Lightened Ralco RZ Pulley. Thoughts...
02-25-2010, 10:11 AM
#41
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02-26-2010, 03:11 AM
#43
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Location: Baton Rouge, LA
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I started offering on the ebay site above... their first price was 139. I offered 30 
They came back with 125, and I countered with 40. Again, they sent back 115, and I put 45. Waiting on a response now...
They came back with 125, and I countered with 40. Again, they sent back 115, and I put 45. Waiting on a response now...
02-26-2010, 06:15 AM
#44
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Join Date: Jul 2007
Location: Minnesota
Posts: 1,044
Good luck I tryed the same thing and I couldnt offer any more so I sent them a message and asked how low they would go and they said 95....so I dont know how this guy got his from them for 40.
02-26-2010, 06:25 AM
#45
02-26-2010, 06:35 AM
#46
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Join Date: Jan 2007
Location: Long Island, NY
Posts: 203
Mine was BNIB from what I could read. I offered 50.. and got it.
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWNX%3AIT
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWNX%3AIT
02-26-2010, 07:08 AM
#47
2slow has said everything correct so far. This mod really shouldn't be considered a HP mod. The reason you see MINIMAL hp gains is because the pulley is attached to other belt driven accessories and it now allows them to function with less startup drag. The reason you see larger gains on FI cars is because they usually have more HP. Think if the hp gains were always 2%, then on the Maxima it would be around 4rwhp gained and on a 300zxTT it would be around 7rwhp gained. (NOTE: All of this is talking about a LWP, an UDP will see more gains because it does slow down all the accessories which adds more HP due to lowered parastic losses--this part is similiar to replacing a clutch driven fan with an electric fan, lower parasitic losses equals HP gains. It can also add strain to your alternator and cause your water pump to cavitate because they are not turning at the OEM spec so I suggest staying away from UDP.)
The real benefit of a LWP is the lowered weight reducing startup inertia. What this means is that a LWP has no real benefit except when accelerating. Think of a light weight fly-wheel, two-piece rotors, 1 piece driveshaft, or light weight wheels; nobody asks "how much HP did you gain" when they are installed. The same goes for the LWP. They lighten the unsprung weight on the car and therefore allow it to start turning easier. This means that you can get into motion easier. It also means that the engine will "fall out of motion" easier which results in quick dropping rpm's and that needs to be overcome with solid quick shifting to keep the car in the higher rpm range to get the acceleration benefits.
The real benefit of a LWP is the lowered weight reducing startup inertia. What this means is that a LWP has no real benefit except when accelerating. Think of a light weight fly-wheel, two-piece rotors, 1 piece driveshaft, or light weight wheels; nobody asks "how much HP did you gain" when they are installed. The same goes for the LWP. They lighten the unsprung weight on the car and therefore allow it to start turning easier. This means that you can get into motion easier. It also means that the engine will "fall out of motion" easier which results in quick dropping rpm's and that needs to be overcome with solid quick shifting to keep the car in the higher rpm range to get the acceleration benefits.
02-26-2010, 07:32 AM
#49
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Join Date: Jan 2007
Location: Long Island, NY
Posts: 203
2slow has said everything correct so far. This mod really shouldn't be considered a HP mod. The reason you see MINIMAL hp gains is because the pulley is attached to other belt driven accessories and it now allows them to function with less startup drag. The reason you see larger gains on FI cars is because they usually have more HP. Think if the hp gains were always 2%, then on the Maxima it would be around 4rwhp gained and on a 300zxTT it would be around 7rwhp gained. (NOTE: All of this is talking about a LWP, an UDP will see more gains because it does slow down all the accessories which adds more HP due to lowered parastic losses--this part is similiar to replacing a clutch driven fan with an electric fan, lower parasitic losses equals HP gains. It can also add strain to your alternator and cause your water pump to cavitate because they are not turning at the OEM spec so I suggest staying away from UDP.)
