Preferred Underdrive Pullies?

RobBush · Feb 23, 2010

I'm looking at adding a set of Underdrive Pullies to my '99 GT and am looking for suggestions.

Looking at AmericanMuscle.com, I see they have a Steel Steeda set and a nice looking BBK Aluminum set.

My first reaction would be to go with steel, but am looking for other input.

Thanks, Rob

Winters98GT · Feb 23, 2010

steeda. /thread

sneaky98gt · Feb 23, 2010

Winters98GT said:
steeda. /thread

^^What he said.

RobBush · Feb 23, 2010

sneaky98gt said:
^^What he said.

Thanks guys, That's what I needed to here!

sneaky98gt · Feb 24, 2010

Sorry for the short/smart-ass answer. It would probably help for you to hear why.

The reason for the Steeda's isn't because of the steel vs aluminum. It's because the Steeda crank pulley comes with its own SFI certified harmonic dampener. No one else's does, that I'm aware of. That's also why the Steeda's are a good bit more expensive. I've heard horror stories of people putting the piggyback style (i.e. BBK, Mac, etc.), and it screwing up the harmonic balancing, and causing internal failure. That would majorly suck.

Everyone says Steeda because the Steeda pulleys don't have that problem. I have had them on mine for a while now with no problem, as have thousands of people in the 2 valve world. I can't tell you anything about how much they gained, but I believe Winters98GT has said that he documented a solid .1 gain in the 1/4. I like them because the motor revs up a LOT quicker. It's worth it for that if you ask me.

trinity_gt · Feb 24, 2010

SFI certification doesn't necessarily mean that the damper will not increase the risk of internal engine damage. It simply means that the damper won't come apart in racing conditions. One random damper site I found describes the SFI 18.1 testing as:

"The SFI foundation performs destructive testing on sample fluid dampers to ensure that the steel and methods of construction used meets their stringent requirements. This means they spin the sample dampers up to 12,500 RPM for over an hour, then they literally rip the metal apart while measuring how much force it takes for it to bend, stretch and finally break. SFI's minimum specifications to certify a damper to pass their 18.1 testing includes a yield strength of 40,000 pounds, a tensile strength of 60,000 pounds, and a maximum 10 percent elongation."

They're more interested in safety than in engine health.

What you really want is to have your damper manufacturer to have worked with the manufacturer (Ford) to design the damper such that the critical dampening characteristics are retained while the accessories are slowed.

Or you can leave the OE dampers in place and search for the 4-5HP gains available elsewhere. :|

Kilgore Trout · Feb 24, 2010

I would never in a million years consider pulleys.

flstang65 · Feb 24, 2010

Back before I stopped buying from RPM Outlet, I put a set of their under drive pulleys on. I don't know who makes them for RPM Outlet. They too have an SFI approved harmonic dampener on them. I have had them on for 2 years with no problems. If I did have to buy another set though, I would go with the Steeda's. As every one else said. Stay away from the piggy back deals.

Were the gains noticeable? A little. Would I buy them again? Probably not but, they came in one of their packages. I think it's one of those mods that compliment a few other bolt ons.

Spend the money one some good control arms or something else. What mods do you have already?

trinity_gt · Feb 24, 2010

The fact that piggybacks use the original damper as engineered by Ford and validated by Ford engineers in thousands of hours of dyno cell testing makes piggybacks the only damper style I'd consider.

The goal of UDPs is to slow down accessories. There should be as little change as possible in the torsional vibration damping characteristics of the damper.

If it's about weight, all I'll say is this: There are certain instances where the laws of physics simply require a certain mass for desired mechanical characteristics. Not all weight loss is good weight loss especially if it impairs the ability of the device to perform its essential function. IMO, it's better to leave that critical part be and search for weight savings/power gains elsewhere. Given that the benefit is only a few HP you'd probably get more benefit from tossing the spare tire and jack and carrying a can of tire-goo than going to pulleys and increasing the risk of internal engine damage.

sneaky98gt · Feb 24, 2010

trinity_gt said:
What you really want is to have your damper manufacturer to have worked with the manufacturer (Ford) to design the damper such that the critical dampening characteristics are retained while the accessories are slowed.

