Drag Racers: Optimum gearing suggestion
#2
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Your ET is most affected in the first 60ft.
Figure out what MPH and RPM you want to be at... and gear the car accordingly.
If my motor lays over at 7500RPM... I'll want to cross the finish line at 7499.
Tire diameter, RPM (assuming 1:1 trans gear) and MPH will dictate what rear gears to use. It's just Math.
Here's a cool calculator I like to use...
http://www.race-cars.net/calculators...alculator.html
Figure out what MPH and RPM you want to be at... and gear the car accordingly.
If my motor lays over at 7500RPM... I'll want to cross the finish line at 7499.
Tire diameter, RPM (assuming 1:1 trans gear) and MPH will dictate what rear gears to use. It's just Math.
Here's a cool calculator I like to use...
http://www.race-cars.net/calculators...alculator.html
#5
So if peak hp is @6700 and stays flat and keep pulling to 7200 rpm before it starts to lay down, that would be the optimum rpm to be at the traps? Also, would 400rpm above peak hp considered optimum shift points as well? I apologize with all the questions.
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Butch, your in the same boat I'm in.4.30 seems to be about right. I go threw the traps at about 6,000 now with my 4.10's and will be close to 6,400 with the 4.30
remember though stepping up the gear will essentially tighten up your converter. something to think about.
remember though stepping up the gear will essentially tighten up your converter. something to think about.
#10
Jeff, according to my calculations with the times on your sig, you should have been crossing the line @6289 rpm. With 4.30 gearing, you will be at about 6600 rpm at the traps. Have you done any weight reduction on the car? It's very impressive for a full weight car running those times.
#11
Man it seems like there has been a ton of gearing threads lately. I can tell you its way easier if you've got a Lenco. We had a motor that made peak at like 6200 but it would fall off if you shifted it lower than 8K. Everybody's stuff is different. You look like you're hauling *** where ever your shifting now. Fast car man!
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Jeff, according to my calculations with the times on your sig, you should have been crossing the line @6289 rpm. With 4.30 gearing, you will be at about 6600 rpm at the traps. Have you done any weight reduction on the car? It's very impressive for a full weight car running those times.
Power to Weight Ratio: 6.70
60 Foot E.T. : 1.53
1/8 Mile E.T. : 6.93
1/8 Mile Trap Speed : 98.11
1/4 Mile E.T. : 10.98
1/4 Mile Trap Speed : 122
1/4 Mile Trap RPM : 6,009
#13
Butch, I use the wallace racing caculator and it's dead on for my car except the sixty foot. I haven't done any real weight reduction but I'm starting to now as we speak.
Power to Weight Ratio: 6.70
60 Foot E.T. : 1.53
1/8 Mile E.T. : 6.93
1/8 Mile Trap Speed : 98.11
1/4 Mile E.T. : 10.98
1/4 Mile Trap Speed : 122
1/4 Mile Trap RPM : 6,009
Power to Weight Ratio: 6.70
60 Foot E.T. : 1.53
1/8 Mile E.T. : 6.93
1/8 Mile Trap Speed : 98.11
1/4 Mile E.T. : 10.98
1/4 Mile Trap Speed : 122
1/4 Mile Trap RPM : 6,009
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I didn't think you were crossing the traps at only 6000. I know your stroker is gotta be making its maximum peak power at 65-6700 rpm, maybe a little higher. So you do have to gear it accordingly and be at your maximum power at top end of the track. Jeff, with more weight out, I think you still have plenty on the table. 10.4's, 10.5's easily.
Butch, I don't know about 10.40's but I think once I get it down to 3,300 and put the spool and 4.30's in it will go 10.60's pretty sure.
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I'm going to run Extreme street again this year so I can only lose 150lbs to get down to min weight. Then next year lose another 100lbs and go to aftermarket ecu, singleplane and a solid roller then run Mod.
Funds permitting of course.
Funds permitting of course.
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since im running 3.73s, I wonder if I switch to 4.10s if Ill still have enough gear for nitrous passes.
Jeff if your running a lose 4500 converter and going through the gates at 6000, I would THINK id have room to push to 6800 with 4.10s but I dont know what MPH that would put me at. Is there any good way to calculate for this?
Jeff if your running a lose 4500 converter and going through the gates at 6000, I would THINK id have room to push to 6800 with 4.10s but I dont know what MPH that would put me at. Is there any good way to calculate for this?
#18
since im running 3.73s, I wonder if I switch to 4.10s if Ill still have enough gear for nitrous passes.
Jeff if your running a lose 4500 converter and going through the gates at 6000, I would THINK id have room to push to 6800 with 4.10s but I dont know what MPH that would put me at. Is there any good way to calculate for this?
Jeff if your running a lose 4500 converter and going through the gates at 6000, I would THINK id have room to push to 6800 with 4.10s but I dont know what MPH that would put me at. Is there any good way to calculate for this?
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since im running 3.73s, I wonder if I switch to 4.10s if Ill still have enough gear for nitrous passes.
Jeff if your running a lose 4500 converter and going through the gates at 6000, I would THINK id have room to push to 6800 with 4.10s but I dont know what MPH that would put me at. Is there any good way to calculate for this?
Jeff if your running a lose 4500 converter and going through the gates at 6000, I would THINK id have room to push to 6800 with 4.10s but I dont know what MPH that would put me at. Is there any good way to calculate for this?
Like Butch said, if I hit my car with a 150 shot it would cross between 6500 6600 at somewhere around 133mph.
http://www.wallaceracing.com/accel-calc.php