Lighter pullies installed -md- HHR this is for you
I would like to know the same thing.
The only thing I've gathered is that -md- HHR makes them, because he has a bachelor's degree in Mechanical Engineering (pretty cool btw
)
Other than that... we need info PLEASE!!
The only thing I've gathered is that -md- HHR makes them, because he has a bachelor's degree in Mechanical Engineering (pretty cool btw
Other than that... we need info PLEASE!!
I will disagree with this. On my cavalier. I did a before, and after dyno. I designed and made a lighter crank (1/3 the weight) and alternator pulley (1/2 the weight). I made 8 more whp and 6-7 more ft-lbs across the whole RPM range. I did this for my last project for my Bachelors in Mechanical Engineering. I have sold 34+ sets to the j-body community so far, and ALL said they could tell a difference. I sold a few alternator pulleys to a few HHR owners and cobalt owners. All have been very happy.
Heres the after dyno with my cav. I have the before and after dyno sheets somewhere.
Heres the after dyno with my cav. I have the before and after dyno sheets somewhere.
Crankshaft at 1/3 the weight?? Don't think so, unless you built it out of hollow aluminum, which would only last a very short time.
As far as the HP claims, what else was changed in your before / after tests? Complete rebuild, larger bore, new rings, just new plugs, etc.?? As for the HP claims based upon pulleys alone, I will flatly state that it is impossible! I said it bofore and I'll say it again... When you are measuring HP or torque on a chassis dyno, EVERY rotating assembly, from the front of the engine, to the internals, including the reciprocating mass of the pistons and rods and the rotational enertia of every component, from the alternator, any pulleys, crankshaft, cams, gears, balance shafts, flywheel, torque converter (manual or auto), every transmission gear, driveshafts, hubs, brakes, wheels and finally the tires, comes into play on the total rotational mass enertia that has to be overcome to accelerate the vehicle. The drive pulleys are such an infinitesmal component of this that any benefit would be nearly immeasurable!!
If you want to flaunt your claimed degree, you missed some important principles. If you're trying to "trump" me, I'll just state that "my degree is bigger than your's", and I was building race cars and engines long before your parents thought of having sex.
Unfortunately, there is so much myth, lore and outright BS put out from false advertising, then friends telling others that "I have read..." or "I have heard..." that the average person actually starts believing and if they buy into it, convinces themselves that "Yeh, I can tell a difference...".
And, finally, some are asking how to buy this... Better look into becoming a Supporting Vendor here soon. Then you can make any questionable claims and sell your product to the masses.
^-- its true. People have been doing this for years now. On some small engines the gains can be higher because the engine isn't working as hard. My Prelude I had made just over 10hp to the wheels from a lightened and underdriven crank/alternator/powersteering pulley combo. You're not GAINING horses as much as FREEING up some of the horses you already have.
Think of it like a 10 speed bike. Change gear sizes and its either harder or easier to pedal right? Same thing. Changing the pulley size (or weight) can make it easier for the engine to rev up. Most noticeable for a "butt dyno" would be watching the revs. A pulley swap will make the engine a little more rev happy.
Think of it like a 10 speed bike. Change gear sizes and its either harder or easier to pedal right? Same thing. Changing the pulley size (or weight) can make it easier for the engine to rev up. Most noticeable for a "butt dyno" would be watching the revs. A pulley swap will make the engine a little more rev happy.
Sorry, man, you bought into this and are trying to convince yourself and others that it makes a difference.
I hate getting into a pissing match, so let's agree to keep it civil and to the point.
Crankshaft at 1/3 the weight?? Don't think so, unless you built it out of hollow aluminum, which would only last a very short time.
