Help me pick 'the right' gear ratio...
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From: Waco, TX
Help me pick 'the right' gear ratio... I hate 'which is best' questions, but I've cornered myself in to a bit of a conundrum, and need a tad bit of sage advice.
I've got a 6-speed 98Z. I'm going to be buying a rear end in January (still haven't decided 12-bolt or 9-inch). My long term plan (next summer/fall, whenever the money tree is ripe) calls for a supercharger (ATI D1-SC) to be bolted on to my existing setup (B1, Grots, etc). My goal is to be trapping at 118-120 mph with this combo (at 3700 ft). For NA performance, I'd bet the 4.10's would be preferable, but...
I have been looking at the calculator at http://www.f-body.org/gears/ - my experience thus far has been A4, I'm just now getting in to this M6 "thing". Running 3.73's with the stock sized tires puts me at 5700-5900 through the traps in fourth (an ooch too low). 4.10's puts me at 6300-6400 (an ooch too high if there's any slip whatsoever).
My plans also call for eventually running 27" tires, which would put 4.10's running 6000-6100 - perfect.
However, I'm seriously thinking that I won't be able to hook with 4.10's, even running a sticky like the Hoosier QTP 27" dia tire.
3.73's seem 'too tall', 4.10's seem 'just right', but I'm not sure about them when combined with the blower.
Does anyone have any thoughts on this?
Ford 9" with 3.90's? <img src="images/icons/grin.gif" border="0">
Thanks,
Andrew
I've got a 6-speed 98Z. I'm going to be buying a rear end in January (still haven't decided 12-bolt or 9-inch). My long term plan (next summer/fall, whenever the money tree is ripe) calls for a supercharger (ATI D1-SC) to be bolted on to my existing setup (B1, Grots, etc). My goal is to be trapping at 118-120 mph with this combo (at 3700 ft). For NA performance, I'd bet the 4.10's would be preferable, but...
I have been looking at the calculator at http://www.f-body.org/gears/ - my experience thus far has been A4, I'm just now getting in to this M6 "thing". Running 3.73's with the stock sized tires puts me at 5700-5900 through the traps in fourth (an ooch too low). 4.10's puts me at 6300-6400 (an ooch too high if there's any slip whatsoever).
My plans also call for eventually running 27" tires, which would put 4.10's running 6000-6100 - perfect.
However, I'm seriously thinking that I won't be able to hook with 4.10's, even running a sticky like the Hoosier QTP 27" dia tire.
3.73's seem 'too tall', 4.10's seem 'just right', but I'm not sure about them when combined with the blower.
Does anyone have any thoughts on this?
Ford 9" with 3.90's? <img src="images/icons/grin.gif" border="0">
Thanks,
Andrew
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From: Troy, AL
Re: Help me pick 'the right' gear ratio... Me? I'd go with the 4.10s and 28" Hoosier slicks.
You may find yourself going faster than you think. Might need the extra growing room...especially if you ever come down closer to sea level.
Say you end up running 128 mph some day. 4.10s and 28" Hoosiers would have you turning 6300 and traction will be MUCH less of an issue with these tires.
You may find yourself going faster than you think. Might need the extra growing room...especially if you ever come down closer to sea level.
Say you end up running 128 mph some day. 4.10s and 28" Hoosiers would have you turning 6300 and traction will be MUCH less of an issue with these tires.
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From: Tullahoma TN
Re: Help me pick 'the right' gear ratio... If you go N/A then get the 4.10s. BUT since you will be getting the supercharger, go with the 3.73s. With the supercharger and 4.10s you will either need to shift into fifth before the traps or run taller tires. 4.10s are much noisier than 3.73s and I would stick with the 12 bolt. The 9 inch is heavy and eats up lots of hp.
Re: Help me pick 'the right' gear ratio... Forget that <img src="images/icons/wink.gif" border="0"> Go with a 28" slick in the 12 bolt with 4.33's <img src="images/icons/tongue.gif" border="0"> <img src="images/icons/shocked.gif" border="0"> <img src="images/icons/smile.gif" border="0"> That'll get up and go <img src="images/icons/wink.gif" border="0">
<img src="images/icons/grin.gif" border="0">
<img src="images/icons/grin.gif" border="0">
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From: Monroe, SD
Re: Help me pick 'the right' gear ratio... the 9" may eat up more power but do you think i will have a problem when i put ove 700rwhp threw it i dont but the 12 bolt i would worry <img src="graemlins/burnout.gif" border="0" alt="[Burnout]" /> but that is me
i run moser 9" 4.10 and a 26" tire i pull 1.7 with stock clutch the cartek is waiting to go in
i run moser 9" 4.10 and a 26" tire i pull 1.7 with stock clutch the cartek is waiting to go in
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From: Waco, TX
Re: Help me pick 'the right' gear ratio... Thanks for the replies, guys. I will be running the 16" ET Streets in the spring (I got 'em for my '94, but it's being de-commissioned as the 'track car' - it's too slow), so about the time the blower goes on, I should be ready for some new tires. My tires will be track-only, so slicks certainly aren't out of the question. It does indeed sound like 4.10's are the route I'll go, so I'll just go bigger tire when I get blown. <img src="images/icons/smile.gif" border="0"> I'm not sure about the 28" ones, though... may require too much wheel well massaging for my tastes...
