4.77 track data
10-31-2019, 07:47 AM
#11
I know this is a track focussed topic, but I have 2 questions.
1. I know the 4.77 is a track based decission, but can anyone who drove a 4.77 actually tell me how it feels compared to stock on na stock engine? In other words, does it feel like a lot more power when you put your foot down or only a minor power improvement?
2.
Does anybody know the part number of the Kia 4.77 final drive gears? Or another way to source them? Kia itself cannot find the part just by asking for the 4.77 sportage diff final drive!
Kia and its dealers cannot find this part without a chassis number or car specific details!
Any help is welcome. Based in Europe.
1. I know the 4.77 is a track based decission, but can anyone who drove a 4.77 actually tell me how it feels compared to stock on na stock engine? In other words, does it feel like a lot more power when you put your foot down or only a minor power improvement?
2.
Does anybody know the part number of the Kia 4.77 final drive gears? Or another way to source them? Kia itself cannot find the part just by asking for the 4.77 sportage diff final drive!
Kia and its dealers cannot find this part without a chassis number or car specific details!
Any help is welcome. Based in Europe.
11-01-2019, 01:42 PM
#12
I know this is a track focussed topic, but I have 2 questions.
1. I know the 4.77 is a track based decission, but can anyone who drove a 4.77 actually tell me how it feels compared to stock on na stock engine? In other words, does it feel like a lot more power when you put your foot down or only a minor power improvement?
.
1. I know the 4.77 is a track based decission, but can anyone who drove a 4.77 actually tell me how it feels compared to stock on na stock engine? In other words, does it feel like a lot more power when you put your foot down or only a minor power improvement?
.
From 30mph, 4.77 @ 7100rpm in 1st, 4.10 @ 6100rpm in 1st, advantage 4.77 (~30hp)
From 40mph, 4.77 @ 6100rpm in 2nd, 4.10 @ 8100rpm in 1st, advantage 4.10 (~45hp)
From 50mph, 4.77 @ 7700rpm in 2nd, 4.10 @ 6600rpm in 2nd, advantage 4.77 (~25hp)
From 60mph, 4.77 @ 6700rpm in 3rd, 4.10 @ 7900rpm in 2nd, advantage 4.10 (~30hp)
etc.
11-01-2019, 01:53 PM
#13
100% depends on what speed you're starting from.
From 30mph, 4.77 @ 7100rpm in 1st, 4.10 @ 6100rpm in 1st, advantage 4.77 (~30hp)
From 40mph, 4.77 @ 6100rpm in 2nd, 4.10 @ 8100rpm in 1st, advantage 4.10 (~45hp)
From 50mph, 4.77 @ 7700rpm in 2nd, 4.10 @ 6600rpm in 2nd, advantage 4.77 (~25hp)
From 60mph, 4.77 @ 6700rpm in 3rd, 4.10 @ 7900rpm in 2nd, advantage 4.10 (~30hp)
etc.
From 30mph, 4.77 @ 7100rpm in 1st, 4.10 @ 6100rpm in 1st, advantage 4.77 (~30hp)
From 40mph, 4.77 @ 6100rpm in 2nd, 4.10 @ 8100rpm in 1st, advantage 4.10 (~45hp)
From 50mph, 4.77 @ 7700rpm in 2nd, 4.10 @ 6600rpm in 2nd, advantage 4.77 (~25hp)
From 60mph, 4.77 @ 6700rpm in 3rd, 4.10 @ 7900rpm in 2nd, advantage 4.10 (~30hp)
etc.
11-01-2019, 02:16 PM
#14
Nope, acceleration is directly related to the POWER you're making, that's the metric to go by.
Torque only gives scaleable acceleration results *if you are in the same gear*. With power, it's directly comparable whatever different gears the cars are in.
Feel free to work it out!
But basically thrust at the wheels is horsepower divided by speed. If you go by torque, you have to multiply by transmission ratio, diff ratio, and divide by tire radius to get thrust at the wheels.
