This is topic 3.73s VS 2.73s how much different? in forum Tech Talk at Northern California Ford Owners  .


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Posted by KCmustangboy (Member # 1927) on :
 
What kind of 1/4 mile time change can I see here? I have 2.73s I am running a 2.35 60ft and ET at 14.58@ 95.8 With the 3.73s how much change should I see? Thanks for the help guys.
Casey
 

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Posted by street_illegal_stang (Member # 1554) on :
 
at least 3-5 tenths
everyone is gonna say its probably the best mod you can do is gears
 

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Posted by PeNiNsula302 (Member # 1061) on :
 
night and day, it really wakes up the car, i love my 3:73's ... As for the times, well as far as i know its goot for like 3-5 tenths, but im not sure on that one. It all comes down to the driver, how many runs have you had with your 2:73's? With some sticky tires, pullies, and gears you can pull some serious 60 ft's and break into the 13's...
 

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Posted by street_illegal_stang (Member # 1554) on :
 
right on ...that was cool..we both though of the same thing at the same time
 

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Posted by PeNiNsula302 (Member # 1061) on :
 

quote:

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Originally posted by street_illegal_stang:
right on ...that was cool..we both though of the same thing at the same time

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great minds think a like, hehehe
 

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Posted by KCmustangboy (Member # 1927) on :
 
Well I have headers and X pipe and Pullies. My 60fts aren't great but its tough with 17s and 2.73s. But I know I need to get better as a driver. Still I know I have room for at least one tenth in my 60ft now. Are the gears really worth 5 tenths?? that is amazing to me lol I am in a vert Gt and its not the quickest but I am having fun getting there.
 

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Posted by MRBiggs (Member # 513) on :
 
You sure your t-lok doesn't need to be rebuilt ? I run 17s at the drags and I used to pull 2.2 - 2.3x 60 fts because I had the dreaded "one wheel peel" going on...

After I got it fixed and had the 3.73s put in and learned how to launch the car again... 2.0x were the norm.
These days I'm seeing 1.95s on the average almost every run.
 

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Posted by st5150 (Member # 51) on :
 

quote:

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Originally posted by KCmustangboy:
What kind of 1/4 mile time change can I see here? I have 2.73s I am running a 2.35 60ft and ET at 14.58@ 95.8 With the 3.73s how much change should I see? Thanks for the help guys.
Casey

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3.73's and a set of drag racing tires will put you into the 13's
 

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Posted by andyman_2k01 (Member # 1448) on :
 
i had 3.27's and put in the 3.73's and it was a huge difference. you will definetly notice a difference not only in performance but in E/T's too. i highly suggest the gear change.
 

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Posted by street_illegal_stang (Member # 1554) on :
 
maybe you should gets some flow bastard mufflers dumped of course and bump up your timing to like 15 degrees and get a 70 mm mass air meter to go with those pullies and maybe some better tires too.
a 5.0 shouldn't run 14's...with all do respect,thats kinda weak-no it is weak . work on your lanches..stock i would hold the rpm's to like 1700 and kinda ride the clutch so you don't break traction
1st run it up to 5400-37mph
2nd 5200-62mph
3rd 4900-85mph
4th 5150-115mph

oh these numbers where on my car(3:08) peg legged
manage to run low 13's on comp ta's zr rated
but it really shouldn't make to much differnce
"2:73-3:08"
you did read my post right?

[ February 26, 2003, 01:33 AM: Message edited by: street_illegal_stang ]
 

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Posted by 91 5.0 (Member # 1527) on :
 

quote:

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Originally posted by st5150:

quote:

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Originally posted by KCmustangboy:
What kind of 1/4 mile time change can I see here? I have 2.73s I am running a 2.35 60ft and ET at 14.58@ 95.8 With the 3.73s how much change should I see? Thanks for the help guys.
Casey

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3.73's and a set of drag racing tires will put you into the 13's

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13's with a 95.8 trap? That takes one hell of a driver, slicks and a hard ass launch.

[ February 25, 2003, 07:25 AM: Message edited by: 91 5.0 ]
 

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Posted by PseudoCobra (Member # 1689) on :
 
3.73's are nice but 4.10's would probably work even better since you really don't have too much on that car. If you plan on doing a lot more than 3.73's is probably a good idea and you'll notice a world of difference. Bump that timing up and get some stickies on it, and make sure your not doing any one leggers if so get that t-lock fixed then you should be in 13's easy. I love my 4.10's and you can see my list of mods, very similar. DOn't have any times with all these mods but I can tell you it helped out a whole shit load.
 

