I just bought a perrin pully on tuesday for my xA(im gonna install in on sat.) and i was just curious as to what kind of hp gains or how much quicker it makes the car. I've heard that it makes a difference in acceleration, but that all ive heard.

 

you also might find it smoother power too well thats what i felt when i did mine

 

you won't see any real gains...but the motor will run better because the rotational mass is less...


try searching, many people have done this and explained what they found as the result of the change...

 

There's a lot of confusion when it comes to pulleys. So many people say there's no power gain...then others say it frees up power you already had but they imply that isn't a 'gain'. I don't know...it makes sense that if the rotational mass is less and the engine accelerates quicker, there is a power increase somewhere in the rpm range. It may not increase your peak hp numbers, but somewhere in the powerband, there has to be a definite change.

This mod is not just like removing weight from the car where I'll agree that no additional power is made but the car will still be faster. This actually reduces parasitic loss in the engine and will free up extra power. Not much, though. Maybe enough to feel in daily driving at lower RPM's, but I don't think you'd see any difference at the track.

Anyway, what does it matter? You may or may not notice a difference. Every car I've ever used them on felt different, but I have no dyno sheets or 1/4 mile times to prove it.

 

you need to think of it as this...

there is HP at the crank of the motor...HP

and there is the power that makes it the ground. WHP

if you disconnect the air conditioning, does the motor suddenly get more HP???
no.
the HP wasted turning the AC is now freed up and going to the WHP...

now you also brought up power/weight ratio. but if the weight is reduced (from a pulley or removing the seats) this ratio will change.
as this is about a 2-3lb savings...it will not give any notable changes.

 

that's not really 100% accurate. Take the engine out of the car...put it on an engine dyno. Add air conditioning compressor and functional A/C system and run it. Now, take off the A/C and run it again. It's going to GAIN hp on the graph. To say it wouldn't is just handing out misinformation.

To say there is no more engine hp but more power available at the wheels would be like the lightweight wheel example, not the pulley. Or lightened flywheel or drive axles. In these cases, the engine is putting out a specific hp but more is making it to the ground. A crank pulley is an engine part, however. It's like reducing the weight of the valvetrain...it helps add HP (or reduces power loss, resulting in a higher hp number on a dyno). I challenge anyone who says that a lightweight pulley will not add HP on an engine dyno but will on a chassis dyno, I'd like you to produce some proof of that.

I agree with you that Rotational weight removal is immensely more helpful than static weight removal. i.e. - lightweight wheels or a pulley. I wasn't referring to the 2lb savings of a pulley to help remove weight from the car.

 

Our Pulley is made from 6061T6 aluminum and weighing in at 1.3lbs, the our pulley is more then 4 lbs lighter then the stock crank pulley. The PERRIN pulley is not under driven and will not affect the life of your engine. The pulley is a redesigned, lighter rendering of the stock crank pulley.

Our pulley achieves power and performance by reducing the rotating mass of the crank assembly.

That reduction is effectively the same as removing 100 pounds of weight from your vehicle. The PERRIN pulley will not wear out engine bearings or the oil pump, and will not add any additional vibration or noise.


Most aftermarket, under driven, pulleys are prone to charging and drivability problems from being excessively under driven. Also our lightened crank pulley will have no effect on your cars charging system.

Here are the pictures

 

missinformation???
why would anyone add accessories to a motor on an engine dyno??????
you are testing the raw power of the motor.
you can indeed test the motor without any pulleys on it...i can't do it cause i don't have an engine dyno, but it is done...

show me a reputable shop that gets crank HP with anything more than a coolant pump and ALT hooked up.

no, the pulley is not an engine part as far as gauging how much HP it makes....
engine parts are what you would get in a long block setup...(crank, bearings, pistons, cams, valves....everything inside the block/head).

it is an engine part as far as you need one to drive the car.
both stock and lightweight are parasitic. both cause the motor to loose HP to the ground.
it is a matter of which one causes the least amount of loss to the ground.

let me ask this question, would you describe this pulley swap as reducing rotational mass??? or lighting the valvetrain???

oh, wait, you already did....

that is the split between something that robs power or something thats involved in making of power.

you are the one spreading some misinformation here.

 

Not to be nit-picking, but is there some mis-information published from Perrin? I have no doubts that their products are top-notch, but here's a thread that shows the actual weight of the stock pulley at 3lbs-11oz as weighed by SkinnerBox:

https://www.scionlife.com/forums/vie...y+weighs+scale

According to Perrin, the stock weight should be at least 5.3lbs (or 5lbs-5oz).
This is calculated by 1.3lbs + "over 4lbs lighter" = 5.3lbs
(0.3lbs x 16oz = 5 oz)

Soooooo, if a 4lb reduction (according Perrin) is equivalent of removing 100lbs, then a 2lb-6oz reduction (3lb-11oz minus 1lb-5oz) would equal removing less than 60lbs.

