3.0i Remapping

[X-S-Z]

I have been speaking to Plowy about his remapping experience as its something I am considering getting done. However the companies I have approached so far just offer a software remap that was designed and tested on a rolling road, not actually remap your car on a rolling road. It is my understanding that each engine is fairly 'unique' and from the factory and life usage the standard '231 bhp' can vary significantly? I know they're all made on a production line but that has tolerances too.... Thereby meaning any 'standard' remap you have configured on a certain base car will have a different effect on each car, thus to get the best out of an individual car it should be undertaken on a rolling road? Are my assumptions correct?

When I raised this question with a company my response went as follows:

"Engines are not unique from the factory, they are all the same, cylinder heads, pistons, block ect ect are all build on the production line. Then the software is loaded into the ECU, job done. BMW do not "custom map" or fine tune each map to each engine built, it’s the same map applied to all the same engines built on the production line. Some engines when checked on a dyno will push out more or less power, this isn’t down to the way the engine was built or the mapping, its down to the way the engine has been driven, servicing, quality of oil ect ect. A engine that is low mileage and driven very sedately will be tighter than a engine that has been thrashed and done higher miles as its looser. A tight engine will give lower bhp than a loser engine.

There are a lot of tuning companies offering "live mapping", "custom mapping", this is merely a marketing gimmick which gives people the reassurance that they are getting a better job checked on a dyno owned by the company doing the remap. I personally would not use a company who does remapping and checked on a their own dyno, for obvious reasons."

What are these apparent obvious reasons? That they may 'rig' the dyno results? Does anyone have any experience and recommendations?

 

[tedster]

give simon a ring at E Maps very knowledgeable guy very honest, i heard about him from the bmwland forum loads of people on there have used him for a remap. He has done my 3 litre to 246 bhp and +20nm of torque but its the responsiveness thats best and how much eager it is to go threw the rev range it removes the 155mph limiter aswell if your that brave. (i aint) http://www.e-maps.co.uk/

 

[Curtis]

It is possible to 'rig' a dyno to show improvements so be carefull! Generic remaps tend to be fine for cars with little or no modifications. A good company like ESS will spend a massive amount of time modifying and testing a map, not just on a dyno but out on the road too. These maps will generally improve throttle response, torque, hp etc and remove the two built in flat spots used for emmisions testing. The torque and hp gains can be fairly minimal but it's the overall effect that makes it worthwhile, things like smoother power delivery etc. Live remaps tend to be used on race cars or heavily modified road cars where the standard remap can't take into account the changes you've made to the standard engine. You will get away with minor changes such as exhaust, air filter and such with a generic remap. Be very careful of any company who advertise a huge power gain. That's what attracts the public to buy their product over someone elses so they have been known to lie!! A good honest company will tell you to expect moderate HP gains but remember, HP isn't everything.

The response you got from the company is quite correct. The software map in each car is the same however it's the engines themselves that vary in power output and characteristics. Although each engine is built the same there will always be minor differences between them which will effect performance. I watched a programme once on a NASCAR team who of course built their own engines by hand. Each engine was fitted as you would expect with the best parts available on the market and everything was done to exact tolerances. Each engine was dyno'd and there were power differences of up to 35hp! The high output engines were kept for racing and the low power ones were used elsewhere. That's what can happen when seemingly identical engines using the best parts available are built to a very high standard so it's not surprising that mass produced engines which to be honest are built to a budget using mediocre parts can produce varying outputs.

Also a loose engine will rev more freely than a tight one as mentioned. I have always thrashed the sh*t out of every car I've ever owned from new, partly because that's just the way I drive and partly to loosen the thing up. Being from the UK you'll probably remember the crappy old Peugeot 405's. They practically had a full engine rebuild with new liners and pistons with every 18k service but if you got one that had been thrashed from new they were brilliant trouble free engines! BMW ask you to break your car in gently when new but I've never understood why, if they were built to a good standard ( which BMW say they are ) you shouldn't need to worry about bedding in the engine. I build a lot of engines for racing and once they're complete I don't trundle round town with them for 1200 miles before pushing them. They either go straight on a dyno and get thrashed or go straight in a race car and get thrashed. If there was any benifit to breaking them in gently you would see loads of days where race cars just chugged round race circuits bedding in their engines ready for the big day when they would be used in anger. That's just my opinion and experience as well as everyone else I know in the racing world but I'm sure there are a load of people out there who will say " if BMW say that's the best way then I trust their judgement" and that's fine. The last time I trusted BMW's judgement my propshaft fell off but that's another story.