I'm not trying to be a smart ass, but didn't Steeda do that with Ford? Seems like I remember reading an article or something talking about Steeda and Ford working together on it.

Edit: Found it. On Steeda's website, they say, "Our underdrive pulleys are the only pulleys engineered through our unique partnership in Ford's technology transfer program to have the proper torsional vibration dampening characteristics for your 4.6L engine. No other manufacturer can make this claim."

RatStang · Feb 24, 2010

Not to mention that whatever testing you did to develope the dampening characteristics of the stock dampner are null and void the second you put a piggy-back on it. That testing was not conducted with that additional part installed. Better to purchase one that is, if you're insistant on getting a set of pullies.

For the most part, I think pullies are hype. It's a mod that many do so that they can say that they've modded. I'd do it for asthetics but that's about it considering that I've seen dynoes on stroked pushrod Fords that indicate a 5 RWHP increase with NO acessories driven (probably similar with Modular motors). A 20% under-drive? Yeah... not so much.

trinity_gt · Feb 24, 2010

sneaky98gt said:
I'm not trying to be a smart ass, but didn't Steeda do that with Ford?

No, you're right: if you're going to go standalone on the pulleys I'd go with Steeda for that reason.

With piggybacks I don't think it's as critical since the OE damper is preserved, and while "DontGivaRatz" has a point when he contends that the OE testing didn't include the piggyback arrangement, I'm willing to bet someone else's money that this arrangement is closer to OE damping characteristics than, say, a damper-less pulley spun on a lathe out of aluminum whose only design criteria was to slow down the accessories.

I also agree that that for the most part, the bang/buck ratio isn't great and the bang/risk ratio sucks even more.

Gearbanger 101 · Feb 24, 2010

sneaky98gt said:
Sorry for the short/smart-ass answer. It would probably help for you to hear why.

The reason for the Steeda's isn't because of the steel vs aluminum. It's because the Steeda crank pulley comes with its own SFI certified harmonic dampener. No one else's does, that I'm aware of.

UPR and Summit pulleys are built the same way. As are Innovators West, ATI and a couple of independants.

That being said....go with the Summit Pulleys. All the quality of the other guys (and in most cases made by the same manufacturer), but they're about $60 cheaper than the UPR's and about $80 cheaper than the Steeda's.

Got a set of them on my '06 F150 and they're great.

8.8mustang · Feb 24, 2010

I had a underdrive damper on my 99 gt it was like $110.00 or something like that from summit bought it like 5 years ago. Honestly I really hope it fit's with the supercharged cobra motor it made the steering so much nicer just a touch stiffer and the alt never had a problem charging even with sub's and amps in the trunk. It's the first thing that should be done to any mustang with a 4.6 in my opinion

98COBRA281 · Feb 24, 2010

my steeda pulleys we put on in about 1999, or 2000, and are still fine, i knew the previous owner and thats when he bought the car, with them already installed... so they have 75k+ miles

AdRock · Feb 24, 2010

trinity_gt said:
The fact that piggybacks use the original damper as engineered by Ford and validated by Ford engineers in thousands of hours of dyno cell testing makes piggybacks the only damper style I'd consider.

Good luck with that philosiphy man. LOL.

trinity_gt · Feb 25, 2010

AdRock said:
Good luck with that philosiphy man. LOL.

"Philosiphy"?

I have sound engineering rationale. You apparently haven't moved beyond Hooked On Phonics. Good luck with that.

RobBush · Feb 25, 2010

flstang65 said:
Back before I stopped buying from RPM Outlet, I put a set of their under drive pulleys on. I don't know who makes them for RPM Outlet. They too have an SFI approved harmonic dampener on them. I have had them on for 2 years with no problems. If I did have to buy another set though, I would go with the Steeda's. As every one else said. Stay away from the piggy back deals.

