Tuning 20i

Has anyone ever spoke to BMW about tuning and whether the the warranty is void or not after tuning. I have read a lot of hearsay on these forums but have yet to read my engine went bang and BMW didn't cover it cause it was remapped. I have a ford transit sport which we put on the rolling road at PDT in Sunderland. Power increased from 139hp to 174hp after nearly a full day of tinkering and numerous dyno runs. Fuel economy was also improved. The van was tuned at around two months when the engine had bedded in. I informed the insurance company that the van had been remapped for fuel efficiency and they said that was fine, I told them that as a side effect of this there were gains in torque and horsepower, they were ok with this too and there was no increase in premium. I then contacted the dealer complaining about fuel economy and asked them if I could try improving it with a remap. The dealer told me a vehicle can be remapped in the interest of fuel economy on a rolling road no problem but plug in type devices would void the warranty.

I spoke with the BMW dealer yesterday regarding this and was told that in cases of fuel economy a car can be remapped. I didn't know this but evidently there were a lot of problems with Minis fuel economy a few years back and many had to be remapped by private companies as the BMW update didn't always work. My dealer is checking with BMW for me to see if the warranty is still valid if the ECU is remapped on a rolling road in the interest of fuel economy. I'll report back when I receive an answer. As for insurance already spoke to them today and it's covered if no more than 25% increase which is quite a chunk on a 35is.
 
Quadracer said:
Has anyone ever spoke to BMW about tuning and whether the the warranty is void or not after tuning. I have read a lot of hearsay on these forums but have yet to read my engine went bang and BMW didn't cover it cause it was remapped. I have a ford transit sport which we put on the rolling road at PDT in Sunderland. Power increased from 139hp to 174hp after nearly a full day of tinkering and numerous dyno runs. Fuel economy was also improved. The van was tuned at around two months when the engine had bedded in. I informed the insurance company that the van had been remapped for fuel efficiency and they said that was fine, I told them that as a side effect of this there were gains in torque and horsepower, they were ok with this too and there was no increase in premium. I then contacted the dealer complaining about fuel economy and asked them if I could try improving it with a remap. The dealer told me a vehicle can be remapped in the interest of fuel economy on a rolling road no problem but plug in type devices would void the warranty.

I spoke with the BMW dealer yesterday regarding this and was told that in cases of fuel economy a car can be remapped. I didn't know this but evidently there were a lot of problems with Minis fuel economy a few years back and many had to be remapped by private companies as the BMW update didn't always work. My dealer is checking with BMW for me to see if the warranty is still valid if the ECU is remapped on a rolling road in the interest of fuel economy. I'll report back when I receive an answer. As for insurance already spoke to them today and it's covered if no more than 25% increase which is quite a chunk on a 35is.
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Spoke to my BMW dealer and they so nope would void warranty full stop.

I think though in reality, they would have to prove that a remap would have contributed to any component failure.

To be honest for me more hastle than its worth plus I have a certain amout of mechanical sympathy for my cars :wink:

Tim.
 
On the flip side -----

I knew a chap who bought a Vauhall Corsa Arctic (VXR thing) He bought it from a main dealer and had been the dealerships demonstrator. It was known to have been remapped and sold as such.
The motor did go bang within the manufactures warranty period and can you guess what Vauxhall said when it needed a replacement????

They did replace the motor eventually but he spent some very sleepless nights!
 
As an observation - Ive looked back over this thread and there seems to be a pattern.

Newer members say "Tune / Remap"

Older Members say "Dont do it"
 
ronk said:
On the flip side -----

I knew a chap who bought a Vauhall Corsa Arctic (VXR thing) He bought it from a main dealer and had been the dealerships demonstrator. It was known to have been remapped and sold as such.
The motor did go bang within the manufactures warranty period and can you guess what Vauxhall said when it needed a replacement????

They did replace the motor eventually but he spent some very sleepless nights!
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I had the Corsa VXR,



The problem with them is, unlike the Astra VXR the pistons on the Corsa weren't forged but hollow :o There were alot of owners tuning them but resulting in the engine running lean which can cause excessive heat build up and the pistons to melt or snap with dire results. Its not unknown for standard cars to fail.

Nice car but the build quality wasn't great.

Tim.
 
These days there are tuning companies everywhere and it can be difficult to get booked in if they are good which means there is a great number of cars getting tuned. I have had pretty much everything I buy tuned and keep the vehicles 18-24 months 10k-15k miles per year. I have part exchanged at main dealers and as I look after them are sold with the remainder of the warranty on their forecourts. As there are thousands of cars sold at main dealers like this how would customers know whether a second hand car is remapped or not.

