Anyone running 6 speed gearbox?

TDIMeister

Phd of TDIClub Enthusiast, Moderator at Large
Joined
May 1, 1999
Location
Canada
TDI
TDI


I'm also not concerned about the 6th gear ratio in and of itself but rather in relation to the other gears, particularly 5th, which is why I post the sawtooth patterns to compare among different ratios.
There is a better way to illustrate this than mere words and that more precisely explains why .622 is the most optimal 6th gear ratio in the case where the other 5 speeds are CTN-stock. It starts with plotting a logarithmic trendline on the speed-vs-RPM points on the bottom after a gear shift:



A stock-CTN + 0.622 6th gear fits pretty nicely in this curve and without going through a great deal of complexity, it means that the engine revs build up progressively at the bottom of each subsequent upshift from the assumption of a constant upper RPM where the shifts take place. The engine is more likely to have a torque backup at the lower RPM after the upshift as long as the shift point does not fall much below the exponential curve. OEMs engineer their cars and choose gear ratios not out of thin air but rather following this principle. Trucks and transmissions for other vehicles may use a different strategy (e.g. a horizontal or linear progression instead of logarithmic as I've illustrated, but gear ratios for passenger cars are done this way almost without exception.


By contrast, you can see in the example of poorly chosen ratios:



Even without the exponential trend curve in place, you can imagine that in the above case, it will be very annoying to row through the gears, especially from 3rd to 4th, because the engine sounds corresponding to the RPM will be off from the expected progressiveness and then the deep RPM drop into 5th will bog the engine down.
 
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Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
There is a better way to illustrate this than mere words and that more precisely explains why .622 is the most optimal 6th gear ratio in the case where the other 5 speeds are CTN-stock. It starts with plotting a logarithmic trendline on the speed-vs-RPM points on the bottom after a gear shift:



A stock-CTN + 0.622 6th gear fits pretty nicely in this curve and without going through a great deal of complexity, it means that the engine revs build up progressively at the bottom of each subsequent upshift from the assumption of a constant upper RPM where the shifts take place. The engine is more likely to have a torque backup at the lower RPM after the upshift as long as the shift point does not fall much below the exponential curve. OEMs engineer their cars and choose gear ratios not out of thin air but rather following this principle. Trucks and transmissions for other vehicles may use a different strategy (e.g. a horizontal or linear progression instead of logarithmic as I've illustrated, but gear ratios for passenger cars are done this way almost without exception.


By contrast, you can see in the example of poorly chosen ratios:



Even without the exponential trend curve in place, you can imagine that in the above case, it will be very annoying to row through the gears, especially from 3rd to 4th, because the engine sounds corresponding to the RPM will be off from the expected progressiveness and then the deep RPM drop into 5th will bog the engine down.
Very good information to have. The emphasis on not having to over rev the engine in 5th to drop into the new 6th is important I think.

If we look at it logarithmically and use the .971 4th gear and the new .586 6th gear option what does the optimal new 5th gear really end up being?

Steve
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
This is a wonderful philosophical conversation, but at the end of the day, you are limited to the ratios offered by the vendor... :D

Eurotuning has .74 and .71 5th coupled with a .65 or .59 6th.

Having put over 100,000 km on the .74/.59 combo, it was perfect for my driving - which is (ahem) the speed of traffic.

If I was more inclined to occupy the right lane, I would opted for .65, but more likely I would not have bothered with the kit at all.

As above, you will find the optimal cruise speed for .59 at 65mph or higher. A tune helps in that you won't need to downshift as often when loaded, going up hills, into a headwind or combination of the above.

You've got three testimonials for the .74/.59 combo on the B4 equipped with a CTN. Heck, I had mine to Florida and back twice and out to eastern Canada twice (around the Cabot trail) fully loaded with kids and luggage and never had a concern with 6th being too tall. I think I downshifted to 5th maybe once or twice going up a steep hill in Virginia, but other than that - 6th all the way.
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
This is a wonderful philosophical conversation, but at the end of the day, you are limited to the ratios offered by the vendor... :D

Eurotuning has .74 and .71 5th coupled with a .65 or .59 6th.

Having put over 100,000 km on the .74/.59 combo, it was perfect for my driving - which is (ahem) the speed of traffic.

