Hello.
I plan to upgrade the engine. The stock spec is an 08 Exige S 240 HP.
I will put bigger injectors (siemens 630 cc) + 2,9" pulley + remap.
I’m targeting 290 WHP.
AFAIK, the stock pump won’t be sufficient. I wish I could avoid that mod as it is a pity to change but I think I have to …
2 choices: Walbro 255 GSS-342 or Denso 951-0003?
Does anyone has some feedback on both?
Also, apart from Lotus, where could I find the Denso pump?
Cheers.
Fran�ois
you will only need 550’s at most and with a 2.9" pulley you are only likeley to get to around 270whp which is what mine is, I’m not sure which pump Sinclaires put in sadly but I think it was the Lotus sport one?
Yes it is the Lotus sport.
Regarding the injectors, I have found pros and cons of the Rc 550. I might give a try to the Siemens 630. Yes it is a bit bigger but I do not think it might cause a problem…?
Regarding the pulley, Dan has told me it was the limit for the speed of the supercharger RPM.
Fran�ois
What Dan said is not true, you can run a smaller pulley but then you will break the engine, 2.9" will give you about 9.5psi of boost which along with around 300hp is the limit for the piston ring lands.
the larger the injector size the more difficult it is to manage and maintainlow speed running, ther come a point where the injector is putting in too much fuel even with the shortest opening time.
As for the RCs loads use them with few issues, I think if you look hard enough all injector companies will have some form of issue.
Adrian, do you know how the boost pressure is measured?
Is Dan able to measure it when tuning?
I’ll try the 630cc and post my feelings.
Fran�ois
I have a drilling in the exit pipe from the charge cooler and this is connected to the dyno, so Dan can measure it while tuning, even if the boost pressure shows below 9.5psi with the 2.9" pulley do not use a smaller one, as I have put on better exhaust the boost shows a drop off as the air is being used more, the MP62 is a pump not a compressor, you will see a dramatic dip as the the cam change happens then another steady rise to the 2nd peak. If you measure before the CC you will see a higher pressure due to the CC core being a restrictor.
That make sense?
Yes it does!
Can you post of a pic of this hole? Do you display the pressure inboard?
Does Dan have a sensor for measuring the pressure that he plugs into this pipe?
Fran�ois
Ade, I understand the bit about measuring the boost after the chargecooler, but not the part about not reducing the pulley size if the boost is lower due to increased flow due to the larger bore exhaust.
Is your concern over the rpm of the charger, rather than the engine internals?
[quote=evo_ufo]Ade, I understand the bit about measuring the boost after the chargecooler, but not the part about not reducing the pulley size if the boost is lower due to increased flow due to the larger bore exhaust.
Is your concern over the rpm of the charger, rather than the engine internals? [/quote]
You really have changed haven’t you, speaking all that supercharge lingo… 
I’ll try to get a picture when I get the car back home. I do not have a guage in the car as I don’t want one and can’t see the point. Dan just attaches a tube to the pipe when he does the dyno runs.
Will you could try a smaller pulley but the risk is too great in my books and everyone who has tried smaller breaks the pistons, its all about cylinder pressure and 300ish hp of cylinder pressure is about as much as they can handle a good rule of thumb for a SC CC is no more than 10psi.
Adrian,
Have you found some time to make some pics???
Fran�ois
Nope, sorry, car is still at Sincs waiting for Dan to remap it for the bigger injectors and new exhaust.
Ok, please keep us updated!
Glenco have produced for our vx220 friends a direct replacement uprated fuel pump designed for the high powered SC conversions for a very reasonable price! My understanding is the vx220 runs the same fuel pump as the lotus (can anyone confirm…?). If so, possibly a cheaper alternative?
This is the post from vx220.org…
Having heard and read about the miseries surrounding fuelling and uprated engines and all that malarky and having seen some peoples solutions including a secondary pump and swirl pot I thought it was about time we had a direct fit replacement in tank that ticked the boxes.
Glenco have had a standard VX220 in-tank pump/sender unit off me and have developed a direct replacement fit kit that uprates the pump to a 255 litres per hour pump that is good for up to 500BHP (they say).
This is ideal for all VXs, tubby or NA and will work as a replacement for a tired pump at less than a standard replacement part as well as being ideal for the S/C conversions and modded tubbies.
This will not need a secondary pump or swirl pot I am told as it delivers all the fuel needed. It is a DIY kit but is not totally straight forward but if you can get the tank out yourself then I am sure you can work this out.
£92 plus the vat plus P&P for the pump and fitting kit from Rob at Glencoe on 01784 493555.