You'll never get full boost from idle we're purely looking for higher low down torque, reduced spool time and higher efficiency.what it does show tho, is you dont get full boost from idle, EVEN with a S/C
You have earnt a pack a chocolate biscuits my good man. I understood all of that... so my post just above using the smaller 65% line is heading in the right direction?Start by working out the pressure ratio, In our test case, thats 1.5/1= 1.5
So start at the Y axis on 1.5. As you go from left to right on the 1.5 line, your flow rate goes up as is the x axis. You pass through the red lines, which are your s/c rpm lines. As rpm goes up, flow rate goes up. The blue lines tell you the power draw from the engine crank the sc requires at that flow rate in kw. As the flow rate goes up, the power required goes up. Next is the curvy lines are the eficiency lines. You want to be inside the smallest zone defined by the curve to be most efficient.
that turbo lag is only present if you hit the throttle below 3k tho andy, when you boot it through the gears the boost is instant (after 1st gear) because when you change to 2nd etc the engine is already running at 3k+But below 3.5k the turbo is at 0% providing no air at all.
If the s/c can provide sufficient air using 4:1 @13,465rpm.. that brings it up to 65% @ 3300 engine rpm.
All the while this air is flowing into an intercooler and before it gets chance to heat up sufficiently the S/C will have dropped off for the turbo to take over
It's personal preference though eh. I appreciate turbo's, just not my cup of tea for examplethat turbo lag is only present if you hit the throttle below 3k tho andy, when you boot it through the gears the boost is instant (after 1st gear) because when you change to 2nd etc the engine is already running at 3k+
if you are tootling along at 2 k in top then the lag is huge, but drop to 3rd and its instantaneous
fitting a S/C just because you cba to drop a gear or two is overkill imo
i,m not knocking superchargers andy, just super-turbo,sIt's personal preference though eh. I appreciate turbo's, just not my cup of tea for example
I think of it as more efficient and less need of yobbish driving to remain in boost.that turbo lag is only present if you hit the throttle below 3k tho andy, when you boot it through the gears the boost is instant (after 1st gear) because when you change to 2nd etc the engine is already running at 3k+
if you are tootling along at 2 k in top then the lag is huge, but drop to 3rd and its instantaneous
fitting a S/C just because you cba to drop a gear or two is overkill imo
Wouldn't say it'd affect safety but it'd definitely help keep air charge temps downIsn't it 'safer ' fir the engine to use a bigger turbo? (Less heat?)
Wouldn't say it'd affect safety but it'd definitely help keep air charge temps down
Exactly like that
Efficiency is the whole point of twin charging.You could have a big supercharger AND a big turbo and get some good efficiency gains. I personally would want to try this on a 1l rather than a 1.3 to make the most out of the efficiency aspect. Nissan obviously think the same thing with the MA09
Gear ratios are the limiting factor eh, smaller engines notice the gear lengths more so get more out of it? (struggling to find an elegant way to explain what am thinking haha)Efficiency is the whole point of twin charging.
There's no reason why it wouldn't be as efficient on a larger engine (within reason)
yeh, i would love to try my setup on a CG10, but with the rev limiter raised to 9k.You could have a big supercharger AND a big turbo and get some good efficiency gains. I personally would want to try this on a 1l rather than a 1.3 to make the most out of the efficiency aspect. Nissan obviously think the same thing with the MA09
I'd say it would only be the same as gearing up/down any engine. You'll notice it more. Like large changes in wheel diameter etcGear ratios are the limiting factor eh, smaller engines notice the gear lengths more so get more out of it? (struggling to find an elegant way to explain what am thinking haha)
Replacing a preface 1.0gearbox with a 1.3 will make the gears noticeably longer (like vw do with the bluemotion), then you can use the efficeint compound charging to make up the torque difference. Nowhere to go if you start with a 1.3 box (facelift 1.0 isn't a significant difference)I'd say it would only be the same as gearing up/down any engine. You'll notice it more. Like large changes in wheel diameter etc
Basically gearing it up and providing the power to cope with itReplacing a preface 1.0gearbox with a 1.3 will make the gears noticeably longer (like vw do with the bluemotion), then you can use the efficeint compound charging to make up the torque difference. Nowhere to go if you start with a 1.3 box (facelift 1.0 isn't a significant difference)
11 KW parasitic power drain @ 14k rpm eh ! that would need a hefty beltDruckverhältnis = Pressure ratio
Isentroper Wirkungsgrad in % = Isentropic efficiency
Leistung in kW = Power in kW
That's helps me out alot at least
and weight of course... (assuming cast manifolds)Basically gearing it up and providing the power to cope with it
Efficiency aside. Low down drive ability and reliability are significantly increased too. Normally on just a turbo application anti-lag would be used which shortens the life of manifold and turbo. You can run lower boost in a turbo where compound charging is concerned.
The only reason I'd say it isn't mainstream is cost and complexity or it'd be everywhere
In our example we only reach 5.5kW eh11 KW parasitic power drain @ 14k rpm eh ! that would need a hefty belt
Weight is forever an issueand weight of course... (assuming cast manifolds)
5.5ftlb of torque...11 KW parasitic power drain @ 14k rpm eh ! that would need a hefty belt
I thought I recognised it. I was going to buy one a while back. Seems to have served you wellIts an SC12 from a MR2, yeah there's a bit of weight to it.
I thought I recognised it. I was going to buy one a while back. Seems to have served you well
Spot onSo far its been pretty solid, in fact (and i'm probably tempting fate here) the only issue i've had or maybe the only issue i currently know about lol was from a drive belt being destroyed after a bolt backed out and even then i can't really blame the sc for that.
It's done what i wanted it to do and that's about all i can ask of it really.
I'm looking at having it behind and slightly above the engine (bonnet bulge needed XD ) and boosting almost straight into the MAFJus borrowed my mates m45 to size up quickly lol
Never realised they were that small, obviously it won't go where it is in pic, jus for scale purposes, m24 will be even smaller, so should go where the alternator is
Then I'd have to move turbo somewhere
no intercooler andy ? and there,s not much room for an electromagnetic pulley down by that offside chassis rail eh guysI'm looking at having it behind and slightly above the engine (bonnet bulge needed XD ) and boosting almost straight into the MAF
no intercooler andy ? there,s not much room for an electromagnetic pulley down by that offside chassis rail eh guys
i guess thats why kris front mounted his eh neilThat's what my main concern was all along really , whether I could get that clutch in place or not , no point doing othewise
I'm only after about 5psi on mine so with a big s/c I doubt I'll have DET issues, and I don't plan on compound charging..no intercooler andy ? and there,s not much room for an electromagnetic pulley down by that offside chassis rail eh guys
just being realistic if some members resort to notching the chassis to clear the waterpump pulley, then how is an extra electroclutch pulley gonna fit !Where's the optimism people? There's loadsa room for that electro pulley.
I'm not sure about Andys top mount plan but if he's not compounding he wont need an electro clutch?
If that M24 is the size I remember it to it will sit snug under the alternator, completely missing the chassis leg, leaving plenty of room for the elecro pulley
Ah very good point but I'm relating this to Neils car K10 = loadsa roomjust being realistic if some members resort to notching the chassis to clear the waterpump pulley, then how is an extra electroclutch pulley gonna fit !
I'm going electric water pump now, no chassis notchingjust being realistic if some members resort to notching the chassis to clear the waterpump pulley, then how is an extra electroclutch pulley gonna fit !
case in point ^