Why does my car seem slow?

84convertablegt

New Member

Nov 6, 2004

589

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Columbus, OH

Apr 11, 2005

#1

• Apr 11, 2005

• #1

OK, maybe im just biased because my previous mustang was a Kenne Bell supercharged 94 cobra, but i had a 84 gt covertable with a performer intake and holley 670 carb and it seemed alot faster than my 65. u can see my sig, i have a decent combo. edelbrock cam., holley 4v 600 carb, performer intake, tri-y's, electronic ignition, etc. the car is lighter than the 84 and is supposed to have more power, so why does it feel like im driving a truck? timing is 10' base. car sounds mean as hell, but i think my 02 explorer could take it in the qtr. mile just doesmt seem right! the heads on my 65 are rebuilt with slightly larger valves, hardened seats. ported and polished. it is weird. i figured it would feel real good. whats up with this 289? anything else to really help me out? ive done all the bang for buck mods, whats next? i feel like i need at least 50 more solid hp to be happy

 

D

declankelly

New Member

May 25, 2004

6

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Boston, Ma

Apr 11, 2005

#2

• Apr 11, 2005

• #2

That setup should rock ...

I had a similar problem and changing out my rear-end gears helped a lot.
Can you tell us speed Vs RPM on highway.
-d

 

84convertablegt

New Member

Nov 6, 2004

589

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Columbus, OH

Apr 11, 2005

#3

• Apr 11, 2005

• #3

well, its a 2.80 rear end 8" stocker pos. I was recently at the spring swap in columbus and didnt see anything decent, they were all 9". trust me, i know the gears are hurting me. you're right though, i should have more. i am thinking a 3.50 rear gear set will be nice, no highway use here

 

redhotcomet

New Member

Mar 30, 2005

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Western Canada

Apr 11, 2005

#4

• Apr 11, 2005

• #4

The edelbrock performer intake is not much better than stock. Edelbrock actually cast the stock Ford 4v intake in those years, and the performer is basically the same except for ford parts #'s etc.

What cam are you using? Is this a hipo or reguluar 289? What compression?

I agree with the gear swap. Also you could try advancing your timing a bit. I know the 5.0's like around 14 degrees inital. You could try 12 or 14, see if that helps, but watch out for detonation.

 

84convertablegt

New Member

Nov 6, 2004

589

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Columbus, OH

Apr 11, 2005

#5

• Apr 11, 2005

• #5

its not a hipo block no, its the edelbrock performer cam, dont know the exacts off hand. i have no clue what my compression ratio is, but im sure its stock, the motor was rebuilt with the same type of pistons and the combustion chambers are still stock size. I think i will bump up the timing a little, i always run 93 octane gas so i may have some room to work in that area. Would different heads really make a hug difference or not? I am also starting to think that im not hitting wot when flooring the accelerator. I may need to make some adjustments there. i already had to make some adjustments for the 65 rod style kickdown to work with the performer intake. my secondaries may not be fully engaging or something.

 

Dark Knight

Founding Member

Feb 1, 2000

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Chandler, Az.

Apr 11, 2005

#6

• Apr 11, 2005

• #6

is the 84 a 5spd car? T-5's have a steep 1st gear vs. the C-4, 3.35 vs. 2.46..even with the converter, off the line with the stick is going to be quicker

and the 84 isnt THAT heavy... mine weighed 3375 with me in it and 1/4 tank of gas..

 

Max Power

Active Member

Jul 31, 2003

1,774

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St Paul

Apr 11, 2005

#7

• Apr 11, 2005

• #7

Engines are just air pumps. Your intake, heads, cam, and even to some extent, your Tri-Ys are holding you back. And of course some gears would be nice.

Dyno it and see where it compares to other engines with similar mods. At least that will tell you if something is wrong.

 

84convertablegt

New Member

Nov 6, 2004

589

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Columbus, OH

Apr 11, 2005

#8

• Apr 11, 2005

• #8

yeah, my 84 was a 5 speed. funny thing is, i miss that car. anyway, the tri y's may not be as good as a regular set of longtubes, but they are way better than the stock manifolds that were on there. my tri y's arent regular ones anyway, they have larger tubes and larger collectors 2 1/2 inch instead of the cheapy tri y 2" sizes... maybe the paxton supercharger would be an option, but for that price, i could sure get a nice set of heads, a new intake, and a better carb. hummm, choices choices choices. i have until june to get this thing right.... if i were gonna get some new heads, what would be the best choice as far as ease of bolt on and keeping all my other stuff, i.e headers and such? and bang for the buck, which heads are the best option. i want to gain at least 50 hp here. i think thats reasonable!

 

84convertablegt

New Member

Nov 6, 2004

589

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Columbus, OH

Apr 11, 2005

#9

• Apr 11, 2005

• #9

ok well i found one big problem. sure enough my throttle linkage was adjusted wrong and i was about 3/4" away from full throttle. i re adjusted it and went for a drive and it is definately much better than before. off the line the car is still a dog, but thats just the gearing im sure. ill still look at the timing when it cools down.

 

302 coupe

Founding Member

Mar 2, 2000

1,952

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36

Macon, Ga.

Apr 11, 2005

#10

• Apr 11, 2005

• #10

sometimes its the simple things that make all the difference.

 

3

3spd on floor

Founding Member

Aug 13, 2002

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Acworth, GA

Apr 11, 2005

#11

• Apr 11, 2005

• #11

302 coupe said:

sometimes its the simple things that make all the difference.

Click to expand...

my buddies afr headed 331 fox couldnt break outta the 14's, turned out the carpet was bunched up and stopping the pedal from going all the way down.

 

65fastback2+2

New Member

Aug 4, 2003

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Louisville, KY

Apr 12, 2005

#12

• Apr 12, 2005

• #12

3spd on floor said:

my buddies afr headed 331 fox couldnt break outta the 14's, turned out the carpet was bunched up and stopping the pedal from going all the way down.

Click to expand...

lol, now that is great

 

84convertablegt

New Member

Nov 6, 2004

589

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Columbus, OH

Apr 12, 2005

#13

• Apr 12, 2005

• #13

3spd on floor said:

my buddies afr headed 331 fox couldnt break outta the 14's, turned out the carpet was bunched up and stopping the pedal from going all the way down.

Click to expand...

well thats what was basically happening. when i was driving i could tell i wasnt hitting full WOT. i was trying to bash the pedal down and my kickdown wasnt even engaging unless i smashed it real hard and then it would upshift right away again. instead of carpet, it was a misadjusted rod, oh well, all is well now. its not like i built this thing to be a race car or anything, but if you've got a decent v8 in there, you want to know it when you hit the gas.

 

R

Ronstang

New Member

Apr 4, 2004

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Houston Texas

Apr 12, 2005

#14

• Apr 12, 2005

• #14

Your initial timing is too low in my opinion, especially with a an aftermarket camshaft. Bump it up to at least 14 and maybe more. I used to run 18 initial on my coupe and I run 25 initial on the Shelby. Adjust the advance curve int the distributor to keep total advance under 38 and all in by 3000 rpm.

 

LMan

Founding Member

Aug 10, 2002

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Mom's basement

Apr 12, 2005

#15

• Apr 12, 2005

• #15

gears. gears. gears.

 

allcarfan

The Answer Man

Founding Member

Apr 8, 2001

2,458

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North Atlanta

Apr 12, 2005

#16

• Apr 12, 2005

• #16

if you dont get it fixed....im going to be in columbus on business for three weeks...leaving this Sunday. Id be more than happy to take a look at it for you.