best gear for 1/8 mile & a4?? shifting about 100ft from line with 3.73
#1
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best gear for 1/8 mile & a4?? shifting about 100ft from line with 3.73
Current combo is in sig. Heads and cam are laying here waiting to go on soon as suspension is sorted out but I'm worried about my gear choice.
Last year I had a 2.73 and ran through the 1/8 in 2nd pulling hard. This year with the 3.73/tp4400 combo I shift to 3rd at about the 550 mark....just guessing.
As you can see the new cam is prety large....any chance I can drag it out and run through in 2nd??
If not should I go a little lower and shift sooner or go a little higher so I could for sure run it through in 2nd. Or should I just stop worrying and run the 3.73?
Hey Chris....your running this cam. What are you shifting at and what gear are you running??
Last year I had a 2.73 and ran through the 1/8 in 2nd pulling hard. This year with the 3.73/tp4400 combo I shift to 3rd at about the 550 mark....just guessing.
As you can see the new cam is prety large....any chance I can drag it out and run through in 2nd??
If not should I go a little lower and shift sooner or go a little higher so I could for sure run it through in 2nd. Or should I just stop worrying and run the 3.73?
Hey Chris....your running this cam. What are you shifting at and what gear are you running??
#2
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Re: best gear for 1/8 mile & a4?? shifting about 100ft from line with 3.73
What height tire? I think you'll need AT LEAST 28" tires to run through the traps in 2nd gear with those gears at your current trap speed. That would put you at about 6900 taking into consideration a converter efficiency of about %95. I don't think you want to spin that high. 29s would get you closer but they do require some trimming to make fit.
So, going to a 3.42 gear would allow you to cross in 2nd even with 26.2" tires. That would be about 6670 RPM.
But...your off the line performance would suffer a bit. I think you'de be better off staying with your 3.73s and shifting into 3rd than running 3.42s and crossing in 2nd.
What would be the ultimate 1/8 mile gear? (Probably not what you'de want to put up with on the street!) How about a 5.88 gear with 29" slicks? <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> You could cross at about 6650 RPM in 3rd. <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />
But all of this is assuming your current trap speed which is surely to go up so...
IMO, about the most gear you would want to run on the street with an A4 is 4.10s which would put you at about 5450 RPM assuming a trap speed of 96 MPH and stock height tires. Would the gain by going from 3.73s to 4.10s be worth the cost and the drop in streetability? That's up to you but there are probably other areas the money could be better spent. <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />
<small>[ June 04, 2002, 02:39 PM: Message edited by: Colonel ]</small>
So, going to a 3.42 gear would allow you to cross in 2nd even with 26.2" tires. That would be about 6670 RPM.
But...your off the line performance would suffer a bit. I think you'de be better off staying with your 3.73s and shifting into 3rd than running 3.42s and crossing in 2nd.
What would be the ultimate 1/8 mile gear? (Probably not what you'de want to put up with on the street!) How about a 5.88 gear with 29" slicks? <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> You could cross at about 6650 RPM in 3rd. <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />
But all of this is assuming your current trap speed which is surely to go up so...
IMO, about the most gear you would want to run on the street with an A4 is 4.10s which would put you at about 5450 RPM assuming a trap speed of 96 MPH and stock height tires. Would the gain by going from 3.73s to 4.10s be worth the cost and the drop in streetability? That's up to you but there are probably other areas the money could be better spent. <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />
<small>[ June 04, 2002, 02:39 PM: Message edited by: Colonel ]</small>
#3
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Re: best gear for 1/8 mile & a4?? shifting about 100ft from line with 3.73
Thanks Colonel....
Looks like it will 3.73's for life.....cause I do run a 26" tire.
Thanks.
Looks like it will 3.73's for life.....cause I do run a 26" tire.
Thanks.