Can anyone tell me what the breakdown of Pulley Diameter to Boost is for the gmpp SC (eaton m45)
I have found just about every specification except a break down of the changes based on pulley diameter.
I would like to find or put together a chart of each pulley available for the M45 SC (as used in the GMPP 2.4 kit on a otherwise stock engine)...
for a given pulley size, its expected
1. maximum boost PSI
2. SuperCharger RPM
3. charged air temperatures
I know stock is
2.8" pulley at 4.5-5psi boost and no idea on intake temps or the RPM....
I heard a 2.6" pulley is supposed to be near 10.5psi... again the rest i dont know....
I see that the smallest i can find is a 2.5" pulley.. Does anyone know the RPM and boost expected at that diameter?
And what about all those in between...
I have read that a M45 is capable of spinning up to 15k rpm (manufacturers ratings) But have read of people spinning them up to 16k and above... but supposedly anything over 16k just increases charge temps and puts undue stress on the unit, and produces no real gains due to excess heat, cavitation and shearing at that RPM..
So if you know of a chart or link to some good info on this, let me know...
Otherwise just post what you do know, and I can compile a chart from all our colaborative experience.
my poor baby is sick... someone help me...
(2.4L engine in my cavy is ticking bad... need to make it stop)
it is kind of hard to say exactly what IAT x pulley yeilds. Where the air is drawn from will have some effect but outside air temp and use of alky will have a huge effect on IAT. All things equal the faster you spin the sc the more the heat.
FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!
yeah, i know there wont be consistant results with that.... temps in arizona in august may be a tad different than alaska in february... but just saying in general... the guys who know... on a pleasant spring day... at like 70-80 degrees... what are they seeing with what setup.... does it seem like the guys with 2.5" pulleys are blowing 200 degrees, and the guys at 2.6 are only at 150... or what...
more for general ideas.... like to get an idea as to at what point you should consider Alch Inj, or how much alch changes things at a given psi...
help people get an idea what will happen at what level.
my poor baby is sick... someone help me...
(2.4L engine in my cavy is ticking bad... need to make it stop)
To put it bluntly, alcohol injection is a good idea no matter what pulley size you're running. The smaller the pulley the more important it becomes. Generally anyone running 2.7" or less would definately require it.
14.330 @ 96.37mph
... over drive crank pulley,
2.6 chager pulley
92 deg day.
and some watter.
78 deg intake air temps.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
ok one of my sources tells me the following.....
Stock pulley 2.8" = 4-5psi boost (we all know this much is true)
upgraded 2.7" = 6-7psi
upgraded 2.6" = 8-9psi
this doesnt completely agree with my findings elsewhere....
I know somewhere i read that the 2.6" pulley should put you near 10.5psi... not 8-9...
but again, all i am doing is reading it elsewhere, and spitting it back out here.
I hope some of you guys can give me some hard numbers, and confirm or disqualify my computer-chair research.
I was lead to believe the M45 was capable of more than a mere 9psi.... but i had no proof, just heresay.
my poor baby is sick... someone help me...
(2.4L engine in my cavy is ticking bad... need to make it stop)
well you can throw on a 2.4" pulley and make sure you don't port anything so boost (resistance to flow) increases.. most port & polish their heads and superchargers, etc. so their boost level may be lower, but power is far higher.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Taetsch Z-24 wrote:... over drive crank pulley,
2.6 chager pulley
92 deg day.
and some watter.
78 deg intake air temps.
Chris
And what kind of boost are you seeing with this setup?
how large of an overdrive crank you running?
you still run all your other engine driven accessories on stock pulleys? AC, Alt, etc etc...
you still find the SC gains outweigh the added drag of the other accessories?
doesnt 2.6 alone put you darn near the max RPM of the M45 (or MP45 as you claim it is)
wouldnt 2.6 and an overdrive really push that thing too hard?
my poor baby is sick... someone help me...
(2.4L engine in my cavy is ticking bad... need to make it stop)
[ion wrote: C2]well you can throw on a 2.4" pulley and make sure you don't port anything so boost (resistance to flow) increases.. most port & polish their heads and superchargers, etc. so their boost level may be lower, but power is far higher.