A properly tuned engine is safer from developing major faults as it has been tuned like a musical instrument. Every engine from the factory is slightly different, so picking out the minute flaws in the power curves and adjusting to smooth the curve makes the engine run at its best, providing an engine which not only will be more economical and have more power, but run cooler. Plug in devices are a no no, as they are just a generic map some of which allow the engine to rev a lot higher thus damaging the engine and use more fuel.

If you are going to have your car tuned have it done properly.
 
Ah forged pistons!

In my youth a bought a set for my 999 (970 +0.40) tuned cooper S - They cost me £35 for the set of four forged pistons - Two weeks wages I have to tell you! To make matters worse I suffered a melted piston only two or three thousand miles later. :(

As more power is extracted from an engine the stress levels inevitably go up !
 
Methods seem to have changed. To tune a motor years ago we started around gas flowing heads, manifolds carbs /fuel injection etc - then into camshaft changes etc.

How it seems that the tuners go directly to the electronics and control systems.


Is the breathing of the engine so good and efficient these days that it doesnt require any additional tweaking?
 
More power by fitting high comp pistons, cam shafts or gas flowing the head causes more heat and stress to the crank, clutch and gearbox selectors but remapping the ECU actually helps the engine runs better, has less stress on the engine and runs cooler. The extra HP and torque gains are only because the engine is running perfect and not because performance parts have been fitted. Many people fit a race pipe and k & N filter to help the engine breath easier increasing power, but don't remap the ECU on a dyno and this can cause considerable damage.
 
It's certainly easier now than with carbs. Changing needles, needle positions and jetting took forever. Many cars fried forged pistons due to incorrect jetting.
 
Quadracer said:
It's certainly easier now than with carbs. Changing needles, needle positions and jetting took forever. Many cars fried forged pistons due to incorrect jetting.
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Yes - Two weeks wages down the pan and I'm sure it was all down to the wrong jets in the SU's Oh happys days! :(
 
why would BMW miss a trick on mpg or power to weight unless there is a good reason?

downtuned engines have their afficianados. Reliability is more important than output to the vast majority of people. This mapping lark looks symptomatic of a throwaway society to me. I think that the people that do it professionally should be licensed and regulated. Any car that has been fettled should be identifiable as such throughout its lifespan.
 
When engines are built it is impossible for them to be identical. Castings, valves, valve springs etc, even slightly different packing or welds in an exhaust system can all make a difference. Think of it like a musical instrument. You can build a piano, trumpet or guitar but fine tuning has to be fitted to hit the exact note. A cars fine tuning is altered these days by means of the ECU. BMW could not set every engine to be perfect so they opt for a generic safe setting. The main reason for this is because the generic settings need to cover cars in all parts of the world at different temperatures and altitudes.
 
Quadracer said:
The main reason for this is because the generic settings need to cover cars in all parts of the world at different temperatures and altitudes.
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How does an engine system cope if for instance, I have it tweaked fo use at sea level in the UK, then take the car up into the Alps? Is that why maufacturers apply a one size fits all map to cover that potential variation?
 
Yes that is correct. Going back to the musical instruments. Tune your piano in the alps and it would be out of tune on a Mexico beach. The temperature change wouldn't be to much of a problem as the cars cooling system will cover just fine to keep things stable but prolonged use at altitude would need the mapping changed to suit.
 
Given your comments above, would you think a car tuned for sea level performance, suffer any lasting effects/damage if subjected to regular alpine runs. Or would it just feel a bit off key?
 
At altitude the air is thinner and has less oxygen in it to burn. This wouldn't cause damage, in fact it would run cooler. The higher you go the more power the engine looses anyway. The cars engine management system will self adjust to compensate to some extent as modern vehicles have sensors everywhere.
 
Are any of these tweaks noticeable doing the daily drive to work/shops etc? Especially in town/city traffic. I use my car for mixed motorway and urban trips and struggle to average 30 mph according to the trip computer.
 
TitanTim said:
Spoke to my BMW dealer and they so nope would void warranty full stop.
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BMW cannot void warranties under EU law. Otherwise they could void your warranty for fitting a stubby, dressing in a loud shirt after dark etc. :roll:

The reality is if you tune the engine they would be within their rights to turn down a warranty claim on the engine because it was tuned. They can't void the warranty on the whole car or any unrelated components. In practice, this doesn't happen often as even untuned cars develop engine faults occasionally but it's why we give a warranty with all our products, including our engine tuning.
 
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