The real benefit of a LWP is the lowered weight reducing startup inertia. What this means is that a LWP has no real benefit except when accelerating. Think of a light weight fly-wheel, two-piece rotors, 1 piece driveshaft, or light weight wheels; nobody asks "how much HP did you gain" when they are installed. The same goes for the LWP. They lighten the unsprung weight on the car and therefore allow it to start turning easier. This means that you can get into motion easier. It also means that the engine will "fall out of motion" easier which results in quick dropping rpm's and that needs to be overcome with solid quick shifting to keep the car in the higher rpm range to get the acceleration benefits.
The real benefit of a LWP is the lowered weight reducing startup inertia. What this means is that a LWP has no real benefit except when accelerating. Think of a light weight fly-wheel, two-piece rotors, 1 piece driveshaft, or light weight wheels; nobody asks "how much HP did you gain" when they are installed. The same goes for the LWP. They lighten the unsprung weight on the car and therefore allow it to start turning easier. This means that you can get into motion easier. It also means that the engine will "fall out of motion" easier which results in quick dropping rpm's and that needs to be overcome with solid quick shifting to keep the car in the higher rpm range to get the acceleration benefits.
We wouldn't call it or care about performance products if it didn't do anything under accleration! That's the reason why I got this pulley...When I open up the gate, she pulls harder. Is there a 10hp or 10ftpds gain? No. In the area of 5 would seem true.
A gain is a gain. You can't dilute fact with YOUR opinion.
02-26-2010, 08:00 AM
#50
Benefits:
1. Quicker acceleration
2. Stock altenator output @ idle
3. Oem spec'd belts
4. Possble gain in whp(minimum)
5. Looks cool!
6. Lower cost than UR's
Downfall:
1. Drops rpm quickly, no inertia
2. Quality Questionable IMO haven't seen one yet!
1. Quicker acceleration
2. Stock altenator output @ idle
3. Oem spec'd belts
4. Possble gain in whp(minimum)
5. Looks cool!
6. Lower cost than UR's
Downfall:
1. Drops rpm quickly, no inertia
2. Quality Questionable IMO haven't seen one yet!
02-26-2010, 08:04 AM
#51
While most of what you said is quite correct, You just contradicted yourself. If its not considered a "HP mod" then it WOULDN'T affect the Torque or Hp curve under acceleration.
We wouldn't call it or care about performance products if it didn't do anything under accleration! That's the reason why I got this pulley...When I open up the gate, she pulls harder. Is there a 10hp or 10ftpds gain? No. In the area of 5 would seem true.
A gain is a gain. You can't dilute fact with YOUR opinion.
We wouldn't call it or care about performance products if it didn't do anything under accleration! That's the reason why I got this pulley...When I open up the gate, she pulls harder. Is there a 10hp or 10ftpds gain? No. In the area of 5 would seem true.
A gain is a gain. You can't dilute fact with YOUR opinion.
This still should not be considered a HP mod, but a very good weight reduction mod. Saying "When I open the gate, she pulls harder" doesn't mean it made more RWHP or that you lying. If you take your car as it is now and run 0-60, then remove your passenger seat, it should pull harder too. You didn't gain any HP, but reduced weight (why do you think a low HP Lotus can be fast--they are light).
Know that it is something like for every 1lb. of unsprung weight reduced, it is similiar to reducing 5lbs. of weight above the springs. Putting an underdrive pully in would be like removing your spare tire plus a few minor HP gains from the reduction of parasitic loss. Usually the reason HP gains show up on a dyno is because you are rolling in 4th gear with no resistance and then floor it. The pully with the reduced weight allows the engine to rev quicker moving your HP and TQ forward which shows up as being higher (but it really just comes on earlier).
In my opinion, reducing unsprung weight on a car that isn't FI and isn't an easily upgradable big block is the best mods you can do. Also, if you took physics you know that the larger a circle is and the further out the mass is from the center of the circle it is, the harder it is to get into motion. That means things like light weight wheels, 2-piece rotors, and flywheels will show the largest gains in the unsprung weight reductions, then somthing like an LWP, then a 1-piece driveshaft (on a RWD car) would have the least gains since it is a smaller diameter.