Example, at 40mph (58.7 ft/s):
4.77-geared car making 140whp at 6100rpm, 4.10-geared car making 195hp at 8100rpm
1hp = 550 ft-lb/sec
Thrust at the contact patch:
4.77-geared car = (140whp * 550 ft-lb/s) / (58.7 ft/s) = 1312 lb. of thrust for acceleration
4.10-geared car = (195whp * 550 ft-lb/s) / (58.7 ft/s) = 1827 lb. of thrust for acceleration
Simple!
Or you could do it the hard way using torque * gear ratio * diff ratio / tire radius to get the same results:
4.77-geared car making 120.5 lb-ft @ 6100rpm (= 140hp) in 2nd gear:
120.5 lb-ft * 2.37 * 4.77 / ((25"/2)/12in/ft) = 1308 lb. thrust
4.10-geared car making 126.4 lb-ft @ 8100rpm (= 195hp) in 1st gear:
126.4 lb-ft * 3.63 * 4.10 / ((25"/2)/12in/ft) = 1806 lb. thrust
Close enough, if you get the relationship between speed and rpm and working tire radius correct it will equal the results from whp*550/speed in ft/s exactly.
Torque only gives scaleable acceleration results *if you are in the same gear*. With power, it's directly comparable whatever different gears the cars are in.
Feel free to work it out!
But basically thrust at the wheels is horsepower divided by speed. If you go by torque, you have to multiply by transmission ratio, diff ratio, and divide by tire radius to get thrust at the wheels.
Example, at 40mph (58.7 ft/s):
4.77-geared car making 140whp at 6100rpm, 4.10-geared car making 195hp at 8100rpm
1hp = 550 ft-lb/sec
Thrust at the contact patch:
4.77-geared car = (140whp * 550 ft-lb/s) / (58.7 ft/s) = 1312 lb. of thrust for acceleration
4.10-geared car = (195whp * 550 ft-lb/s) / (58.7 ft/s) = 1827 lb. of thrust for acceleration
Simple!
Or you could do it the hard way using torque * gear ratio * diff ratio / tire radius to get the same results:
4.77-geared car making 120.5 lb-ft @ 6100rpm (= 140hp) in 2nd gear:
120.5 lb-ft * 2.37 * 4.77 / ((25"/2)/12in/ft) = 1308 lb. thrust
4.10-geared car making 126.4 lb-ft @ 8100rpm (= 195hp) in 1st gear:
126.4 lb-ft * 3.63 * 4.10 / ((25"/2)/12in/ft) = 1806 lb. thrust
Close enough, if you get the relationship between speed and rpm and working tire radius correct it will equal the results from whp*550/speed in ft/s exactly.
11-01-2019, 04:30 PM
#15
If you're shaving tenths against some close TT/Race competitors watch out for lots of extra shifting.
Our local guys are beating each other by less than 0.1 and if you add a bunch of shifts anyone with detailed data will show you each shift looses you time.
Our local guys are beating each other by less than 0.1 and if you add a bunch of shifts anyone with detailed data will show you each shift looses you time.
11-02-2019, 07:23 AM
#16
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I know this is a track focussed topic, but I have 2 questions.
1. I know the 4.77 is a track based decission, but can anyone who drove a 4.77 actually tell me how it feels compared to stock on na stock engine? In other words, does it feel like a lot more power when you put your foot down or only a minor power improvement?
2.
Does anybody know the part number of the Kia 4.77 final drive gears? Or another way to source them? Kia itself cannot find the part just by asking for the 4.77 sportage diff final drive!
Kia and its dealers cannot find this part without a chassis number or car specific details!
Any help is welcome. Based in Europe.
1. I know the 4.77 is a track based decission, but can anyone who drove a 4.77 actually tell me how it feels compared to stock on na stock engine? In other words, does it feel like a lot more power when you put your foot down or only a minor power improvement?
2.
Does anybody know the part number of the Kia 4.77 final drive gears? Or another way to source them? Kia itself cannot find the part just by asking for the 4.77 sportage diff final drive!
Kia and its dealers cannot find this part without a chassis number or car specific details!
Any help is welcome. Based in Europe.
https://www.ebay.com/itm/OEM-Genuine...-/152534506704
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