If I was more inclined to occupy the right lane, I would opted for .65, but more likely I would not have bothered with the kit at all.

As above, you will find the optimal cruise speed for .59 at 65mph or higher. A tune helps in that you won't need to downshift as often when loaded, going up hills, into a headwind or combination of the above.

You've got three testimonials for the .74/.59 combo on the B4 equipped with a CTN. Heck, I had mine to Florida and back twice and out to eastern Canada twice (around the Cabot trail) fully loaded with kids and luggage and never had a concern with 6th being too tall. I think I downshifted to 5th maybe once or twice going up a steep hill in Virginia, but other than that - 6th all the way.
Excellent summary!

I looked at changing 4th gear as well at the same time I did the 5/6 conversion (did not want to tear the trans down again, just too expensive). I also played with different tire sizes. For me, the biggest worry was possibly getting a 6th gear ratio that was too tall for real daily driving. Because I was running a .622 5th gear and oversize tires, I knew the .59 ratio would work with stock size tires exactly the same final drive ratio as the .622 5th and oversize tires. So no worry there.

TDIMeister's graph shows the .622 6th ratio fits exactly in the logrithmic curve. The BoraParts 6 speed may offer that gear ration - just not sure. With Eurotuning, you get either .65 or .59 and 2 choices for 5th gear ratio, .71 or .74. The 6 speed conversion is still the best modification I have done on my car
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
This is a wonderful philosophical conversation, but at the end of the day, you are limited to the ratios offered by the vendor... :D

Eurotuning has .74 and .71 5th coupled with a .65 or .59 6th.

Having put over 100,000 km on the .74/.59 combo, it was perfect for my driving - which is (ahem) the speed of traffic.

If I was more inclined to occupy the right lane, I would opted for .65, but more likely I would not have bothered with the kit at all.

As above, you will find the optimal cruise speed for .59 at 65mph or higher. A tune helps in that you won't need to downshift as often when loaded, going up hills, into a headwind or combination of the above.

You've got three testimonials for the .74/.59 combo on the B4 equipped with a CTN. Heck, I had mine to Florida and back twice and out to eastern Canada twice (around the Cabot trail) fully loaded with kids and luggage and never had a concern with 6th being too tall. I think I downshifted to 5th maybe once or twice going up a steep hill in Virginia, but other than that - 6th all the way.
Ok, abandoning the philosophical angle I read that you had some importation hassles with your eurotuning kit, do you mind sharing what those were?

Thanks
Steve A
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
Not really any importation hassles per se, the only issues were that communication stopped for about two weeks after I sent payment due to holidays at Eurotuning. That coupled with a little lost in translation made for about a week of wondering if I was going to get anything for the $1500 I wired to the Czech republic - all good in the end though.

The other "issue" (not really) was that I had to pay about $250 in import tariffs once the package was in the country - US duty/tariff may be less, but do your homework on this so you know your final price.

Shipping was fine once the communication was sorted out, and the quality of the kit and packaging was good.

Go through the install instructions a couple times, as the translation there was also a little lacking.
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
My import tax/duty was $40-45 on the kit at $1500 value. So not bad in the States. As I recall, shipping went first to London by a low cost Eurozone shipper, then on to San Diego by DHL. Very well packed and arrived just fine. Because I was the first U.S. buyer, there was a little bit of a problem with the wire transfer. It was solved in 24-48 hours. No one else has had that issue.
 

GEE-BEE

Veteran Member
Joined
Oct 27, 2009
Location
SO CALIF
TDI
1.9 AAZ
Iam doing a custom build ( ahu / GTB 2265 / tubular exhaust / Rover 300 mtdi pumps )so i think this will be fine for the 36psi

I have two trans and powdercoater now, and will be installing LSD's

There going into very light VW MK1's..

Happy New Year All

GB
 

dan30thz28

Veteran Member
Joined
Jan 7, 2006
Location
Cream Ridge, NJ
TDI
2002 Jetta GLS TDI 5-speed Manual 2013 VW Sportwagen TDI 6-Speed Manual
Hello,
Does anyone know what their mileage was before the swap, and what it is now? Also, I was thinking of doing this mod as well, because when I have 330,000 miles, I was going to get the clutch done, and go with a tune (stage 2 malone) anyway. I have the original turbo, and trailer occasionally. My commute is done with the cruise @ 78 mph. Any concerns with me doing it with high mileage? Thanks for all your advise as always.

