2004 to 2016 Mazda 3 Forum and Mazdaspeed 3 Forums banner

1 - 20 of 70 Posts

·
Registered
Joined
·
519 Posts
Discussion Starter #1
omfg it's jeremy just pm'd me asking about whether we were going to do underdrive pulleys.

Right now, we offer a lightweight crank pulley for the early BP powered Protege's, etc. Here's a link to one for an example: CORKSPORT Lightweight Pulley For Mazda 1.6/1.8 DOHC

The 2010 is a little more complex as it features an integral crank angle sensor wheel, which we can easily accomplish. Cost would be around $159.

In my experience, the lighter weight pulleys for the accessories are a nice addition, but the main gains are seen in the crankshaft pulley lightening. Underdrives aren't my cup of tea because I don't like my radio to fritz out or my headlights to dim when I'm at a stoplight. The genesis of underdrive pulleys was for use on dedicated racing vehicles where the rev's were kept high and accessories would crap out due to being overdriven.

Right now I'm prototyping a trigger wheel and aluminum pulley for the 2010 Mazdaspeed3 and could easily do one for the 2010 Mazda3 as well.

Is there interest in such a product?

Thanks,

Jason
 

·
Registered
Joined
·
58 Posts
The BP product is quality and I imagine this would be too. I think this is a great "bolt on" mod for everyone doing your standard i/e/h/timing.

I think a lot of people will express concern with their warranty since this isn't exactly on the same level as an intake. Then again, if someone is interested in this product, warranty probably isn't a concern.

I'm with you though on crank vs underdrive.
 

·
Registered
Joined
·
519 Posts
Discussion Starter #5
Yeah underdrive works great when you're spinning a balanced and blueprinted engine to 7500rpm all day long when it spun 3500 stock. But not on a street car.

Ease of install is probably a 4-5, pull the belt, pull the passenger side wheel, pull the fenderwell liner and pull the pulley afaik. I'll get some further info on it when ours comes in and I have to install it! Toughest part is the crank nut/bolt. Cheap upgrade, similar to lightening the flywheel, but easier to install.

Jason
 

·
Registered
Joined
·
5,636 Posts
Enlighten a noob. What would I gain by doing this mod? Pros and cons aside from voiding tha warranty.
 

·
Moderator
Joined
·
1,272 Posts
Enlighten a noob. What would I gain by doing this mod? Pros and cons aside from voiding tha warranty.
From the link Jason provided:

CorkSport said:
The CorkSport pulley is .5lbs compared to the stock pulley which weight 3.5 lbs. This is a 70% decrease in inertial weight on your crankshaft. This effect is similar to installing a lightweight flywheel on your motor, resulting in quicker engine RPM.
I'm honestly not sure what any cons are?
 

·
Registered
Joined
·
5,636 Posts
Thanks. I missed the link in his post. :stupid:
 

·
Registered
Joined
·
987 Posts
what about there being no harmonic balancer? i know that'll kill a v8...what about our i4?
 

·
Moderator
Joined
·
1,272 Posts
Found a con in the install directions for the pulley Jason linked to.

CorkSport Installation Instructions said:
This crank pulley is lighter weight. As a result, your engine will rev-up easier due to the reduction in rotating mass. A slight increase in engine vibration may be noticed. This light weight pulley is not designed as a harmonic balancer.
:/
 

·
Parts test dummy
Joined
·
823 Posts
I would be down for a light weight crank pulley. Also a set of light weight accessory pulleys would be nice, I know they wont provide near as much as the crank pulley but if they come anodized it would be nice to complete the set.
 

·
Registered
Joined
·
2,771 Posts
Sounds like a good mod to me!
 

·
Registered
Joined
·
519 Posts
Discussion Starter #15
On the harmonic balancer, the reason we left out the harmonic balancer on these designs is because the HB is usually there to prevent massive vibration in a heavy steel pulley assembly. With substantially lighter weight and aluminum alloy, the damping rate is similar between the aluminum and the rubber dampened steel version.

Jason
 

·
Registered
Joined
·
987 Posts
cool, quick question, though...when you say 'minor vibration' is it like the vibration you get w/a broken in motor mount, or is it hardly noticeable?
 

·
Registered
Joined
·
519 Posts
Discussion Starter #17 (Edited)
From the people we've talked to who have run these on their cars it's hardly noticeable. But that's with the 1.8BPT engine, not the MZR. When we test fit it, we'll get vibration data at the valvecover as well as at the dash using a 3 axis accelerometer to qualify that.

Thanks,

Jason
 

·
Parts test dummy
Joined
·
823 Posts
do you think you guys will do a whole lightweight pulley set?
 

·
Registered
Joined
·
519 Posts
Discussion Starter #19 (Edited)
Going the extra mile of doing the lightweight pulley set vs. just the crank pulley may reach a point of diminishing returns. If it's something you'd want for looks as much as performance, I could see there being reason to do it.

If we did this, we'd probably sell them separately or as Crank Pulley and Accessory Pulley kits.

Edit: Probably not, I just looked at the factory designs and they're all shelled or stamped steel. Very little if any weight to be saved and probably pretty horrendous manufactureability issues doing a billet aluminum setup. The crank pulley is where the performance lives. If you want some bling at the top end we can look into adjustible cam gears and a two piece valvecover so you can take off the 'front' cover to display the gears at shows. Then the form follows the function, not the other way around. We ran out of turd polish about six years ago and decided not to order any more at that time. :)

Jason
 

·
Registered
Joined
·
477 Posts
is there any difference for this part on the 2.slow and 2.5l engines? or are they similar
 
1 - 20 of 70 Posts
Top