Mike_M
Veteran Member
Re: 5th gear upgrade. .70 ratio!
C'mon...*nudge*...you know you want to!
5th gear upgrade. .681 success 11% RPM drop
- Thread starter david_594
- Start date
Mike_M
Veteran Member
Re: 5th gear upgrade. .70 ratio!
So...if you're talking about your 2002, you can use both charts to calculate what you CAN do...the left chart if you only change 5th gear, and the right chart if you change the final drive, and possibly also change 5th gear.
If you're referring to your '97 or '98, I don't know that any of this chart applies. I don't know if the stock 5th gear in an A3 is .756 or not...guys?
[/QUOTE]
Mike
Actually, the chart on the left is with the stock A4 final drive, which is 3.389. The chart on the RIGHT is using the 3.156 gears. The .756 ratio 5th gear is stock for A4s, and the .700 and .681s are the upgrades available (so is .717, which I forgot to include...sorry watercop).
So...if you're talking about your 2002, you can use both charts to calculate what you CAN do...the left chart if you only change 5th gear, and the right chart if you change the final drive, and possibly also change 5th gear.
If you're referring to your '97 or '98, I don't know that any of this chart applies. I don't know if the stock 5th gear in an A3 is .756 or not...guys?
[/QUOTE]
Mike
Mike_M
Veteran Member
Re: 5th gear upgrade. .70 ratio!
Mike
WOW! That's huge! I think that the jump between 4th and 5th might get too big, then...I wonder if there's a slightly taller 4th that would help bridge the gap?Ok, I'll say out loud: I FOUND A .537,.6 AND .64.
I don't know if they fit, but they are from an Audi.
If nobody find those gears significant I'll just shut up about'em.
Mike
TDIJetta99
Top Post Dawg
Re: 5th gear upgrade. .70 ratio!
How do you calculate hp loss from aero drag for a given speed? I have an older camaro(1979) that I would like to know how much hp is needed to go about 150...
So you're saying it's possible.... My brother's celica GTS can do a little over 150 (according to toyota) and it's rated at 180hp an I think around 160tq.. If I end up with around 150hp/270tq after mods, I should be able to touch 140 without too much trouble as long as I can the engine to breathe up near redline... I think I'm going to look for another cylinder head and break out all the porting stuff I have in the garage... I used everything once when I built my big block a few years ago and I haven't used anything since.... I shouldn't need another oil cooler unless I plan on keeping the car at those speeds for a long period of time.. I will put some kind of temp gauge in the oil pan to monitor it however.. Honestly, I'd be more worried about EGT..
How do you calculate hp loss from aero drag for a given speed? I have an older camaro(1979) that I would like to know how much hp is needed to go about 150...
Rammstein
Top Post Dawg
Re: 5th gear upgrade. .70 ratio!
I would just rev the 4th a little bit higher, then shift.
Yes, you can get different 4th gears too.WOW! That's huge! I think that the jump between 4th and 5th might get too big, then...I wonder if there's a slightly taller 4th that would help bridge the gap?Ok, I'll say out loud: I FOUND A .537,.6 AND .64.
I don't know if they fit, but they are from an Audi.
If nobody find those gears significant I'll just shut up about'em.
Mike
I would just rev the 4th a little bit higher, then shift.
Mike_M
Veteran Member
Re: 5th gear upgrade. .70 ratio!
(1500/2000RPM in 5th)
0.640: 49.5/65.9mph
0.600: 52.8/70.3mph
0.537: 58.9/78.6mph!!!
With the .537, that means you'd better rev it out to at least 60 in 4th before shifting into 5th!
Then, if you upgrade to the 3.156 final drive:
(1500/2000RPM in 5th)
0.640: 53.1/70.8mph
0.600: 56.6/75.5mph
0.537: 63.3/84.4mph!!!!!!
Want to cruise at 80mph and see the tach needle hovering around the torque peak? Get the .537s and a 3.156 final drive. But don't expect to pass ANYBODY or climb any hills without downshifting.
Of course, you'll need to wrap it out past 65 before even getting into 5th, but if you change to a taller 4th too, that might not be so painful.
Mike
With stock 3.389 final drive:Yes, you can get different 4th gears too.WOW! That's huge! I think that the jump between 4th and 5th might get too big, then...I wonder if there's a slightly taller 4th that would help bridge the gap?Ok, I'll say out loud: I FOUND A .537,.6 AND .64.
I don't know if they fit, but they are from an Audi.
If nobody find those gears significant I'll just shut up about'em.
Mike
I would just rev the 4th a little bit higher, then shift.
