 02:31 PM
jelsr jelsr is offline
Inactive User
 
Join Date: Dec 2001
Location: Dighton, Kansas
Age: 84
Posts: 1,253
Default

Back when I was still pulling wrenches for KDOT we had 5 '74 Dodges with 361 BB's that wouldn't run for crap in the hot part of the day when hauling a load of dirt or asphalt. I rerouted fuel lines and all the normal "vapor lock" tricks but finally had to install 70 gph electric pumps to get them to work. This was for a 361 CID governed 2 bbl. A smaller electric wouldn't cut it. Bear in mind this was the period when we started getting the imitation gas we have now and service stations, now there's a term you don't hear nowdays, were having trouble getting it out of their underground tanks.
Reply With Quote
  #9  
Old 01-05-2007, 08:34 PM
ITHURTZ ITHURTZ is offline
Inactive User
 
Join Date: Oct 2006
Location: Chicagoland northern
Posts: 54
Default

its just a weekend warrior/cruiser
Reply With Quote
  #10  
Old 01-08-2007, 02:53 AM
451Mopar 451Mopar is offline
Inactive User
 
Join Date: Sep 2000
Location: Aurora, Colorado
Age: 59
Posts: 1,831
Default

At least the summit kit uses a 14 psi pump and has a seperate regulator and the price seems good. I'm sure it isn't the optimal setup. Just about all the manufacturers probbably recommend 1/2" or -8AN fuel line or larger, with probbably about 250+ GPH pump that can put out at least 15 psi (to over-come launch G-force.)
I think either system would be better with a bypass type regulator mounted near the carburators. The by-pass regulator is easier on the pump allowing it to run cooler, and you also get cooler fuel to the carbs, but it requires a return line back to the fuel tank.
Reply With Quote
  #11  
Old 01-08-2007, 04:18 AM
DartGT66 DartGT66 is offline
Inactive User
 
Join Date: Sep 1999
Location: vantaa,finland
Posts: 4,622
Default

the bigger the fuel line, the more capacity the pump needs to fight against the G-force. Of course, all the requirements considering the G force, depends of the car. In a light tub chassis race cars, you may see G-forces, that really affects teh pump, but at least in our street cars, that are relatively heavy and do not launch that well, it doesn't seem to mean much. With the 140 gph and the 780 hp engine, the best 60 ft was 1.55 (radials, 3.23 gears, 3510 lbs), the same enigne but with two holley blues (180 gph?) was in my old Dart, it run 1.40 60 ft (4.10 gears, 3310 lbs), both had 8AN fuel lines. When the car run 11 flats, it had less than 1/4" inside diameter fuel lines, and the 140 gph mallory.

Lets look at it another way. You have a BG 280 pump, that by many people is the absolute minimum for any credible street car. The fuel runs from the rear to the holley regulator through a 5/8" fuel line, and from there to the holleys bowls with two 6 AN lines. Now we're talking about a fuel system that should be capable, don't we? All this sewer pipe and the gigapump just to force the gasoline through the 0.15" orfice in the holley regulator, and after that through the .11" needles to the bowls?
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump




All times are GMT -4. The time now is 04:49 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
. . . . .