new ** MRZ Performance UDP and Lightweight Crank Pulleys for the 2.2/2.4 NA Ecotec's
09-05-2008, 02:17 PM
#27
if we had a 2.4 in our area i woudl talk them into, but all we have r 2.2's and 2.0's...
also after searching i found what the trq spec for the crank pulley bolt is, which is very important to have
first pass= 74lbs-ft/100 n-m
second pass=75*
also after searching i found what the trq spec for the crank pulley bolt is, which is very important to have
first pass= 74lbs-ft/100 n-m
second pass=75*
Last edited by Jn2; 09-05-2008 at 02:17 PM. Reason: Automerged Doublepost
09-05-2008, 02:21 PM
#28
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i would do it if i had access to a dyno. unfortunately right now there is only a dyno or 2 in the city im from but i just moved to a city of 10,000 people which barely has a garbage dump.
09-05-2008, 02:56 PM
#29
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The vibrations that can be transmitted to the crank are the vibrations from the accessory belt but they are the same on the billet pulley or the OEM pulley since the harmonic on the OEM piece is located inside the pulley itself and not outside like on normal crank pulleys. Take a look at an Ecotec harmonic when it's off the engine and you will see what I'm talking about. That said. Both pulleys contacts the crank and belt directly, so our pulley will transmit the same vibrations as the OEM cast iron pulleys.
I do agree that the best thing will always be to have a true harmonic balancer on an engine with a rubber insulation to cut the belt vibration from the belt. This way of making it is very costly however since 2 parts are needed, vulcanizing, balancing since there are multiple parts assemblem with rubber. This kind of part would sell for a lot more...
Yeah, we provide the torque specs with the instructions as well to be sure the install is done correctly
Last edited by MRZ - RedGTZ; 09-05-2008 at 02:56 PM. Reason: Automerged Doublepost
09-05-2008, 03:40 PM
#32
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09-05-2008, 04:21 PM
#33
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i run SS/Na times if you feel better 
09-06-2008, 01:03 AM
#41
The crank pulley is not a "harmonic balancer" its a harmonic damper. The ECO engine doesnt require the crankshaft pulley to be weighted and act as a "balancer" since the engine is internally balanced. So reducing the weight of the pulley is fine and should obviously result in freed power.
It does however need a a pulley equipped as a damper to absorb/dissipate crankshaft torsional vibrations. There is nothing we can do about these vibrations other than dissipate them in some way(a damper) or just let them happen and risk the consequences. Everytime a cylinder fires it loads the crank, the crank flexes and then unloads, its this constant loading/unloading that we call torsional vibration. All by itself it doesnt sound bad, but ifwhen this vibration in the crankshaft happens at the same frequency as the cylinder firing event there are now massive forces on the crank that it isnt designed to withstand, the damper absorbs these vibrations so that there are far fewer(ideally no) times when the cranks vibration frequency and the cylinder firing frequency match eliminating the possibilty of these vibrations exerting forces on the crank(and bearings!) it isnt designed to take.
The MRZ pulleys look like excellent pieces, will surely free up some power for you and will most likely offer many miles of trouble free service on your ECO. Just keep in mind youre removing an important design feature that virtually every engine in existance designed for endurance uses.
It does however need a a pulley equipped as a damper to absorb/dissipate crankshaft torsional vibrations. There is nothing we can do about these vibrations other than dissipate them in some way(a damper) or just let them happen and risk the consequences. Everytime a cylinder fires it loads the crank, the crank flexes and then unloads, its this constant loading/unloading that we call torsional vibration. All by itself it doesnt sound bad, but ifwhen this vibration in the crankshaft happens at the same frequency as the cylinder firing event there are now massive forces on the crank that it isnt designed to withstand, the damper absorbs these vibrations so that there are far fewer(ideally no) times when the cranks vibration frequency and the cylinder firing frequency match eliminating the possibilty of these vibrations exerting forces on the crank(and bearings!) it isnt designed to take.
The MRZ pulleys look like excellent pieces, will surely free up some power for you and will most likely offer many miles of trouble free service on your ECO. Just keep in mind youre removing an important design feature that virtually every engine in existance designed for endurance uses.
09-06-2008, 12:05 PM
#43
hit a tuning fork, it vibrates and sings, do it with your hand on the fork end and all you get is a dull thud and minimal vibrations, your hand absorbed most of the vibrations. Your hand is the damper.
All that said, if my plans for an ECO powered Stlaker come to fruition I would like to use one of these(the Stalker would be a minimal use vehicle)
09-06-2008, 12:34 PM
#44
very interesting, im going to be testing both model on this one, keeping mu stock, i have 35k on my car, with a 72k warranty, so should anything happend im covered, cuz my bud is a tech at the dealer i wonder how long it will be till it causes problems...hmmm...vey very interesting...but still the thought of faster rev'n entrigues me, MRZ i already mad arrangements at my local shop, well nto set in stone appointment, but they now ma go down to yno 3 times, so we came to 150 would cover the 3 runs
i wonder how long it will be till it causes problems...hmmm...vey very interesting...but still the thought of faster rev'n entrigues me, MRZ i already mad arrangements at my local shop, well nto set in stone appointment, but they now ma go down to yno 3 times, so we came to 150 would cover the 3 runs
09-06-2008, 06:53 PM
#49
thats nice, i know some places have better deals, but im loyal to this dyno shop, they were the ones that didnt laugh because i wanted to dyno a stock car a while back, no since than i have done all my dyno's with them, i dyno every mod :p
i posted that in the 2.4 section, thought i'd post it here too, basically read it, thats what i beleve, i doubt it will add WHP, but i know damn well it will let u MAKE that WHP alot faster...thus helping you get down the track FASTER, now i am still DYNO'n both pullies to see if what/if any HP they make
Originally Posted by Jn2
i doubt any big HP gains will occur, but due to faster reving you will reach ur RPMs faster, thus netting you a faster spool, not b/c u spool in lower RPM's, but b/c you get to your spooling RPM's quicker, but i am going to dyno both the lightwheight and UDP, and my bet is i wont say any hp gain, but i will see that the engine will rev faster, think of it as this
set up 1:
2000-6500rpms took u lets say 3 seconds
set up 2(OEM size MRZ)
2000-6500rpms took u lets say 2.6seconds
set up 3(MRZ underdrive)
2000-6500rpms took u lets say 2.4 seconds
in all examples you made the same HP, but its how fast you rev'd that made the diffrence, while i doubt it will add power it will help you make that power faster, thus helping you get down the track faster, hope that helps
set up 1:
2000-6500rpms took u lets say 3 seconds
set up 2(OEM size MRZ)
2000-6500rpms took u lets say 2.6seconds
set up 3(MRZ underdrive)
2000-6500rpms took u lets say 2.4 seconds
in all examples you made the same HP, but its how fast you rev'd that made the diffrence, while i doubt it will add power it will help you make that power faster, thus helping you get down the track faster, hope that helps
Last edited by Jn2; 09-06-2008 at 06:53 PM. Reason: Automerged Doublepost