Were the gains noticeable? A little. Would I buy them again? Probably not but, they came in one of their packages. I think it's one of those mods that compliment a few other bolt ons.

Spend the money one some good control arms or something else. What mods do you have already?

My initial thought was that underdrive pulley's would compliment the other bolt on modifications I've got on my '99 GT which include:

-C&L Cold Air Intake/Ford Racing Headers, X-Pipe, Flowmaster Exhaust
-Pro Products T/B
-MAC Intake Plenum
-SCT Tuner
-Spec Stage 2 Clutch
-Spec Aluminum Flywheel
-Ford Racing Diff
-Richmond 4:10 Gears

The more mixed opinions I'm hearing, the more I'm leaning away from pulley's completely considering the minimal power increase vs. potential problems......let me know your thoughts. Thanks! Rob

RatStang · Feb 25, 2010

I'd prolly add that money to like a Mazier (sp?) electric water pump or something. Not only will it likely reduce parasitic drag more than a 20% underdrive (just a guess) but I've always liked the idea of circulating coolant through the motor for 15 - 30 seconds after engine shut-down.

IIRC, those pumps are one of the few things that are cheaper for a modular than they are for a pushrod. You'd have to check Summit or whatever your favortie parts outlet is.

Gearbanger 101 · Feb 25, 2010

First off....there's no need to get snippy here folks. This is just a debate.

trinity_gt, I believe your "sound engineering philosophy" may be flawed. If Modular engines are so sensitive to changes in crankshaft harmonics, why is it that all factory Mod Motor crank pulleys...whether they be of the 6 or 8 rib variety, fitted with cast, or forged crankshafts are all, and have all been interchangeable between several varieties of the 2V, 3V and 4V 4.6L, 5.4L and 6.8L engines?

Contrary to what you might believe, the stock modular damper/pulley isn't "precision built" with quality or even great accuracy in mind. I've seen much better craftsmanship and deeper thought put into the design of most aftermarket pulley set ups than the factory damper/pulley combination. The very fact that the stock set up is cast and pressed fit together into a rubber ring, with "best guess" timing accuracy in comparison to the machined billet/steel and balanced precision of the aftermarket versions is more than enough proof of this.

I’ve been running a stock 8-rib 5.4L truck lower damper/pulley on my forged 4.6L 2V for going on 5-years now without a single issue. If the factory pulley was so balanced and precise, I should be experiencing all sorts of issues with vibration, bearing wear and even oil pump failure? I can also tell you with great certainty that the precision machined and balanced two piece damper/pulley design and construction of the Summit brand pulley on my current 5.4L 3V is light years ahead of the stock cast, press fit factory pulley that it replaced.

Also, “piggyback” style pulleys should be avoided. These are what are going to cause problems IMO. Not so much because of their craftsmanship or the balance of the new underdrive portion of the pulleys themselves, but because they’re dependant on the accuracy and condition of the factory crank damper/pulley they’re now combined with. Any imperfections or wear (i.e. rotted rubber ring/separation or slip the stock pulley may have experience over the years) that might be present in the factory damper/pulley are going to be magnified when you add the weight of a new underdrive pulley and move said weight outward from the centerline of the crankshaft.

DontGivaRatz said:
I'd prolly add that money to like a Mazier (sp?) electric water pump or something. Not only will it likely reduce parasitic drag more than a 20% underdrive (just a guess) but I've always liked the idea of circulating coolant through the motor for 15 - 30 seconds after engine shut-down.

Why not add both pulleys and the pump? I did.....and it made a noticeable difference in pep and acceleration (as well as fuel economy) in my 6,000 lb F150 FX4 Supercrew, so I can just imagine the difference it would make in a Mustang weighing nearly half that?

Preferred Underdrive Pullies?

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