Engine remap downsides?
Discussion
Are there any downsides to remapping a modern diesel car? I've always avoided it in the past but wish I had done the last one, and with a newer car on the way (out of warranty, but 5 years old), Celtic Tuning will charge £300 to remap it with additional HP and better fuel economy (apparently). Gearbox should be good for the power, so what, if any, are the risks?
Insurance will be more expensive. Clutch and flywheel won’t last anywhere near as long as stock (around 1/3rd the lifespan), gearbox at risk too. You’ll get through tyres faster, brakes might not last quite as long either - depends how you drive obviously, but if the extra power is there, you’ll definitely be inclined to use it more often.
Edit: boost pipes more likely to split too.
Edit: boost pipes more likely to split too.
Edited by georgeyboy12345 on Friday 25th August 16:51
From remapping 2 diesels.
One company says on their website that more regular servicing should happen so more frequent servicing costs compared to normal maintenance.
Boost hoses failed shortly after a remap so had to get upgraded ones. But silicone hoses are generally fit and forget, but still a cost to be considered.
Some insurance companies will charge more, some don’t.
I’ve always declared them.
Extra power and torque can highlight other weaknesses.
Brakes, suspension and transmissions will be worked harder so make sure they are in good condition before adding power.
My remaps have improved drivability, better lower and mid range grunt, mpg has been better as you aren’t working it as hard to get going etc.
Beware of cheap tuning boxes and over the top power claims.
A remap from someone who specialises on the model you have is a good idea as they should know how much power and torque can be added safely.
One company says on their website that more regular servicing should happen so more frequent servicing costs compared to normal maintenance.
Boost hoses failed shortly after a remap so had to get upgraded ones. But silicone hoses are generally fit and forget, but still a cost to be considered.
Some insurance companies will charge more, some don’t.
I’ve always declared them.
Extra power and torque can highlight other weaknesses.
Brakes, suspension and transmissions will be worked harder so make sure they are in good condition before adding power.
My remaps have improved drivability, better lower and mid range grunt, mpg has been better as you aren’t working it as hard to get going etc.
Beware of cheap tuning boxes and over the top power claims.
A remap from someone who specialises on the model you have is a good idea as they should know how much power and torque can be added safely.
Mapping can make the car more powerful but a bit less pleasant to drive.
I had a Volvo V40 D3 and polestar mapped it to make it a D4 - 177hp vs 150hp original.
Although the D4 has more power, it loses out on a bit of low down torque making it less pleasant when pulling away as there is an initial dead spot that's not there on the standard map.
I had a Volvo V40 D3 and polestar mapped it to make it a D4 - 177hp vs 150hp original.
Although the D4 has more power, it loses out on a bit of low down torque making it less pleasant when pulling away as there is an initial dead spot that's not there on the standard map.
Depends on your specific car and what the mappers are actually doing. Some diesels have torque limits in the first couple of years to prolong clutch and flywheel life, some mappers will remove this to enhance the power delivery experience. You should be able to talk to them and explain you are perhaps not after peak power in 1st an 2nd but want the benefits in the higher gears.
The only diesel I've ever had played with was a 2001 Saab 93 tid which had 30hp added for 40+k miles and it was the fuel pump failing when it was on 170k that saw me get rid. The clutch/gearbox and engine had no issues. On a petrol engine my Mk5 golf gti has had a +50hp stage 1 map from 80k, it had a clutch an flywheel at 130k and is now on 177k! I don't believe any of the component failures I've incurred are remap related. For reference the Golf had a custom map done on it by a local VW specialist, the Saab a generic "Noob tune" from a guy on the Saab forums, I have no experience of Celtic tuning.
The only diesel I've ever had played with was a 2001 Saab 93 tid which had 30hp added for 40+k miles and it was the fuel pump failing when it was on 170k that saw me get rid. The clutch/gearbox and engine had no issues. On a petrol engine my Mk5 golf gti has had a +50hp stage 1 map from 80k, it had a clutch an flywheel at 130k and is now on 177k! I don't believe any of the component failures I've incurred are remap related. For reference the Golf had a custom map done on it by a local VW specialist, the Saab a generic "Noob tune" from a guy on the Saab forums, I have no experience of Celtic tuning.
