Questions on remapping and stainless exhausts?

UK forum for general and technical discussion about the Z3 roadster

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Joined: Mon 18 Jul, 2016 18:38
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  Z3 roadster 1.9

Questions on remapping and stainless exhausts?

Post by swabyk » Wed 31 Aug, 2016 18:58

Anyone had ECU remapping done on their cars, being told it's about a 20-25bhp increase but wondered if it would harm the engine in the long run? Whats your thoughts?

Lastly, anyone with stainless exhaust systems, my car is only used in the summer, garaged most of its life, is it worth it over a 'standard' Kwik-fit type affair for mileage of around 3k a year at best?


Joined: Sat 19 Nov, 2011 18:35
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  Z3 roadster 1.9

Re: Questions on remapping and stainless exhausts?

Post by Del » Wed 31 Aug, 2016 20:09

I have had both done on my 1.9 (M44 engine). The remap was done by a reputable local firm. They did what they called a “stage 1” remap which was designed for a naturally aspirated, standard engine. The BHP increased from the standard 138 to 152 – one or two other forum members have had a similar job and enjoyed a similar BHP increase. The car runs more smoothly, is more responsive, gives slightly better economy and does not require higher octane fuel. The car spent a couple of hours on a rolling road followed by tweaks via a laptop. From memory it cost around £275. This generation of BMW seems to have been slightly “detuned” from the factory to cope with some poor fuel around the World – I believe I’m correct in saying that fuel can be poor quality in the US? Furthermore, the “maps” on these cars were put together some 20-years ago and the “mapping facilities” available today are much more sophisticated and better facilitate “optimum fine tuning” across the rev range.

My cat failed a few years back and the rear section was in poor condition. I have a “Longlife” stainless steel system with the same dual silencers for the quietest option, although stainless steel systems are a bit louder than the BMW mild steel systems – something to be aware of when choosing the various options! The “Longlife cats” seem to be rubbish and after two subsequent MOT failures (failed cat) and warranty claims, I went to another firm that fitted just a cat (type approved) – which touch wood has been fine.

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  M roadster S54
Location: Romford Essex

Re: Questions on remapping and stainless exhausts?

Post by Gazza » Wed 31 Aug, 2016 22:29

I had my previous 2.8 and my M remapped, each gave better 'drivability'

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

Z3 S54 M roadster Image, BMW Z1, BMW M3 CSL, Z4M Coupe

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