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Engine Power Band
Lozer49 - 22/4/12 at 04:37 PM

I know its not a locost but i figured someone on here could point me in the right direction, ive got a 2003 skoda fabia vrs and its no good through the gears for competition use. The ratios in it are in sufficent for performance use.

I need to calculate the power band on the a dyno run and match this with a new set of gear ratios, i want to aim so the gear runs out just as the power band drops off so get best possible acceleration. Does anyone on here know the accurate way to caluclate the power band or is it just the revs between peak horse and peak torque power??

I need to evaluate the map before i can go an further but just struggling to understand it. Does anybody have a knowledge about this on here that could point us in the right direction??

Thanks in adavnce

D Beddows - 22/4/12 at 04:59 PM

You need this

Four-stroke Performance Tuning by A.Graham Bell, HardCover, BRAND NEW | eBay

There's a whole chapter about that exact subject

Lozer49 - 22/4/12 at 05:13 PM

Thanks for the reply mate, and it does look very useful. I cant find somewhere to view it online as unfortunatly i need the information to write up the findings for wednesday. I am going to order the book but i doubt it will get here in time.

Do you know anywhere i could view other relavant information online as google and google scholar search does not result in many academic articles

Thanks

metro6r4 - 22/4/12 at 05:20 PM

if you are thinking of getting it rebuilt you might want to give paul mason a ring at first motion the number is 01462 732389 or 07966497815 he is currantly building me a straight cut box at the moment

this program might be of use to you

http://locost7.info/gearcalc.php

zilspeed - 22/4/12 at 05:46 PM

quote:
Originally posted by Lozer49
I know its not a locost but i figured someone on here could point me in the right direction, ive got a 2003 skoda fabia vrs and its no good through the gears for competition use. The ratios in it are in sufficent for performance use.

I need to calculate the power band on the a dyno run and match this with a new set of gear ratios, i want to aim so the gear runs out just as the power band drops off so get best possible acceleration. Does anyone on here know the accurate way to caluclate the power band or is it just the revs between peak horse and peak torque power??

I need to evaluate the map before i can go an further but just struggling to understand it. Does anybody have a knowledge about this on here that could point us in the right direction??

Thanks in adavnce


Fabia VRS, so a diesel if I'm not mistaken.

Also, being a TDI, the power band is as narrow as a gnat's G string.

It's all about keeping it over 1900rpm where all the torque arrives (229lb/ft IIRC) and below about 3000, where it's given up.

You might want to find a 6 speed box out of another VAG car.
6th gear isn't any higher than 5th on a 5 speed box, but the gap between ratios is much smaller.
That's precisely why they developed this box, for keeing the engine on the boil.

I've had a few VAG diesels and without exception, they all behaved like this.
Nothing below 1900rpm, then it all comes whooshing in, before buggering off again above 3000.
6 speed helps a great deal, that's what I had in my B5.5 Passat and in ym current B6, although the latter is a DSG which is a wondrous thing in terms of keeping the engine in the zone.

snapper - 22/4/12 at 06:15 PM

Gear it for a few hundred extra revs over peak power, you will always encounter moments where you need to hang on to the gear a bit longer