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Discussion Starter #1 (Edited)
Had a great Saab Club tech day yesterday that included 3 runs on a dynodynamics dyno for aud$45. This was a shootout type run with just kW and a/f ratio measured. Thanks to Lance Dixon Saab Dealership for a great day!

My 2002 9-3 Aero specs: Stock ECU, Genuine Saab 3" S/S DP, racing cat, Abbott Racing 3" S/S cat back system, Genuine Saab open intake, Forge FMIC, Hyperboost BPV.

The temperature was 27C and pretty warm. Dyno operator said I should make between 5 to 7 more kW if the day was much cooler.

Best run was 150.3kW at the wheels. This is 201hp at the wheels... so if we take the 20% drive train lose into consideration that is 180kW at the crank (or 242 hp). Which is pretty damn good running stock ECU and jsut using solid HW upgrades!

So this gives me a good solid base for for future tuning. Next up is a Nordic Stage 3 or 4 ECU.

As a comparison to other cars on the day.

A stock c900 convertible Aero S ran 85kW at the wheels.

A friends 2001 9-3 Aero with just open intake ran 136kW at the wheels.

One of the Saab Techs from Lance Dixon who owns a stage 3 Maptun 9000 Aero ran 184kW at the wheels.

A very very rare 1985 BMW 745 M power (6 cylinder 3.7 litre M Power engine, one of 190 in the world) ran 150kW at the wheels.

Onto some pics:
My exhaust set up:






and video of the run from outside the car:
http://members.ozemail.com.au/~sbunton/sleds/dyno/sabdyno_clip.mov

and video of the run from inside my car:
http://members.ozemail.com.au/~sbunton/sleds/dyno/sab_dyno_readout.MP4

Will upload the print out of the run when I can get time to scan it in.

Pretty happy with the result tho!

sab
 

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Discussion Starter #3 (Edited)
It is a 5 speed manual... one of about 4 in Australia in this colour and a 3 door coupe, and sold in 2002. So its quite rare and took me about 18 months to find. Most 9-3 Aeros were 5 door automatics.

:)
 

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What made you decide to use 20% as your drive train loss figure? :confused:
 

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Discussion Starter #5
heard from many sources that around 20% Drive Train Loss is the standard for a FWD Saab... including Saab techs. With over 20% the recommended calculation for a RWD car.

Why what are your figures for DTL for a Saab? :confused:
 

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I'm simply curious as so many websites and people use different percentages.

I have read FWD losses put at 12-18% with the lower being for the manual, RWD at 18-20, and silly high figures for the AWD cars..........

I guess its probably easier to compare the wheel figure with the other Aero dyno'd???

Confusing isnt it :confused:

This chap at Puma Racing is well respected:
www.pumaracing.co.uk said:
My own figures for transmission losses have been stated in previous articles but to recap they are usually no more than 15% of the flywheel power for FWD vehicles and no more than 17% for RWD ones. A good guide is to deduct 10% of the flywheel figure plus another 10 bhp for FWD and 12% plus 10 bhp for RWD. If you are starting from a wheel bhp figure then you have to apply those equations in reverse - add 10 bhp then divide by 0.9 for FWD or 0.88 for RWD to get back to a flywheel figure. Those figures were not just plucked out of thin air. They represent the culmination of many years of research and testing combined with the views of reputable companies like Bosch and VW.
 

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Discussion Starter #7
I guess we will never know without putting it on an engine dyno to be sure... either way I am really happy with the output (maybe its just easier to say the WkW output as a base. The run I did does gives solid credit to the HW I have installed... and with stock ECU.
 

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If you look here
http://www.rototest.com/performance-graphs/graphs.php?Visitor=1&DN=33&List=S-T
there are tens of dyno sheets from std saabs and if you compare what they give on the wheels in relation with the rated figures, the average loss is <10% for the FWD saabs. The loss figure can be found from any sheet under "details".

Of course if the engine in real life gives more than what it is rated the % figure will be lower, but genarally speaking, >12% is figure inflation IMHO for manual gearbox.
 

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Discussion Starter #9
Thanks Vigge... good link. I dont see a 2002 9-3 Aero on there tho (which is 155kW stock and the engine).... but still a good comparison.

Question... won't a rototest dyno be slightly closer to a crank output (ie. less drive train loss and therefore less percentage loss) than another type of dyno due to the fact that it will have less rolling resistance as the dyno is attached to the hubs and not rolling on the tyres? Using tyres would have to include some sort of friction?

I would expect a dyno similar to the dyno-dynamics (that I tested on) to have a greater drive train loss than a rototest dyno, which would spin freer and and less frictional inertia).

What are your thoughts there?
 

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sab aero said:
Thanks Vigge... good link. I dont see a 2002 9-3 Aero on there tho (which is 155kW stock and the engine).... but still a good comparison.

Question... won't a rototest dyno be slightly closer to a crank output (ie. less drive train loss and therefore less percentage loss) than another type of dyno due to the fact that it will have less rolling resistance as the dyno is attached to the hubs and not rolling on the tyres? Using tyres would have to include some sort of friction?

I would expect a dyno similar to the dyno-dynamics (that I tested on) to have a greater drive train loss than a rototest dyno, which would spin freer and and less frictional inertia).

What are your thoughts there?
Yes the rototest whp figure will be slitly higher due to the issues you listed above, but in real life the difference isnt that big. Normally the used figure for losses is 10% if whp figures are measured in Rototest.

Cost down based losses estimation for my car has been 10...12% and have had the car in four different dynos.
 
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