power output

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el torro
DDK addict
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power output

Post by el torro »

1970 911t 125bhp,measuring138 on rolling road,fitted with luminition,facet silver top fuel pump,zenith 40tins. any suggestions why the extra power,not that i am complaining?
old cars do my head&bank balance in but i never learn
Lightweight_911
Nurse, I think I need some assistance
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Post by Lightweight_911 »

Hi John - every dyno/rolling road is different & power outputs can't really be directly compared between them.
Andy

“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
Glenn75S
DDK above all
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Post by Glenn75S »

13Bhp is not a huge increase in power, and as mentioned there will always be a variation in readings from rolling roads so there may be an element of over reading.

Standard variations in component tolerances will contribute to a difference in power, There is an urban myth that Porsche claimed figures quoted for BHP were always under the actual measured.

Porsche would have set the car up to their optimum performance vs fuel economy. Chances are that if your carbs may have been set up with new jets, and set up more towards performance an increase is likely. Check you MPG.

The Luminition ignition was supposed to improve things as well.

Whatever ever the reason enjoy your new found power!!! :bom:
1975 Porsche 911S (SOLD)
1990 Porsche 964 Carrera 2 (Distant Memory)
2000 Audi TT 225
2007 Volvo V50 D5 SE Sport
2009 Hungarian Vizsla AWD
baggy_aggy

Post by baggy_aggy »

Sorry to highjack the post but is this Luminition ignition a replacement for the points and condenser similar to the ignitor system for flat fours? If so does anyone know a supplier?

Thanks

Lewis
dasonba
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power output

Post by dasonba »

You might want to ask your dyno guy a couple of questions:

1. Where is the power figure reported? hub or flywheel (I suspect flywheel in this case).
2. What transmission losses does his dyno assume?
3. What standard does he report the figures in, i.e. SAE or DIN? (this defines the atmospheric conditions that the results are normalised to, i.e. temp, humidity ande very importantly pressure. I can post a link that explains this in more detail if you want to check your figures against publisehed Porsche)

All these things will modify your result, but if you do know the answers you can make comparisons. To be honest it is probably best just going to the same guy each time and using the reaults comparatively to check that the mods you are making are actually helping you in the way you want.
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