As far as the HP claims, what else was changed in your before / after tests? Complete rebuild, larger bore, new rings, just new plugs, etc.?? As for the HP claims based upon pulleys alone, I will flatly state that it is impossible! I said it bofore and I'll say it again... When you are measuring HP or torque on a chassis dyno, EVERY rotating assembly, from the front of the engine, to the internals, including the reciprocating mass of the pistons and rods and the rotational enertia of every component, from the alternator, any pulleys, crankshaft, cams, gears, balance shafts, flywheel, torque converter (manual or auto), every transmission gear, driveshafts, hubs, brakes, wheels and finally the tires, comes into play on the total rotational mass enertia that has to be overcome to accelerate the vehicle. The drive pulleys are such an infinitesmal component of this that any benefit would be nearly immeasurable!!
If you want to flaunt your claimed degree, you missed some important principles. If you're trying to "trump" me, I'll just state that "my degree is bigger than your's", and I was building race cars and engines long before your parents thought of having sex.
So, let's not play that game.
Unfortunately, there is so much myth, lore and outright BS put out from false advertising, then friends telling others that "I have read..." or "I have heard..." that the average person actually starts believing and if they buy into it, convinces themselves that "Yeh, I can tell a difference...".
And, finally, some are asking how to buy this... Better look into becoming a Supporting Vendor here soon. Then you can make any questionable claims and sell your product to the masses.
Crankshaft at 1/3 the weight?? Don't think so, unless you built it out of hollow aluminum, which would only last a very short time.
As far as the HP claims, what else was changed in your before / after tests? Complete rebuild, larger bore, new rings, just new plugs, etc.?? As for the HP claims based upon pulleys alone, I will flatly state that it is impossible! I said it bofore and I'll say it again... When you are measuring HP or torque on a chassis dyno, EVERY rotating assembly, from the front of the engine, to the internals, including the reciprocating mass of the pistons and rods and the rotational enertia of every component, from the alternator, any pulleys, crankshaft, cams, gears, balance shafts, flywheel, torque converter (manual or auto), every transmission gear, driveshafts, hubs, brakes, wheels and finally the tires, comes into play on the total rotational mass enertia that has to be overcome to accelerate the vehicle. The drive pulleys are such an infinitesmal component of this that any benefit would be nearly immeasurable!!
If you want to flaunt your claimed degree, you missed some important principles. If you're trying to "trump" me, I'll just state that "my degree is bigger than your's", and I was building race cars and engines long before your parents thought of having sex.
Unfortunately, there is so much myth, lore and outright BS put out from false advertising, then friends telling others that "I have read..." or "I have heard..." that the average person actually starts believing and if they buy into it, convinces themselves that "Yeh, I can tell a difference...".
And, finally, some are asking how to buy this... Better look into becoming a Supporting Vendor here soon. Then you can make any questionable claims and sell your product to the masses.
When it comes to parasitic losses, GM pays a lot of attention to that these days to maximize fuel mileage. Alternators are sized to the minimum required. The water pump in the EcoTec is driven off the crank via chain, not the serpentine belt. Power steering??? Hey, look under your hood! Do you see a power steering pump? Nope, it's an electronic assist, with less drag and loss.
Sorry, man, you bought into this and are trying to convince yourself and others that it makes a difference.
Sorry, man, you bought into this and are trying to convince yourself and others that it makes a difference.
Try writing to Sport Compact Car with your muscle head BS about pulleys NOT making power and see what kind of response you get. But I'm sure the readers of popular hot rodding, muscle car, or any "v8" mag will agree with you. SCC magazine has plenty of articles as well as DYNO RESULTS performed on DYNAMOMETERS that SHOW a PROVEN GAIN to wheel horsepower numbers by changing to a underdriven or lightened pulley setup. Some with NO MODS other than the pulleys or some with simple bolt ons. Just because you have never seen it doesn't mean it doesn't work.
Whoever you are you need to keep with up and coming times, cars, and modifications. "An average of 2.7 HP is gained from every pound lost off the crank shaft." You can read the rest here...Unorthodox Racing Pulleys
Last edited by captain howdy; Jun 14, 2007 at 08:15 PM.


