1G-GTE+Eaton M90 (or similar...)

[amichie]

AFAIK the sc14 is about 1460cc per rev and the M90 is about 1490cc per rev. I'm guesiing there won't be much difference between the two. M62 will undoubtedly be worse than a SC14.

[TERRA Operative]

I have an excel calculator that still needs some tweaking, but will get you in the ballpark. (if you make any corrections or improvements, let me know. )
It's SC blower centric, but put your own figures in and you can use it for any blower.

http://www.jdmlevin.com/files/BlowerCalculator.xls

[big_zop]

Thanks for the kudos amichie, but I only know what the stock setup is like because of the amount of work I have done one mine. I have had a look at modifying and there isnt a lot of information out there so mullets guess is as good as mine.

As for the calculations, the SC14 puts out 1420cc/rev which is quite similar to the M90 (the eaton website says 1500cc/rev) but you also need to remember that the 1G-GZE only has a 6500rpm rev limit so that alters the comparison somewhat. Although, the SC12 flows more than the M62 with 1200cc/rev.

TERRA Operative has likened the SC1x superchargers to the Ogura ones so if you look at their maps, and the ones on the Eaton website, this should give you a good indication of their efficiency - EDIT see next post (thanks Jared)

Eg (at the PR and speed you have indicated):

M90 - 56% (a PR of 2.0 is the top of the chart - http://www.eaton.com/ecm/groups/publ.../ct_128485.gif)
M62 - doesnt go to 15000rpm (suggests a max of 13500rpm) - http://www.eaton.com/ecm/groups/publ.../ct_128484.gif

TX15 (SC14 equivalent) - < 50% (PR of 1.8 is max recommended for sustained use and 10000 is the max rpm limit)


There is also a few extra graphs on the CAPA website regarding power consumption, temperature rise and airflow, though i would think they are interpolations of the efficiency chart to make it simpler for the average punter to understand.

[TERRA Operative]

Here's the Ogura charts.

http://www.jdmlevin.com/files/OguraSuperchargerMaps.pdf

I have had confirmation from Ogura themselves that the SC blowers are made by them, but they won't divulge any more information than what's linked above.

Also, if you want to buy new blowers (say an SC20) you have to buy a pallet load of them......

[Duk]

Just did some rough calculations, to get 14psi of boost I'd need to spin an M90 to about 10,000rpm (in a perfect world)

Engine air usage (at 1ATM)= 2L*7500rpm/2=7500L
Pressure ratio 2:1= 15000L/min airflow
M90=1470cc/rev= roughly 10,000rpm
M62=1000cc/rev= 15000rpm

So an M90 would seem to be the more logical choice, obviously it becomes less efficient at this high of a boost level, so my 'ideal' calculation isn't perfect, but the engine would also use less than 7500L of air, as it wouldn't have perfect pumping efficiency.

The side note of that is that an SC14 running at 10,000rpm would move the same amount of air...but certainly wouldn't make the power. Pumping losses? Heat loss? How much more efficient IS an M90?

Where an M90 is a much better SC than the SC14 come from the fact that it has much less internal leakage. It's my guess that that is why Toyota used such a large SC on such a small engine, they used an inefficient supercharger.

From a clever person who has done a lot of research about supercharger used in the real world: http://www.alfabb.com/bb/forums/boxe...y-charger.html

Supercharger VE is somwhat complex, and most people don't really understand it. The supercharger's VE number doesn't really have a meaningful effect on peak horsepower (all other things equal). However where in the curve the supercharger operates has an effect on power throughout the RPM.

Think of it this way, if the supercharger had equal VE numbers throughout the RPM range, boost would be relatively constant throughout the the engine's operating range. Set it up for 10psi, and it's going to have about 10psi from idle to redline. If the supercharger has 100% VE at the engine's redline of 6000rpm but only 70% when half way there, it's going to have about 7psi at 3000rpm.

As a general rule, because of the way the VE curves are shaped a smaller supercharger spinning fast will have a more consistant VE throughout the RPM range, and thus more power throughout the RPM range. I hope that's clear, because it confuses a lot of people.

The supercharger's heat output DOES increase with supercharger RPM, but only a little bit. That's why at 10psi the temp increase is about 180F regardless of supercharger RPM/Flow. The temp advantage here, goes to the bigger supercharger turning slowly, but it's really insignificant.

[Hiro]

Well, put it this way, the M90 powers the TRD Aurions which are a 3.5 V6....

No it doesn't. The TRD Aurions run an Eaton TVS (R1320 I think), which is different to the M90 (4-lobe compared to 3-lobe for instance, and 160 degree twist compared to 60).

