sigma power

[radical78]

is increasing the horsepower from 125 to 150 just done in ecu or are engine internals changed

[Dr Slotter]

IIRC, the official Caterham upgrade to 140 (as it is now, rather than 150) is cam change, different flywheel, different air intake, bigger rad, ECU remap.

A number of other companies do similar powerhikes.

[CaterBram Jnr]

Always some confusion with this as the K Series upgrade was to lift to 150BHP whereas the sigma is 140

Have a look at http://www.caterhamparts.co.uk/product.php?id_prod...

As they say a pictures worth a thousand words

saying that just seen one company offering a upgrade to 200BHP from a sigma

Edited by CaterBram Jnr on Monday 3rd December 21:45

[CaterBram Jnr]

Always some confusion with this as the K Series upgrade was to lift to 150BHP whereas the sigma is 140

Have a look at http://www.caterhamparts.co.uk/product.php?id_prod...

As they say a pictures worth a thousand words

saying that just seen one company offering a upgrade to 200BHP from a sigma

Edited by CaterBram Jnr on Monday 3rd December 21:45

[Dr Slotter]

That and the Sigma was upgradable to 150 (and indeed sold already as a 150) for while until CC decided it was better remapped to 140.

[framerateuk]

Any idea why the upgrade was switched from 150 to 140?

Mine's a 140. I was wondering if it was reliability related or if they just found the power delivery worked better with a 140bhp map.

[Smollet]

My Sigma 150 was dynoed at 138.4 so the cynic in me thinks that perhaps CC are now just branding the car nearer its true output rather than its claimed.

[Steve C7S]

The 150 upgrade is different from the 140:

150 - http://www.caterhamparts.co.uk/product.php?id_prod...

140 - http://www.caterhamparts.co.uk/product.php?id_prod...

I have looked at http://www.premierpowerengines.co.uk/ in case 140 turns out to not be enough once I've got used to the car.

[framerateuk]

I've not read any feedback on the Premier engine upgrades yet. 200bhp from a 1.6 seems a lot to me, I just wonder how usable it would be?

I bet it's not cheap either. You could probably convert to a Duratec for the price it costs. N/A tuning isn't cheap. I spent 2k getting my old Fiesta ST's Duratec from 150 to 185.

[BertBert]

Steve C7S said:

The 150 upgrade is different from the 140:

150 - http://www.caterhamparts.co.uk/product.php?id_prod...

140 - http://www.caterhamparts.co.uk/product.php?id_prod...

I have looked at http://www.premierpowerengines.co.uk/ in case 140 turns out to not be enough once I've got used to the car.

Very interesting. What's the new flywheel in the 140 upgrade that's not in the 150? Similar priced upgrades. Intriguing.

[Dr Slotter]

My understanding of this is it was remapped for to improve the light throttle response and it ended up be nearer to 140 but with much better drivability. I drove a 150 last year sometime and it was certainly 'interesting' pulling away from junctions and driving through towns.

I think the upgrade kit to 150 in the on-line shop is just a legacy part/kit that you can't actually buy anymore and has been replaced by the 140 'Supersport' kit.

[Dr Slotter]

Also, I think if you bought a 150 they would remap it to 140 for you at a service.

[Dr Slotter]

I'm guessing, but the (presumably lighter) new flywheel is to offset some of the power loss, amd contribute to the drivability by allowing the engine to spin up quicker.

[Steve C7S]

It is a lighter flywheel; see the spec. for the Supersport car.

[mic]

The 140 is not a remapped 150.

[downsman]

The 150 had 4 throttle bodies, while the 140 has just one and a new air box.

[Dr Slotter]

mic said:

The 140 is not a remapped 150.

I don't think anyone has said it was? Some of the original 150 Sigma engines have been remapped to improve drivability and that has resulted in a power output of 140. The new Supersport (and Sigma 125 upgrade kit) coincidently achieve the same power output.

[mic]

Just didn't want anybody think it was possible to put the 140 map on their car when it was in for service.

[Dr Slotter]

Good point!

[Smollet]

Dr Slotter said:

My understanding of this is it was remapped for to improve the light throttle response and it ended up be nearer to 140 but with much better drivability. I drove a 150 last year sometime and it was certainly 'interesting' pulling away from junctions and driving through towns.

That's interesting as I had mine remapped to improve throttle response which explains the reduced power output. Thanks for the info.