Sincerely,
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
Hello,
Does anyone know what their mileage was before the swap, and what it is now? Also, I was thinking of doing this mod as well, because when I have 330,000 miles, I was going to get the clutch done, and go with a tune (stage 2 malone) anyway. I have the original turbo, and trailer occasionally. My commute is done with the cruise @ 78 mph. Any concerns with me doing it with high mileage? Thanks for all your advise as always.

Sincerely,
Doing the 5/6 conversion at the same time as the clutch makes sense. The conversion will not stress your engine as far as I am concerned.
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
Not really any importation hassles per se, the only issues were that communication stopped for about two weeks after I sent payment due to holidays at Eurotuning. That coupled with a little lost in translation made for about a week of wondering if I was going to get anything for the $1500 I wired to the Czech republic - all good in the end though.

The other "issue" (not really) was that I had to pay about $250 in import tariffs once the package was in the country - US duty/tariff may be less, but do your homework on this so you know your final price.

Shipping was fine once the communication was sorted out, and the quality of the kit and packaging was good.

Go through the install instructions a couple times, as the translation there was also a little lacking.
Going to order this soon, one last question. Were you able to install the kit on the B4 without pulling the transmission? On a Mk3 I see no problem with in-car install but on the B3/4 the frame horns have those metal reinforcement curtains to contend with and it looks like you have to drop the trans tail end way down to clear that.

If that's the case I'm just pulling the engine / trans back out. I haven't really hooked up all that much yet, I think it would be easier to pull and do the install on the ground and then drop it back in.

I will say that with the additional space of the new tail cover a person would have to dump that end in first before dropping the engine side down, it can't go in level like I did it before.

Also, since I didn't get any communication back from them regarding starting the process I assume they want you to pay first and then they'll talk to you about it?

Thanks guys
Steve
 

dan30thz28

Veteran Member
Joined
Jan 7, 2006
Location
Cream Ridge, NJ
TDI
2002 Jetta GLS TDI 5-speed Manual 2013 VW Sportwagen TDI 6-Speed Manual
Hey,
Thanks so much for all feedback. I ended up just swapping out the 5th gear, and I'm getting almost 52 mpg, where I was getting 48 before. If you can't afford to do the 5-6 swap, then a smaller 5th is the next best thing!

Sincerely,
Dan
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
Steve,

I had no problems with communication before or after the sale. Sometimes a couple of days delay, but no problems.

Here is the post from Matt-98ahu on doing the installation without removing the trans:

http://forums.tdiclub.com/showpost.php?p=3810411&postcount=96

I have been running this conversion for more than 3 years with zero problems.
Thanks for the pointer on that post. I was afraid that the metal reinforcement would be in the way, it sounds like he just bent it to get better access. I'll probably just wait for it to get here and then pull the engine / trans back out to fit the new components.

As for communication I emailed them over a week ago and still haven't gotten a reply. I think I'll email them again and see if I get a response.

Thanks
Steve
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
I got an email from them today, unfortunately I was too lame to include the trans code in the initial email so I sent it in the response.

I don't envision any problems from here on out.

I've decided that I want the .59 6th but am still somewhat undecided about which option for 5th gear. Since I live in the great flatness that is the mid-west and spend most of my time (at present) traveling around this area I don't foresee a problem with using the .59 6th.

I'd really like to know where both of the 5th gear options put engine rpms around 55 - 60 mph. I tend to drive some county roads and ideally I'd like rpms to stay around 2k at 60 mph.

If the .71 let me travel at 60 around 2k rpms that would be fine. The .74 5th is so close to stock CTN ratio I would imagine very similar rpm's to what I have now, which is around 1950rpm at 55.

Steve
 

dan30thz28

Veteran Member
Joined
Jan 7, 2006
Location
Cream Ridge, NJ
TDI
2002 Jetta GLS TDI 5-speed Manual 2013 VW Sportwagen TDI 6-Speed Manual
I got an email from them today, unfortunately I was too lame to include the trans code in the initial email so I sent it in the response.

