lol....yeah, honestly not surprised....I've heard of that before, but never seen it....to me that is just really weird. Like I said, everybody does business differently.
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
Joshua Dearman wrote:[quote=97cavie24ls(™)]
yes its a cheaper upfront to do the s/c pulley , but the crank pulley will be lighter and lessen the rotating mass on the motor , and if you decide to swap in the M62 from the LSj eco , youll still be able to use it and still get more boost from the M62 with the larger s/c pulley , as well as most people will never see the larger crank pulley , so they will think your running less boost than you are , which is a great thing is your into street racing
Well...yes the pulley will physically weigh less...but you have mass further away from the center point so you will be increasing the moment of inertia and will slow down your engine response....similar effects of steel flywheel and aluminum flywheel. Kind of a bad example since the diameter of the flywheel is consistent and only the density of the material is changing. That said, going from stock to a larger alum pulley you 'might' not see any differences from the similar concept...don't really know without seeing the design and doing the math.
Also, I know everybody does their business differently but who pops hoods before they race? I've only seen that in the movies man.
I really don't see the pro's outweighing the con's, but to each his own. To me a stock sized alum pulley will give you better engine RPM response and a smaller pulley on the SC will only help with similar results(reducing wasted energy in the form of angular acceleration). When you can achieve the same results(SC RPM) and gain on the back side as well......why is it even a question? Not to mention it would be reasonable to assume the smaller pulley will be cheaper, also, you will not see any belt slip @ even 2.3" if the pulley is well made and you run a good belt and tensioner.
Anyway, I'm not here to rub noses or prove a point...just bringing the facts.
my hood is always open , even on my n/a toys
as far as the mass being farther out , yes there is that , but really how much of a effect is it hurting when its only 1/2" larger in diameter ? id say the weight loss is more than enough to make up for the for the difference in the outter mass
as the saying goes every bit helps
the pro's still out weigh the cons to me
now i know im not anywhere near as knowledgable as mr technical boy dearman up there^^^^^
so i won't presume to even guess in this subject.
but i do have something id like to know...
so the s/c is spinning too fast after 17,000.. right? and anything above would just be hot air? correct? so if one would say spin it to 20,000 but have an extreme cooling setup on it, wouldn't it then be fine?
or did i miss something?
Every time I scream "Release", I mean it, you know it. I feel the day. Black 7.
[quote=97cavie24ls(™)]my hood is always open , even on my n/a toys
as far as the mass being farther out , yes there is that , but really how much of a effect is it hurting when its only 1/2" larger in diameter ? id say the weight loss is more than enough to make up for the for the difference in the outter mass
as the saying goes every bit helps
the pro's still out weigh the cons to me
Yes, I see your point, but you have to remember a good 50% of the pulley weight is on the outer lip(not to mention just about all the real mass that actually rotates with any high angular velocity)....the material added for the 5rib flares out. So, honestly we are splitting hairs here I know....but just keep that in mind. How much power are we talking?....probly not even a dyno could tell you since the difference would fall into the % accuracy deviation of the dyno itself.
z yaaaa wrote:now i know im not anywhere near as knowledgable as mr technical boy dearman up there^^^^^ so i won't presume to even guess in this subject.
but i do have something id like to know...
so the s/c is spinning too fast after 17,000.. right? and anything above would just be hot air? correct? so if one would say spin it to 20,000 but have an extreme cooling setup on it, wouldn't it then be fine?
or did i miss something?
I LOL'd at the comment...
Honestly, I really couldn't answer that question with a great deal of confidence either way. Those graphs supplied by MP on their site are varied by displacement with pressure being held constant....those graphs are pretty much worthless other than finding out a single "point" on the graph that your setup will be equal to...that being exactly @ 5psi and @ 10psi. Can't really use those graphs for any indication on what will actually happen with heat generation and flow with relation to the SC RPM. They are pretty much useless unless your setup is very consistent with it's pressure thru the powerband....then we could actually plot some relationships.