And I don't really plan on taking this car down to sea level. Once I get it dialed in for high altitude, it wouldn't run very well at sea level. And since I don't have a trailer / tow vehicle, the breakage factor always rears its ugly head. It'd suck to be in Memphis and have to rent a U-haul for the 750 mile drive home...
I don't think I will really go faster than 120 with a blower. I ran 100-101 bone stock (5200 ft DA), I'm expecting about 105-106 NA with the cam and Grots, and then tacking on something like the GWP Stage II ATI system will add a good solid 12-14 MPH or maybe a tad more - but I'll probably only see 6-7 lbs of boost with a 10# pulley.
Thanks again,
Andrew
And I don't really plan on taking this car down to sea level. Once I get it dialed in for high altitude, it wouldn't run very well at sea level. And since I don't have a trailer / tow vehicle, the breakage factor always rears its ugly head. It'd suck to be in Memphis and have to rent a U-haul for the 750 mile drive home...
I don't think I will really go faster than 120 with a blower. I ran 100-101 bone stock (5200 ft DA), I'm expecting about 105-106 NA with the cam and Grots, and then tacking on something like the GWP Stage II ATI system will add a good solid 12-14 MPH or maybe a tad more - but I'll probably only see 6-7 lbs of boost with a 10# pulley.
Thanks again,
Andrew
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Re: Help me pick 'the right' gear ratio... B1, M6, supercharger, and 4.10's and you will for sure need 28" slicks to go thrut the traps in 4th.
I think it depends on how hardcore you want to be.
I have a Moser 9" with 4.10's, Tractech soft locker, 31 spline axles, and Strange nodular iron case. Did a 1.58 on 28" tires so I should do 1.55 or better on 26's next time.
I think it depends on how hardcore you want to be.
I have a Moser 9" with 4.10's, Tractech soft locker, 31 spline axles, and Strange nodular iron case. Did a 1.58 on 28" tires so I should do 1.55 or better on 26's next time.
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From: Troy, AL
Re: Help me pick 'the right' gear ratio... "I'm not sure about the 28" ones, though... may require too much wheel well massaging for my tastes..."
How about none? I only had to alter my wheelwells when I went to 29s.
How about none? I only had to alter my wheelwells when I went to 29s.
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From: Knoxville, TN
Re: Help me pick 'the right' gear ratio... One benefit from the 'big gear/big tire' combo is that you get the extra torque multiplication of the lower gear (4.10 or 4.30 or whatever) AND the extra traction benefit of the taller tire/slick. That is because those taller slicks put more 'meat' on the pavement because of their circumference, and also because they have more sidewall to 'tune'.
Don't fear the gear, dude. <img src="images/icons/smile.gif" border="0"> Good luck to you.
Don't fear the gear, dude. <img src="images/icons/smile.gif" border="0"> Good luck to you.
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From: Melbourne, FL
Re: Help me pick 'the right' gear ratio... I have an automatic with a really loose converter, 28" slicks, and a 4.33 gear. I go through the traps at 6700 or so on a 123mph pass. My converter has tons of slippage compared to a M6 car, which would have virtually none... 4.10's or 4.33's would probably be perfect...
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From: Tullahoma TN
Re: Help me pick 'the right' gear ratio... [quote]Originally posted by AAron:
<strong>the 9" may eat up more power but do you think i will have a problem when i put ove 700rwhp threw it i dont but the 12 bolt i would worry <img src="graemlins/burnout.gif" border="0" alt="[Burnout]" /> but that is me
i run moser 9" 4.10 and a 26" tire i pull 1.7 with stock clutch the cartek is waiting to go in</strong><hr></blockquote>
I have seen many, many a Ford 9" rears explode at the track on cars with less than 700 rwhp. It is not invincible.
<strong>the 9" may eat up more power but do you think i will have a problem when i put ove 700rwhp threw it i dont but the 12 bolt i would worry <img src="graemlins/burnout.gif" border="0" alt="[Burnout]" /> but that is me
i run moser 9" 4.10 and a 26" tire i pull 1.7 with stock clutch the cartek is waiting to go in</strong><hr></blockquote>
I have seen many, many a Ford 9" rears explode at the track on cars with less than 700 rwhp. It is not invincible.
