Where would you shift from looking at my graph?
06-10-2009, 10:34 PM
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Where would you shift from looking at my graph? Stock T-56, 3.42 gears, 265/40 18 tire, other mods below. It's a roots so..... I'm wondering if shifting too late is slowing my E.T.'s. Where would you shift from this?
06-10-2009, 11:36 PM
#3
I'd say around 6300 that way you stay in the sweet spot but it hasn't fallen off. I might even play with shifting at 6500 to see if it falls off or picks up. The curve is pretty flat up there so I don't think you'd see much difference between the two but the car may like one or the other better.
06-10-2009, 11:40 PM
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Yeah, it's pretty torquey, it will blow the mickey's off at the line if I'm not careful. I'm racing at 6800 DA also
I've been consistently improving and making adjustments. The graphs are really similar to what I had NA, just higher. I just can't really feel when the car starts to fall off to feed it another gear so I'm back in the powerband at the best spot. I'm only trapping at about 110-114 at the top of third. I'm thinking if I can get into 4th earlier, I'll be quicker overall.
Should I be hitting fourth in the quarter at all or just finish out in third is my big question I guess? I used to hit 4th occassionaly on a shorter tire.
I've been consistently improving and making adjustments. The graphs are really similar to what I had NA, just higher. I just can't really feel when the car starts to fall off to feed it another gear so I'm back in the powerband at the best spot. I'm only trapping at about 110-114 at the top of third. I'm thinking if I can get into 4th earlier, I'll be quicker overall.
Should I be hitting fourth in the quarter at all or just finish out in third is my big question I guess? I used to hit 4th occassionaly on a shorter tire.
06-10-2009, 11:46 PM
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I'd say around 6300 that way you stay in the sweet spot but it hasn't fallen off. I might even play with shifting at 6500 to see if it falls off or picks up. The curve is pretty flat up there so I don't think you'd see much difference between the two but the car may like one or the other better.
06-11-2009, 04:17 PM
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Wow, all these views and hardly any replies!
Spoke to my mechanic who did the blower and cam install for me, said my peak HP range is between 5800 and 6000. Guess I'll drop the shift light to 5700 and give it hell tomorrow.
Spoke to my mechanic who did the blower and cam install for me, said my peak HP range is between 5800 and 6000. Guess I'll drop the shift light to 5700 and give it hell tomorrow.
06-12-2009, 09:45 AM
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I guess I'm the odd ball. 
Being that your peak power starts at 5500 and basically carries till about 6300where it starts to tail off. If it where me I'd shift around 6500. So that when you go into the next gear you're at or near your peak torque (4500ish). Don't know the ratios of your T56 can you post them?
-Mark
Being that your peak power starts at 5500 and basically carries till about 6300where it starts to tail off. If it where me I'd shift around 6500. So that when you go into the next gear you're at or near your peak torque (4500ish). Don't know the ratios of your T56 can you post them?
-Mark
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06-12-2009, 10:01 AM
#8
Shift at max rpm, or what you would call rev limiter. Increase if the bottom end allows. When you shift the rpms do drop but the higher your are in the rpm curve, when the drop occurs you may end up in a better spot for the next gear.
The big question is from 1-2, 2-3, and 3-4. What does the rpm drop down to on each shift and then correlate it with the graph.
The way I figure it is that with your peak power your not having any drastic drop off and the higher you can go could mean the diff in big power for the next gear and you wont hit any "wall" as you climb back up the curve.
The big question is from 1-2, 2-3, and 3-4. What does the rpm drop down to on each shift and then correlate it with the graph.
The way I figure it is that with your peak power your not having any drastic drop off and the higher you can go could mean the diff in big power for the next gear and you wont hit any "wall" as you climb back up the curve.
06-12-2009, 10:17 AM
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OK I would originally have said 63-6400, but using the calc in my sig, it looks like for the 1-2 shift you would settle into 2nd @ 4300ish RPM (middle of the torque curve but after peak and while it is starting to head down (still pretty flat for a little while), but as HP is on a nice rise), but for the 2-3 shift (shifting @ 6400) it will settle back to 4650ish+ RPMS and torque starts falling off shortly after as the HP raises, then with the 3-4 shift you enter 4th gear at just over 4900 RPM's...
So instead I think you should try to vary your shift points from gear to gear just because of the roots setup...
try 63-6400ish 1-2 shift, 6000ish 2-3 shift, and 5800ish for the 3-4 shift, or if trying for consistancy try both the 2-3 and 3-4 shift @ ~5900ish...
So instead I think you should try to vary your shift points from gear to gear just because of the roots setup...
try 63-6400ish 1-2 shift, 6000ish 2-3 shift, and 5800ish for the 3-4 shift, or if trying for consistancy try both the 2-3 and 3-4 shift @ ~5900ish...
06-12-2009, 12:19 PM
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Thanks for the replies. Two weeks ago I was shifting around 6200, last weekend I went up to 6300 and my MPH dropped, I definitley felt it dropping off on the backend at that RPM with not much time at all to hit 4th. Also, that graph and numbers are corrected while I'm actually racing at over 6800 DA.
I know each gear is different and your shift points are going to be different to maximum forward motion in each gear. I wish I had a dyno run in each gear and could go from there. I've been hearing lots of different things and there are many ways to looks at it but I don't have a shiftlight with multiple settings and cannot watch my tach while doing the quarter.
My rev limiter is set way after peak HP and torque has started to drop off, 6600 I think.
I'm going to lower the shift point to try and get into 4th faster if at all, and take advantage of not just the max HP level, but also try and get into torque before it falls off too much.
I know each gear is different and your shift points are going to be different to maximum forward motion in each gear. I wish I had a dyno run in each gear and could go from there. I've been hearing lots of different things and there are many ways to looks at it but I don't have a shiftlight with multiple settings and cannot watch my tach while doing the quarter.
My rev limiter is set way after peak HP and torque has started to drop off, 6600 I think.
I'm going to lower the shift point to try and get into 4th faster if at all, and take advantage of not just the max HP level, but also try and get into torque before it falls off too much.
