Underdrive Pulleys - Cost VS Quality

Forty61

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So with tax return season coming up I’m eyeballing a few parts for my car. Alongside the stuff it actually needs I’m looking at adding a set of underdrive pulleys as it’s one of the last bolt-ons I don’t have.

So the question, are the BBK/Steeda ones that much better than the cheaper SR ones that American Muscle sells? I already know the boards feeling on AM so I don’t need much feedback on that, but are the pulleys any better or worse? Are they more pricy just because of the name or is there something I’m not aware of?
 

Dino Dino Bambino

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Pentalab

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I can definitely recommend the Steeda pulleys. I've had them on my car for 7 years with absolutely zero problems, while the 8-9rwhp gain and a small mpg gain are definite pluses. At $250, they're pretty good bang for the buck.

https://www.cjponyparts.com/steeda-...F-9lxb901I5mcZoZXtgAOnLayE-CHu6caAvmNEALw_wcB

I guess the important factor behind the cost is the SFI approval for quality.
So exactly how does the under drive pulley setup work ? Oem 6.5" crank pulley replaced with a smaller diam pulley ? Then everything on the fead belt will also spin slower, is that the idea ? Meanwhile the blower folks will use a 12% bigger diam pulley on the crank.
 

Forty61

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So exactly how does the under drive pulley setup work ? Oem 6.5" crank pulley replaced with a smaller diam pulley ? Then everything on the fead belt will also spin slower, is that the idea ? Meanwhile the blower folks will use a 12% bigger diam pulley on the crank.

Yeah you’re just changing the ratio between the crank and the accessories, spinning the accessories slower (under driving them) so there’s less drag on the motor.
 

Dino Dino Bambino

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So exactly how does the under drive pulley setup work ? Oem 6.5" crank pulley replaced with a smaller diam pulley ? Then everything on the fead belt will also spin slower, is that the idea ?

Yup. The smaller diameter crank pulley/harmonic balancer slows down the rotational speed of the water pump, alternator, PS pump, and AC compressor, thus reducing parasitic drag. This increases SAE net HP output at the crank and at the rear wheels, while also improving gas mileage. It's a win win. There are none of the undercharging or overheating problems that have been associated with some underdrive pulley kits on the older pushrod 5.0
To allow the reuse of the stock length drivebelt, the kit includes a larger diameter water pump pulley. Keep in mind that you won't want to do this mod if you're planning to add a supercharger later on, as the smaller diameter crank pulley would also underdrive the supercharger and lower the boost. OTOH, you can keep the UDPs if you add a turbo since that's driven by exhaust gases instead of the crankshaft.
 
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Pentalab

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Yeah you’re just changing the ratio between the crank and the accessories, spinning the accessories slower (under driving them) so there’s less drag on the motor.
Ok, so the water pump, AC compressor, alternator, all spin slower. Dunno if I like the idea of the water pump spinning slower. The alternator might be marginal at idle, with a big load, dunno.
 

ShelbySteve

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Ok, so the water pump, AC compressor, alternator, all spin slower. Dunno if I like the idea of the water pump spinning slower. The alternator might be marginal at idle, with a big load, dunno.
I’m in Texas and have UD pulleys. Never had any issues with overheating.
 

ShelbySteve

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Good to know, I’m in Texas too.

I am leaning towards the Steeda set as I do like that they seem a higher quality unit plus it’s an excuse to go to the Summit store and troll around..
Pretty sure I have the BBK ones, but they were installed already when I got the car. I have the receipt for them though
 

Forty61

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Pretty sure I have the BBK ones, but they were installed already when I got the car. I have the receipt for them though

Im sure they’re basically the same. It seems a choice of about $250 for ‘nice’ ones and like $180 for ‘cheap’ ones. $70 isn’t much difference but it could go to other things if the quality isn’t a huge variance.
 

ShelbySteve

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Im sure they’re basically the same. It seems a choice of about $250 for ‘nice’ ones and like $180 for ‘cheap’ ones. $70 isn’t much difference but it could go to other things if the quality isn’t a huge variance.
Don’t know what the cost difference would be, but they were installed over 10 years ago lol
 

RED09GT

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Since the balancer is incorporated in the crank pulley, I'd chose the Steeda over American muscle house brand.

I have a set of roush pulleys and their balancer is made by powerbond, who are a very good manufacurer-not sure who Steeda sources their stuff through.
 

MasterofDisaster

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I installed the Steeda pulleys about a year or so ago. I like that I didn't have to change belts. I live in Michigan, but I haven't had any problems with engine temp.
I had underdrive pulleys on my Foxbody 5.0, and drove it all over Georgia, Colorado, and the Mojave Desert. Never had a problem with engine temps.
 

Enfield

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Mine came with the Steeda pulleys, installed in 2011. No problems. I asked DOB if running a smaller S/C pulley would compensate for smaller crank pulley; they said no way.
 

Green Mamba

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Been running a set from Steeda for about nine years on my '08 Bullitt here in Texas. Bought them hardly used for a hundred bucks. 60K miles later still running with zero problems.
 

07 Boss

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So with tax return season coming up I’m eyeballing a few parts for my car. Alongside the stuff it actually needs I’m looking at adding a set of underdrive pulleys as it’s one of the last bolt-ons I don’t have.

So the question, are the BBK/Steeda ones that much better than the cheaper SR ones that American Muscle sells? I already know the boards feeling on AM so I don’t need much feedback on that, but are the pulleys any better or worse? Are they more pricy just because of the name or is there something I’m not aware of?


Just a suggestion, but why not leave all the pulleys and go with an electric H2O pump? The gains from eliminating parasitic drag will be about the same and you will get a more efficient cooling system. And if you go blower down the road you won't have to change anything.
 

Forty61

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I'd just save the 250 towards a dob blower setup, you don't want the small crank pulley when driving a blower.

I like this idea but the chances of me having that kind of funds available and then choosing to invest that kind of money into my personal hobby are remarkably slim.

Been running a set from Steeda for about nine years on my '08 Bullitt here in Texas. Bought them hardly used for a hundred bucks. 60K miles later still running with zero problems.

Ah, I miss my Bullitt. I had an ‘08 too, number 0152. Good to know another Texas owner with no problems.
 

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