Regearing a G50/20 - Questions
10-12-2010, 02:33 PM
#31
My only addition to this thread is that if it's not a racecar I personally think the 2.375 or 2.400 2nd gear ratios that are being discussed are too short. Stick with something like the 2.25 in the Zonker or a 2.176.
Same goes for third. 1.789 is a really really short third gear. It's a tiny little gear with huge overhang on the dogteeth. It's a motorsports gear with a short lifespan. Again, go with the 2.684 in the Zonker or even a 1.650 or 1.632.
Also, as has been mentioned, the LSD is totally optional. They don't seem to get much love around here, but for a car like this a TBD (torque biasing differential) is actually a very good option to consider. When barnstorming and canyon carving it lets you get on the power sooner and put more to the ground coming out of the corners. The usual argument that the LSD gives you lock up under braking doesn't apply as much on the street. On the track when you're bringing it down from 120mph to make a corner at 60 it matters. On a drive through the woods braking from 65 to 35 for that next hairpin it's not as relevant.
Same goes for third. 1.789 is a really really short third gear. It's a tiny little gear with huge overhang on the dogteeth. It's a motorsports gear with a short lifespan. Again, go with the 2.684 in the Zonker or even a 1.650 or 1.632.
Also, as has been mentioned, the LSD is totally optional. They don't seem to get much love around here, but for a car like this a TBD (torque biasing differential) is actually a very good option to consider. When barnstorming and canyon carving it lets you get on the power sooner and put more to the ground coming out of the corners. The usual argument that the LSD gives you lock up under braking doesn't apply as much on the street. On the track when you're bringing it down from 120mph to make a corner at 60 it matters. On a drive through the woods braking from 65 to 35 for that next hairpin it's not as relevant.
10-12-2010, 03:00 PM
#32
Nordschleife Master
10-12-2010, 03:34 PM
#33
Drifting
Thread Starter
Now I'm a touch worried. I'm not in a position to agree or disagree with the 3.0/2.0 ratio choices but changing 1st/main shaft just blows the whole project out of the water economically for street use. I expect that for most street regear projects, the 3.818 1st is not going to change. The 3.0 and 2.0 ratios, which are /31 ratios, are replicated with the 3.818/2.4 ratio as far as rpm drop goes as does a 1.789 3rd. The used box I just purchased is using the 3.818/2.4 1st/2nd and I can't recall the 3rd gear ratio. I'm not concerned with stop n go city driving as the car sees very little of that. I guess I'll see first hand how it all works out.
10-12-2010, 04:03 PM
#34
Nordschleife Master
Matt,
I wouldn't be overly concerned. I was talking "perfect world" where you do exactly what you want. 90% of life is a compromise.
It's going to be a short quick little box you've picked up. What you bought is clearly a race ratio box. If it turns out you don't like it, you regear it and sell off the race gears in a year or two. I can tell you one thing for sure and that's that is going to be way quicker to 75mph than what you've got in there now.
I wouldn't be overly concerned. I was talking "perfect world" where you do exactly what you want. 90% of life is a compromise.
It's going to be a short quick little box you've picked up. What you bought is clearly a race ratio box. If it turns out you don't like it, you regear it and sell off the race gears in a year or two. I can tell you one thing for sure and that's that is going to be way quicker to 75mph than what you've got in there now.
10-12-2010, 04:08 PM
#35
Drifting
Thread Starter
Matt,
I wouldn't be overly concerned. I was talking "perfect world" where you do exactly what you want. 90% of life is a compromise.
It's going to be a short quick little box you've picked up. What you bought is clearly a race ratio box. If it turns out you don't like it, you regear it and sell off the race gears in a year or two. I can tell you one thing for sure and that's that is going to be way quicker to 75mph than what you've got in there now.
I wouldn't be overly concerned. I was talking "perfect world" where you do exactly what you want. 90% of life is a compromise.
It's going to be a short quick little box you've picked up. What you bought is clearly a race ratio box. If it turns out you don't like it, you regear it and sell off the race gears in a year or two. I can tell you one thing for sure and that's that is going to be way quicker to 75mph than what you've got in there now.
10-12-2010, 06:16 PM
#38
Nordschleife Master
Matt,
You can see the sort of compromises I was talking about on your 4-5 shift and the larger than optimum rpm drops. Because the builder of your gearbox used a stock 3rd gear in the 4th position, they had to stretch 5th out a ways to hit the 130mph top speed it looks like they were trying to run on the track. In your application it likely won't impact you much, if at all.