^Thats actually a pretty good idea...somebody write down the MAP pressures they get vs. engine RPM..PM them to me..I want to plot this @!#$ out and actually see if there is a real close relationship @ high SC rpm between heat generation and VE. - Please be from somebody who is pushing the SC...2.5" pulley preferred.
EDIT: would be interested in seeing two setups....two ideal setups to use for comparison would be one setup where the engine RPM is being pushed more than the SC persay...ie 2.8" pulley with a 7k+ redline and another setup with a stock redline and a 2.5" pulley. If possible please disable any WI injection as to not interfere with the data...since there is no direct air temp measurement post SC...I don't want to the WI to effect the boost which could possibly skew the results. I will have to make relativity assumptions to plot out the delta T plot and need pretty much the same conditions as were present when MP tested it. The results of this might just surprise people.
I could live with a stock SC setup: 2.8" w/ stock redline and 2.5" with a 7k+ redline....that would work too, since that is probly more of a realistic request given the setups I've seen around here.
Edited 1 time(s). Last edited Thursday, August 13, 2009 11:24 PM
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
Joshua Dearman wrote:[quote=97cavie24ls(™)]my hood is always open , even on my n/a toys
as far as the mass being farther out , yes there is that , but really how much of a effect is it hurting when its only 1/2" larger in diameter ? id say the weight loss is more than enough to make up for the for the difference in the outter mass
as the saying goes every bit helps
the pro's still out weigh the cons to me
Yes, I see your point, but you have to remember a good 50% of the pulley weight is on the outer lip(not to mention just about all the real mass that actually rotates with any high angular velocity)....the material added for the 5rib flares out. So, honestly we are splitting hairs here I know....but just keep that in mind. How much power are we talking?....probly not even a dyno could tell you since the difference would fall into the % accuracy deviation of the dyno itself.
not sure id say 50% of its weight , maybe 40% , but i do agree it would be hard to measure any difference , which lends to a plus for the larger crank pulley to stock crank pulley comparison
Joshua Dearman wrote:
z yaaaa wrote:now i know im not anywhere near as knowledgable as mr technical boy dearman up there^^^^^ so i won't presume to even guess in this subject.
but i do have something id like to know...
so the s/c is spinning too fast after 17,000.. right? and anything above would just be hot air? correct? so if one would say spin it to 20,000 but have an extreme cooling setup on it, wouldn't it then be fine?
or did i miss something?
I LOL'd at the comment...
Honestly, I really couldn't answer that question with a great deal of confidence either way. Those graphs supplied by MP on their site are varied by displacement with pressure being held constant....those graphs are pretty much worthless other than finding out a single "point" on the graph that your setup will be equal to...that being exactly @ 5psi and @ 10psi. Can't really use those graphs for any indication on what will actually happen with heat generation and flow with relation to the SC RPM. They are pretty much useless unless your setup is very consistent with it's pressure thru the powerband....then we could actually plot some relationships.
^Thats actually a pretty good idea...somebody write down the MAP pressures they get vs. engine RPM..PM them to me..I want to plot this @!#$ out and actually see if there is a real close relationship @ high SC rpm between heat generation and VE. - Please be from somebody who is pushing the SC...2.5" pulley preferred.
EDIT: would be interested in seeing two setups....two ideal setups to use for comparison would be one setup where the engine RPM is being pushed more than the SC persay...ie 2.8" pulley with a 7k+ redline and another setup with a stock redline and a 2.5" pulley. If possible please disable any WI injection as to not interfere with the data...since there is no direct air temp measurement post SC...I don't want to the WI to effect the boost which could possibly skew the results. I will have to make relativity assumptions to plot out the delta T plot and need pretty much the same conditions as were present when MP tested it. The results of this might just surprise people.
I could live with a stock SC setup: 2.8" w/ stock redline and 2.5" with a 7k+ redline....that would work too, since that is probly more of a realistic request given the setups I've seen around here.
wont be able to do any of that until tuning is done , but the readings would be with the larger crank pulley , and unknown s/c pulley , on a built 2.4 with meth injection
^Ya, I do admit...the 'gains/losses' would be splitting hairs but the differences might be more than some mods. Kinda like a "Why be counter progressive if there is another way to achieve the same goal with an 'unmeasurable gain' instead of doing the same thing and getting an 'unmeasurable loss' in the system." Eh, to each his own.