Having had 3 totally brilliant remapped bmw 3 series, im now at the point when whenever i consider what car to buy next, the first thing i do is see what a remap will do for it. Even more so these days given 95% of cars have a turbo.
In my opinion, if diesel engines are used properly and serviced regularly, theyre pretty bulletproof. Its everything else that'll wear out faster.
Rear tyres on my remapped 330d take a pounding, theres a lot of torque applied when right foot is deployed!
In my opinion, if diesel engines are used properly and serviced regularly, theyre pretty bulletproof. Its everything else that'll wear out faster.
Rear tyres on my remapped 330d take a pounding, theres a lot of torque applied when right foot is deployed!
brillomaster said:
Having had 3 totally brilliant remapped bmw 3 series, im now at the point when whenever i consider what car to buy next, the first thing i do is see what a remap will do for it. Even more so these days given 95% of cars have a turbo.
In my opinion, if diesel engines are used properly and serviced regularly, theyre pretty bulletproof. Its everything else that'll wear out faster.
Rear tyres on my remapped 330d take a pounding, theres a lot of torque applied when right foot is deployed!
BMW diesel engines are far from bulletproof. The police have dropped 30d cars after catastrophic failures. In my opinion, if diesel engines are used properly and serviced regularly, theyre pretty bulletproof. Its everything else that'll wear out faster.
Rear tyres on my remapped 330d take a pounding, theres a lot of torque applied when right foot is deployed!
Whataguy said:
Mapping can make the car more powerful but a bit less pleasant to drive.
I had a Volvo V40 D3 and polestar mapped it to make it a D4 - 177hp vs 150hp original.
Although the D4 has more power, it loses out on a bit of low down torque making it less pleasant when pulling away as there is an initial dead spot that's not there on the standard map.
My VEA D4 doesn’t feel like it loses out on torque with the Polestar software. It’s a really pleasant thing to drive. However I do think the auto would suit it better. That gets a tune with the map too. I had a Volvo V40 D3 and polestar mapped it to make it a D4 - 177hp vs 150hp original.
Although the D4 has more power, it loses out on a bit of low down torque making it less pleasant when pulling away as there is an initial dead spot that's not there on the standard map.
If we’re talking basic remap, then 15-2-% more power yes?
In my experience, you get a bit more power, but a dramatically better engine to use.
Faster spool time in Turbo cars, generally cures drivability issues.
Clutch and flywheel life will only be effected if you use them poorly. If you don’t slip them and hot shift, you’ll never have an issue.
If you have added enough power to wear an engaged clutch, then that’s a different story!
Downsides for me?
Warranty. They are mostly flagged instantly, so there is no such thing as ‘Cheeky re-map’ on newish cars anymore.
Insurance. Probably costs a bit more.
Resale. Narrows clientele. Or you have to pay to revert to standard and then not disclose (but a dealer might tell them if they plug in)
Corrupted steering and avoiding wheel spin/hop. Generally Turbo FWD cars are too compromised by their drivetrain layout.
Tyre wear if you indulge. Although on the road, no need to worry about brakes, as you terminal speed on straights will be more about licence preservation, than maximum achievable.
Any more?
In my experience, you get a bit more power, but a dramatically better engine to use.
Faster spool time in Turbo cars, generally cures drivability issues.
Clutch and flywheel life will only be effected if you use them poorly. If you don’t slip them and hot shift, you’ll never have an issue.
If you have added enough power to wear an engaged clutch, then that’s a different story!
Downsides for me?
Warranty. They are mostly flagged instantly, so there is no such thing as ‘Cheeky re-map’ on newish cars anymore.
Insurance. Probably costs a bit more.
Resale. Narrows clientele. Or you have to pay to revert to standard and then not disclose (but a dealer might tell them if they plug in)
Corrupted steering and avoiding wheel spin/hop. Generally Turbo FWD cars are too compromised by their drivetrain layout.
Tyre wear if you indulge. Although on the road, no need to worry about brakes, as you terminal speed on straights will be more about licence preservation, than maximum achievable.
Any more?
Roboticarm said:
I had my old 320d remapped, was much quicker, but kicked out black smoke on WOT and the clutch didn't last long.
