BlueMotion Gearbox (JDD) fitted into 1.4 TDI AMF engine

Zoltar

A2OC Donor
Backstory


Looked into the Polo BlueMotion gearbox as an option for my A2. I always felt that the standard A2 was undergeared for motorway driving with the high engine RPM noise too loud.

A few other options are covered on this site for gearbox mods, but they are either too expensive (6th gear upgrade) or meant having to ‘manage a gap’ (Longer 5th) from 4th to 5th, neither appealed to me.

After doing some research it seemed the 1.4 TDI Polo BlueMotion gearbox (JDD VAG code) would fit onto the A2 engine. It had the ratios I was looking for with the added benefit of improved MPG.

The gears on the BlueMotion have longer ratios compared to the A2's EWQ ratios, this keeps rpm down, therefore noise and running costs are reduced.

Red lines - OEM Gearbox, Blue - BlueMotion JDD Gearbox, Wheels - 215/45/16

JDD Ratios.jpg

The wider even spread of the gears in the JDD is very appealing and since my gearbox needed to be taken off in an upcoming clutch change anyway....it was easy to transpose them at this point.

After cross-checking part numbers for compatibility, and some crossed-fingers! I bought a JDD gearbox to hopefully conjoin with the 1.4 TDI AMF engine.

VW also did an update to the weak synchro which older gearboxes had (A2's are known for it), the JDD gearbox has the updated synchro.

More details and info can be found on this thread Which gearbox?



Installation


The gearbox was installed by Vince at Stealth Racing. He had previously done the car’s remap and with all the experience that Vince has had with gearboxes, I couldn’t think of anyone better to do the job.

After taking the old gearbox off, we checked the EWQ casing against the new JDD. A few slight casing differences prevented the job from being a straight bolt on.

Addition lugs on the JDD needed to be cut off and some washers added to a couple of bolts.

Lug OEM.jpgLug JDD.jpg

The lower gearbox mount on the JDD is also different. It only has two mount holes, unlike the three used on the EWQ box.

Vince and John were not bothered by this at all, they said it was more than enough to hold it in place.

He even showed me a lower mount bracket from a VR6 which also had two mount bolts only.

(If you are going to do the same conversion, it may be worth also buying the lower mount bracket from the car you are sourcing the gearbox from....just in case it fits onto the A2 chassis?)

LowerMount.jpg


Once the supplementary work to fit the different JDD housing was done, the rest of the job was uncomplicated with everything else being a straightforward fit.

2L of Titan Sintofuild gearbox oil, a quick check and the car was fired up. It ran all the new gears from the start without any problems and together with the new clutch it felt smooth and fluid.


Thanks to Vince for the first class work fitting this gearbox, he’s a very adept mechanic with an impressive knowledge of cars and the A2, plus he’s a good bloke to boot!



The New Gears


1st and 2nd Gears.

Although the JDD ‘box has slightly higher 1st and 2nd ratios than the EWQ (both geared up by the longer final drive ratio and longer 2nd), after a few drives, you get used to them very quickly.

Setting off in 1st, changing up to 2nd and 2nd gear corners feel no different and can be considered as no major difference to OEM.


Link - 1st Gear Range Youtube Video

Link - 2nd Gear Range Youtube Video


3rd Gear

3rd gear is the biggest adjustment to driving style with the JDD gearbox, you need to change up from 2,400rpm (2nd to 3rd) onwards due to the drop in revs changing up to the longer 3rd gear.

The remapped engine will still pull the car along if you change earlier, especially at these lower speeds(dropping down as low as 1,200rpm in 3rd) but you can feel that is not optimal for the engine.

It does feel more like a gear 3 ½, but I got used to that very quickly, and learned to change up to 3rd a little later than normal.

Saying that, the slight gearing up of the 1st and 2nd gears does aid the reach to 3rd and it doesn’t feel as much of a stretch as you would think coming from the EWQ gearbox ratios.

