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I've been looking at Ben's gearbox tunings with much interest, so let's start with a quote of him in his resto thread:
I've been driving an F20C3.42 for a while and never liked it much because the 1st gear was so darn heavy the car was hard to get in motion. Then after a while needed to replace the engine and got my hands on an F18+C3.45 and even though the differences are not that dramatic it's a pretty nice gearbox.
Now I have done a big resto on the car and made it much more silent other sounds start to irritate me a bit. Right now when I drive the motorway at 120Kmh (about 75Mph) in 5th gear I get around 3760 rpm and at that rate the engine does start to become a little bit noisy again. I cabn imagine it'll irritate me a lot on longer drives. So I've been looking at all the gearbox ratios and done some math and saw some boxes that bring it down to around 3000 rpm, some at 3200/3300-ish...
I've used this online calculator:http://www.csgnetwork.com/multirpmcalc.html
And this website as a reference for the box ratios:
I've seen there are two versions of F16 and the version 1 will have the heavy 1st gear again, the version 2 a considerably lighter 1st as I've had so far. F16 boxes also come nicely cheap... Though how can I distinguish the 1st or 2nd version?? Any way to tell the ratios without having to try it out? For instance marking the input shaft and a drive shaft and then spinning it counting the revolutions??
So I've looked at my options and wondered what you guys think?
Also many say the F28 box isn't any good on a C20XE as it would not be able to spin it round efficiently, but looking at the ratios the 6th isn't very much different from many WR boxes and the 1st is still nicely light.
Could also open up the F18 and place an F16 final ratio in of 3.55 and swap the 5th gear for the 0.707....
Originally posted by BenH
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I was looking at the box I got with the replacement engine today, just to see what I had..
F18W with 3.94 final drive! Proper result and the hydro release bearing should fit a f16/20 ect if I go down that route in the future.
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
So came up with a plan, strip the f18 for the final drive and 5th gear. Then mix it up with a spare F20 I had, I'd not wanted to strip my 'good' F16 just in case I need a spare but the F20 was untested as it's not from one of my cars.
So pulled out the diff then popped off the 5th gear cluster, I needed to put a little tension with a puller then heated the gear gently with the oxy set it made a pop and slid off.
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
Then pulled out the cluster the F18 is next to my spare F16C cluster in the pic, just to check if they looked the same. I gave it a check over and it all looked good so stripped that down.
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
Then did the same on the spare F20, that too looked good if not just a little dirty
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
That gave me in total 2.5 gearboxs on the floor in bits.... So many bits...
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
Had a little compair up of the bits, F18W left and F20 3.55 right.
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
Just for interest a F16 F18 and F20 diff, the 16 and 18 are the same the F20 is much more meaty. Not that matters with a LSD.
Also inside they look the same really, other than the F20 having more roller in one bearing than the F16. But the same bearings are used in F20/18 and they are all interchangable. The main difference I can see between them is the case having more ribs on the F20 and the diff.
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
So started with the F18W output shaft, and built that back up with the F20 1-4 gears after cleaning and inspecting them for wear and damage.
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
Just need to clean up the case and a couple of little bits, then pop it all back together. I think I will be seeing cogs when I go to sleep tonight !
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
F18W with 3.94 final drive! Proper result and the hydro release bearing should fit a f16/20 ect if I go down that route in the future.
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
So came up with a plan, strip the f18 for the final drive and 5th gear. Then mix it up with a spare F20 I had, I'd not wanted to strip my 'good' F16 just in case I need a spare but the F20 was untested as it's not from one of my cars.
So pulled out the diff then popped off the 5th gear cluster, I needed to put a little tension with a puller then heated the gear gently with the oxy set it made a pop and slid off.
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
Then pulled out the cluster the F18 is next to my spare F16C cluster in the pic, just to check if they looked the same. I gave it a check over and it all looked good so stripped that down.
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
Then did the same on the spare F20, that too looked good if not just a little dirty
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
That gave me in total 2.5 gearboxs on the floor in bits.... So many bits...
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
Had a little compair up of the bits, F18W left and F20 3.55 right.
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
Just for interest a F16 F18 and F20 diff, the 16 and 18 are the same the F20 is much more meaty. Not that matters with a LSD.
Also inside they look the same really, other than the F20 having more roller in one bearing than the F16. But the same bearings are used in F20/18 and they are all interchangable. The main difference I can see between them is the case having more ribs on the F20 and the diff.
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
So started with the F18W output shaft, and built that back up with the F20 1-4 gears after cleaning and inspecting them for wear and damage.
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
Just need to clean up the case and a couple of little bits, then pop it all back together. I think I will be seeing cogs when I go to sleep tonight !
F16 F18 F20 Gearbox Hybrid by ben a.k.a me, on Flickr
Now I have done a big resto on the car and made it much more silent other sounds start to irritate me a bit. Right now when I drive the motorway at 120Kmh (about 75Mph) in 5th gear I get around 3760 rpm and at that rate the engine does start to become a little bit noisy again. I cabn imagine it'll irritate me a lot on longer drives. So I've been looking at all the gearbox ratios and done some math and saw some boxes that bring it down to around 3000 rpm, some at 3200/3300-ish...
I've used this online calculator:http://www.csgnetwork.com/multirpmcalc.html
And this website as a reference for the box ratios:
I've seen there are two versions of F16 and the version 1 will have the heavy 1st gear again, the version 2 a considerably lighter 1st as I've had so far. F16 boxes also come nicely cheap... Though how can I distinguish the 1st or 2nd version?? Any way to tell the ratios without having to try it out? For instance marking the input shaft and a drive shaft and then spinning it counting the revolutions??
So I've looked at my options and wondered what you guys think?
Also many say the F28 box isn't any good on a C20XE as it would not be able to spin it round efficiently, but looking at the ratios the 6th isn't very much different from many WR boxes and the 1st is still nicely light.
Could also open up the F18 and place an F16 final ratio in of 3.55 and swap the 5th gear for the 0.707....
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