Please don't get a offended by what I am saying. It is a good mod. It will be faster. I like discussing things like this because there is alot of information floating around by companies that market this stuff that is wrong. Most people wouldn't buy the pulley if it didn't have a HP gain attached to it. That is why they say 5hp is gained with a grounding kit. Usually a grounding kit will smooth the idle, even the electrical load on accessories, and improve things on cars with lots of electrical equipment on them (read: all new cars). You COULD gain 5hp, and they probably have a dyno for some car that did gain. YOu COULD save gas mileage. The greater chance is your car will just start up easier and run smoother when you are using lots of accessories (lights, a/c, stereo at the same time). But if you had two advertisements for grounding kits and one said: "For only $50 make your car start easy and run smooth" or "For only $50 make your car run smoother, gain gas mileage, and add 5hp (and had a dyno for one car that actually did)", which would you buy?
02-26-2010, 08:17 AM
#52
To build off my last post I have two comments.
We as car enthusists are addicted to HP numbers, especially the peak number. I saw a post on here yesterday that was talking about an intake spacer adding 5-6 HP in the middle of the curve but only like 1 HP on the top so it wasn't worth it. The TQ at the beginning is what gets you going and the "meat" in the middle is what kicks you into upper rpm's. Most people just judge peak HP numbers which really don't matter. You want TQ early and a good enough amount of HP with a smooth rise to the top, making the middle stuff VERY important.
Second, weight is very important in speed, but is rarely talked about by most people. How often do you hear somebody say "my car has 400rwhp" and somebody else say, "well what's it weigh?" Hardly ever. Only real racers do. That is why they have carbon fiber that isn't wet cast and heavy. They do it for weight reduction, not looks. That is why people who ride bikes. The HP/LB ratio is great and they are freakin fast because of it.
We as car enthusists are addicted to HP numbers, especially the peak number. I saw a post on here yesterday that was talking about an intake spacer adding 5-6 HP in the middle of the curve but only like 1 HP on the top so it wasn't worth it. The TQ at the beginning is what gets you going and the "meat" in the middle is what kicks you into upper rpm's. Most people just judge peak HP numbers which really don't matter. You want TQ early and a good enough amount of HP with a smooth rise to the top, making the middle stuff VERY important.
Second, weight is very important in speed, but is rarely talked about by most people. How often do you hear somebody say "my car has 400rwhp" and somebody else say, "well what's it weigh?" Hardly ever. Only real racers do. That is why they have carbon fiber that isn't wet cast and heavy. They do it for weight reduction, not looks. That is why people who ride bikes. The HP/LB ratio is great and they are freakin fast because of it.
02-26-2010, 02:38 PM
#53
You REALLY need to stop calling it unsprung weight.
Do you even know what the term means?
The gain from a light weight pulley is from the drop in rotational mass, and is much of a HP mod as a knife edged crank, small skirted pistons, and low drag rings.
Just a heck of a lot easier and cheaper, but does the same thing. The engine does less work powering itself, and leaves more go to drive the wheels.
mmmm....small skirts....is it spring yet?
Do you even know what the term means?
The gain from a light weight pulley is from the drop in rotational mass, and is much of a HP mod as a knife edged crank, small skirted pistons, and low drag rings.
Just a heck of a lot easier and cheaper, but does the same thing. The engine does less work powering itself, and leaves more go to drive the wheels.
mmmm....small skirts....is it spring yet?
02-26-2010, 03:06 PM
#54
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Join Date: Jan 2007
Location: Long Island, NY
Posts: 203
You REALLY need to stop calling it unsprung weight.
Do you even know what the term means?
The gain from a light weight pulley is from the drop in rotational mass, and is much of a HP mod as a knife edged crank, small skirted pistons, and low drag rings.
Just a heck of a lot easier and cheaper, but does the same thing. The engine does less work powering itself, and leaves more go to drive the wheels.
mmmm....small skirts....is it spring yet?
Do you even know what the term means?
The gain from a light weight pulley is from the drop in rotational mass, and is much of a HP mod as a knife edged crank, small skirted pistons, and low drag rings.