I found changing up at 3,000rpm (2nd) was optimal as the revs would drop to 2,000rpm (3rd) and the remapped car’s torque was fully on tap here to pull the car along without any problems at all, with speed and urgency.

3rd60mph.jpg


Link - 3rd Gear Range Youtube Video


4th Gear

4th is now effectively the EWQ's 5th. The revs are ever so slightly higher than the EWQ's 5th but they feel more or less the same.

You now have the OEM spread of gears 1st to 5th, compressed into just four gears. This felt strange to begin with.

Example: Doing around 55mph on an A-road in 4th......felt odd. I wanted to change up, but if I did the revs would drop too low for the longer 5th gear to pull. So I needed to change back down.

Driving around in 4th took some getting used to, it felt like I was wasting fuel being in 4th instead of 5th and I needed/wanted to be in 5th gear somehow?

But, I thought if I still had the original EWQ gearbox in, I would only have been in old 5th anyway and doing more or less the same rpm with no option to change up at all.

After just a one weeks use, I now like the being able to get up to old EWQ 5th (now JDD 4th) in less gears.

The wider torque band of the remapped engine really helps pull the wider 1st to 4th ratio gears along without losing any driveability.

After getting used to the new 4th, it now seems strange that this is was my highest gear before? Reving up to 80mph in 4th (3,100rpm) seems is very noisy now, although it’s similar RPMs as the old EWQ's 5th.

4th60mph.jpg4th70mph.jpg


Link - 4th Gear Range Youtube Video


5th Gear

5th gear is amazing for the relaxing transformation it gives the car on fast A-roads/Motorways.

The revs are so much more ‘civilised’ at motorway speeds, I didn’t think there would be so much difference in engine noise (compared to the EWQ).

At 60mph I cannot barely hear any engine noise at all. No wonder why the longer 5th and 6th gear chaps have been so happy with their mods!

If you do a lot of motorway miles then in my humble opinion a longer cruise gear is the best mod you can make.

5th70mph.jpg


Link - 5th Gear Range Youtube Video



Motorway Driving

I found that cruise control in 5th can be set to a minimum of 58mph, any lower and the engine would splutter slightly going up larger hills. From 58mph upwards I can cruise all day without any problems.

The reduced noise took some getting used to, I had to rely on cruise for a few days to keep my licence points free.

On the EWQ 'box cruising at 2,600rpm is 70mph, with the JDD gearbox you will be doing 85mph at those revs.

I did this a few times at first without realising, I accelerated until I got to the same noise levels as before, but now I was doing 85mph instead of 70mph!



Driving Normally

The 2009 Polo BlueMotion, which I have driven(a friend's car) has a shift light that comes on at 3,500rpm. This is the optimal shift point for the Polo.

There is no need to rev this high on the A2 and I found that 2,800-3,000rpm is the ideal shift point for the remapped A2.

The Polo has less power/torque and so it needed to be driven harder than the mapped A2 which pulled these longer gears with ease and less effort than the Polo.

I let my friend drive my A2 which now has the same gearbox as his BlueMotion, he was so impressed that he wants a remap for his car!


Link - Driving Normally Youtube video



Eco Driving

I am getting the following cruise MPG figures:

60 MPH = 75 MPG
70 MPH = 65 MPG
80 MPH = 55 MPG


As you can see it's quite a linear curve if you were to plot a graph. These figures are an average I have taken doing a few runs over distance in the past 8 months.

Using the brim to brim technique to work out MPG.

Don't think I am getting quite as high an MPG figure as possible with my car(compared to other members) due to a high -5 toe in on both my rear wheels.

Finding that on average I am getting about an 8% increase in MPG compared to the old EWQ 'box in all driving situations.


Link - Eco Normally Youtube video



Spirited Driving

The remapped A2 and JDD gearbox are very nicely matched indeed. Instead of frantically changing gears when doing some spirited driving you can just hold onto each gear longer and let the engine do the work.

Thought I would lose some acceleration when fitting this gearbox, but in fact I am using the power/torque band a lot more when I accelerate as you have to rev longer in each gear and acceleration seems the same.

