how many mph's will i be off after my 4.30 gear install??

98blackstallion

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mtn home arkansas

May 23, 2005

#1

• May 23, 2005

• #1

I have a 98 GT 5 speed and I am just wondering how far i am gonna be off stock with my 4.30's that will be installed within the next 2 weeks. I figure like 15mph what do you guys think?

 

E

Erskine

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Sep 11, 2004

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Detriot

May 23, 2005

#2

• May 23, 2005

• #2

alot

 

98blackstallion

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mtn home arkansas

May 23, 2005

#3

• May 23, 2005

• #3

i think i have 3.27's in the rear right now.

 

Give Me TP

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Republic of Texas

May 23, 2005

#4

• May 23, 2005

• #4

My estimate is you will show 79 mph when you are actually going 60 mph.

 

J

jimfitzgerald

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May 23, 2005

#5

• May 23, 2005

• #5

4.30/3.27=1.315 You will register 31.5 percent faster than your actual speed. At 60 mph, you will register 79 mph.

 

Give Me TP

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Jun 17, 2004

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Republic of Texas

May 23, 2005

#6

• May 23, 2005

• #6

Same math I used.

If you keep track of your miles driven after changing the gear ratio, you can correct the odometer to the true amount if/when you get a SpeedCal.

 

crazynorwegian

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Nov 6, 2003

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azusa, ca

May 23, 2005

#7

• May 23, 2005

• #7

http://www.corral.net/tech/gearcalc.html


at 65mph your speedo will read 85mph.

 

stangGT97

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Dec 22, 2004

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Boston area, MA

May 23, 2005

#8

• May 23, 2005

• #8

get a new speedo gear to go with your 4.30s and avoid the need for a tuner

 

98blackstallion

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mtn home arkansas

May 23, 2005

#9

• May 23, 2005

• #9

Ok so about 19-20 miles an hour off thanks guys

 

K

kolkid

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Mar 30, 2005

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May 23, 2005

#10

• May 23, 2005

• #10

98blackstallion said:

Ok so about 19-20 miles an hour off thanks guys

Click to expand...

No, i think its more like a 31 % percentage gain not a 20mph gain it wont be like when it shows 20mph ur ganna be going 1mph but it will be true when ur going 60 when it shows 79mph
i dont know if u knew this already but i thought id clear it up anyway

 

J

jimfitzgerald

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May 24, 2005

#11

• May 24, 2005

• #11

kolkid said:

No, i think its more like a 31 % percentage gain not a 20mph gain it wont be like when it shows 20mph ur ganna be going 1mph but it will be true when ur going 60 when it shows 79mph
i dont know if u knew this already but i thought id clear it up anyway

Click to expand...

Right. At 40 mph, you'll indicate 53. At 100 mph, you'll indicate 131.

 

98blackstallion

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mtn home arkansas

May 24, 2005

#12

• May 24, 2005

• #12

ok thanks guys I just needed to know that.