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Senior Member
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Discussion Starter · #1 ·
I am deciding on gears this week. With a T 5 speed what are you tac 'n at 55. Any regrets?
Should I go higher? Off the line satisfactory?

Thanks

Henry
 

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I have a 3550 tremec and tach about 2500 in fith gear at 55 if that helps
 

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I have a T-5 with 3.55 rear gear and tach 2000 rpms at 70 MPH in 5th gear.
 

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About 2200 @ 65 in 5th with 3.73, T5 and 275-45/R17.
 

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at 3000 I am at 100mph in 5th - but then I could not get my speedo to report perfectly with the 3:73 speedo cog - it always seemed to be reading too fast so I ended up using a 4:10 speedo cog - hmmm - maybe it was correct.
 

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Oh, I have 295 50R's.
 

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Henry,
Here's what your set-up looks like. 2300 RPM at 70. That's pretty good for cruizing. At 1800 RPM it will lug at 55mph in 5th unless you are running a diesel. You would need to shift to 4th to accel.
Your tranny has a pretty low first, so that gear will not be very usefull with a 3.73 diff. Redline at 35 mph is pretty low. If you are thinking of quarter mile runs, you should think of 2nd gear starts.


You can make 1st gear useful with a 3.27 diff. but 5th is pretty useless unless you are going 80 or so.


There's no one good solution for a T5 since the ratios are so wide. Pick your poison. The 3.73 gives you gears 2-5. The 3.27 gives you 1-4 useful. You pretty much need to go to a closed ratio TKO road race tranny to get all of the gears to work. Here's what it looks like with a 3.55


HTH,
Pete
 

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Oh, on 15 inch rims. blah blah blah
 

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Henry at 55mph I'm right about 1800-1900 rpm. 2000 [email protected] 60mph. I have 17"'s. First gear with either 355's or 373's will seem to short for these light wt. cars.
Engine combo is a factor when looking at what gears to run. Stock engine will benifit from the 373's,as will the 355's if used. Really not a huge difference between these two ratios if you have the chance to drive them back to back. I can hardly notice any difference in first gear when driveing cars with these two ratio's. Most noticable difference is when in 3rd and 4th gears between the two ratio's.
 

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Pete,

That's an excellent spreadsheet you have there. Any chance of you sending it to me in a PM? I could play with that thing all day!!!

Eric
 

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I am exactly the same as gbranham with my Mark III. I have a 302 with T-5.
 

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Discussion Starter · #15 ·
Thanks all. I guess 373 is a safe number 410s too low. I just want to make sure I can give an impression off the line. Lots of lights in Los Angeles and Corvettes and Vipers to roust!

Henry
 

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FFCobra Craftsman
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Pete beat me to it. After a long question on this a few years back I went with the TKO road race, 373's backing up the 418w 1,800 at 55 in 5th but the torque of the 418 saves the down shift if I need to go go go..
 
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