One area where I feel the remapped TDI engine really helps here is above 3,000rpm.

Before the remap, the car would still accelerate past 3,000rpm, but was no linear power increase……just more noise!

A remapped TDI engine would really sing above 3,000rpm. It feels more like a petrol car because the revs and power keep climbing up progressively.

Now if you want to make swift driving progress you can use this RPM area(above 3,000rpm is where the biggest gains are from the remap) in 3rd or 4th effectively,.

Using the EWQ gearbox I was hardly going above 3,000rpm. There was no need to with the close ratio box keeping everything in the power band....why rev higher?

In fact, I don’t think I would recommend the JDD gearbox without a remap, I think the standard engine would struggle to pull the higher ratios swiftly.


Link - Spirited Driving Youtube video



City Driving

At first, I thought that this is the area where the JDD would suffer most, in this config you are replacing both the EWQ's 3rd and 4th gears with the JDD's 3rd only.

But if you look at the 3rd gear range video you will see that this gear has a range of 25mph-70mph! This makes it a great versatile gear for for most driving situations.

Using only 2nd and 3rd now until I get over 50mph, this is fine for city driving and I have no problems at all with these gears in the city.

Like being able to drop it into 3rd when approaching urban areas and leaving it there, again the extra pull from the remap really helps pull the wide-ranging 3rd along.

Still feel that the EWQ 'box would be better for out and out city driving as you have more choice of gears at these speeds but the JDD can be driven in the city without any problems using 2nd and 3rd.

If it was so undriveable in the city, I don't think they would sell many BlueMotion type cars for owners/reviewers complaining about the longer gears in town.



Conclusions

There aren’t as many compromises using this gearbox as I first thought before installation.

I can cruise in 5th doing 60mph, there are no big gaps in the gears to manage and drivability is well suited to a remapped TDI engine.

The only downside I have found so far is the high 3rd gear. Sticking to 30mph (1,750rpm) is awkward compared to the EWQ.

The low revs at 30mph make progress slower in 3rd gear, I use 2nd (2,800rpm) for 30mph now which is not ideal.

EDIT: Got used to driving in 3rd@30mph and I no longer regards it as a problem as will be stated later on in the thread.

But, after just a short time using it, the gears are natural to me now and in my opinion it’s a much better fit with a remapped TDI engine than the EWQ ‘box.

A few people have contacted me about test driving the car to check compatibility with the JDD 'box (I will PM you). To anyone thinking of the gearbox swap and wondering what it would be like before fitting.

I would suggest road testing a BlueMotion. The gear ratios feel the same in both cars. Just compensate for the lack of power in the BlueMotion compared to the remapped A2.

Once fitted, you will not feel the 23% increase in ratios as much as you would think. I know, I didn’t.

The adjustment comes very quickly and it does not feel massively different to the EWQ since the gaps are spread out so evenly. With general use and time, it does become second nature and I honestly prefer it now.

If you spend most of your time city driving and hardly ever get over 60mph, then the JDD 'box is not for you. You would lose out on using the longer 5th gear and be limited to just four gears, I do not engage the 5th until over 55mph.

I didn’t tell the other half about the gearbox change (she couldn’t care less about things like this!) and she didn’t comment on any difference when she drove it except for when we got onto the motorway.

Then she noted the stark difference in noise!

So, just a week of driving around with the new gearbox and I am absolutely delighted with the decision to change to the JDD gearbox. For my driving needs this combination is perfect.

I would even go so far to say - in my humble opinion the JDD box with a remapped TDI engine is the best 5-speed option for people who regularly drive over speeds of 60mph.


Thanks :D
 
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MikeMarsUK

A2OC Donor
Very well written report, and congratulations on the trailblazing mod :)

Roughly how much in total did it cost to fit etc given the work needed on the lugs (excluding the cost of the JDD gearbox)?
 

a2sumo

A2OC donor
As mike says very good mod and thanks for sharing -- nice to see our cars moving on and pushing the economic envelope. Mike
 

Hooley

A2OC Donor
How about a mini group meet (social) ?
Then we can all discuss the merits and pretend not to be jealous together...