I just like facts to be stated as facts. I just wish the actual picture of the stock pulley on the scale was still linked properly.

- Al

 

Actually all car manufacturers now quote their HP and TQ figures according to the new SAE J2723 standard which requires them to run accessories like A/C, alternator, etc.

 

djhotlava, you're relying VERY heavily on technicalities.

You've avoided the fact that, if the pulley/damper was included on the dyno (ALL MANUFACTURERS do this, since you wanted to know who), the run with the lighter pulley is going to make more hp. How can you refute that?

And you are implying that lightening the valvetrain adds power for some other reason than reducing mass?!?!?! But then you say a pulley wouldn't do the same thing. What's the deal?

What are your credentials for answering my post with more questions instead of factual answers? I like it when people who know more than me about engines call them "motors". That's great.

 

WHAT WAS YOUR POINT EXACTLY SIR??? JUST A LITTLE MISUNDERSTOOD??

 

Hey Perrin pat I have ine of your pulleys and the inner part of the pulley where the crank bolt is attached is completely destroyed can you help me out? I can bring it out to you guys to look at or I can e-mail pics. let me know.
And as far as gains, I didn't dyno before and after but the car definately pulls a lot harder with the lighter pulley.

 

Pat,

Sorry if you thought I was insulting you. Like I said, I'm sure your products are top-notch quality.

What I was referring to was the claim that the Perrin pulley was "more than 4 lbs lighter then the stock crank pulley", and that was "effectively the same as removing 100 pounds of weight from your vehicle". The link I posted shows the stock pulley being 3lbs-11oz. Perrin's is 1lb-5oz. The difference is 2lbs-6oz, which is not "more than 4lbs".

So my point/questions are: is the Perrin really more than 4lbs LIGHTER than the stock pulley? And if not, is the 100lb reduction really the virtual weight savings?

Like I said in my initial post, I may be nit-picking, but in this wonderful world of bolt-on 8-10hp increases, exaggeration seems to be more common than not - hence my inquiries.

Thanks, Pat, for responding to my questions.

- Al

 

Perrin says this about all there pulleys so do their sellers.. i think that the 100lbs of weight reduction, is possible just not on our cars or our pulleys. its just a technicallity they rigged into their marketing. The key word being that "weighing in at 1.3lbs, the PERRIN™ pulley is more then 4 lbs lighter then the stock crank pulley." if these were the conditions of our crank then their would be a 100lbs of rotational mass removed from the engine. BUT all in all there is probably some kind of gain as far as hp, not that it makes it, it just frees it up. just like takin some weight out the car. as for as faster acceleration imagin riding a bicycle with 20 pound wheels and one with 5.

 

Here are some links where they claim the same weights and losses of other stock pulleys and theirs lightened one.


http://www.perrinperformance.com/pro...ank_pulley.htm
http://www.perrinperformance.com/pro...ank_pulley.htm
http://www.perrinperformance.com/pro...ank_pulley.htm


these are most likely best case senarrio for their product for different cars, its not the first time someone has claimed something that wasnt true or only in certain situations was.

 

metal112524,

Yeah - I know it's probably a "spin" on their marketing, but with all the car enthusiasts looking for the "silver bullet" that will net them a bunch of HP, I'm just trying to get the facts straight for myself. Take for example my OBX header: I KNOW that it won't net me 8-10 HP as claimed on eBay (and by numerous butt dynos). But I do feel an ever-so-slight kick in the pant when I get on the throttle. What is that - maybe 1 HP? I guess if I advertised it as a 1HP gain, no one would buy it, huh?

Thanks for responding - again, I'm not trying to bash Perrin. In fact, I may be considering the pulley as another "kick in the pants" benefit for my little xA. But I do like to get my facts in order, as I'm not one to pull up to someone and say I've got an I-H-E and now I'm running 140+HP based on manufacturer claims.

- Al

 

So if i get this right the pully adds no real hp, but "frees" up hidden power which cuases the car to be quicker due to the lighter wieght of the pully? Also will i feel the difference in how the cars pulls off the line?

 

Exactly! Most aftermarket performance parts just "free" up horsepower the car already has the potential to make. If you aren't adding more fuel or air to the mix, you aren't making new HP.

You will feel the difference in the entire RPM range. The car feels perkier and the power feels smoother.

 

just the water pump would be hooked up no need for a alternator to be hooked up the shop covers all the connections anyways...