Looking to replace my time machine
- Thread starter Catanonia
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Spot the typo 
Soldato
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- 3 Jun 2005
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[TW]Fox;23053013 said:
Oh ok, I thought over 3 litre the running costs grew significantly. I stand corrected. I remember you saying in the past the running costs for 2.0, 2.5 etc were roughly the same as the 3 litre.
Two turbos?
One small one which stops at 3k and another (larger) which takes over afterwards. A remap in this configuration would have little effect on two turbos over just one.
Most respectable tuners won't take the N54 x35i past 370bhp and even that is pushing it
Most respectable tuners won't take the N54 x35i past 370bhp and even that is pushing it
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![[TW]Fox](/data/man-of-honor/2009.png){kind=avatar}
Nope, thats the 335d. The 335i isn't sequentially turbocharged.
If you turn off the map is it still the same MPG on the motorway? I get almost 10mpg more with the same engine (no map) in my Z4 on my M4 commute (averaging about 70 on motorway for 30 miles) so I was impressed you got sub 30 I must admit.
Either way, you should keep the beast.
Either way, you should keep the beast.
If I recall it says up to 80BHP at the wheels.
The "map" won't make any noticeable difference when cruising at low rpm.
Why not (genuinely interested)? The JB3/4 isn't just a tool for turning up max boost, it alters lots of different parts of the car. The JB+ is a tool for just turning up the turbos, but the JB3 is far far more complicated and advanced.
The theory behind maps achieving better mpg (until you rag all that extra power) is better gearing for given speeds (meaning 5th rather than 4th, 6th rather than 5th) for instance.
In the real world though, these claims are moot are best.
In the real world though, these claims are moot are best.
The map for part throttle cruising shouldn't need to be altered as the car will be running on closed loop lambda control, and so the fuelling won't need to be increased reducing economy.
The main changes will be to try and bring the boost in earlier and harder and to increase the max boost and possibly remove any programmed in tail off. As these are full throttle conditions they won't affect cruise.
If the car has hardware modifications such as a free flow inlet system, less restrictive exhaust (especially if the cat is deleted) and intercooler then the VE of the engine will change. It is then possible to map the engine to a leaner condition and change the timing at cruise and so economy will improve.
Update.
Ok switched off the JB3, stuck the car in auto shift and used the cruise control to maintain 75mph where possible depending on traffic on the M6 in the morning. The journey is 70 miles each way, 60 of which is motorway. Guessing I am about 80% of time on cruise control on the motorway section with the traffic congestion.
Results on 2 days worth are an average of 34MPG with me a 12 stone person in the drivers seat only.
Not too bad, but not brilliant.
Ok switched off the JB3, stuck the car in auto shift and used the cruise control to maintain 75mph where possible depending on traffic on the M6 in the morning. The journey is 70 miles each way, 60 of which is motorway. Guessing I am about 80% of time on cruise control on the motorway section with the traffic congestion.
Results on 2 days worth are an average of 34MPG with me a 12 stone person in the drivers seat only.
Not too bad, but not brilliant.