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Discussion Starter #1 (Edited)
Currently running a N/A 347 a 3.73 gear on a 26" et street tire with a T-5 in a 3150 lb. car 93GT. My power starts gradually falling off around 5800 rpm. I currently shift at 5600 rpm and hit the traps around 115mph and 5550 rpm. Im trying to rationalize if it really makes sense to go with 4.10 gears when I switch over to a spool. When I have upped my shift point to 5800 I see no benefit in ET. It looks as if I will hit the traps around 6100 with 4.10's. Does it make sense to swap gears in your opinion and if so ...why?
 

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Discussion Starter #3
Any reason or like the Nike commercial...just do it?
 

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it makes no sense to do it right now.have you ever tried to speedshift 5th??? until you get your motor to rev higher,leave it alone.
 

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Discussion Starter #6
I dont know why I would shift into fifth? Im talking about going from a 3.73 to a 4.10 not the other way around.
 

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don't do it.
 

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If you're going through the traps almost at your shift point now, installing lower gears will make that rpm higher thus the need for another gear with the motor the way it is now. T5s do not like to go into 5th fast plus there is a much bigger difference between 4th and 5th than any other two gears. Also this last shift will happen right at the finish line=something you never want to happen with any car. You must stay in 4th gear or you ET will fall off. The real problem is not being able to go past 5800 or so without power falling off. A 347 is capable of more than that easily depending on how it's set up.
 

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Discussion Starter #10 (Edited)
obviously,you're not the sharpest tool in the shed
Hmmmm, obviously your an ass....hows that Einstein? Listen carefully. I currently dont trap above my useable power range...why would I shift into fifth gear? Now when and if I install the 4.10's I could see your point however dull it may be.. As seen above Im not the only one who thought your reply was...lame. Unless you are being sarcastic which doesnt come through so good on a keyboard.
 

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Discussion Starter #11
If you're going through the traps almost at your shift point now, installing lower gears will make that rpm higher thus the need for another gear with the motor the way it is now. T5s do not like to go into 5th fast plus there is a much bigger difference between 4th and 5th than any other two gears. Also this last shift will happen right at the finish line=something you never want to happen with any car. You must stay in 4th gear or you ET will fall off. The real problem is not being able to go past 5800 or so without power falling off. A 347 is capable of more than that easily depending on how it's set up.

Yes I understand, my cam is a bit smallish due to having to pass emissions checks back in the day. I would never want to set my car up to shift into 5th gear as some suggest due to the reasons you just mentioned. I have been told by some that I may still see a slight advantage to the 4.10s even before I make a cam switch due to my car weight. Thanks for your reply.
 

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I would find the reason for the lack of upper RPM power first. The combination could have simply been designed that way. More RPM doesn't always make you go faster.

What does Ed say?
 

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Hmmmm, obviously your an ass....hows that Einstein? Listen carefully. I currently dont trap above my useable power range...why would I shift into fifth gear? Now when and if I install the 4.10's I could see your point however dull it may be.. As seen above Im not the only one who thought your reply was...lame. Unless you are being sarcastic which doesnt come through so good on a keyboard.
in my first post i said dont do it. asking if you had ever tried to speedshift 5th was a rhetorical question meaning its damn near impossible and when you do finally get it in,it bogs the hell out of the motor.i wasn telling you to try it with your current setup,which is almost perfect as your crossing the traps at or near the top of your usable rpm range. i thought it was obvious that i was saying if you switched to 4.10's and ran the same mph or faster,you would have no option except to shift to 5th.hence,why i said dont do it.maybe my sarcasm and the extra question marks didnt come through as intended.on my second post,i was being an ass because i didnt know what the hell you were trying to say.go back and read my 1st post again and you should see where i was coming from
 

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Discussion Starter #14
in my first post i said dont do it. asking if you had ever tried to speedshift 5th was a rhetorical question meaning its damn near impossible and when you do finally get it in,it bogs the hell out of the motor.i wasn telling you to try it with your current setup,which is almost perfect as your crossing the traps at or near the top of your usable rpm range. i thought it was obvious that i was saying if you switched to 4.10's and ran the same mph or faster,you would have no option except to shift to 5th.hence,why i said dont do it.maybe my sarcasm and the extra question marks didnt come through as intended.on my second post,i was being an ass because i didnt know what the hell you were trying to say.go back and read my 1st post again and you should see where i was coming from
Thanks for explaining that. I got it. Sounds like if I change gears now while I have it apart I can expect nearly the same et's or worse. I realize I need a more aggressive cam profile and after changing cams I may see an advantage to the 4.10's if my power band raises up say 300 or so rpm?
 

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If power "gradually" starts dropping off at 5800, the 4.10's should still benefit you. If it flattens out at 5600-5800, then you'll probably slow down or stay the same. If the car hooks well, your 60 fts may improve with the 4.10s possibly helping out with ET.
 

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I also have a 347 but with a T-56. I just switched my gears from 4.10's to 3.73's. But I also shift at around 6200. I have noticed quite a difference with the new gears and will test them at the track soon. Keep the 3.73's if you ask me.
 

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If power "gradually" starts dropping off at 5800, the 4.10's should still benefit you. If it flattens out at 5600-5800, then you'll probably slow down or stay the same. If the car hooks well, your 60 fts may improve with the 4.10s possibly helping out with ET.
That was my reasoning, I just didn't feel like typing it out. I was thinking more of in the first part of the track rather than the last.
 
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