98 vs 96,97

[justinschmidt1]

98 4.6 has 9.0:1
96,97 4.6 is 9.5:1

anyone know why this is?

 

[reivaxtorres]

i assume you are talking about compression ratio? and it shouldnt be different at all.

 

[xsoutherngun89x]

where did you see/hear that justin? seems weird, never heard of anything like that. wouldnt mind lookin into it though, lol

 

[DFG_magic]

Never heard of that either. Any literature on this jason?

 

[Brian95SVT]

I thought they were the same...

 

[Jrgunn5150]

:rollinglaugh:

 

[justinschmidt1]

if you go to that free service manual at the top and go to 1996 mustang gt
then engine and click the top picture.



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[Jrgunn5150]

I dunno where that came from, but it's incorrect.

 

[justinschmidt1]

lol

I dont know...I was just posting it to see if anyone has heard this...

It is a ford service manual/ ford spec sheet

 

[Jrgunn5150]

I have a Ford service manual, it list's compression at 9.5:1 for all 2v's of all year's through 2001 (that's as high as it goes because it's old, lol)

 

[GaryG]

what is the reasoning the '98 gt's have like a 5-10 hp increase over the 96-97's?

 

[SRT Handz]

 

[xsoutherngun89x]

damn handz, you fail again...lol. thats like the 30th time that red x has came up. :hammer:

 

[Mustangman9812]

what is the reasoning the '98 gt's have like a 5-10 hp increase over the 96-97's?

More Agreesive Tune, and refinded exhaust which I think is BS :bla:

 

[voidfinger]

wow this again lol. Anyway, I don't think there is a diff. with CR... although i'm not 100% sure. They did change a lot of stuff for the 98 so i don't know, could be but probably not.

 

[xsoutherngun89x]

^lol, took the words right out of my mouth

 

[voidfinger]

yea i hear ya. I wish the 98's weren't so different. Can't get a strait answer out of anyone on this durn fuel pump.

 

[Jrgunn5150]

yea i hear ya. I wish the 98's weren't so different. Can't get a strait answer out of anyone on this durn fuel pump.

Ask Lizzyfan

 

[97stanger]

Yeah i would talk to fred, he has a heavily modded 98.

 

[reivaxtorres]

yea i hear ya. I wish the 98's weren't so different. Can't get a strait answer out of anyone on this durn fuel pump.

what did you need to know?

96 - 97 = continuous voltage pump, always pumps out the same amount of fuel regarless of engine load. Fuel Pressure Regulator (FPR) controls the amount of fuel that goes back into the tank (return style system)
98 = hybrid system. alternating voltage, meaning the flow of fuel is based on the amount of voltage sent to the pump, which is controlled by the ecu. FPR still controls the amount of fuel that gets returned to the tank, so this is still a return style system. not exactly sure why ford decided to create a hybrid system for this year tho, but it incorporates the alternating voltage pump style of the 99+ cars with the return style of the pre 97 models.
99+ = alternating voltage pump, ECU controls the voltage sent to the pump with in turn controls the amount of fuel it pumps out. it is no longer a return style system, so there is no FPR present in these cars. fuel flow is solely based on voltage input from the ECU

my general understanding of this is that you can use either the pre 97 pumps or the 99+ pumps (cant remember which one is semi-compatable with the 98 model year. one is and one isnt), but you run the risk of frying the pump.