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Posted by Chosen1 (Member # 1906) on :
 
I have a set of 4.10's for sale...
 

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Posted by st5150 (Member # 51) on :
 

quote:

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Originally posted by 91 5.0:
13's with a 95.8 trap? That takes one hell of a driver, slicks and a hard ass launch.

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He should be running 98 mph when he goes from 2.73's to 3.73's..... and 5.OBrian ran 13.9@96 mph with his stock 5.O on street tires
 

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Posted by KCmustangboy (Member # 1927) on :
 
So I am getting a lot of comments and thanks for the advice everyone. I am farely new at this. I am going with the 3.73s for sure. Another question, I am always traping about 95.8 or 95.7 at the lowest. Will my trap speed be the same with the 3.73s if not how much higher? Also When I lauch I just go from 900rpm or 1000 and try and not brake traction but I find myself either letting the clutch out to fast and spinning the tires or I lug the motor down real hard to like 400 rpm then it pulls from there. Should I try adding more rpms or what? thanks for the advice everyone.
 

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Posted by PeNiNsula302 (Member # 1061) on :
 

quote:

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Originally posted by KCmustangboy:
[QB]Should I try adding more rpms or what?QB]

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quote:

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Originally posted by street_illegal_stang:
maybe you should gets some flow bastard mufflers dumped of course and bump up your timing to like 15 degrees and get a 70 mm mass air meter to go with those pullies and maybe some better tires too.
a 5.0 shouldn't run 14's...with all do respect,thats kinda weak-no it is weak . work on your lanches..stock i would hold the rpm's to like 1700 and kinda ride the clutch so you don't break traction
1st run it up to 5400rpm-37mph
2nd 5200rpm-62mph
3rd 4900rpm-85mph
4th 5150rpm-115mph

oh these numbers where on my car(3:08) peg legged
manage to run low 13's on comp ta's zr rated
but it really shouldn't make to much differnce
"2:73-3:08"

you did read my post right?

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[ February 26, 2003, 01:37 AM: Message edited by: street_illegal_stang ]
 

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Posted by KCmustangboy (Member # 1927) on :
 
Yes I read the post thanks for the advice. only problem is feathering my Spec clutch with 2.73s is not easy, I either lug out the motor or break traction. Also when I hit the traps I am in 3rd gear at 4700rpms and 95 to 96 mph. So no need to use 4th. I am gettting the 3.73s this week and I guess I am going to rearend specialists unless someone else can do it. cough cough drew cough
 

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Posted by rob (Member # 50) on :
 
for the best ET/MPH, if you have to shift to 4th before the stripe, shift before you enter the traps so you are accelerating all the way thru the last 66 ft.
 

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Posted by 87 Saleen (Member # 1549) on :
 
I just ordered my 3.73's a couple days ago and I already love them.

They get here tomorrow
Should be in tomorrow too.
 

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Posted by rokcrln (Member # 2536) on :
 


[ March 04, 2003, 05:00 AM: Message edited by: rokcrln ]
 

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Posted by rokcrln (Member # 2536) on :
 
Also I have not checked the diff cover yet but as far as gears my 91GT is good for
1st 40mph
2nd 83mph
3rd 110mph
4th and 5th no idea untill the tires are replaced and car is aligned so what does it sound like I have stufed in their for gears? 2.73/3.08?
 

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Posted by KCmustangboy (Member # 1927) on :
 
sounds like the same as me, 2.73s They are killers on the track, no get up and go. 3.73s will be in next week I am hoping!
 

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Posted by KCmustangboy (Member # 1927) on :
 
3.73s are going in right now see you all next wednesday...I expect to be all over the place with no traction so look out!
 

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Posted by st5150 (Member # 51) on :
 
rokcrln- Check the drivers side door tag. Tell us what it says under the "AX" table. It should be a single letter like A, M or Z.
 

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Posted by rokcrln (Member # 2536) on :
 
st5150~ It is an M under the ax table!
 

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Posted by KCmustangboy (Member # 1927) on :
 
M code is a 2.73 rearend with limited slip
 

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Posted by jmcclesk (Member # 1355) on :
 
I have a rebuilt diff do you need it
 

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Posted by rokcrln (Member # 2536) on :
 
How much and give some info on it!
 

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