super charger

frank said:
what it does show tho, is you dont get full boost from idle, EVEN with a S/C :)
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You'll never get full boost from idle we're purely looking for higher low down torque, reduced spool time and higher efficiency.

That S/C graph shows me that whilst it's at 5,140rpm its moving 100+ cubic metres of air per hour.
Which on a ratio of 6:1 is 856rpm at the engine... pretty close to idle
I've no idea how that relates to boost pressure or the pressure ratio... but I'm self teaching myself slowly :)
 
Druckverhältnis = Pressure ratio
Isentroper Wirkungsgrad in % = Isentropic efficiency
Leistung in kW = Power in kW

That's helps me out alot at least :)
 
6:1 is very high , and with 60% efficiency @ 14k rpm (4:1 pulleys, and 3.5k rpm engine speed) thats a lot of hot air !
neils TD04 is nearer 75% efficient, all the way to 1.5 bar :)

td04-13g.gif
 
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.
 
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 :)
 
Enuo said:
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.
Click to expand...
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?
(This was before I understood pressure ratio)
 
Well it's important to remember you can use a bigger sc and run it at lower speeds for better efficiency, but the smaller the sc the less rotating mass, less power draw... all compromise, but reading the graphs helps you make that decision :)
 
h701micra said:
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 :)
Click to expand...
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 :)
 
frank said:
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 :)
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It's personal preference though eh. I appreciate turbo's, just not my cup of tea for example
 
frank said:
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 :)
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I think of it as more efficient and less need of yobbish driving to remain in boost.
From my experience dropping a gear to get in boost can be detrimental because numerous reasons. Being able to remain in that higher gear for that split second would be extremely advantageous. Where we have a chicane you can't drop a gear as it makes the car too jumpy and unsettled and people end up coasting through. If I can leave it in 3rd and have the torque necessary in almost an instant that will pull me round the chicane with the turbo spooled on exit... that'd be perfect. All I can say is the Delta S4 was the fastest rally car for a reason :)

Its less strain on the engine and turbo to generate the usual power figures and a win win imho :)
 
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 :)
 
Enuo said:
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 :)
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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)
 
h701micra said:
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)
Click to expand...
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)
 
Enuo said:
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 :)
Click to expand...
yeh, i would love to try my setup on a CG10, but with the rev limiter raised to 9k.
same 130hp, same combustion chamber pressures, and same piston speeds (but 1 bar boost, and higher rpm)
 
Enuo said:
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)
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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
I can understand why a smaller engine would respond better
 
h701micra said:
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
Click to expand...
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)
 
Enuo said:
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)
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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
 
h701micra said:
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
Click to expand...
and weight of course... (assuming cast manifolds)
 
I'm pretty sure my dyno graphs are in the build thread somewhere (if that helps anyone)...the results on that were with a questionable fuel map (lean and rich in places - hadn't finished the map and the dyno run was used as r&d :D) but the engine ran out of revs before the supercharger did.

With mine 5th gear is great as the car just wants to go, makes motorway driving so easy, in fact i hardly ever drop down a gear...its fun if you do but not really needed.

So while i agree you probably don't need to have both, it doesn't mean its not worth trying out :D (IF you can find all the bits cheap enough and you can workout how the hell to get it all in place - probably the two hardest bits).
 
h701micra said:
I thought I recognised it. I was going to buy one a while back. Seems to have served you well :)
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So 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.
 
solarice said:
So 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.
Click to expand...
Spot on :)
I'll be re-reading through your blog again soon, as and when I start this twin charge malarky. Except I'll be using the GA16
Which as we all know is a CG just older, bigger and heavier
 
Jus 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

ytese3yj.jpg


Then I'd have to move turbo somewhere
 
pork said:
Jus 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

ytese3yj.jpg


Then I'd have to move turbo somewhere
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I'm looking at having it behind and slightly above the engine (bonnet bulge needed XD ) and boosting almost straight into the MAF
 
Enuo said:
I'm looking at having it behind and slightly above the engine (bonnet bulge needed XD ) and boosting almost straight into the MAF
Click to expand...
no intercooler andy ? and there,s not much room for an electromagnetic pulley down by that offside chassis rail eh guys :)
 
frank said:
no intercooler andy ? there,s not much room for an electromagnetic pulley down by that offside chassis rail eh guys :)
Click to expand...

That's what my main concern was all along really , whether I could get that clutch in place or not , no point doing othewise
 
frank said:
no intercooler andy ? and there,s not much room for an electromagnetic pulley down by that offside chassis rail eh guys :)
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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..
 
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
 
h701micra said:
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
Click to expand...
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 ! :)
case in point ^
 
Looks like it dont it and just added a pullet onto the water pump.
With a bypass valve inplace pre turbo.... clever people :D
Bypass valve in the airstream is simpler than an electro pulley as air will take the path of least resistance which would be the secondary inlet once a valve is opened
 
frank said:
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 ! :)
Click to expand...
Ah very good point :) but I'm relating this to Neils car :) K10 = loadsa room
But then again if mounted under the alternator.. you clear the chassis leg and are near on inline with the crank pulley :)
 
frank said:
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 ! :)
case in point ^
Click to expand...
I'm going electric water pump now, no chassis notching :)
 

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