6970K has planted a seed in my head about changing the Supercharger Pulley for a smaller one, i believe that it improves the torque and BHP. There seems to be quite a few different sizes available, the 3:1 and 3:0 being the ones you can fit with out the need to get a smaller belt. I have had the CN 260 upgrade done, my car was already a 240. Do you need a rolling road set up after fitting or does the ECU adjust its self.
Cheers.
I think if you go for quite a mild pully the ecu should be fine, JFK went pretty wild with his and nothing has popped other than the gearbox. 
Best get the popcorn at the ready
Oh and his popcorn pop’s too
Don’t forget I fitted 550 injectors to up the fuel delivery too.
It,d be a brave move to just fit the pulley and hope nothing happens,although a few did in USA hence RLS selling em …
I was also thinking of later on getting the RLS intercooler shroud with the ducting too the side pods which might help a bit with the temps. With previous posts it seems a waste of money changing the OEM intercooler unless you go down the route of having a chargecooler fitted.
Hi jfk does that depend on what size pulley you use, the smaller the pulley the greater the boost the more fuel is needed.
[quote=gp_fisher]6970K has planted a seed in my head about changing the Supercharger Pulley for a smaller one, i believe that it improves the torque and BHP. There seems to be quite a few different sizes available, the 3:1 and 3:0 being the ones you can fit with out the need to get a smaller belt. I have had the CN 260 upgrade done, my car was already a 240. Do you need a rolling road set up after fitting or does the ECU adjust its self.
Cheers. [/quote]
I think I’d best see if there are any more spares in the garage !!! 
Yep lol Chris your right. Just dreaming and planning ahead.
I had the 2.9 fitted on my 240PP but i have the Gotham tune and had the car re tuned the day the pulley was fitted .
I think it says on the RLS website what size needs a smaller belt.
Yep seems to be anything under 3:0 and dependant on whether you have aircon.
I have the 3.1, same belt no retune. You should have had the pump upgraded in the CN 260 upgrade and the 240PP has the 440 injectors which will be OK for 270ish BHP which is what we are talking about here.
No point doing it unless you stop retardation (CC or more air)
Yes 661 its got the larger fuel pump and 440 injectors and thats what i thought the BHP might be. The RLS 3.1 pulley costs $175 delivered. Does it make the supercharger sound louder as i have the TRD fitted also.
Correct … Beware the Lotus factory map tho cos general opinion is that Lotus have made settings on the lean side to begin with… any more boost just leans things further.
Essex make the A/F much richer than standard when a car goes for mapping.
When I fitted a 2.9 to mine it went waaay lean so I pottered back home and sorted out 550 injectors…
It then went too rich so i fitted a 2.8 pulley and it was still too rich but not by a huge amount,over time it leaned out a little and has levelled out to just where I want it, only time will tell if stays like it…
As Frank says the ECU will try to get back to it’s target AFR which mine tried to do. The big question is… can it trim the fuel back enough to achieve it ?
I believe that it can’t correct enough to bring mine back because with 550,s fitted it runs out of range on the fuel trim…
I,ll tell you now though that just because it works for me there’s no guarantee it’ll work for everyone because things like exhaust/manifold,inlet temps,fuel pump pressure etc all differ…
You pays your money …
[quote=661]I have the 3.1, same belt no retune. You should have had the pump upgraded in the CN 260 upgrade and the 240PP has the 440 injectors which will be OK for 270ish BHP which is what we are talking about here.
No point doing it unless you stop retardation (CC or more air) [/quote]
Did it make any difference?
[quote=Boothy][quote=661]I have the 3.1, same belt no retune. You should have had the pump upgraded in the CN 260 upgrade and the 240PP has the 440 injectors which will be OK for 270ish BHP which is what we are talking about here.
No point doing it unless you stop retardation (CC or more air) [/quote]
Did it make any difference? [/quote]
Difficult call. I didn’t have the 260 v long before I swapped the pulley.
As you appreciate, the 260 is a pretty noticable improvement, I’d be lying if I said the pulley made much more of a noticeable gain.
The 2.9 does , even with the standard 240 pump and 440 injectors , once I change them I can open the taps a bit more in the tune .
Anybody know the cost of 550 injectors and where they might be bought from ?
I have larger fuel pump, 440’s and 2.9 pulley.
Next week I will be experiemnting with a range of smaller pulleys so am sure I will need 550’s.
Thanks
Ex77
This is where the world seems to get their injectors.
Good company to deal with, fast shipping and they seem to stock every injector on the planet!!
Co ordsport in Tipton … about 200 quid .
Oops sorry 300 quid I mean.