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Correct bhp?
- Thread starter The Seer
- Start date
The power loss depends on a lot of things. The revs, the throttle opening, the gear you're in, the size of the tyres, the tyre pressures.
If you're talking about the power loss at maximum power 20% is too high a number for a 182 Cup.
The experts, the people in the car manufacturers and dyno manufacturers, will tell you that for an east-west FWD car it shouldn't exceed 15%, for a north-south RWD car it shouldn't exceed 17%, and for a 4WD it might well get to 20% or more, especially if its a real off-road 4WD.
Unfortunately I've lost track of it, but I did at one point see a table of wheel and flywheel horsepowers that a dyno manufacturer had produced, and if my recollection is correct is was something like 12-13% for a Clio Sport.
The problem is you get mechanics of limited intellectual and mechanicing skills who fancy themselves as being able to do performing tuning, or being able to make a few bucks from people who want performance tuning done and are easily conned, who buy dynos they don't understand and tell people things that aren't actually true. For example they quote what they claim is flywheel horsepower, because that's a bigger number and people spending money hotting up cars want as big as possible number to quote to their friends, when all they've done is measure torque, factored that up by a constant percentage irrespective of the revs and irrespective of the car, and turned that into a horsepower curve. That produces repeatable results, ie if what you want to know is whether a modification has produced more or less power, but it doesn't give you an accurate number.
If you're talking about the power loss at maximum power 20% is too high a number for a 182 Cup.
The experts, the people in the car manufacturers and dyno manufacturers, will tell you that for an east-west FWD car it shouldn't exceed 15%, for a north-south RWD car it shouldn't exceed 17%, and for a 4WD it might well get to 20% or more, especially if its a real off-road 4WD.
Unfortunately I've lost track of it, but I did at one point see a table of wheel and flywheel horsepowers that a dyno manufacturer had produced, and if my recollection is correct is was something like 12-13% for a Clio Sport.
The problem is you get mechanics of limited intellectual and mechanicing skills who fancy themselves as being able to do performing tuning, or being able to make a few bucks from people who want performance tuning done and are easily conned, who buy dynos they don't understand and tell people things that aren't actually true. For example they quote what they claim is flywheel horsepower, because that's a bigger number and people spending money hotting up cars want as big as possible number to quote to their friends, when all they've done is measure torque, factored that up by a constant percentage irrespective of the revs and irrespective of the car, and turned that into a horsepower curve. That produces repeatable results, ie if what you want to know is whether a modification has produced more or less power, but it doesn't give you an accurate number.
Last edited:
Martin_172
ClioSport Club Member
agreed ^^ i was once told by a tuner a FWD car loses 25% power and a 4wd loses 50% power!!! lol we all know thats complete bollox!
Monaro VXR/Cupra TDi
The reason I asked is this:
When I got of the 182 Cup it seemed rather gutless so took it for a dyno run at Engine Advantage in Witham, Essex. An at the wheel figure was given of 134 bhp, with 150 lbs/ft and 178 at the flywheel. If a 12-13% power loss is present these figures can't be correct. 17K on the clock, no mods, standard.
A 12-13% loss would mean the 182 only had 154 bhp!!!???:S
Since that dyno run the car has covered 32K and has certainly feels like it has unwound somewhat. I'd guess it's making an 6-8 bhp. This would mean a wheel figure of 142 bhp. Though this equals around 165 bhp at the flywheel. Something doesn't add up.:dapprove: :S
When I got of the 182 Cup it seemed rather gutless so took it for a dyno run at Engine Advantage in Witham, Essex. An at the wheel figure was given of 134 bhp, with 150 lbs/ft and 178 at the flywheel. If a 12-13% power loss is present these figures can't be correct. 17K on the clock, no mods, standard.
A 12-13% loss would mean the 182 only had 154 bhp!!!???:S
Since that dyno run the car has covered 32K and has certainly feels like it has unwound somewhat. I'd guess it's making an 6-8 bhp. This would mean a wheel figure of 142 bhp. Though this equals around 165 bhp at the flywheel. Something doesn't add up.:dapprove: :S
ITB'd MK1
losses aren't done as a percentage, it can't be done, just the condition of a gearbox can make a huge difference to transmitted power. Losses are measurable if a dyno is used correctly, dont ask me how though lol.
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