Ok forget my last post. please only reply if you have relavent experience.
for eaton m90 unit:
Q: what is max boost?

factory v6 commodores run 6psi, i will assume this is somewhat towards the lower end of its efficiency. so, say somewhere between 6psi and 2bar.... 24psi. using the www.sprintex.com.au/files/Blower_Calculator.xls the FACTORY v6 comes in with (3.791l, 6psi, 5500rpm) 217kw. with the software warning "low drive ratio" of 1.66. s/c spinning to only 9,114 rpm.

so on the SR if we go for(yes, the cr is gonig to be boost friendly 8.5:1)
6>24psi, >9,114rpm(s/c),
eg: at 22.1psi (150kpa), and 6500rpm(eng), you get 10,065rpm(s/c) and 1.55 drive ratio.
which save for the high boost level, is quite akin to the v6 setting.
so.... what is the most crutial factor, boost/rpm(s/c) or drive ratio.
I would assume it would be rpm, much like any turbo/enginepump?

please only reply with relevant knowledge or experience, as i have already had many conflicting opinions expressed and very little constructive help.

_________________
"Stroked is fun, but I'ld rather get blown"
"Redlines are merely suggestions"

my shrinking garage is down to.....
2x 1600s
1x GQ Tray back
1x 300ZX
1x FZR600

while becoming a bit "old kit", eaton M90s are still big bang for bucks and can handle a fair bit.

if you browse the "forced induction" section and search for "M90" on www.lextreme.com/forums/ i'm sure ALL your questions will be answered re: the supercharger and it's efficiencies / pitfalls.

and after seeing the quality of datman55s water injection setup - and seeing his results with and without it, i would say this would be the way to go.

W2I intercooling a supercharger can be messy unless you can fit it UNDER the charger. again check out lextreme for all your queries there too.

and no, i don't receive sponsorship from lextreme it's just a really informative site with LOTS of tech heads.

_________________
frankenstein projects R us.

The Republic of Western Australia -
Propping up the Nation's Economy since 1901.

By my quick calculations, you'll be getting well over 30psi boost if you run at about 2:1 1.98:1 will still be up in this region (its only 0.02 difference after all)

That's not accounting for any losses or inefficiencies in the whole conversion.

To get 15psi out of an M90 on a 2 litre motor, you're only going to be running something like 1.25:1. This, I believe, is way too low for the Eaton to perform well.

Personally, I reckon its WAAAYYYY too big

_________________
1970 ex Group A Rally P510
1971 P510
1972 180B SSS
1965 SP310 Fairlady
1966 SP311 Fairlady

depends on the application though - wild cams, custom plenum, 2.2L stroker, tuned length exhaust or a stock engine with a charger.

_________________
frankenstein projects R us.

The Republic of Western Australia -
Propping up the Nation's Economy since 1901.

bump

_________________
"Stroked is fun, but I'ld rather get blown"
"Redlines are merely suggestions"

my shrinking garage is down to.....
2x 1600s
1x GQ Tray back
1x 300ZX
1x FZR600

Please accept my apologies for trying to apply my 6 months of research into determining what supercharger will best suit a 1.8 - 2.0 litre motor to your question.

_________________
1970 ex Group A Rally P510
1971 P510
1972 180B SSS
1965 SP310 Fairlady
1966 SP311 Fairlady

dave dun worry bout appologies, just anything that can get me closer to success. your input is appreciated (everyone) but i just wanted some rock solid answers, not the crap SPRINTEX/AEC/HARROP have tried to feed me.

also, anyone out there with an associate of mate who could be of assistance, go on and dob him in to me.... i am getting no where.

thanks guys.

_________________
"Stroked is fun, but I'ld rather get blown"
"Redlines are merely suggestions"

my shrinking garage is down to.....
2x 1600s
1x GQ Tray back
1x 300ZX
1x FZR600

I don't have any practical experience at all of supercharging. I only have two books which cover it. Both say: Eaton + 20psi = bad move. They're not designed for that kind of thing. Some of the yanks have run them up to 16psi (mustang cobras), but they acknowledge that's pushing it, and really they need something bigger.

