TDI 75 remap longevity

[Malcyb]

I fear I risk making myself very unpopular by posting this, but I promise I’m not trolling, just doing my homework before buying.

So I was discussing A2s with my dad this afternoon; he used to own one, and a 30 year career as a research scientist for Shell means that he’s got more knowledge about the internal combustion engine than an awful lot of people - not that he likes to talk about it . I spoke to him about how lots of people had remapped their 75 TDis, and evidently had very good results, and he was adamant that it was a really bad idea. His opinion was that the TDI 90 had the DMF and balancer shaft for a good reason, to combat the vibration inherent in a 3 cylinder engine, but they were absent from the 75 because it’s lower output didn’t necessitate them. By performing a remap so the output of the 75 is similar to, or even higher than, the standard 90, he asserted that this would put stress on the engine that it wasn’t designed to take without the DMF and balancer shaft, and that this could have a fairly drastic effect on longevity. I have to say I could see the cold logic in his argument.

So would anybody here like to provide evidence to refute his claim, either from practical experience or technical knowledge? How long have people been running remapped 75s without issues, and has anybody experienced problems?

Sorry again if it appears I’m being controversial for the sake of it, honestly that’s not my intention. But if the TDI 75 is seen as one of the most reliable options, I don’t want to risk significantly compromising it at the expense of improving the driving experience.

 

[Andrew]

No need to be sorry about being controversial you ask a valid question. I have petrol so cannot comment but I am sure you will have some opinions in due course.

Andy

 

[Edwrai]

I fear I risk making myself very unpopular by posting this, but I promise I’m not trolling, just doing my homework before buying.

So I was discussing A2s with my dad this afternoon; he used to own one, and a 30 year career as a research scientist for Shell means that he’s got more knowledge about the internal combustion engine than an awful lot of people - not that he likes to talk about it . I spoke to him about how lots of people had remapped their 75 TDis, and evidently had very good results, and he was adamant that it was a really bad idea. His opinion was that the TDI 90 had the DMF and balancer shaft for a good reason, to combat the vibration inherent in a 3 cylinder engine, but they were absent from the 75 because it’s lower output didn’t necessitate them. By performing a remap so the output of the 75 is similar to, or even higher than, the standard 90, he asserted that this would put stress on the engine that it wasn’t designed to take without the DMF and balancer shaft, and that this could have a fairly drastic effect on longevity. I have to say I could see the cold logic in his argument.

So would anybody here like to provide evidence to refute his claim, either from practical experience or technical knowledge? How long have people been running remapped 75s without issues, and has anybody experienced problems?

Sorry again if it appears I’m being controversial for the sake of it, honestly that’s not my intention. But if the TDI 75 is seen as one of the most reliable options, I don’t want to risk significantly compromising it at the expense of improving the driving experience.

The TDi 75 does still have a balancing weight which runs off the oil pump chain, this is the same between the 90 and the 75, the differences is the DMF


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[Malcyb]

The TDi 75 does still have a balancing weight which runs off the oil pump chain, this is the same between the 90 and the 75, the differences is the DMF


Sent from my iPhone using Tapatalk

Ok, thanks for putting me straight on that. However I think the question sill stands partially since I believe the DMF is there to reduce vibration. If it’s standard on the 90, wouldn’t it be strictly necessary on a remapped 75?

 

[depronman]

The DMF was put on the 90 to protect the gearbox not the engine
The extra torque that is delivered at very low revs on the TDI 90 due to the VVT turbo would put the transmission at risk if you where repeatedly to rev it and drop the clutch very abruptly (boy racer ish)
A remapped 75 will not develope the same torque as low down, but some degree of care should still be used when setting off from a stand still to respect the gearbox

 

[Malcyb]

The DMF was put on the 90 to protect the gearbox not the engine
The extra torque that is delivered at very low revs on the TDI 90 due to the VVT turbo would put the transmission at risk if you where repeatedly to rev it and drop the clutch very abruptly (boy racer ish)
A remapped 75 will not develope the same torque as low down, but some degree of care should still be used when setting off from a stand still to respect the gearbox

Thanks Paul that’s quite reassuring. I was looking for details about the remaps you do; do you still do them? Do you have comparative torque curves, before and after remap, so I could compare with a 90?