I don't envision any problems from here on out.

I've decided that I want the .59 6th but am still somewhat undecided about which option for 5th gear. Since I live in the great flatness that is the mid-west and spend most of my time (at present) traveling around this area I don't foresee a problem with using the .59 6th.

I'd really like to know where both of the 5th gear options put engine rpms around 55 - 60 mph. I tend to drive some county roads and ideally I'd like rpms to stay around 2k at 60 mph.

If the .71 let me travel at 60 around 2k rpms that would be fine. The .74 5th is so close to stock CTN ratio I would imagine very similar rpm's to what I have now, which is around 1950rpm at 55.

Steve
Steve,
Here's my rpms from 70-78 with a .658 5th (stock 195/65/15 tires).
70 mph--2050 rpms
75 mph--2250 rpms
78 mph--2300 rpms

Hope this helps you out.

Sincerely,
 

Abacus

That helpful B4 guy
Joined
Nov 10, 2007
Location
Relocated from Maine to Dewey, AZ
TDI
Only the B4V left
Most of the roads here are country roads with moderate hills. I took these shots to help people determine what rpm's they'd see at normal country speeds. Anything below 1750 rpm on less than flat ground is a nuisance, so I keep it in a lower gear unless I'm cruising level roads.


55 mph in 5th




55 mph in 6th




60 mph in 5th




60 mph in 6th




65 mph in 5th




65 mph in 6th

 

tripl-e

Veteran Member
Joined
May 22, 2006
Location
Basking Ridge, NJ USA
TDI
b4 sporting a new ET 6th gear!
I got an email from them today, unfortunately I was too lame to include the trans code in the initial email so I sent it in the response.
What code did they want, CTN or 02something?

I don't envision any problems from here on out.
Geez I love an optimist!:D


I'd really like to know where both of the 5th gear options put engine rpms around 55 - 60 mph. I tend to drive some county roads and ideally I'd like rpms to stay around 2k at 60 mph.
Can you measure the loaded rolling circumference for a wheel/tire similar to the one you'll be using? After you have that number speed/rpm relationships are simple arithmetic.

Keep us posted please, this looks like such a great mod for a b4.

Good Luck!

EEE
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
They are looking for CTN.

And it IS the best mod I have done to my B4V. Not the cheapest, but the best mod.

What code did they want, CTN or 02something?



Geez I love an optimist!:D




Can you measure the loaded rolling circumference for a wheel/tire similar to the one you'll be using? After you have that number speed/rpm relationships are simple arithmetic.

Keep us posted please, this looks like such a great mod for a b4.

Good Luck!

EEE
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
Yeah, they wanted to know it was the 02A CTN gearbox, and now they do.

I told him I wanted the .75 5th and the .59 6th and I think I'm sticking to that. I still wouldn't mind hearing from someone with the .71 5th what rpm's their turning at 55 and 60 mph though...just for comparison. Based on the above though I think dropping to the .71 might put me below 1900 rpms at 55 and there are some heavily patrolled roads I travel on my way to NE Iowa where you do not want to speed so it's important for me to have a good 5th for the 55mph stuff. Do not want to get stopped for speeding and experience any asset forfeiture.

Frans got back to me today, he has the 6N0 gearbox shifter in an Ibiza so that'll be headed this way too.

Now I'm contemplating ordering two of the gearbox kits. It would make both cars consistent and second, it might save something on shipping. I can't imagine it would cost double to ship two...but who knows. I'll be asking about that. If I do I'll have to hit up Frans for a second shifter box....

Guess I might be doing my own 'group buy' thing...haha.

Steve
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
Steve,

MrDave ordered 2 of these conversions at the same time. One with the .65 ratio and the other one with the .588 ratio. Getting 2 at the same time should save you almost all the freight on the second set. They are not very heavy. It would be a smart move.

How much for the shifter from the Ibiza?

Yeah, they wanted to know it was the 02A CTN gearbox, and now they do.