That would really be cool to get some #'s tho man and either dispel some 'common logic' around here....or....prove it correct. I really don't know which way it will go....but either way it would be interesting to see. Kinda disappointing when I saw the MP graphs tho....very miss leading. Unless you had the absolute perfect engine match which was perfectly sized for the charger those graphs are pretty much meaningless. In their defense they can't go around and test every engine either...so what options do they have....at least they tried to get their customers something.
Anyway, one thing I really do need is to make sure there is no intake charge cooling of any sort...at least for one set of numbers. I need that to make sure the data is comparable to the MP testing they show. It would also be pretty cool to see your tune with and without WI to measure the effectiveness of the cooling too....but those #'s can only come from a dyno since there is no post charge IAT. The BEST #'s would be both a moderately high pressure setup with and without WI(both, engine RPM vs. boost pressure AND dyno graphs) and the same 4 sets of #'s on a stocker system. With that kind of data, all being the assumption that the data is reliable, there would be no question that couldn't be answered about this setup.
Edited 2 time(s). Last edited Friday, August 14, 2009 11:48 PM
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
My Engine was stock, Nothing was done to it besides the OS crank pulley with a newer (less then 15K on it) charger.
The 13.7 run was with a M5 water nozzle, with water only, and the aid of a .031 N2O jet though first gear (@!#$ micro switch)
Later that summer I switched out to a 2.6 charger pulley And the OS crank pulley, this set up felt STRONG, it was at about 17500 at my shift point, and was around 12 PSI. With water injection my Intake Air temps were around 70-90* on a summer day.
I was using LSJ injectors that were at 110 Duty Cycle, but my mSec open was below 17..... and held a nice mid 11's AFR. Kept me happy.
Bar NONE, the best ad on to the blower was the OS crank backed up with >WATER< INJECTION.
Yes, I said water, not meth.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
Agreed, water takes out the most heat. If you dont need to add octane and only looking to take out heat, water is the way to go.
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
Was the oversize crank pulley he one md enforcer makes? And what belt is then used with the os crank pulley and stock supercharger pulley? Thanks in advance!
Chris used a 7" oversized crank pulley. Race"something" made five pulleys a long time ago. "2005ish if I remember correctly" He used one of those. I made 15 and sold 14 over sized crank pulleys. They are also 7" in diameter, and are the absolute largest that will clear the timing cover. Mine should produce the about the same boost as the old pulleys did, since they are the very close to the same diameter. Mine are slightly larger and are measured from the center line of the pulley grooves, where the old ones were measured to the top of the pulley grooves.
No one has agreed on the proper belt size, and I left it up to the customer to decide on the proper belt size. Look up
Kevin Richter and ask him. Last I knew, he was running my Over Sized crank pulley with a completely stock blower.
Edited 1 time(s). Last edited Wednesday, March 02, 2011 1:14 PM
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
Got my car running the other day, took it out last night. Cold out probly below 40 out. 2.6 on the charger and md's crank pulley, not giving it full throttle I saw 12 lbs. And it felt real strong. Just say with out the over sized crank I saw 6-7 lbs. So there you go. Worth it in my book? Damn right.
Nate, make sure to re-check to ensure the crank pulley is tight after driving 25-50 miles.
Most people seem to see 2-4 more psi with my crank pulley, depending on other mods.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
Will do bro next drive will be to my shop like we talked about before. Lots on the todo list. Allot of retorqing about to go down.pretty fun so far. If you have the m45 and don't have md's pulley you are sleepin'. "Put the gloves on and do the math". More boost=more smiles.
I have the 2.5 pulley and MD OS crank as well.
Even in the phoenix heat i see about 10psi (rounding down, sometimes its as much as 12) at full throttle, before that i would see about 6. The mod is 110% worth it, plus it makes that blower screeeeeaaaammmmm
Eat my shift
