sigma 150 engine re maps

[Derek Batty]

Any body with 150 sigma had cat removed a remap to smooth out engine who recommend  any problems a was it worth doing 

[ChrisC]

Hi Derek 

It all depends on what you are looking for.   My 150 is smooth, and pulls clean from almost idle in 5th all the way to the red line.  I can also happily drive it at low speeds, and pull away is easy at slow speeds, but it wasn't always like that.  It has to be setup accurately and to a specific setting, and have the latest Caterham map, and throttle quadrants fitted.  I would not take this as read, even if you have had it recently serviced.  It appears the sweet spot is not well known.  I can tell when my throttle pot is 0.01v out as hesitation starts to creep back into driving experience!

If you have all of this and are looking for that bit extra then a Custom map is the next step.   I would looks at the two Steves and Road and Race, because they have the code needed to unlock your MBE ECU, and hence saving you the cost of a replacement ECU and mapping from scratch. 

 

[Derek Batty]

Thanks crisis have you a phone no or add for a road and race will give them a ring as usual getting dif info from diff places  but just spoke t o helpful, bloke Craig at cater ham he said same as you thanks

[ChrisC]

Sorry it's Track n Road, not Road and Race.   Road and Race are transmissions.

I believe the number is 01708 869189 or http://www.tracknroad.co.uk

If you are local, I could do the basic throttle pot set and throttle body balance for you, to see if that solves your problem.

Chris.

[ChrisC]

I have just looked at your profile, looks like your Isle of Man based, so not local.

There is an MBE lead in the tool lending library,  so you could do the TP setting yourself. 

Chris.

[Derek Batty]

Thanks for help cross wil be over  later in year so will call to try get sorted poss book a track as nearest thanks.     Derek. Iom. 

[Eccles]

Hi Chris,

What do you set your pot to? 1.37V comes to mind with between 4-5 on the synchronometer for the flow at tickover.

I used to have a workshop notice for this but seem to have lost it somewhere over the years :-( Do you know when the latest map was released?

Cheers

Ivan

 

[ChrisC]

Engine warm

idle 950 rpm + or - 25 rpm

4-5kg/h on the synchronometer 

And the Throttle Pot at 1.04v, which is right on the boarder of the TP site 0 and 1, so as soon as the throttle is touched it's into site 1, and as soon as you lift off its site 0.  I believe this is the key to getting the smooth transition from off to on throttle, which so may 150 owners complained about.   To get it spot on you have to use an MBE lead and let the computer tell you what voltage the ecu is seeing.  

As soon as you touch one thing, the rest needs adjusting so it takes a bit time consuming.

hope this helps

[Eccles]

Thanks very much for that, bit out on the thoughts for the pot voltage but it's been a long time since I last set it 

 

[Derek Batty]

Any body with 150 sigma engine removed cat and fitted by pass pipe does it make much difference and do you have to have it remapped also where get bypass pipe was it worth doing

[ChrisC]

I can't tell you if the remap with the bypass pipe is worth doing, but I can say it didn't make a huge difference.   I used one to protect the cat from the pops and bangs, didn't fancy replacing a dead cat each year at MOT time. 

[martyn]

The bypass pipe doesn't make a lot of difference in terms of performance.  It does change the sound significantly and causes more pops and flames.  Although that may be more to do with the fact that I haven't used any sealant to make swapping easier.  Main benefits for me are that its not destroying my cat and it looks better.

I think I actually prefer the sound with the cat.  It is a deeper rumble rather than a higher rasp.  But again that may be solved with some sealant around the ends of the primaries.

I wouldn't go to the effort of getting a remap specifically because of the removal of the cat.  If you want a remap anyway then that is a different matter.  Lots of people report improved drivability and better top end performance.