J
 

Zoltar

A2OC Donor
Roughly how much in total did it cost to fit etc given the work needed on the lugs (excluding the cost of the JDD gearbox)?
Originally quoted four hours labour to change the clutch, Vince added another hour due to the extra work in fitting the JDD.

Total £250 + VAT
 

chubbybrown

Member
So all the driveshafts were the same?

my polo Bm 1.4 80bhp does 70mph at 2,000 rpm,you can toddle down to 40mph in 5th.3


After seeing this,I realise maybe Im not hard enough on my car going to 3000 anytime is hard let alone 4000rpm.
seems I need to do an italian tune up soon
 
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Zoltar

A2OC Donor
So all the driveshafts were the same?
After seeing this,I realise maybe Im not hard enough on my car going to 3000 anytime is hard let alone 4000rpm.
Yes, they are the same.

Don't normally drive like that! :eek:

I'm sure MPG will take a big hit on this tank with all the high revving action in 3rd, 4th and 5th doing those pictures and videos! ;)
 

dan_b

A2OC Donor
Is the Polo BM a 4-cyl diesel rather than our 3-cyl? I just wonder whether if it is that gives the Polo more tractability at load lower RPMs vs our rather old-fashioned lumpy 3-cyl motors, meaning it's actually more usable at low RPM even with less apparent torque?
 

MikeMarsUK

A2OC Donor
Originally quoted four hours labour to change the clutch, Vince added another hour due to the extra work in fitting the JDD.

Total £250 + VAT
I guess the JDD swap on it's own would probably be somewhere in the middle there, since some of the work needed would have been done as part of the clutch change.

It sounds like it is a very cost-effective mod if you are doing the clutch anyway ... about the same price as the 5th speed mod if you can get hold of a reasonably cheap JDD box, and a lot cheaper than the 6-speed mod.
 

RAB

Technical Specialist 1.2 TDI
3-pots help with torque in comparrison to a 4-pot; the 'pot' has a larger bore which assists torque - they have a natural uneveness though which needs to be smoothed out, typically by using a contra-rotating balancer shaft. The BlueBowelMotion has quite specific mapping though and whilst a remap helps the A2 use this box, the BBM is tuned specifically to perform at engine speeds the 1.4TDI is less happy at (i.e. below 1600rpm).
According to ETKA the current 1.2 and 1.6Tdi's use the same piston, so the bores are the same.

RAB
 

RAB

Technical Specialist 1.2 TDI
I was refering to a smilar size 4-pot engine, a 3-pot will have a bigger bore and/ or stroke NOT that the 3-pot 1.2 and 4-pot 1.6 have different size cylinders. A 1200cc 3-pot will have cylinders of 400cc each, a 4-pot will have cylinders of 300cc
The advantages of a 3-pot over a 4-pot of the same capacity are less frictional losses and that they can use components common to the proportionately larger 4-pot.

RAB
 

nuttinnew

A2OC Donor
BlueBowelMotion?!
One of the current three cylinders uses a weighted flywheel instead of a balancer shaft; looked at on it's own, it's out of balance, but when fitted it it's in sync with the engines natural wobble.
I think the current 70bhp petrol 1.2 would suit an A2 well.

Anyhow, back on topic; :cool: It looks like similar gearing to my Passat 130tdi, something I only mention because a remapped 90 has similar torque but 300-400kg less to move.

Can any 3L owners say how it compares to one of those? Just curious because it's about the only set of ratios we haven't seen.
 

RAB

Technical Specialist 1.2 TDI
The 3L ratios are 3.45, 1.95, 1.18, 0.81 & 0.64 with 3.33 final drive. 70mph at 2000rpm in 5th. Not so different from a JDD!

RAB
 

dan_b

A2OC Donor
So how does the 3L box compare to the standard 75TDi gearset then? Interesting to compare if you consider the 3L has longer gearing as well as less power/torque? Ok it's got even less weight to lug around, but still!
 
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