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Best Modification for upgraded 4.6 DOHC

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Old Aug 9, 2004 | 11:41 AM
  #1  
Cobra ZR1's Avatar
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Default Best Modification for upgraded 4.6 DOHC

4.6 DOHC Ford Cobra into AC Cobra 1966.
Very Fast car
Good powerband ( better 3000 to 7500 RPM )
specification;
No AC
No Air Pump Anti-polution
Header 1 3/4 Equal lengt ...straigt
No catalyser
2 side pipe 4 into 4 Low restriction
Special Chip from "Reinhard Racing" for upgraded H"P
Fresh air intake special because restrictive space.

Question?
Best way for more Horsepower... naturel aspired
Way for No lag at very low RPM .
Header with side pipe Low restriction is it a problem?
Vortex Cone in side pipe is it a solution.

Thanks for your time

Sorry for me English
Old Aug 9, 2004 | 11:47 AM
  #2  
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Default RE: Best Modification for upgraded 4.6 DOHC

4.6 Dohc AC Cobra Picture

[IMG]local://upfiles/8413/539BA4F5291F4DC99EA12AA38EA2415E.jpg[/IMG]

[IMG]local://upfiles/8413/A08D8779CF8F498AA662DFFEAA8194A5.jpg[/IMG]

[IMG]local://upfiles/8413/BA7BB9F6D7CD45D0AA56D686F689DA51.jpg[/IMG]
Old Aug 9, 2004 | 11:53 AM
  #3  
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Default RE: Best Modification for upgraded 4.6 DOHC

WIth a powerband that high theirs nothing you can do to prevent a crappy low end powerband - if you've got an auto then gettting a torque converter with a stall speed up higher, like 3500 - 4k with your powerband, or if you have a stick getting numerically higher rear end gears will help get you moving, but with a car as light as that you should have much of a problem just slipping the clutch. nice car by the way.
Old Aug 9, 2004 | 12:51 PM
  #4  
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Default RE: Best Modification for upgraded 4.6 DOHC

Really nice car and engine you have there! A set of new gears would help get the engine up into the powerband quicker like MD says buy you may already be able to blow the tires off of it at will, so I would see what I could do with the suspension to improve the traction at the rear tires.
Old Aug 9, 2004 | 01:28 PM
  #5  
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Default RE: Best Modification for upgraded 4.6 DOHC

I have 5 speed tremec
Gear ratio 3.55 with IRS Diff.
Good traction Tire with two 335 / 35 ZR17

Maybe upgraded gear ratio to 3.73 for the best Drag time.

Drag is not a priority for me.

I like drived my car on a race track ( street )

But this is not my real problem.

If I turn quickly " trottle body cam" I have a little lag.

This problem is , since motor is in my car.
This problem is it caused by Exhaust Low Restriction
TPS sensor
Restriction in Fresh Air Intake
Or WHAT ???

Thanks Guys
Old Aug 9, 2004 | 01:54 PM
  #6  
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Default RE: Best Modification for upgraded 4.6 DOHC

Could be the TPS sensor needs to be adjusted. It should read out .98-.99 volts DC when it is closed. You can check this with a voltmeter by backprobing the two wires coming from it with the key on but the engine off. Loosen the two screws holding the TPS in place and rotate it to change the voltage readout. In some cases, you may need to remove the TPS sensor and elongage the slots where the screws go through it in order to get enough adjustment to get the voltage where it should be.
You might also see if you can move the air filter out of the front of the engine and get it away from the hot air coming off the radiator fan. This will let it get cooler air for more power. Don't think the low restriction in the exhaust is causing the lag in throttle response when turning. Is your fuel pump mounted in the tank or outside the tank? If outside, the fuel pickup may need to be relocated so it stays under the fuel level at all times so the fuel doesn't run away from the pickup in a turn.
Hopes this helps you out some! Where are you located at?
Old Aug 9, 2004 | 02:52 PM
  #7  
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Default RE: Best Modification for upgraded 4.6 DOHC

Hi Roundmanracing.
I live in Québec, Canada.
I check today your information " voltage TPS "

Next Question. If I change for a BBK trottle body ( bigger bore size),
the performance is it bigger.
This modification only or with obligatory big size
Mass Air Flow & Bigger injector & more pressure valve
Fuel.

P.s My fuel pump is in me tank.
Old Aug 9, 2004 | 03:01 PM
  #8  
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Default RE: Best Modification for upgraded 4.6 DOHC

ORIGINAL: Cobra ZR1



Next Question. If I change for a BBK trottle body ( bigger bore size),
the performance is it bigger.
This modification only or with obligatory big size
Mass Air Flow & Bigger injector & more pressure valve
Fuel.
dont waste your money on a bbk throttle body. get an accufab, single blade throttle body. you dont have to upgrade injectors and maf. a bigger maf would help, but your not making enough power yet to NEED bigger injectors.
Old Aug 9, 2004 | 03:08 PM
  #9  
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Default RE: Best Modification for upgraded 4.6 DOHC

With a new accufab; How many H.P
More fast respond ( quickly trottle)

Thanks to Nomocobra & Roundmanracing
Old Aug 9, 2004 | 03:44 PM
  #10  
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Default RE: Best Modification for upgraded 4.6 DOHC

ORIGINAL: Cobra ZR1

With a new accufab; How many H.P
More fast respond ( quickly trottle)

Thanks to Nomocobra & Roundmanracing
im not sure how much hp an accufab single blade throttle body is good for. but its def alot more than a bbk unit. why dont you supercharge or turbo you motor? heres my old setup



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