St170 Engine

[Guest gdc]

i spoke to nigel tonight and he is happy with the rr sesion in fact i will be down his way on sun and we hope to see each other , the rain has stopped him giving the st a work out so far .

re stated out puts from r/ roads , its a bit of a minefield re the read outs as some give actual bhp

and some give a recalculated reading based on a figure to give flywheel reading .

to my mind the only real flywheel reading comes from a dyno . all others are calculated to take into account the loss through the drive train and give a calculated reading to support the actual flywheel reading .

a lot of people get a reading from a rr and assume because the wheels gave the reading that is the bhp of the engine . or the reading from the wheels +the losses of the drive train .gives the reading .

its all about how acurate the rr is and the calculation made to give the flywheel reading .

i know how this can cause confusion and indeed if inacurate can be annoying as my car was rroaded at 201 bhp at the flywheel , only to be proved wrong some months later on a new road opperated by the same man , then down to 187 at the flywheel .

graham

graham

[Guest dinger]

Ok, for all that dont know, Below is how BHP is worked out,

 

 

Brake horsepower and Torque are all very well, but the main figure that counts

is Bar Horse Power, this is the figure that you tell your mates down the pub.

 

 

To calculate this use the following rules:

 

STARTING POINT

The manufacturers generally handpick an engine that they know is on the right

end of tolerances for testing, this means that often its a higher figure than

an average new engine actaully makes, ignore this fact and swear blind that

your smoking nasty example of a now half f***ed engine makes the figure

claimed, round up whenever possible, so 152bhp = 160bhp etc

 

BOLT ON MODS

Obviously the correct way to get more power from your smoking engine with poor

valve seal and rings that are about as tight as Freddy Mercury's arse, the way

to get more power is to ignore those facts (see "starting point") and just bolt

tat onto the outside of it.

 

These mods can include filters/exhaust/dumpvalve etc, or even semi-internal mods

like cams, we wont cover things like bearings or rings cause those arent very

shiney so you wont want to replace them.

The manufacturers always state the gains that you will get from a mod, often

your car wont be listed specifically with a power gain, so just pick the

biggest one that is, if a skyline can pick up 22bhp from an exhaust, then so

can your saxo, again dont forget the golden "always round up" rule.

The figures should all be added up, and round up again.

 

 

ITS A GOOD'UN

You need to add a proportional value based on the "its a good'un" factor of your

engine, basically, as this is YOUR engine not anyone elses, its special, so the

mods will all make more difference, so multiply the number up a bit to take

this into account.

 

STICKERS / SPOILERS

Race cars have them, so you need them too, the key thing here is to not buy ones

that apply to anything you have fitted, go for stuff that isnt even made for

your car, so Greddy/HKS/Blitz is ideal for an XR2i.

Now the thing to remember with modifications to a vehicle is that they work in

harmony, it all comes together as a package, exhaust will compliment head mods,

filter will work well with a decat or whatever, now stickers are about attitude,

and attitude is what counts out there on the street (or halfords car park).

Take the % of your car covered by stickers and spoilers and add that onto your

BHP figure as an attitude adjustment (dont forget to round up!!)

 

 

 

WORKED EXAMPLE:

Fiesta XR2

quoted figure (use a guess if you cant find the manufacturers), 94bhp

filter (using the figure for a porche 911) - 11bhp

Exhaust (using figure for a skyline) - 22bhp

decat (never had one so you get this without doin anything, PHAT!) - 12bhp

sticker coverage = 47%

spoiler coverage = 12%

Its a good'un factor = 25%

 

 

We'll do the rounding first:

So the calcs are:

94 round up = 100

filter round up = 20

exahust round up = 30

decat round up = 20

sticker round up = 50%

spoiler round up = 20%

good'un round up = 30%

 

So 100 + 20 + 30 + 20 = 170

plus stickers 50% = 255

add spoiler factor 20% = 306

add good'un factor = 397.8

 

Final round up = 400bhp

 

?????????????????????????????????????????????????? ????????????????????????

This however is only your basic Bar Horse Power figure, make sure when you quote

it you increase it inversely to the age of the girl you have with you at the

time, and in direct proportion to the number of pints you have consumed.

[stevedohc2b]

Ok, for all that dont know, Below is how BHP is worked out,

 

 

Brake horsepower and Torque are all very well, but the main figure that counts

is Bar Horse Power, this is the figure that you tell your mates down the pub.

 

 

To calculate this use the following rules:

 

STARTING POINT

The manufacturers generally handpick an engine that they know is on the right

end of tolerances for testing, this means that often its a higher figure than

an average new engine actaully makes, ignore this fact and swear blind that

your smoking nasty example of a now half f***ed engine makes the figure

claimed, round up whenever possible, so 152bhp = 160bhp etc

 

BOLT ON MODS

Obviously the correct way to get more power from your smoking engine with poor

valve seal and rings that are about as tight as Freddy Mercury's arse, the way

to get more power is to ignore those facts (see "starting point") and just bolt

tat onto the outside of it.

 

These mods can include filters/exhaust/dumpvalve etc, or even semi-internal mods

like cams, we wont cover things like bearings or rings cause those arent very

shiney so you wont want to replace them.

The manufacturers always state the gains that you will get from a mod, often

your car wont be listed specifically with a power gain, so just pick the

biggest one that is, if a skyline can pick up 22bhp from an exhaust, then so

can your saxo, again dont forget the golden "always round up" rule.

The figures should all be added up, and round up again.

 

 

ITS A GOOD'UN

You need to add a proportional value based on the "its a good'un" factor of your

engine, basically, as this is YOUR engine not anyone elses, its special, so the

mods will all make more difference, so multiply the number up a bit to take

this into account.

 

STICKERS / SPOILERS

Race cars have them, so you need them too, the key thing here is to not buy ones

that apply to anything you have fitted, go for stuff that isnt even made for

your car, so Greddy/HKS/Blitz is ideal for an XR2i.

Now the thing to remember with modifications to a vehicle is that they work in

harmony, it all comes together as a package, exhaust will compliment head mods,

filter will work well with a decat or whatever, now stickers are about attitude,

and attitude is what counts out there on the street (or halfords car park).

Take the % of your car covered by stickers and spoilers and add that onto your

BHP figure as an attitude adjustment (dont forget to round up!!)

 

 

 

WORKED EXAMPLE:

Fiesta XR2

quoted figure (use a guess if you cant find the manufacturers), 94bhp

filter (using the figure for a porche 911) - 11bhp

Exhaust (using figure for a skyline) - 22bhp

decat (never had one so you get this without doin anything, PHAT!) - 12bhp

sticker coverage = 47%

spoiler coverage = 12%

Its a good'un factor = 25%

 

 

We'll do the rounding first:

So the calcs are:

94 round up = 100

filter round up = 20

exahust round up = 30

decat round up = 20

sticker round up = 50%

spoiler round up = 20%

good'un round up = 30%

 

So 100 + 20 + 30 + 20 = 170

plus stickers 50% = 255

add spoiler factor 20% = 306

add good'un factor = 397.8

 

Final round up = 400bhp

 

?????????????????????????????????????????????????? ????????????????????????

This however is only your basic Bar Horse Power figure, make sure when you quote

it you increase it inversely to the age of the girl you have with you at the

time, and in direct proportion to the number of pints you have consumed.

 

 

love it made me smile.

On the sticker count mine is really fast.

 

Shame I cant drive for 5 weeks as have broken my elbow (Doh )

 

Stephen