[oldcorollas]

the TVS is a nice bit of gear.. a twinscrew without internal compression (effectively)

edit, supercharger VE is effectively a function of leakage, which is a function of boost level and rpm.
temperature on the other hand is a funny one, since the SC does no compression itself, there si little temp rise IN the SC, whereas all the compression occurs int he manifold, and the constant back and forth of air rushing from the manifold into the lower pressure SC cavity as it opens to the manifold is what causes most temp rise... and that varies with boost levels..

[boxh34d]

A couple of questions Mullet:
Are you sure you'll need 1 bar, and will the engine actually need to rev to 7500RPM.
At those kind of figures, the M90 will be running at around 11500RPM, heating the air about 150 odd deg C, and probably taking around 50HP to drive.
Are you sure you'll need that kind of pressure at that flow to make the power you want? You really need to nut out how much airflow you need to make the power you want, and work backwards from there.
From my limited readings, *I think* it should come out something like this:
It takes around 10lb/min of air to make 100 HP at the engine.
Your goal of 170RWKW would mean around 300 odd FWHP (30% driveline loss), so would need 30lb/min of air, / 0.076lb/cu.ft (air density at sea level) = 395CFM.
Roughly 400cfm from an M90 would require about 9000RPM at 10psi.
With these kind of speeds, it would only raise the temp about 80 odd deg C, and require about 25 to 30 HP to drive.
I'm not sure if the 1GG head could flow these kind of figures at that pressure, please, anyone in the know, feel free to shoot me down for lack of understanding with the calcs.
Hope that helps.

[oldcorollas]

at higher pressure, the head flows the same volume, just more mass (give or take)

[Pimpin_1JZ]

No it doesn't. The TRD Aurions run an Eaton TVS (R1320 I think), which is different to the M90 (4-lobe compared to 3-lobe for instance, and 160 degree twist compared to 60).

My bad, you are right. It is the TRD Hilux's which run the M90.

[mullett]

A couple of questions Mullet:
Are you sure you'll need 1 bar, and will the engine actually need to rev to 7500RPM.
At those kind of figures, the M90 will be running at around 11500RPM, heating the air about 150 odd deg C, and probably taking around 50HP to drive.
Are you sure you'll need that kind of pressure at that flow to make the power you want? You really need to nut out how much airflow you need to make the power you want, and work backwards from there.
From my limited readings, *I think* it should come out something like this:
It takes around 10lb/min of air to make 100 HP at the engine.
Your goal of 170RWKW would mean around 300 odd FWHP (30% driveline loss), so would need 30lb/min of air, / 0.076lb/cu.ft (air density at sea level) = 395CFM.
Roughly 400cfm from an M90 would require about 9000RPM at 10psi.
With these kind of speeds, it would only raise the temp about 80 odd deg C, and require about 25 to 30 HP to drive.
I'm not sure if the 1GG head could flow these kind of figures at that pressure, please, anyone in the know, feel free to shoot me down for lack of understanding with the calcs.
Hope that helps.

That's the kind of info I was chasing!

I was considering running it to a max of 10,000rpm, I just don't want to be dissapointed with the power. For reference, nathan made about 180rwkw with 18psi of boost (BAG 1G twin turbos)

-RM

[boxh34d]

I wouldn't take it as gospel, as I'm fairly new to this side of things, and as stated, I could be misinterpreting some of the calcs. I was hoping someone else might chime in with some theory on this one to confirm or adjust my figures and assumptions.

Oldcorollas: I can't really remember much to do with gas constants and vol vs temp and pressure other than 1 mole of gas occupies 24.5L at SLC ( IIRC ).
Do you care to elaborate any further on how this effects the above example? Is there any way to get a rough idea on if the desired mass of air will be able to be fed into engine at any particular pressure and flow?

[JustCallMeOrlando]

After driving this, I reckon you don't bother with the charger, get it tuned

[oldcorollas]

PV=nRT

ie "pressure x volume" is proportional to "mass x temp"
you can use the expected CFM for X powahs, but then change it to a smaller volume based on the pressure and temp.

regardless, the air going into the SC at ambient pressure has to be nough to support the power required. hat happens between SC and piston just affects the likelihood of that actually happening

[oldcorollas]

to put some numbers in.. roughly...

170rwkw = maybe 200kw at flywheel?
at 6000rpm and 90% "engine VE" = about 313Nm and about 0.75bar boost = 11psi

but that doesn't include power loss from SC..
say another 30kw
so 230kw = 360nm = 1 bar boost, say 15psi (could be 14 but...depends on many things)

maybe worst case = 1 bar boost into 2L @ 6000rpm= 12000L/min
abotu 420-430CFM = abotu 10,000rpm on SC = 1.67x overdrive on SC pulley.

this is all for 6000rpm.... and an asumed engine VE of 90%. could be up to 95, = less boost = less SC rpm/temp