Ford Sigma engine

[jrgibb72]

Hi,

Soon to be a first time owner, was previously planning to get a K Series car but may now be heading for a Roadsport 150 an engine I know nothing about. I'm very familiar with the K having owned Elise for some years both the std 1.8 and the VVC so I'm interested in learning both the comparative driving characteristics and the upgrade options for the ford engine.

i understand that the 150 is the std 125 unit but Caterham have altered the intake, added ITBs and a remapped ECU? Is this correct?

• Are there any upgrades for this engine that are regularly undertaken?
• Can the std ECU be remapped?
• I assume little value in any upgrades on the exhaust side?
• What are the common faults?
• Any ancillary components that are worth considering upgrading?

Thanks in advance.

Jason 

 

[DJ.]

I believe the 150 had different cams, modified belt tensioner, and a lightened flywheel. The MBE ECUs are locked, but I have heard some have the ability to unlock.

 

Premier Power do upgrades of 175  and 200 bhp, but they're expensive. Good by all accounts though

[Domus]

The 150 has a standard flywheel and a locked ECU.  However, The Two Steves did work with Caterham on this engine and can re map to give a much smoother drive.  Premier can supply a lightweight flywheel as well as a lighter alternator as well as offering several upgrades.

Mine is booked in for the 175.   

[ChrisC]

I had my 125 upgraded to 150.   A Caterham specialist will be able to upgrade the ECU for you, no need for a new unit.

The 150 has the loverly throttle bodies, cams, valve springs, tensioner, coolant hose, wiring adapter  and injectors, plus the remap.   The 140 kit replaced the 150 kit in 2011, but is actually a better drive, but lost the throttle bodies and gained the lightened flywheel (well worth it).   Power wise they are the same, but the 140 apparently have better torque.   

Caterham still does the 140 kit  https://caterhamparts.co.uk/other/4817-engine-upgrade-pack-sigma-125-to-140bhp-supersport.html?search_query=140+&results=37

If you have a 270 Sigma, you can get the 310 kit. 

Never driven a Premier Power Sigma upgrade, but a lot of good words have been said/written about them. 

[SM25T]

Couple of friends had the Sigma in 150 tune ..... very difficult to drive ... one had it modified to the 140 set up which transformed the car. The other reverted to the 125 set up that he had started with ! I recall CC dropped the 150 option around that time.

[ChrisC]

I am the biggest 150 defender, if they are not set "just so", then they are difficult to drive.  Set "just so" they are magical.   When I first got my 150 kit done it was a pig to drive because even specialist didn't know the best setting.    When I sold my car, on a test drive a potential buyer commented how smooth it was compared to the cars he had driven at Caterham.  

Swapping back to the 140 would mean a swap back to manifold pressure based maps (from throttle pot) which means the map is better more generic and will work with "any" engine in that state of tune.   Caterham couldn't get manifold pressure to work on the 150, so they swapped it to throttle pot on the last map, however this means the 150 will only work with one specific setting of TPS voltage, get that spot on and the car drive as the Track n Road/Caterham intended, get it wrong and you will find hesitation around part throttle making low speed driving experience painful.  

One of my biggest regrets about my recent change to a 360R is the tune and the way it drives compared to my 150.  Obviously the map is manifold pressure driven and I have made improvements changing / upgrading various bungs on the plastic manifold which where originally very flexible, but I would love to have the map changed back to TPS driven.  I understand Track n Road can do this for my Caterham. 

[mossy7]

ChrisC,.. You mentioned a regret comparing your Sigma 150 to your current 360 R. May I ask how so?

back to the OP and I am ccurrently planning a Premier Power upgrade to my Sigma 140 and have has numerous chats wth Stuart at PP. I have found him friendly and very helpful. There is not a bad word said of his work on the net and he comes very recommended. Give him a call. 

[Dave Rayner]

Just a word of support for Stuart Creswell at Premier Power, I had the F200 conversion on my 140 Supersport and it has transformed the car and I'm just in the throws of upgrading the gearbox to better make use of the power. Give him a ring, he will talk you through the options

Dave

[ChrisC]

The stock tune in my 360R is not a refined as my Sigma 150, it's just the way it drives at road and low speeds.  The Sigma was smoother over the entire rev range with loverly TB noise, where as the Duratec has resonance around 2500 rpm, and hesitation at low rpm / slow pull away.   I have to think about not stalling the Duratec, especially when on a slight incline.   Driving in stop start traffic is a constant fine line between, stall, bog, kangaroo and wheelspin, just something I didn't have to think about with my Sigma.  

I have improved it with the swap to the latest plastic plenum (mine had the more flexible 2015 one), and changes to some of the rubber bungs, but its not perfect. 

I can see why with easymap, but obviously I can't change it.  

[jrgibb72]

Hi all,

I assume the 150 out of the factory is the same as the 125 / 140 with an upgrade kit? 

