Trust me I considered that 
Question for Ronin,
I have been following this thread with interest. The only unresolved part for me is, if the AFR is “just” Ok now in the cooler months why will it be worse in the summer months ?
Air is at it’s densest when cold and will be less dense when warmer. How will this warmer (less dense) air make the AFR and risk of pistons melting higher ?
Thanks
Ex77
The AFR in summer needs to be richer for the simple reason that the intake temps will be higher. Higher intake temps mean a higher combustion temperature which will promote engine knock.
If the ECU can’t richen the mixture, you will get knock. What will probably happen in the case that the ECU will be fuel limited and cant richen in open loop, when it senses knock, it reduces spark ignition timing thus limiting power quite substantially. I have never played with a lotus ECU but if it does not correct fuel or ign timing in open loop then in summer you are in danger of killing the engine.
Usually ECUs do have an intake temp correction factor…
The Lotus ECU does retard spark … Markedly …
When the car has been sitting in traffic in warm temperatures I estimate only 50% of power is produced in extreme cases …
First time this happened to me I thought the motor was a gonner !
This was 2 years ago with standard ic,it hasn’t happened since.
I’m sure Frank can expand on this .
Henry,
That knocking, are you sure it’s not your 3rd gear rattling around the bottom of your gearbox?
Been there done that 
Sincs put some bubble wrap in the box so next time it won’t make so much noise
Mine was mapped according to the “Gospel of Frank” so should be well fuelly all the way. Just want to understand the AFR Winter v Summer.
Ex77
As CIN stated if it’s hotter you will get knock with a very lean mixture…When it knocks the ECU will pull timing and when the water temps are over 200f it will pull timing…
Keep the water temps cool in summer by having the fans come on full tilt at 190f and you will keep your power… The fans control are in the ecu program, Essex can change the setting or you can wire in a manual switch to give them both full power…
[quote=Exige77]Been there done that
Sincs put some bubble wrap in the box so next time it won’t make so much noise
Mine was mapped according to the “Gospel of Frank” so should be well fuelly all the way. Just want to understand the AFR Winter v Summer.
Ex77 [/quote] The AFR maps are connected to air and water temps so when ambient conditions change so does the AFR but only to a fixed point in the programing… That’s why a custom tune is needed when changes are made…
When we did Spa last summer it was warm and we dident have an issue in the 2010 Cup 260
Should we be worried and if so who do we take the car/ECU to, to have a remap?
We have standard exhaust
[quote=darryl]When we did Spa last summer it was warm and we dident have an issue in the 2010 Cup 260
Should we be worried and if so who do we take the car/ECU to, to have a remap?
We have standard exhaust [/quote] YES … as far as I know Essex are the only dealer/tuner that can tune the stock ECU…
I can also conclude that removing the plastic mesh on the side pods drops water temps to 83 degrees on my car. Previously they were 85/86.
So if your cranking up the power probably a good idea to get as much cooling into the engine bay as possible.
[quote=frank][quote=darryl]When we did Spa last summer it was warm and we dident have an issue in the 2010 Cup 260
Should we be worried and if so who do we take the car/ECU to, to have a remap?
We have standard exhaust [/quote] YES … as far as I know Essex are the only dealer/tuner that can tune the stock ECU… [/quote]
Seriously I am not having that a car sent out from the factory with an OEM tune is anything other than spot on or it would cost a fortune in warranty claims.
The issue is getting a bit muddled here guys I think…
1: OEM headers + CN ‘260’ upgrade = NO problems with AFR and hence Boothies ‘warrantee issue’ comment.
2: Free flowing headers etc + CN ‘260’ upgrade = MAYBE problems with AFR etc.
So ‘2’ as above needs a specific ECU re-map, eg by Essex, to ensure AFR’s etc are all sorted for the much freeer flowing system and to optimise the power etc etc.
Just like re-tuning my Emerald on my VHPD after DVA’s work on flowing the head… before the re-tune of the ECU it made 190, then Dave Walker weaved his magic and got another 12 BHP and nice balanced non lean AFR’s.
So, logic says the same would apply to the Yota! 
Well, that my take on it anyway! 
^^ but that still doesn’t explain why my headered car is considerably richer than Boothys non headered car …
Somewhere … something IS going on …
HELP ???
Mine did actually go a bit richer after the header swap and THAT is what is confusing me …
No doubt I could benefit from a remap,both in terms of power optimisation and more safety …
But as yet NO ONE can offer any reason why I have managed to go richer by fitting the tubes ???
Shoot …
Just had a thought folks of (maybe) a slight explanation …
At the same time as fitting the exhaust I also removed the rear panel and now run with it open…also I removed a lot of heat insulation.
Blacktoys post about him running cooler by de-meshing has got me thinking .
And Jim did say that by removing the standard system, back pressure drops making things run cooler too…
Any thoughts ?
Anyone ?
Ps. And Boothys car was much hotter than mine when we tested.
[quote=Boothy][quote=frank][quote=darryl]When we did Spa last summer it was warm and we dident have an issue in the 2010 Cup 260
Should we be worried and if so who do we take the car/ECU to, to have a remap?
We have standard exhaust [/quote] YES … as far as I know Essex are the only dealer/tuner that can tune the stock ECU… [/quote]
Seriously I am not having that a car sent out from the factory with an OEM tune is anything other than spot on or it would cost a fortune in warranty claims. [/quote]
^^ I totally agree Boothy, there is no way Lotus would send out a track focused car like the cup 260 and risk issues like you are saying Frank, and Ive never heard of any warranty issues either which surely confirms this.
Maybe you have seen evidence of this in the states but over here with fairly low waether temps im sure Lotus know what they are doing.
Hey what do I know…enjoy your rides boys.
Frank they do have a point on the low temps. It never stops raining in England haha.
I know I have problems with tempretures in Malta and had to modify my maps to suit.
[quote=CIN]Frank they do have a point on the low temps. It never stops raining in England haha.
I know I have problems with tempretures in Malta and had to modify my maps to suit. [/quote]
So are we saying that the standard 260 map is OK for ‘normal’ temps but if we get 25 degree plus temps there might me an issue
Boothy makes a valid point though on warranty. On the std 260 Cup cars you only get 12months warranty and I bet none if you retro fit the 260 upgrade to a standard 220 or 240.
SO I guess the question is would I see benefits in AFR and potentially performance gains from re mapping my 260 ECU ?
[quote=chrisexigegt]
SO I guess the question is would I see benefits in AFR and potentially performance gains from re mapping my 260 ECU ? [/quote]
Nicely volunteered Chris !
If 1000 people all send you �1 each it,d even be free !!