You can see the sort of compromises I was talking about on your 4-5 shift and the larger than optimum rpm drops. Because the builder of your gearbox used a stock 3rd gear in the 4th position, they had to stretch 5th out a ways to hit the 130mph top speed it looks like they were trying to run on the track. In your application it likely won't impact you much, if at all.
10-12-2010, 06:38 PM
#39
Drifting
Thread Starter
Matt,
You can see the sort of compromises I was talking about on your 4-5 shift and the larger than optimum rpm drops. Because the builder of your gearbox used a stock 3rd gear in the 4th position, they had to stretch 5th out a ways to hit the 130mph top speed it looks like they were trying to run on the track. In your application it likely won't impact you much, if at all.
You can see the sort of compromises I was talking about on your 4-5 shift and the larger than optimum rpm drops. Because the builder of your gearbox used a stock 3rd gear in the 4th position, they had to stretch 5th out a ways to hit the 130mph top speed it looks like they were trying to run on the track. In your application it likely won't impact you much, if at all.
10-12-2010, 09:44 PM
#41
Racer
I passed up this box because I didn,t need to spend the money now not because I was convinced it was too short.I,m sure you will like this box on the street. I can,t see a need for a higher top speed than 156 anyway. Cruise will still be at or under 3k. If you don,t like it you can easily resell it. Also matt remember it has the motorsport shaft with a loose 1 and 2. so any future changes are easier. Also you are getting improved shift forks and steel syncros etc. Lots of premium parts,even if you end up regearing it again.
10-12-2010, 09:54 PM
#42
Drifting
Thread Starter
I passed up this box because I didn,t need to spend the money now not because I was convinced it was too short.I,m sure you will like this box on the street. I can,t see a need for a higher top speed than 156 anyway. Cruise will still be at or under 3k. If you don,t like it you can easily resell it. Also matt remember it has the motorsport shaft with a loose 1 and 2. so any future changes are easier. Also you are getting improved shift forks and steel syncros etc. Lots of premium parts,even if you end up regearing it again.
I wasn't going to say much until I got it in my hot little hands. It only shipped today.My first impression is that it was exactly what I wanted. There are a lot of great parts in there. The second guessing on the ratios only started today.
I did think of flipping it to Steven (Trophy) and making a few bucks (just kidding Steven). I knew #2 was loose but I didn't realize #1 was too LOL. I think I just pulled the trigger quickly because it looked like what I wanted. Perhaps I don't know what I'm doing. That hasn't stopped me before.
10-12-2010, 10:05 PM
#43
Racer
I have never had a car I didn,t mod,some a great deal. I am still kicking myself for not buying this box but economics were telling me not to . I am also pretty happy with my car the way it is. I just bought a set of corner scales since we were talking about this box last week.
10-31-2010, 03:31 PM
#45
Drifting
Thread Starter
I've got a few miles on the regeared box and a new LWF. I'm pretty happy with the set-up. Here are a few of my thoughts after the first 100 miles:
LWF
Close Ratio Gearbox
Time for an oil change now.
LWF
- Its more of a subtle change than I expected
- No stalling yet; engine rpm bounces around for a few seconds after coming to a stop
- no gearbox rattle; PO said he didn't have any either???
- engine rpm rise quicker when blipping the throttle on the downshifts. Very nice.
- Increase in acceleration due to LWF is not known as the gearing has changed too
- Isn't more difficult starting off; no change in driving style required
- For some reason the install was a b*tch as the fork kept falling off of the TO bearing. I swear I had the tranny off 6 times before I got it. Perhaps this is because the TO bearing geometry is different. I didn't have any problems last time I changed the clutch.
Close Ratio Gearbox
- This is how the gbx should have been from the factory. It justs feel right.
- An acceleration run is now a quick series of upshifts with the engine always in the power band
- The car does feel quicker. 50hp quicker? I don't know about that one.
- I don't want to upgrade the engine now (at least temporarily)
- Second and third gear have a little whine to it in deceleration; probably due to aftermarket gears
- I didn't miss the extra tall 6th. It might be nice to have a somewhat taller 6th for long hauls to help with mileage but it really doesn't seem like a big deal now. I'm not sure whether I'll have enough motivation to spend another $1k on that one.
- Better gear selection in city driving (that is just a side benefit)
Time for an oil change now.
