Zetec 2.0 versus Sigma 1.6

[Angelo]

I would like an opinion from anybody that has driven a Seven with both of these motors. Is there a discernible difference in available power between these two engines?

[Croc]

Yes I have driven both extensively. Have in the past owned two zetec Caterhams - one an SVT (say 165FWHP) and one a regular cooking version (say 140FWHP). I have also driven a UK Caterham 310 a lot on track - it has the 150fwhp version of the Sigma.

 

No question in my mind, I think the Sigma is the better engine - more modern plus likes to rev out more freely than the Zetec. Sounds a little better to my ears than the Zetec. No real feel of having less power than the SVT Zetec.

 

Sigma engines now have power upgrade paths via Premier Power in the UK so you can add more if needed.

Edited October 1, 2020 by Croc

[Angelo]

Thank you. Finally a response from a knowledgeable individual with experience with both engines. in your opinion What would be the least expensive mod to the Sigma to give it a little more umph?

[Angelo]

I see you are from NYC. I sold my Seven to someone in upstate NY.

[11Budlite]

In your opinion What would be the least expensive mod to the Sigma to give it a little more umph?

 

I'm in the process of building my 310S. Everything I read said to go with the Premier Power lightweight flywheel/clutch setup as a first mod. Not cheap, but the quality looks to be really nice and it cut the weight almost in half from the stock Ford setup. I'd have to check at home but I think it weighs just under 15 lbs.

 

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[JohnCh]

Croc, how noticeable is the weight difference between the engines when changing direction? Is it subtle, or an obvious improvement?

 

Thanks,

John

[Croc]

Thank you. Finally a response from a knowledgeable individual with experience with both engines. in your opinion What would be the least expensive mod to the Sigma to give it a little more umph?

 

The first mod I would do is make sure the Caterham is on 13 inch wheels. Less unsprung weight which allows it to feel more perky as it accelerates. Also has other benefits. Better ride. Transmits feel better to the driver.

 

If you have room for a second upgrade (or even make it the first upgrade), I definitely would look at the Premier Power flywheel upgrade like what Bruce is showing above. The Caterham supplied sigma package comes with the standard road car flywheel - designed for something 3 times the weight of a Caterham. Replacing the flywheel for a Caterham specific version will allow the engine will spool up quicker, feeling like you have more power. Plus you drop a good amount of weight out of the car. By contrast, Caterham supply the Duratec with a lighter flywheel from the beginning so you do not need to change that one out.

 

Premier Power does some really cool products - a friend of mine in the UK put his sigma engine car through one of their upgrade packages and was very happy with the end results. But this is where you start to spend real money and that is not what you were looking for.

 

 

Croc, how noticeable is the weight difference between the engines when changing direction? Is it subtle, or an obvious improvement?

 

John - you raise a really good point that I forgot. Its noticeable. The zetec is around 220lb and the sigma is around 180lbs. I preferred the balance of the sigma car for handling - it was more nimble than I remember my zetecs being. The video below is the 310 car with sigma engine I drove in 2018 at 6 UK circuits - it was brilliant at Donington.

 

Edited October 2, 2020 by Croc

[Vovchandr]

I see you are from NYC. I sold my Seven to someone in upstate NY.

 

Do you know where to? How long ago?

[Angelo]

About 13 years ago. Somewhere in upstate NY.

[Mark IV]

The "R" package on a new Caterham includes a lightweight flywheel as standard. It may not be as light as the aftermarket package but is is reduced in mass.

[11Budlite]

cut the weight almost in half from the stock Ford setup. I'd have to check at home but I think it weighs just under 15 lbs.

 

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So I checked the weights from my shipping scale and came up with the following:

 

Ford flywheel: 15.68 lbs

 

Ford fly/clutch: 28.36 lbs

 

Prem Power flywheel: 7.74 lbs

 

Prem Power fly/clutch: 14.88 lbs

 

This includes the clutch disc and pressure plate but no hardware.