Just a heck of a lot easier and cheaper, but does the same thing. The engine does less work powering itself, and leaves more go to drive the wheels.
mmmm....small skirts....is it spring yet?
02-26-2010, 03:28 PM
#55
I like my crank pulley. I also regret paying 2 bills for it.
02-26-2010, 04:12 PM
#56
Senior Member
Join Date: Jul 2007
Location: Minnesota
Posts: 1,044
Mine was BNIB from what I could read. I offered 50.. and got it.
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWNX%3AIT
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWNX%3AIT
In his defense, pionkej has written more text in his first few posts than some people do throughout their entire membership. That's gotta count for something, eh? It all sounds technically authoritative, but I have to say I nodded off half way through.
I like my crank pulley. I also regret paying 2 bills for it.
I like my crank pulley. I also regret paying 2 bills for it.
02-26-2010, 04:46 PM
#57
Yeah, well, it'd count for a lot more if it was technically accurate, rather than just sounding like it.
02-26-2010, 07:33 PM
#58
I still contest that a LWP is not a HP mod. The other examples you gave are internal to the engine. Light weight pistons or light weight valves are not a HP mod in that they add HP to the motor (if they do it is negligible), and a lightened crank is only there to balance the whole assembly. These modification DO reduce rotational mass which helps overcome startup inertia which DOES shift your powerband forward which does increase performance, but not generally HP.
Now a knife-edged crank does also reduce rotational mass, but it also reduces windage which is where the HP gains come from, it is not only reducing startup inertia but also reduces drag across the entire rev cycle which will equate in not only shifting the power band but also by increasing it. The same goes with friction reducing coatings on rings. These are less in line with a LWP and more in line with efficiency gains like ceramic coating valves and pistons to keep more heat in the chamber to increase power losses AND decrease the risk of detonation allowing for more boost, higher compression, advanced timing, or a leaner A/F ratio.
A light-weight flywheel is NOT considered a HP mod, but DOES reduce rotational mass. People buy them to get into the powerband quicker. A LWP is on the other end of the crank from the flywheel, so why should it be any different? Again, I believe it is a very worthy mod, and I believe small HP gains may be seen from the reduced mass leading to reduced resistance from the belt driven accessories attached to it (though not like you would see from an UDP), but I still do not think it is a HP mod. Certainly not on the level of intakes, exhausts, cams, etc.
If you still believe I am wrong, I would love to continue this discussion, but please don't accuse me of "sounding like" I don't know what I am talking about because I wrote like ten paragraphs and transposed one phrase and stuck with it. I made a mistake there, but it doesn't make me dumb.
03-21-2010, 08:28 PM
#60
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Thread Starter
iTrader: (3)
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Location: Lewis Center, OH
Posts: 1,806
Part # 914924.
Here is the closed auction...
$40 RALCO Pulley
03-21-2010, 09:35 PM
#61
I concede that I mixed my terminology up a bit. I should have said "reduced rotational mass" when speaking of the LWP. All the items I mentioned above are examples of "reduced rotational mass" while only the rotors and wheels are "reduced unsprung weight".
I still contest that a LWP is not a HP mod. The other examples you gave are internal to the engine. Light weight pistons or light weight valves are not a HP mod in that they add HP to the motor (if they do it is negligible), and a lightened crank is only there to balance the whole assembly. These modification DO reduce rotational mass which helps overcome startup inertia which DOES shift your powerband forward which does increase performance, but not generally HP.
Now a knife-edged crank does also reduce rotational mass, but it also reduces windage which is where the HP gains come from, it is not only reducing startup inertia but also reduces drag across the entire rev cycle which will equate in not only shifting the power band but also by increasing it. The same goes with friction reducing coatings on rings. These are less in line with a LWP and more in line with efficiency gains like ceramic coating valves and pistons to keep more heat in the chamber to increase power losses AND decrease the risk of detonation allowing for more boost, higher compression, advanced timing, or a leaner A/F ratio.
