Genuine question re remapping downsides

[Welshbeef]

As per the title what are the disadvantages of remapping? List I have

1. Cost to do it
2. Increased insurance premiums
3. Wear in gearbox but if you have an auto say a 330d auto and map it then it's up to 335d power and torque yet exactly the same gearbox
4. Increased fuel consumption

[TheEnd]

Warranties for drivetrain components can be voided on newer cars.

[GenePoolReject13]

I would strike a line through number 4, when I had my Focus TDCI remapped I got ever so slightly better mpg. Not enough to recover the cost in a reasonable time but I did see a slight increase.

Biggest downside would be the extra strain on things like injectors on turbo diesels not sure about petrols. Could cause some expensive components to wear quicker than expected.

[Engineer1]

The fact you are tweaking something outside the manufacturer's parameters, but consider most vehicles are tuned for a world market so different variable fuel qualities, -40 to +40c temperatures, altitudes etc. some of which aren't relevant to a car in the UK.

[PUA]

especially with turbo's its the risk to other parts so it's advisable to also change things like dump valves, also reduces the life of the clutch.

In my experience it can also bring to the fort underlying mechanical problems that would otherwise have gone unnoticed..

[Welshbeef]

Say in an example where it's auto so no clutch and the gearbox is used for a higher powered model as is and that you are increasing torque and power to that higher value? Would drive train be unaffected?

[Ecurie Ecosse]

It really depends on the car. In your example, where the car's gearbox can handle the power, it will be fine.

An example would be the 123d, which has a strong manual box so remapping is fine, but the auto is near the top end of its power already so you need to be careful.

Another issue is potential warranty claims, but of the car is older that isn't a problem.

[Pints]

A colleague at work had his mk4 Golf remapped a couple of months ago. I don't think it's entire coincidence that he now needs a new headgasket.

Although he did say his fuel consumption had improved since having it done, re point 4 above.

[VolvoT5]

I think it depends on how old the car is and how long you are planning on keeping it.

I've had 2 older cars remapped, first one blew the head gasket <1k later and the second one saw the clutch slipping within 50 miles.

It will increase your insurance premium (if you declare..) and your fuel consumption will go up if you use the extra power.....

I wouldn't bother again unless it was on a new car and a remap/performance pack offered by the original manufacturer which didn't void the warranty.

[Rakoosh]

Not all remaps are to increase power. For example I have heard of Elise R owners changing the mapping to provide a slightly more even and usable power curve (albeit I think less top end power). These remaps are ok I would say??

But I am guessing you mean increased power remaps in which case I think the question can be flipped...

What are the remapping upsides to make it worthwhile?

Do people really need the greater power a remap provides? Is there not a car model that provides that power and would the cost difference not really equal out?

I've often wondered why people choose to do it but thats just me I guess. This is not meant to be a judgement and I have considered cars (and a van!) that have been remapped.

Interestingly (I cannot speak for other people) - often I have ruled out on the basis that I'd like the car to be standard.


I'll therefore add another downside:
I think its harder to sell certain cars that have been remapped and it can have a negative impact to the sale price.

[Ozzie Osmond]

Welshbeef said:

As per the title what are the disadvantages of remapping? List I have

3. Wear in gearbox but if you have an auto say a 330d auto and map it then it's up to 335d power and torque yet exactly the same gearbox

Yes, but don't forget the driveline runs all the way from combustion chamber to wheels. The first place your enhanced power/torque arrives is at the crank-shaft where the "bottom end" of your engine has to handle the force, then your auto box, then the diff. In a car like yours the auto box is quite likely the weakest link and the manufacturer will have designed a careful torque management strategy into the car's software.

[Engineer1]

I suspect a lot depends on the engine and if it's a BMW/ Audi 0ne engine five states of tune situation in which case you may be able to get the top performance out of a lower engine with little risk but take an already highly tuned engine and tinker some more is opening you up to oops that was just at its limit already.

[Welshbeef]

Engineer1 said:

I suspect a lot depends on the engine and if it's a BMW/ Audi 0ne engine five states of tune situation in which case you may be able to get the top performance out of a lower engine with little risk but take an already highly tuned engine and tinker some more is opening you up to oops that was just at its limit already.

Is the E90 330d 231 bhp close to its limits? (honestly do not know).

[Willy Nilly]

Welshbeef said:

Is the E90 330d 231 bhp close to its limits? (honestly do not know).

How much power do you need?

Lets be honest, 231hp is probably about enough on public roads

[Wills2]

I remapped/chipped my 2.7V6 allroad with no issues, the people I know running a re-mapped 3.0d BMW have had no issues.

Most 3.0d maps will give you an additional 50bhp and slightly more in ft/lb say 60-70lb/ft so you're increasing by 20% can't see that causing any real issues, best to get the car checked so everything is in tip top nick before you start.

I had a re mapped e60 530d for a week and it was a great drive and the engine was very strong, my daily car at the time was e92 M3 and it didn't seem like a step down driving the 530d.

[anonymous-user]

GenePoolReject13 said:

I would strike a line through number 4, when I had my Focus TDCI remapped I got ever so slightly better mpg.

I can explain, in really fundamental technical terms why this is extremely unlikely to be true, so can you explain the science behind your statement that it is true?

[davepoth]

Welshbeef said:

Engineer1 said:

I suspect a lot depends on the engine and if it's a BMW/ Audi 0ne engine five states of tune situation in which case you may be able to get the top performance out of a lower engine with little risk but take an already highly tuned engine and tinker some more is opening you up to oops that was just at its limit already.

Is the E90 330d 231 bhp close to its limits? (honestly do not know).

Unlikely - it appears to be identical to the 335d except for the turbos so the bottom end and the rest of the drivetrain can certainly take more. Mapping it for more power might result in premature turbo wear or increased inlet temperatures but that would be very dependent on the specifics of the vehicle.

[philmots]

Welshbeef said:

Is the E90 330d 231 bhp close to its limits? (honestly do not know).

Nowhere near it's limits! It remaps to around 300hp and 500lbft so there's LOTS left in the standard car.

It's the car I'm buying next, and having done weeks of online research it's an ideal car as it's running gear is the same as the 335d anyway. Although, manuals struggle with torque so knackers the clutch and DMF's.

Go for it.

[Welshbeef]

Car is touching 100k miles would it do another 100k mapped or would that be pushing your luck?

Does mapping damage injectors in any way or is it purely turbo clutch gearbox big end bearings?

[philmots]

davepoth said:

Welshbeef said:

Engineer1 said:

I suspect a lot depends on the engine and if it's a BMW/ Audi 0ne engine five states of tune situation in which case you may be able to get the top performance out of a lower engine with little risk but take an already highly tuned engine and tinker some more is opening you up to oops that was just at its limit already.

Is the E90 330d 231 bhp close to its limits? (honestly do not know).

Unlikely - it appears to be identical to the 335d except for the turbos so the bottom end and the rest of the drivetrain can certainly take more. Mapping it for more power might result in premature turbo wear or increased inlet temperatures but that would be very dependent on the specifics of the vehicle.

and +1