Eaton's own graphs tell the story. The M90 has peak volumetric efficiency at about 11500RPM, and the adiabatic efficiency peaked way before that.

_________________
Recommended trading: datto-510

so beef, that brings us back to running a SC & a turbo to maximise torque/hp throughout the rev range (think supermarch)

did i read in the "other" thread that commy eatons are M62s?

_________________
frankenstein projects R us.

The Republic of Western Australia -
Propping up the Nation's Economy since 1901.

see thats the sh@t that really gets me, I was under the impression that commo's were m90, but i also found info stating they are m62. further to that FIT (forced induction technologies) a W.A. company that specialises in Supercharged V6 commo's says that they are infact the m90. now why is there so much comflicting info on OEM AUSTRALIAN car(s)?????

well, if that is the max boost range they (eatons) are good for then that is at least a starting point.
no one seems to be able to answer this:
is it POSSIBLE to use a m90 on a SR20, if so how "hard" do i need to spin it?

to the best of my understanding is it only a case of needing to spin it up enought to create boost? the SR20DE is very toquey anyway, this must only lend to it being more capable(than other 2l 4cyl) of driving a comparably bigger s/c?
i think its time to revisit my ever faithful Corkey Bell piece of lierature....

thank again guys.

_________________
"Stroked is fun, but I'ld rather get blown"
"Redlines are merely suggestions"

my shrinking garage is down to.....
2x 1600s
1x GQ Tray back
1x 300ZX
1x FZR600

Jeff,

Compounding is an interesting idea, but I think the KISS principle is a better one! I'm not smart enough to work that stuff out!


Pro,

I could've sworn it was you who first mentioned the commo charger is an M90 quite a while back... It might have been the same thread where you lost your left nut in a bet?

More to the point, every reputable source I have seen, says it's an M90.


SC1600,

I'm sure it's possible to fit an M90 to an SR20 - it's just a question of how well it'll work.

How hard to spin it? Corky is your friend. You'll want to have a good read of the rootes blower chapter - everything you need is in the book and Eaton's data sheets.

The SR20 will drive the charger, no worries. The required drive power of those things is about 30-40HP at 10psi, IIRC. Hell, an L16 could drive it!

FWIW, I think you've hit a common snag. There aren't many people who seem to genuinely understand how to spec this stuff out. You're not alone.

_________________
Recommended trading: datto-510

Sizing a blower is similar to sizing a turb.
depends how much power you want to make & when you need it.
its easy to work out.
first you need to decied the above.
work out the CFM you need for the grunt.
The size the blower.
from experience, if one blower is too small & the next size is to large,
go the smaller unit.
If memory serves me right about 360 cfm @ 2 bar abs. will make a very grunty SR.

_________________
A little knowledge is a dangerous thing.
www.datsport.com

"R.I.P. Baz. 29 April 2022. Thank you for all your contributions to the Datsun community over the years. You will be missed." - OZDAT

checkout the speedworks supercharged S13 drift car driven by Jimmah, not sure whats been done but i remember reading somewhere his setup is worth a shitload, and makes about 400hp and 400nm, with full boost by 2200rpm!



and a vid too, about 17mb

http://video.franzonline.net/AFARCC-Jim ... llo-05.wmv

try getting ahold of these blokes, sure they'd be very helpful, and have the experience your after

_________________
Dave W

The 1600

Recommended traders: Nissanman, pro240c, 2door510, Datsport, mkyle, Green510, Um_510, jdmdatsun510, Ludachris

yeah - and i still do swear by it. i remember the holden tech brochure saying it was as well - back in 1997.

now someone has said it's an M62... that's a huge size difference there - would prob be boosting at idle on a 3.8 V6.

and nah- i lost my left nut in that *grinds teeth* martin donnon *grinds teeth* 240Z thread.

_________________
frankenstein projects R us.

The Republic of Western Australia -
Propping up the Nation's Economy since 1901.