As I have proved with my car when it was mapped about 2month ago that if the alternator is not working properly you will lose lots of power, I had it mapped not knowing the alternator wasn’t working and it was running on the batter all the time it was mapped and I got 306bhp, BUT as soon as I got home the car started to blow white smoke out he exhaust which was not a good sign I then found that the battery was almost dead and the alternator was not charging So I replaced the alternator and recharged the battery all was well and I noticed the power fell much better, but I seem to be over fuelling so I took it back to my mapped on Saturday with everything working and on the first power run the car made 340bhp so I had gained 334bhp just by fixing the alternator , so as you can see a faulty charging system or bad earthing and any thing to do with the electrics of the car will lose you power and performance

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Rate of rise of current in injectors, and hence opening delay, is directly proportional to supply voltage so mixture will be directly affected. Also, reduced voltage will mean a weaker spark which will also have some effect.
Most ECU's sense voltage and allow a trim to be applied. I guess something most mappers won't look at or alter from the generic values.

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If at first you don't suck seed, try drier grain.

Now that's what I call a result!

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Don
GT4DC Chairman
1994 Toyota Celica GT-Four ST205WRC JDM 269bhp @ 0.9bar
1994 Toyota Celica GT-Four Special GT 590bhp @ 1.8bar
1989 Van Diemen RF88/89 Formula Ford 1600
2008 Nissan Patrol GU 3.0L ZD30DDTi 154bhp

Wise words Chris and Mixer

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Kris
95 ST205 - slept for 10 years, now waking up...
Avensis
http://www.gtfours.co.uk
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Turbocharging - the replacement for displacement

wish i had gained 334bhp i ment to say 34bhp lol witch is still a good result and now mapped to 353bhp and 300ft/lbs at 1.2bar

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