(1500/2000RPM in 5th)
0.640: 49.5/65.9mph
0.600: 52.8/70.3mph
0.537: 58.9/78.6mph!!!
With the .537, that means you'd better rev it out to at least 60 in 4th before shifting into 5th!
Then, if you upgrade to the 3.156 final drive:
(1500/2000RPM in 5th)
0.640: 53.1/70.8mph
0.600: 56.6/75.5mph
0.537: 63.3/84.4mph!!!!!!
Want to cruise at 80mph and see the tach needle hovering around the torque peak? Get the .537s and a 3.156 final drive. But don't expect to pass ANYBODY or climb any hills without downshifting.
Of course, you'll need to wrap it out past 65 before even getting into 5th, but if you change to a taller 4th too, that might not be so painful.
Mike
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LNXGUY
Top Post Dawg
Re: 5th gear upgrade. .70 ratio!
Ugh, I'd kill for a .681 5th gear. Does anyone have a realiable source for these?
Ugh, I'd kill for a .681 5th gear. Does anyone have a realiable source for these?
DrSmile
Veteran Member
Re: 5th gear upgrade. .70 ratio!
Just remember that changing 4th is going to be much more involved than changing 5th. I'm not sure you HAVE to take the transmission out but you'd definitely have to consider it as you'll have to take apart the gear stacks. You'll probably need new bearings/races at that point, and you may need to reshim. This is pretty major transmission work and almost certainly too expensive to ever recover with fuel savings. If I'm going to do this I think the .64 is sounding like a great compromise.
Just remember that changing 4th is going to be much more involved than changing 5th. I'm not sure you HAVE to take the transmission out but you'd definitely have to consider it as you'll have to take apart the gear stacks. You'll probably need new bearings/races at that point, and you may need to reshim. This is pretty major transmission work and almost certainly too expensive to ever recover with fuel savings. If I'm going to do this I think the .64 is sounding like a great compromise.
david_594
Top Post Dawg
Re: 5th gear upgrade. .70 ratio!
I ordered and am waiting for a .681 set to arrive so I can make sure they work before anyone else trys and gets them.
I ordered and am waiting for a .681 set to arrive so I can make sure they work before anyone else trys and gets them.
Re: 5th gear upgrade. .70 ratio!
EGT's is an issue. But those EGT's will heat up the oil. Thus if trying for max speed an oil cooler is a good thing.
I posted the link on page 2 or 3 for an online place to find out how much aero drag at XXX speed.
Peak speed will depend on having the correct amount of torque towards the end of redline. 140mph is do able. any more speed requires a heck of a lot more power.
EGT's is an issue. But those EGT's will heat up the oil. Thus if trying for max speed an oil cooler is a good thing.
I posted the link on page 2 or 3 for an online place to find out how much aero drag at XXX speed.
watercop
Veteran Member
- Joined
- Aug 13, 2002
- Location
- Clay County, FL
Re: 5th gear upgrade. .70 ratio!
If we may ask, how much did the 0.681 gearset cost?
If we may ask, how much did the 0.681 gearset cost?
IndigoBlueWagon
TDIClub Enthusiast, Principal IDParts, Vendor , w/
Re: 5th gear upgrade. .70 ratio!
I thought someone posted earlier that it's about $250.
I was thinking about this today as I drove home at 90 MPH; engine turning about 3200 RPM and not that audible above the wind noise. My A4 really likes to run at that speed and I enjoy the ability to accelerate easily in 5th at 70-100 MPH. I may be sacrificing some top end but when would I use it? I rarely drive over 90 for any lenght of time, and when I'm on a road trip I tend to set the cruise at 75 so I don't have to worry about getting a ticket.
At 75 my wagon gets 50 MPG. And it'll loaf at 40 MPH in fifth if I don't want to accelerate fast. What I think I really want is a six speed--in my '97. Now that would be unusual.
I thought someone posted earlier that it's about $250.
I was thinking about this today as I drove home at 90 MPH; engine turning about 3200 RPM and not that audible above the wind noise. My A4 really likes to run at that speed and I enjoy the ability to accelerate easily in 5th at 70-100 MPH. I may be sacrificing some top end but when would I use it? I rarely drive over 90 for any lenght of time, and when I'm on a road trip I tend to set the cruise at 75 so I don't have to worry about getting a ticket.
At 75 my wagon gets 50 MPG. And it'll loaf at 40 MPH in fifth if I don't want to accelerate fast. What I think I really want is a six speed--in my '97. Now that would be unusual.