A light-weight flywheel is NOT considered a HP mod, but DOES reduce rotational mass. People buy them to get into the powerband quicker. A LWP is on the other end of the crank from the flywheel, so why should it be any different? Again, I believe it is a very worthy mod, and I believe small HP gains may be seen from the reduced mass leading to reduced resistance from the belt driven accessories attached to it (though not like you would see from an UDP), but I still do not think it is a HP mod. Certainly not on the level of intakes, exhausts, cams, etc.
If you still believe I am wrong, I would love to continue this discussion, but please don't accuse me of "sounding like" I don't know what I am talking about because I wrote like ten paragraphs and transposed one phrase and stuck with it. I made a mistake there, but it doesn't make me dumb.
I still contest that a LWP is not a HP mod. The other examples you gave are internal to the engine. Light weight pistons or light weight valves are not a HP mod in that they add HP to the motor (if they do it is negligible), and a lightened crank is only there to balance the whole assembly. These modification DO reduce rotational mass which helps overcome startup inertia which DOES shift your powerband forward which does increase performance, but not generally HP.
Now a knife-edged crank does also reduce rotational mass, but it also reduces windage which is where the HP gains come from, it is not only reducing startup inertia but also reduces drag across the entire rev cycle which will equate in not only shifting the power band but also by increasing it. The same goes with friction reducing coatings on rings. These are less in line with a LWP and more in line with efficiency gains like ceramic coating valves and pistons to keep more heat in the chamber to increase power losses AND decrease the risk of detonation allowing for more boost, higher compression, advanced timing, or a leaner A/F ratio.
A light-weight flywheel is NOT considered a HP mod, but DOES reduce rotational mass. People buy them to get into the powerband quicker. A LWP is on the other end of the crank from the flywheel, so why should it be any different? Again, I believe it is a very worthy mod, and I believe small HP gains may be seen from the reduced mass leading to reduced resistance from the belt driven accessories attached to it (though not like you would see from an UDP), but I still do not think it is a HP mod. Certainly not on the level of intakes, exhausts, cams, etc.
If you still believe I am wrong, I would love to continue this discussion, but please don't accuse me of "sounding like" I don't know what I am talking about because I wrote like ten paragraphs and transposed one phrase and stuck with it. I made a mistake there, but it doesn't make me dumb.
If you guys want power mods go get headers or nitrous or get your car dyno/street tuned. On OBD2 cars it takes some money (not $40) to improve the actual net horsepower/ability to move air in and out of the engine efficiently.
Last edited by MoncefA33; 03-21-2010 at 09:41 PM.
03-21-2010, 11:19 PM
#62
Anything that reduces weight whether in the bottom end reciprocated mass, lighter weight wheels/tire combo, stripped down interior to lose overall vehicle weight translates into more efficient hp or more hp/lbs....which will decrease your ET and increase your MPH in the 1/4 mile......Cheap/free hp is good hp....
03-28-2010, 05:05 PM
#64
03-28-2010, 07:50 PM
#67
Senior Member
Join Date: Jun 2005
Location: Sacramento
Posts: 383
When the car is idling there is a visible wobble in the crank pulley, from my reading the rubber in them can fail and cause them to wobble. I want to know if i can use the 3.5 Ralco stock sized pulley to replace the crank pulley. The UR one is not worth the money so i'm looking for options besides ordering a stock one from Dave B.
03-29-2010, 09:15 AM
#69
Yea I got my Ralco RZ UR pulley on ebay brand new for 59.99 on a Make an offer option.
http://cgi.ebay.com/ebaymotors/ws/eB...ht_1761wt_1165
http://cgi.ebay.com/ebaymotors/ws/eB...ht_1761wt_1165
04-03-2010, 12:27 PM
#71
04-09-2010, 08:48 PM
#72
04-09-2010, 09:03 PM
#73
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Location: Lewis Center, OH
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04-10-2010, 08:09 AM
#74
04-11-2010, 03:54 PM
#76
And dyno results can be easily skewed. All it would take is dynoing the car in the thick of the day with the humidity and heat on the rise and then dynoing the car "after" the modification has been done in the cool of the night. Instant gains. There are many different methods. That's why I don't take dyno numbers as definitive answers about certain modifications gains.
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