Scotsman

iTrader: (3)

Noticed over on the dyno results page that even non modified UK cars are around 240 bhp. Is it the case that all cars are more than the listed output (i.e. my MY99 is not actually 215 but higher?).

Neil Smalley

You've hit on a massive area of debate and discussion, so i'll add my 2p. I'm sure wiser sages than me will correct and add more, but here goes.

What BHP reading is produced depends on a number of variables(assuming the same car, mileage and fuel etc). These can be
1. Temperature
2. Air pressure
3. The type of rolling road used
4. The version of rolling road software used
5. The operator

The only true way to get an accurate figure is to take the engine out and bench dyno it. Obviously this costs ££££

I'm told Subaru have done this and come up with a figure of 215Bhp. Other people have used OEM rolling roads and produced higher figures, which are usually not as accurate.

How much and why individual scoobs differ in BHP and Torque is another huge question.

For example Doc Jock's car with a prodrive performance pack can only just get in front)1 car length) of Puff the magic wagon's car(standard MY99) on a 1Km straight. While other cars will be blown away by a PPP'd car

I see it as Subaru rate the engine at a minimum of 215Bhp but it can vary by 10-20 Bhp depending on the car and how the car was run in and driven.

Over to an engine guru...

Scotsman

iTrader: (3)

Weird

Strange that there can be so much variation from the same engines.

Butty

iTrader: (2)

The dynos for Stis all seem to be as quoted at 280 bhp.
Is it something to do with insurance in the UK that HP is quoted at a conservative figure?

Fangoria

iTrader: (1)

I heard this insurance a while ago on a Peugeot 306 GTI - LAD motorsport had had it on their dyno and said that the power was significantly more at the wheels than expected - they believed it was to get insurance rating down - though I suspect this is subject to very stringent criteria - so I doubt it!

TRIGGER

The biggest reason for the difference is what percentage is used to estimate the loss of power through the transmission. Different companies use different figures.
Also, regarding imports, the Japanese have an agreement not to produce these cars with anything more than 280bhp, but in reality they regularly produce more, so just dont advertise it.