Drivbiwire
Zehntes Jahr der Veteran
- Joined
- Oct 13, 1998
- Location
- Boise, Idaho
- TDI
- 2013 Passat TDI, Newmar Ventana 8.3L ISC 3945, 2016 E250 BT, 2000 Jetta TDI
Re: 5th gear upgrade. .70 ratio!
I would suggest have a low profile puller for removing the gear. The problem is you have very little clearance between the housing and the base of the gear. You could get a regular puller set and grind down the forks so they clear.
DB
From the Bentley Manual:
They don't mention it for re-installation but if you get it to 100C it drops right on without a press.
I would suggest have a low profile puller for removing the gear. The problem is you have very little clearance between the housing and the base of the gear. You could get a regular puller set and grind down the forks so they clear.
DB
VelvetFoot
Top Post Dawg
Re: 5th gear upgrade. .70 ratio!
It's all coming back to me.
I think I tried using a torch. I also broke the hooks on that VW puller and finally got it off with a modded Sears puller.
It's all coming back to me.
TDIJetta99
Top Post Dawg
Re: 5th gear upgrade. .70 ratio!
Cool.. I found the link, I just need to find what the drag coefficient is for a 79 camaro... I'll be installing a few gauges in another week or so, I was planning on just boost and EGT, but I think I'll add the oil temp as well just so I can keep an eye on it... As far as I can tell, it already has an oil cooler that uses engine coolant... I have a similar style cooler on my pickup (big block chevy) and I never, repeat never see oil temps more than about 50 degrees over coolant temp, highest oil temp I saw was 250... well within the limits of synthetic oil, and that was towing a trailer at high speed for a good distance up the highway.. And I only have a 4qt oil pan.. I'll see what kind of oil temp I get at a steady 125.. If it stays normal, then I shouldn't need an extra cooler for brief spouts to 140 or so.. But like you said, an oil cooler is a good thing, I just don't want to plumb one in if the o.e. cooler is adequate enough...
david_594
Top Post Dawg
Re: 5th gear upgrade. gears are here!
I would have to say that USPS priority mail from germany is impressively fast as my gears arrived today and had only shipped out last friday. They are the 32/47 .681 ratio and I will post pictures of them later today. Saddly I have no time this weekend to tear into my tranny to swap them, so hopefully next weekend.
I would have to say that USPS priority mail from germany is impressively fast as my gears arrived today and had only shipped out last friday. They are the 32/47 .681 ratio and I will post pictures of them later today. Saddly I have no time this weekend to tear into my tranny to swap them, so hopefully next weekend.
david_594
Top Post Dawg
Re: 5th gear upgrade. gears are here!
Anyone remember what these gears are supposed to look like? I'm really really hoping something like these....
Anyone remember what these gears are supposed to look like? I'm really really hoping something like these....
watercop
Veteran Member
- Joined
- Aug 13, 2002
- Location
- Clay County, FL
Re: 5th gear upgrade. gears are here!
They look like what I recall mine looked like
Wish you had time to get into it thos weekend
They look like what I recall mine looked like
Wish you had time to get into it thos weekend
DrSmile
Veteran Member
Re: 5th gear upgrade. gears are here!
Yep those are gears alright
Be careful though, for some reason every time I open up my transmission there seem to be a few of those darn little teeth missing...
Good luck on the swap, if you haven't done one before pulling gears off a shaft is either a piece of cake or a whore of a job depending on the tightness of the gear, which is a total crapshoot. If you cuss like a sailor it means you're probably on the right track.
Yep those are gears alright
Be careful though, for some reason every time I open up my transmission there seem to be a few of those darn little teeth missing...
Good luck on the swap, if you haven't done one before pulling gears off a shaft is either a piece of cake or a whore of a job depending on the tightness of the gear, which is a total crapshoot. If you cuss like a sailor it means you're probably on the right track.
Ed's TDI
Top Post Dawg
Re: 5th gear upgrade. gears are here!
I've been keeping track of this thread for a little while and now I'm getting excited! I hope these things work as everyone expects them to. I'd love a nice little rpm drop while cruising, plus I'd like the added extra gearing for those high-speed bursts I have every now and again (my own version of Tourrett's Syndrome!
) Please keep us posted as I'm sure everyone here is anxiously anticipating the results! Thanks David for being the guinea pig!
I've been keeping track of this thread for a little while and now I'm getting excited! I hope these things work as everyone expects them to. I'd love a nice little rpm drop while cruising, plus I'd like the added extra gearing for those high-speed bursts I have every now and again (my own version of Tourrett's Syndrome!
