My Supercharged V8 Capri Conversion

ChrisJC · Post by **ChrisJC** » Thu Oct 24, 2013 7:06 am

stevieturbo wrote:I'd have thought more power than that actually.

80Amps at 14Volts = 1120Watts
There are 746Watts per horsepower

So 80Amps at 14Volts = 1.501hp

Not enough to be worth worrying about!

Chris.

Post by **katanaman** » Thu Oct 24, 2013 7:17 am

You might well be right as those figures don't take into account any loses. It's really just a straight conversion from amps to watts then to HP (745.7 watts =1hp) . It won't be much more than that though.
Using a really modern alternator would be difficult as they are all ECU controlled now for fuel efficiency. Things like they charge less on acceleration and more on coasting/overrun. Even the 4.0 4.6 rovers had large alternators though, all the serp belt ones basically. They were 110A if I remember right. Not sure if you could drive a large alternator effectively without a serp belt right enough.

DaveEFI · Post by **DaveEFI** » Thu Oct 24, 2013 7:47 am

I have a self contained 100 amp unit on my SD1 EFI driven off the v belt. It's a Marelli A127 type with integral fan. More or less a direct replacement with an extra spacer to one of the original brackets. I do have a turnbuckle for adjustment as the original was a right fiddle to set.

unstable load · Post by **unstable load** » Fri Oct 25, 2013 5:35 am

When the alternator on my P6 packed up I had it rewound to deliver higher amperage. I can't remember how many it delivers, but it was significantly more than standard.

Any decent rewinding place would be able to wind it to deliver higher amps.

Ian Anderson · Post by **Ian Anderson** » Fri Oct 25, 2013 12:48 pm

katanaman wrote:You might well be right as those figures don't take into account any loses. It's really just a straight conversion from amps to watts then to HP (745.7 watts =1hp) . It won't be much more than that though.
Using a really modern alternator would be difficult as they are all ECU controlled now for fuel efficiency. Things like they charge less on acceleration and more on coasting/overrun. Even the 4.0 4.6 rovers had large alternators though, all the serp belt ones basically. They were 110A if I remember right. Not sure if you could drive a large alternator effectively without a serp belt right enough.

Hi Marki
In the old days they used to recon they could power 5hp through a standard V Belt

Things like Lawnmowers with a Brigs & Strattern 4.5 hp motor through a V belt working hard on thick grass held up for ages

Ian

stevieturbo · Post by **stevieturbo** » Fri Oct 25, 2013 2:11 pm

Ian Anderson wrote:
katanaman wrote:You might well be right as those figures don't take into account any loses. It's really just a straight conversion from amps to watts then to HP (745.7 watts =1hp) . It won't be much more than that though.
Using a really modern alternator would be difficult as they are all ECU controlled now for fuel efficiency. Things like they charge less on acceleration and more on coasting/overrun. Even the 4.0 4.6 rovers had large alternators though, all the serp belt ones basically. They were 110A if I remember right. Not sure if you could drive a large alternator effectively without a serp belt right enough.
Hi Marki
In the old days they used to recon they could power 5hp through a standard V Belt

Things like Lawnmowers with a Brigs & Strattern 4.5 hp motor through a V belt working hard on thick grass held up for ages

Ian

Perhaps, but a lawnmower wont see the same rpm's and change of rpm's than a car belt will.

Post by **Coops** » Fri Oct 25, 2013 3:06 pm

this has wandered a bit

Post by **Rossco** » Fri Oct 25, 2013 3:41 pm

Tony......lets admit it though, most lawnmowers have done more miles than the Cappa in the last 2 years

r2d2hp · Post by **r2d2hp** » Fri Oct 25, 2013 6:41 pm

think my chainsaw has vibrated further

mgbv8 · Post by **mgbv8** » Fri Oct 25, 2013 8:26 pm

Rossco wrote:Tony......lets admit it though, most lawnmowers have done more miles than the Cappa in the last 2 years

Ouch!!!

mgbv8 · Post by **mgbv8** » Fri Oct 25, 2013 8:27 pm

r2d2hp wrote:think my chainsaw has vibrated further

Double OUCH !!!

Come on guys! Coops need some support here

Post by **katanaman** » Fri Oct 25, 2013 11:15 pm

sorry

Ian Anderson · Post by **Ian Anderson** » Sat Oct 26, 2013 6:06 am

mgbv8 wrote:
r2d2hp wrote:think my chainsaw has vibrated further

Double OUCH !!!

Come on guys! Coops need some support here

Easily found on line
http://www.amazon.co.uk/s/?ie=UTF8&keyw ... fbmkc45e_b

Darkspeed · Post by **Darkspeed** » Sat Oct 26, 2013 9:35 am

Sorry for still wandering

That assumes no heat produced, no running of the cooling fan required. and no mechanical losses in the system. no belt frictional / heat losses etc.

Expect the system to no more than 40% EFF. maximum and efficiency dropping with RPM.

Just think of the effort required just to spin the alternator and its fan at 10,000 rpm without it actually being connected to anything.

I would say more like 4-5HP at 6000RPM and all losses are worth worrying about. Its a 1% loss even with a 500BHP motor

ChrisJC wrote:
stevieturbo wrote:I'd have thought more power than that actually.
80Amps at 14Volts = 1120Watts
There are 746Watts per horsepower

So 80Amps at 14Volts = 1.501hp

Not enough to be worth worrying about!

Chris.

Post by **katanaman** » Sat Oct 26, 2013 9:57 am

I agree there will be losses but 4-5 HP? That would mean your your using 2.5-3.5 to get 1.5 worth of power. I really doubt that, even a screw supercharger isn't that inefficient and they are fairly poor.

Anyway we better get back on topic before Tony breaks out the big sticks