for 4.44? my car has j's racing 4.44's and runs at around or just a little bit above 3500rpm at 100kmph in 6thQuote:
Originally Posted by zhong
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for 4.44? my car has j's racing 4.44's and runs at around or just a little bit above 3500rpm at 100kmph in 6thQuote:
Originally Posted by zhong
To calculate 4.44 gears revs, you multiply by 1.16.
Cheers.
Just happened to remember it since I only read that in an archived thread on s2ki the night before I posted that. lol.
Actually that's incorrect; with the 4.44 FD, you need to use a multiplier of 1.08(29). The figure of 1.16 you've quoted is needed when making calculations with the 4.77 FD.Quote:
Originally Posted by ludecrs
Dammit!
Memory not so good. lol.
+rep Mikey.
Lol :thumbsup:
Then what does a stock Final Gear run RPM on 100km/h in 6th?
Theoretically, it's about 3,261rpm in 6th using stock gearing, however with friction and wind resistance it's realistically about 3,500rpm.
excuse my ignorance if im missing something here, but how would wind resistance and friction cause a change in mechanical gearing? roadspeed and engine speed should be directly linked through gear ratios, right? if roadspeed is staying at 100km/h but revs are at 3500rpm instead of 3261rpm, doesn't some part of the driveline have to absorb those extra revs? :confused:
That's a good question. Basically, there are effeciency losses throughout the system from things such as slip and friction. To do the calculations, I essentially, multiply RPM by gear ratio by rotations/km based on tyre geometry. Unfortunately, this doesn't account for effeciency losses. These losses are beyond my capability to measure, but I have estimated them based on some testing which have worked out to be fairly accurate with 4.10, 4.56, and 4.57 FD ratios.
Ahh I see. I guess it didn't make sense in my head because I imagined a similar scenario with a bike - ie. if you're riding at a constant speed means your feet are turning the pedals at a certain rpm, but if you're riding into a strong wind at the same speed your feet don't need to turn the pedals faster, just harder. Given that you've done practical testing I guess slip has a something to do with it. Thanks :)