 

[steve_c]

Thanks Paul that’s quite reassuring.

Please read the current A2OC policy on remapping before pursuing this line of discussion any further:
https://www.a2oc.net/community/inde...mapping-services-revised-a2oc-protocol.37302/

 

[Darren C]

Sorry @Malcyb, A2OC does not allow discussion relating to member offered remapping services following a previous issue regarding allegations of copyright.

Thanks Paul that’s quite reassuring. I was looking for details about the remaps you do; do you still do them? Do you have comparative torque curves, before and after remap, so I could compare with a 90?

 

[Robthebank]

I must admit a TDI A2 is always keen to spin its front wheels remapped or not, so I doubt the torque is actually that possible to capture.

 

[Malcyb]

Sorry @Darren C. I’ll keep the question on the general topic of remapping this engine rather than the work of anyone on the forum.

 

[Darren C]

Thank you pal and apologies for interrupting the flow of the thread.

Sorry @Darren C. I’ll keep the question on the general topic of remapping this engine rather than the work of anyone on the forum.

 

[nee777.a2]

My tdi 75 was mapped by Vince at Stealth with print out and proof an unbelievably 114bhp in 2015 I’ve just hit the 106k miles and drive it should I say spritly with not one issue just to add I’ve owned a few tdi A2 and all been remapped with no issues.

 

[Olerype]

From VW motorsport:

 

[Malcyb]

From VW motorsport:

View attachment 61638

Depressingly, this suggests my dad might have had a valid point. You’d expect VW Motorsport to know what they’re talking about, though some may argue “they would say that wouldn’t they?”

 

[Malcyb]

My tdi 75 was mapped by Vince at Stealth with print out and proof an unbelievably 114bhp in 2015 I’ve just hit the 106k miles and drive it should I say spritly with not one issue just to add I’ve owned a few tdi A2 and all been remapped with no issues.

can I ask how many miles you’ve done on them since being remapped?

 

[Olerype]

Depressingly, this suggests my dad might have had a valid point. You’d expect VW Motorsport to know what they’re talking about, though some may argue “they would say that wouldn’t they?”

Not sure, have no further information what kind of remap VW motorsport made. Remap also comes with benefits that promote longevity, closing EGR as one.

I did remove my remap because it probably was the reason (together with age) my engine mounts went, but after replacing those, I am not reluctant to put the remap back again.

 

[Malcyb]

Remap also comes with benefits that promote longevity, closing EGR as one.

Absolutely - the Pro boost FSi remap is completely different, the question just applies to remap to boost performance, and the statement you found seems to be referring to exactly that.

 

[nee777.a2]

can I ask how many miles you’ve done on them since being remapped?

Around 50k

 

[Ian Bigg]

I remapped my own 75 and have done approx 3000 miles since I did it. Changed the oil and filter before hand along with the air filter. MPG is better
No issues so far but I wouldnt be very good at my job if there were.
I am NOT offering my remap on this thread but I understand if this post is pulled

 

[Malcyb]

I remapped my own 75 and have done approx 3000 miles since I did it. Changed the oil and filter before hand along with the air filter. MPG is better
No issues so far but I wouldnt be very good at my job if there were.
I am NOT offering my remap on this thread but I understand if this post is pulled

It would seem like a real shame if this thread was pulled since at the outset I was looking at the remap offered by stealth racing and wasn’t even aware that OC members had done their own. That said I get the point that those members with the most expertise on the subject and properly qualified to comment will be those who’ve done it themselves, in which case it’s getting into delicate territory. If Admin decide to delete it then I’ll reluctantly understand And if they do then it’s already been a learning experience.