Twinspark Supercharger Project
I thought I would post here about the Supercharger idea that Dave came up with a few months ago... I bought an Eaton M45 supercharger, as found on a Mercedes 1.8 engine, and have now fitted it to my (already running on LPG) Twinspark engine!
I've attached some photos...
(1) First job was to remove the air conditioning system, balance belt, oil heat exchanger and it's water pipes, and angle grind a chunk off of the balance belt tensioner bracket.
(2) Next i needed to do some fabrication, so I invested in a bench press drill for my nice clean garage.
(3) I played around with bits of steel until I was happy with the brackets which hold on the supercharger (I will get better photos of these later), and there is also an idler in the same position the air con used to be. In hindsight, I could have left the air con system in place... but the idea was to compensate for the weight of the supercharger by removing the air con system. I think this has worked well, I don't miss the air con, and I just had to fabricate this idler pulley.
(4) I have had a belt running around it, and it works fine... the alignment is quite good in all directions, perhaps a couple of degrees out in one plane. This photo shows how I have left the supercharger for now because I have run out of money for the next phase of the project!! The cable leads to a temperature probe which will be drilled and tapped into the exhaust manifold as soon as my tap arrives from China!! Temperature reading is currently 60 degrees centigrade next to the radiator where it is there (supercharger not running)... a bit warm. Passenger side radiator fan will be refitted only.
(5) This shows the temperature gauge LED readout. It's a bit retro and tacky but it was £5 so don't knock it. Can also pop the ashtray back in there at a later date. Exhaust gas temperature is an old school way of seeing when the mixture is too lean (although for mapping there is the lambda sensor), it is really for me to judge at what point my pistons are going to melt. It's also kinda fun.
(6) A boost gauge replaces the clock (who cares what time it is anyway??), and of course currently the boost is always negative because the supercharger is not running yet. At closed throttle boost is -0.5 bar, open throttle it is 0 bar as you would expect. Super cool. This also shows the LED I have wired up to the air con switch, so when someone presses this I shout "DON'T PRESS THAT" and the LED flashes alarmingly at them...
Soon that 12V signal will be connected up to a manual bypass of the supercharger (connecting outlet to inlet of charger), to immediately remove all boost. I'll also put in an automatic vacuum bypass to remove boost when throttle is closed. These are the next jobs to do as I fabricate the pipe work over the next few weeks!!
Then of course, I will need lots of help getting the fuel system ready to take on the boost! I realise it could destroy my engine to just plug it together so hopefully the other guys with experience on here (theres at least 3 guys who have boosted twinnies here) will be able to guide me with the fuel setup.
My favourite plan of action is currently to use V6 injectors and re-map. Then fit bigger LPG injectors OR simply disable the supercharger for running on LPG economy mode (hence the importance of the red flashing light)
The goal is great fun power + equivilent to 50mpg on LPG when driven normally!! This (and insurance, as I'm only 23) is why a V6 is not an option...
Last edited by Turtle4288; 11-11-11 at 18:35.