What's the process for setting up / balancing correctly is it ECU adjustment or a mechanical process?? (forgive these questions I'm old school, setting up and balancing 45s!)

This is a car that has been run and maintained by Sevens & Classics so I expect it to be extremely well maintained mechanically.

J

 

 

[ChrisC]

The 150 is the most old school because you need to balance the throttle bodies, just like the 45's.   The bit that's not so old school is setting the TPS, which has to be spot on 1.04v.    The only way to set this is pluging it into a PC with easymap running, but the adjustment is just a case of loosening a couple of screws and giving it a tweak.  So your going to need to beg, borrow or buy a MBE Can lead to do it. 

Think of the 140 as the same upgrade as the 150, but without the hassel of balancing and setup, and without the nice noise. 

[DRH]

You will find your Elise 1.8 very much like the 150 as far as performance but the Elise is no where near the same driving experience, I went to Lotus Bell & Colvill the other week to drive the new Elise 250 and the Exige 380 V6 the 250 was boring compared to a 150 Caterham but the 380 I would say is a different thing but still not the same as a caterham for diect contact with the road but the 380 is very fast that I did like and sounds amazing but you would be without a license very quickly, if they didn't see you coming that would definitely hear you.

I just parted with my 150 and I must say the TB`s are wonderful it is one of the best engine set ups I have driven on a Caterham .

ChrisC above is the expert on setting up the engine, he kindly spent one afternoon tuning my car to perfection he really knows this engine inside out so I would suggest talking with him if you buy a 150.

I Like Chris am missing the 150 I think it is the best in this class and I am led to believe Caterham only changed to the 140 because the TB`s on the 150  worked out to be to costly to produce which I can imagine. You wont regret buying one and over a 125 there is no comparison the Sigma engine is very robust revving to 7,200 RPM and really fun to drive. 

The main consideration is what gearbox and Differential, the five speed box is good with the standard 3.92 ratio diff but with a six speed box and the same 3.92 diff you will find it a bit revvy on the motorway but for country lanes its fine and the six speed box is more fun if you want to stay busy, a 3.6 ratio makes 7% difference and a 3.1 diff would make 14% difference the 3.6 is normally fitted when the six speed box is installed.The sixth gear on the six speed box is the same as fourth gear on the five speed box. So really depends on what type of driving you are going to be doing, no one with a Caterham likes motorways they are avoided at all cost.

The Premier Power upgrades to 175 & 200 bhp are said to be very good and the engine is lighter than the Duratec which is always going to be better  to drive on a Caterham the lighter the better.

The only negative of the upgrade is the 175 bhp  is £7500 and the 200 bhp £10,500 and that`s probably plus VAT you will have to check on the VAT part cant quite remember if that price was without or inclusive, I know the prices are correct as I spoke with them last week very helpful I must say and there demo car is available to try, it does sound very good and a lot of people have said so. 

Let me know if you need anymore help with the 150 you are looking at, i was in the same position as you before buying but its only once you have driven a Caterham for a while will you know what you really like and that is different for everybody there is not one car that suites all.

So suck it and see

 

[Kingsley Young]

I got my hands on my first 150 SV last year, it was a car that the first owner had finished building in 2009 had had a few outings in it then his health had started to fail. So when I bought it with less than a 1000 miles on the clock there were issues. Particularly the bogging down at low speed, she just was as lumpy as hell. 

I took it to Luke Stevens at team Leo's Motor sport where he discovered that the throttle position sensor was wired round the wrong way ! After that was sorted it did run a lot better , but still not how I would of expected, so he took it down to the Two Steves where they transformed the car with a remap, she now runs as sweet as a nut and an absolute pleasure to drive. 

As I understand it took Caterham three remaps to get the 150 sorted, by the time the third one was done Caterham had already made the decision to drop it, they could buy the 140 from Ford straight out of the box and drop it into the car without doing a thing. Prices were kept the same,so as DRH comments , without the cost of throttle bodies Caterham were cutting their costs. 

I have the 5 speed gearbox which I find really good for touring , as DRH says you will have to think of what sort of driving you are likely to be doing as to which box you may find best. 

Good luck with your testing. 

Kingsley. 

[SKC]

Hi Chris,

Very interesting comments regarding your 360R...which is basically a Super Sport R spec engine.  We will very shortly be offering a new upgrade for these cars following testing on the rolling road last week.  The results on the car we tested saw peak horsepower increased by some 14 bhp, with a massive increase in throttle response, low end torque and all round driveability.  Our entry level 2.0 Duratec upgrade was our F225 upgrade which features 170ftlbs of torque and 225 bhp, but this new entry level upgrade will really transform what you currently have.  If the F225 upgrade is something you might be interested in, in the future, this new entry level upgrade features parts that can be credited off the price of the F225 upgrade at that time.

The customer we've done this for hasn't stopped raving about it all week.

Please drop me an email if you would like further details.