Custom remaps are probably okay, but those one size fits all are best avoided
Like the ones they put in at the factory ?Custom remaps are probably okay, but those one size fits all are best avoided
Edited by Roboticarm on Friday 25th August 20:46
A standard remap is fine on an otherwise standard car, a “custom” remap won’t be done from scratch as it’s a massive task, so the starting point is a generic map that may, or more likely not, get tweaked, cheeked yea but they won’t ever write a fully bespoke map as it takes ages.
Generally it will be a dyne run to check all is well and some minor changes but won’t be a completely new map as it’s the same hardware.
Actual custom mapping is hours of dyne time by people who know what they are doing, it’s like you don’t expect Elton John or whoever to sing every time for you in the car, a recording is fine.
So many seem to think a standard map is crap, had to be custom but it generally isn’t unless it’s something very special and you have thousands to pay for the time.
It’s a computer, controlling a machine, they all start the same so an optimised version of the original will work all other things being equal, they don’t do bespoke maps at the factory.
Remapped my BMW F10 535d when it reached 100,000 miles and deleted the DPF and EGR.
Now on 225,000 miles and running like a Swiss watch. MPG improved from 39 to 44mpg. Power and torque bumped by about 15% with dyno test to prove before/after. Wish I had done it from the start.
No smoke from the exhaust. I do an oil and filter change every 10,000 miles which is twice a year. I use a competent local independent garage. It is driven with some mechanical sympathy until warm and is not switched off whilst the turbos are red hot etc. It will run for years yet. I am planning on putting another 100,000 miles on it I think as the newer replacements are little different but package in a much more expensive car.
I've also remapped an L322 Rangerover TDV8 and remapped and highly tuned a Toyota GT86. All with zero issues or snags.
Modern cars are so hampered by noise and emissions and efficiency regs that a remap often just frees them of onerous requirements whilst taking them nowhere near the edge of their reliability and maximum performance capability.
Get it done. I use a broker to get insurance and declare the modifications and its never been an issue.
Now on 225,000 miles and running like a Swiss watch. MPG improved from 39 to 44mpg. Power and torque bumped by about 15% with dyno test to prove before/after. Wish I had done it from the start.
No smoke from the exhaust. I do an oil and filter change every 10,000 miles which is twice a year. I use a competent local independent garage. It is driven with some mechanical sympathy until warm and is not switched off whilst the turbos are red hot etc. It will run for years yet. I am planning on putting another 100,000 miles on it I think as the newer replacements are little different but package in a much more expensive car.
I've also remapped an L322 Rangerover TDV8 and remapped and highly tuned a Toyota GT86. All with zero issues or snags.
Modern cars are so hampered by noise and emissions and efficiency regs that a remap often just frees them of onerous requirements whilst taking them nowhere near the edge of their reliability and maximum performance capability.
Get it done. I use a broker to get insurance and declare the modifications and its never been an issue.
I had a Celtic re-map on my Renault Traffc when brand new in 2010, instantly the van was smoother, better fuel consumption and the sweet spot in the rev band was much lower. A 100% improvement overall including 44 mpg on a heavy loaded van. To date it has done 130K miles plus with no issues.
Fast forward to 5 years ago I was upgrading my Mini Clubvan with a Celtic re-map again improved beyond my expectations.
So if you would like the opinion of someone who has used them they are superb.
I was tempted to have my V12 twin turbo CL65 AMG re-mapped but at over 600 BHP standard I thought a re-map would be overkill.
Fast forward to 5 years ago I was upgrading my Mini Clubvan with a Celtic re-map again improved beyond my expectations.
So if you would like the opinion of someone who has used them they are superb.
I was tempted to have my V12 twin turbo CL65 AMG re-mapped but at over 600 BHP standard I thought a re-map would be overkill.
J4CKO said:
Roboticarm said:
I had my old 320d remapped, was much quicker, but kicked out black smoke on WOT and the clutch didn't last long.
Custom remaps are probably okay, but those one size fits all are best avoided
Like the ones they put in at the factory ?Custom remaps are probably okay, but those one size fits all are best avoided
Edited by Roboticarm on Friday 25th August 20:46
It’s a computer, controlling a machine, they all start the same so an optimised version of the original will work all other things being equal, they don’t do bespoke maps at the factory.
I agree that custom remaps are best of customised cars, however I have direct experience with an "off the shelf remap" improving some aspects but at great cost to others
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