I told him I wanted the .75 5th and the .59 6th and I think I'm sticking to that. I still wouldn't mind hearing from someone with the .71 5th what rpm's their turning at 55 and 60 mph though...just for comparison. Based on the above though I think dropping to the .71 might put me below 1900 rpms at 55 and there are some heavily patrolled roads I travel on my way to NE Iowa where you do not want to speed so it's important for me to have a good 5th for the 55mph stuff. Do not want to get stopped for speeding and experience any asset forfeiture.

Frans got back to me today, he has the 6N0 gearbox shifter in an Ibiza so that'll be headed this way too.

Now I'm contemplating ordering two of the gearbox kits. It would make both cars consistent and second, it might save something on shipping. I can't imagine it would cost double to ship two...but who knows. I'll be asking about that. If I do I'll have to hit up Frans for a second shifter box....

Guess I might be doing my own 'group buy' thing...haha.

Steve
 
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Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
Steve,

MrDave ordered 2 of these conversions at the same time. One with the .65 ratio and the other one with the .588 ratio. Getting 2 at the same time should save you almost all the freight on the second set. They are not very heavy. It would be a smart move.
That's nice to hear, it will definitely have a bearing on my decision if the freight for the second setup is minimal.

I have a feeling that the car with this setup will get the majority of use, which is fine until it needs to be laid up for some work and that's when you have to get used to the old setup again.

As Abacus has said before the wagon has become his 'go to' car and I'm sure that's partially due to the transmission. I just think it would be a wise move now to match the drive train in both cars so later on I don't get pissed because I have to drive the Jetta with the 5 speed.....

Still wouldn't mind knowing what the .71 5th crowd sees for rpm's at 55 to 60 mph....

The shifter from the Ibiza was 60 euro shipped...not too bad I think.

Steve
 
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Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
I saw that. Maybe regional group buys?



Sent from my iPhone using Tapatalk
That's a possibility, but I need to get my order here pronto, I've already beaten around the bush long enough on this and the shifter box too.

Had I committed earlier I'd have had all this done and wouldn't now have to go back and undo my install to do the trans upgrade.

All I know is that this is another one of those things (on the B3 anyway) that I don't want to have to go back and do later on. The Mk3 probably would be ok doing with the trans in the car but on a B3/4 that's just a real pita to figure out unless you just pull it out.

Steve
 

Abacus

That helpful B4 guy
Joined
Nov 10, 2007
Location
Relocated from Maine to Dewey, AZ
TDI
Only the B4V left
.

As Abacus has said before the wagon has become his 'go to' car and I'm sure that's partially due to the transmission. I just think it would be a wise move now to match the drive train in both cars so later on I don't get pissed because I have to drive the Jetta with the 5 speed.....

Steve
It has become my DD but only due to laziness on my part. The last 2 days I've been relegated to driving the sedan due to the PS pump failing. The wagon shifts so much better, has less vibrations, has the new radio, MFA, and much better brakes.

But, the sedan is much quicker, even with the worn out turbo (so sue me, I've been busy), handles like it's on rails, and the stock ratio is so much better sounding. The engine is also smoother running and I love hearing the turbo whistle. The stock shifter feels like it's broken due to the long vague throw.

My daily commute is 30 miles each way on non-highway roads with a max limit of 55 mph and I honestly don't notice a difference when swapping vehicles because I never enter 6th gear. At about 65 mph I'm wishing for that extra gear, however.
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
Steve,

A couple of facts from my set up at 55 mph (I have the .71 5th).

With the 10mm injection pump I could cruise just a touch below 55 (say 53/54), but accelerating was not a smooth thing. The engine did not "like" running just below 1500 rpm. Looking back, I tended to down shift between 55 and 60.

Now when I switched to the rebuilt 11mm pump in April, things changed. Oldpoopie changed the pump and the first thing he said to me was that the engine ran much smoother with the new pump than with the 10mm pump. I used to have some "vibration/hesitation" in the 1300-1450 rpm range. With the new pump, that was gone. So I found I was able to run as slow as 50 mph in 6th gear and smoothly accelerate with out that old "vibration/hesitation". That said, I still prefer to be in 6th gear between 55 and 60, because it makes for easier freeway acceleration.

Honestly, I don't think it will matter too much which 5th gear you go with. So play it safe and go with the one closer to the stock 5th gear ratio. And don't look back. Add some larger nozzles and a decent tune for low end torque - if you have not done that.
 
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