Regards

SKC

[diggerman]

Lots of interesting comments on the 150. All I can say is I have now done 26,000 miles of wonderful faultless, exhilarating driving with mine. Its been more or less bomb proof, is easy to drive in all circumstances, there are no flat spots or other bad habits AND the soundtrack complete with pops and bangs on over-run is just amazing.

The one upgrade I would consider is Premier Powers 175 with light flywheel. That's another universe. The ultra light Sigma engine is a great basis for a Caterham. I suspect this would have been Colin Chapman's choice over the Duratech.

peter

[jrgibb72]

Thanks all - really helpful

For those running the 150 have you got / would you recommend an ITG or similar filter over the trumpets?? 

Jason

[ChrisC]

Err - you haven't got an air filter ?

The standard air filter is a Pipercross panel which is a very tight fit under the bonnet. 

The standard filter is 

https://caterhamparts.co.uk/other/2802-air-filter-sigma-150hp.html?search_query=150+filter&results=2

and the back plate is 

https://caterhamparts.co.uk/other/3708-air-filter-back-plate-150hp-sigma.html?search_query=150+filter&results=2

Note the offset on the holes for the trumpets, without this the panel filter won't fit under the bonnet.

Looks like CC are out of stock of the filter, but it's just a very shallow Pipercross PX600, I guess "Box 40mm C6001", but your going to need to confirm that.  

I wouldn't run any engine of mine without an air filter. 

[jrgibb72]

Thanks, will ask Sevens to check this and sort if this is std out the factory - J 

[jrgibb72]

ChrisC 

I wouldn't run any engine of mine without an air filter. 

Agree, have checked and the car has the filter in place - It's been a blur, looking at far too many pictures of cars in my search and must have got it in my head that the car I'm buying was just trumpets 

J

[ChrisC]

[jrgibb72]

Hi all,

Some weeks on now and I've had the 150 for about a month, decat fitted, aeroscreen and the engine is fantastic - as mentioned by DRH above similar characteristics to the Elise (with a ported VVC K series), nice smooth power delivery up past 7000rpm with the induction noise which is magic. There is a little lumpiness at tick over but nothing but smooth delivery as you put the power on.  

Similar in overall performance to my Elise however the handling is on another level. There's not the ever present under steer there is in the Elise, but certainly more twitchy, the Elise feels more sure footed due to the modern rear suspension but actually isn't when you approach the limit. Lovely cars to be able to drive back to back on a Sunday morning!  

In terms of upgrade guessing a flywheel change will not be too taxing plus maybe find someone for a remap. Would like to get the geo setup (don't know how spot on the suspension setup needs to be with thse cars), that just a carry over from by Elise experience, I tend to get that checked and setup once a year with the MOT. 

Thanks for all the comments above! 

(with my mates frighteningly fast 205)

J

[jrgibb72]

Hi All,

Thought it appropriate to say a big thanks to ChrisC for spending the time this weekend to setup my TBs for me on the 150. Clearly someone had been fiddling around with the setup at some point in the past. 

The airflow on one of the TBs was out quite a bit clearly this being the exception to the rule that each pair are usually balanced. As a consequence the two pairs were balanced and the idle adjusted to compensate making it lumpy on idle.

Once sorted the pair were correctly balanced and the idle set, the TPS did’nt need adjusting. Instantly sounded smoother on tick over and a nice smooth progressive acceleration.

Thanks Chris for the 10 min job that I think took almost 2 hours of your time - what a star!! Thanks mate!! 

Jason

[Markymark]

My master plan for buying a 7 is for touring. Bought the SV ( secondhand) with chrome, leather seats heater 15" wheels pack etc - you get the picture. I was not looking for a 150 ( as for road use) but fell in love with the soundtrack. I have the five speed no other engine upgrades. I have too had some problems with getting/keeping the 150 in the sweet spot. Like others on  this forum found Chris C, he kindly invited me over and he showed me what to do. Wont repeat all here but balancing the throttle bodies, tick over at around 1000 rpm and the TPS registering 1.04v as Chris C states is the set up ( with the equipment which I now have even I can do it!). For the road driving, I run out of "runway" before I am anywhere near its limits and the sigma engine pulls smoothly and uniformly when set up as per Chris's advice. No problems with starting off "kangeroo-ing" or flat spots in this state of tune.

I am definitely a deciple/evangelist of the 150. I guess we all can on the 150 (but in on a different scale) relate to Lewis' problems with the W08. Get it right and its arguable one of the best Caterhams. No co-incidence that the 310 is considered by many as the best all round package. This is a sweeter sounding 310! (IMHO).

I too can't thanks Chris enough for the help - given willingly, knowledgeably and enthusiastically!

[ChrisC]

Thanks for the kind words guys.   As any Caterham owner who has meet me knows I love working on Caterhams and enjoy helping where I can.   I will gladly help any fellow owner where I can, especially the SIgma 150s because they got such bad press for such a simple issue to resolve.      Just PM me, and arrange a time and place.