This is all very true... as it is all about air volume, not really pressure... but there is no good way to measure the volume while installed... but boost just needs a gauge.
so that is why i was asking for "stock" numbers... to keep a constant...
what would a STOCK SC and a STOCK 2.4L see PSI wise based on different pulleys....
there have to be guys out there that just added an SC and a boost gauge and the "quick change" pulley kits...
I would love to hear their readings with the different pulleys.
and even guys with porting and all.... just to see their numbers would give us an IDEA.... like taetsch there... i am sure he has done all the porting and fancy stuff... he has a 2.6 pulley AND an overdrive crank pulley... so it is a double whammy. so if he tells us he has 10psi... we can figure that the porting lowers that figure a bit, but the overdrive pulley probably increases it a lot... so whatever his PSI figure is, we probably should expect lower results on a stock setup.
my poor baby is sick... someone help me...
(2.4L engine in my cavy is ticking bad... need to make it stop)
Ok, well i bit the bullet and went out and got me a 2.5" pulley.
I am only seeing 7.5psi max.... and intake temps are only a few degrees higher than they were with the stock 2.8" pulley.... (i have another post about this here, but thought i would follow up here as well for anyone subscribed to this thread, or reading it in the future)
I was getting 4.5-5psi on a nearly stock Z24.
after a full 2.5" exhaust, i was seeing 5-5.5psi.
This was all during a cold cleveland winter, so with outside temps between 30-50 i was seeing temps at a pretty consistant 70-80 degrees under cruise conditions.... peaks of a lil over 100 up to 120 under heavy acceleration for extended periods.
Added meth injection, and set to kick in at 2.5psi... this only knocked the top off, and kept temps to around 100ish under heavy boosted acceleration.
Just installed my 2.5" pulley.... i am only seeing 7.5psi... and cruise temps around 80 IAT... and under heavy boost, with nothing but blue washer fluid in my meth injection system, i was seeing 120 degrees on a 50 degree day.
These all seem relatively mild from what i have heard about the 2.5" pulley.... So hope to hear some other stories from others with similar setups.
from my experience with the M45 kit on two of my cars.. i would never run any thing smaller then a 2.7" with out alky injection (water wont do F'all for you, and i could get into an entirely different argument on the alky mixtures) and as far as running a 2.6" or smaller your going to want to tune it better with HPT to get any kind of gains and defiantly have alky injection or you will not see any more power gains even with tuning.. I have run the following pulleys on a dyno on the same day (2.8", 2.7" and 2.6") and the gains from 2.7 to 2.6 even with alky were not all that much, and once the 2.6" pulley was on the RPM of the supercharger was close if not slightly over 16k i believe (i can check back to my charts i just don't have them on this lap top and this was all like 3+ years ago) and the boost started to become unstable (boost spikes). I personally would never run any thing smaller then a 2.6" pulley if you plan on doing proper tuning (HTP) and alky, and no smaller then 2.7" if you only plan on using GM's re-flash..
As well i know some will claim they get 10psi of boost with their M45 supercharger but i have my doubts that they see this constantly.. And that all they are really seeing is a boost spike to 10psi unless they have some weird insanely poor flowing head..
although im seeing 12+ from my M45 but there is a snail helping it out..
Any way thats my rant about the M45 kit lol, dont get me wrong its a decent kit and the only supercharged kit i would ever use on on 2.4L but its wasnt one of GM's best efforts thats for sure..
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
there is no constant for temps , mine ranged from 85 to about 250 , and never stayed at 1 temp , unless cruising down the highway , and even then it would go up and down a few degrees
once you go into boost temp goes up rapidly , out of boost it slowly drops , its all a continuous cycle , and never the same temp
with the over drive, and 2.6 it was at 10-11 psi ONLY at 7200 RPM.other wise it was at 7-8,
if i remember correctly, the 2.6 with the over drive put me at the same blower RPM as the 2.5 would have.... but i dont really remember.
i was close to the edge of max RPM. but i got the kit for 41* under cost.. so if it goes,, oh well.
IMO water injection is a MUST for ALL positive displacement compressors.
Chirs
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
With straight water I was able to pull 100* out of the manifold temp.
When I was running the 2.4" pulley I calculated the S/C RPM to be around 17,500 RPM at max engine RPM (stock).
i'll leave the rest up to you
14.82 @ 97 mph
thats old Gen II tables...
MP blowers are almost 50-70 CFM higher, and make less heat.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