Rammstein
Top Post Dawg
Re: 5th gear upgrade. gears are here!
Would a gear from an auto tranny would work?
I just remembered that the PD tiptronic have a .68 as 5th...
Just a thought.
03_01_TDI, where did you find a .57?
Would a gear from an auto tranny would work?
I just remembered that the PD tiptronic have a .68 as 5th...
Just a thought.
03_01_TDI, where did you find a .57?
GoFaster
Moderator at Large
Re: 5th gear upgrade. gears are here!
I'd say it's unlikely that the gears from an Audi transmission will work because those are longitudinal-engine arrangements, and unless there is a miraculous coincidence with the center distance of the shafts AND the synchronizers AND the shaft diameters AND the spline arrangement, they won't fit.
There's no chance of gears from a tiptronic transmission fitting a manual gearbox. Tiptronics don't have synchronizers.
I'd say it's unlikely that the gears from an Audi transmission will work because those are longitudinal-engine arrangements, and unless there is a miraculous coincidence with the center distance of the shafts AND the synchronizers AND the shaft diameters AND the spline arrangement, they won't fit.
There's no chance of gears from a tiptronic transmission fitting a manual gearbox. Tiptronics don't have synchronizers.
DrSmile
Veteran Member
Re: 5th gear upgrade. gears are here!
There are many transaxle designs from Audi, including fwd A4 and even quattro A3 designs. All of those transmissions "MIGHT" contain gears that fit.
There are many transaxle designs from Audi, including fwd A4 and even quattro A3 designs. All of those transmissions "MIGHT" contain gears that fit.
GoFaster
Moderator at Large
Re: 5th gear upgrade. gears are here!
... but "might" becomes "WILL" only if the vehicle uses an O2A or O2J transmission, which means it has to be transverse-engine front-drive 5-speed manual. The Audi TT and the Audi A3 are Volkswagens in disguise; 5-speed manual versions of those have the O2J but I don't think either of those came in versions with gear ratios that are of interest to us.
... but "might" becomes "WILL" only if the vehicle uses an O2A or O2J transmission, which means it has to be transverse-engine front-drive 5-speed manual. The Audi TT and the Audi A3 are Volkswagens in disguise; 5-speed manual versions of those have the O2J but I don't think either of those came in versions with gear ratios that are of interest to us.
DrSmile
Veteran Member
Re: 5th gear upgrade. gears are here!
You know I was gonna make a smart-ass comment about that being the definition of a transaxle, but apparently I'm totally, embarrassingly wrong on this.
You could have transaxle designs that are not transverse mounted. And there I thought trans stood for transverse, actually it's just short for transmission! In any case I don't know if any Audi has lower gears, but the only point I was making is that there are Audi transmissions that have gears that fit.
You know I was gonna make a smart-ass comment about that being the definition of a transaxle, but apparently I'm totally, embarrassingly wrong on this.
nicklockard
Torque Dorque
Re: 5th gear upgrade. gears are here!
If I understand correctly, a transaxle is simply what you have whenever the transmission gears and differential unit are combined in the same housing, regardless of the spatial layout whether longitudinal or transverse to the car's body.
If I understand correctly, a transaxle is simply what you have whenever the transmission gears and differential unit are combined in the same housing, regardless of the spatial layout whether longitudinal or transverse to the car's body.
Ed's TDI
Top Post Dawg
Re: 5th gear upgrade. gears are here!
Has there been any updated information about the success/failure of the gear upgrade? Have you had a chance to install it yet, David? Let us know because I'm sure there are lots of people interested in the outcome!
Has there been any updated information about the success/failure of the gear upgrade? Have you had a chance to install it yet, David? Let us know because I'm sure there are lots of people interested in the outcome!
david_594
Top Post Dawg
Re: 5th gear upgrade. gears are here!
From the looks of it I will be attempting this friday night. All I need to do in the mean time is come up with a gear oil to use. If there is anyone in the area who wants to come and watch I'll be doing it in Troy, NY.
From the looks of it I will be attempting this friday night. All I need to do in the mean time is come up with a gear oil to use. If there is anyone in the area who wants to come and watch I'll be doing it in Troy, NY.
greenskeeper
Top Post Dawg
Re: 5th gear upgrade. gears are here!
Yeah I'm interested as well and an A3 owner.
I'm wondering with my lower final drive (stock A3) would I benefit even more of a drop with this gearset?
Yeah I'm interested as well and an A3 owner.
I'm wondering with my lower final drive (stock A3) would I benefit even more of a drop with this gearset?