URD 2.85 stealth supercharger pulley install

This covers the install of the URD 2.85" stealth pulley on the 4.0L TRD supercharger, replacing the factory 3.0" pulley.

The smaller URD pulley spins the supercharger faster raising boost levels from 6.0psi to 8.0psi. The factory 6psi boost results in 69hp and 69ft/lbs, meaning 11.5hp/psi boost. With an additional 2psi, I estimate it should result in approximately 20-23hp, pushing the supercharger output to ~89-92hp over stock. URD claims 15-30hp depending on ambient conditions. The pulley is designed to look extremely similar to the OEM pulley to avoid factory detection. It is printed as a 3.0 pulley even though it actually is a 2.85.



While there are more aggressive URD pulleys are available, they also require cascading fuel system upgrades. And roots blowers typically loose significant efficiency at high boost levels. I believe in moderation in mods for best outcome, hence my choosing of the 2.85 pulley. This pulley makes the most of the factory system without requiring additional modifications.

Though looking at the pulleys side-by-side the matching design is close but isn't perfect. The OEM pulley has a printed part number and a gloss finish. The URD pulley has an engraved part number and a matte finish. It is also printed as a 3.0 but the stock one is printed as 3.00. But is likely to go unnoticed by all but the most experienced detail oriented master techs.

Parts needed
URD 2.85 stealth pulley

Special tools needed for this project.
3 jaw pulley puller tool
URD supercharger pulley install tool
Strap wrench
Friend to assist

Step 1
Before starting it is critical that the truck sits overnight so it is completely cold as the install is based on temperature delta from the hot pulley to the cold truck. I waited till winter to do this project so the truck would be as cold as possible.

Step 2
Remove the front skid plate.

Step 3
From underneath the front of the truck, use a 1/2" drive socket and place in the supercharger tensioner bracket and torque toward radiator fan to release tension on the supercharger belt. While holding in this position, have your friend pull belt off the supercharger pulley.

1/2" drive on tensioner bracket:


Belt removed from supercharger pulley:


Step 4
Using a quality 3 jaw pulley puller remove the OEM 3.0" supercharger pulley. First wrap pulley in strap wrench to keep the pulley from spinning. For claw clearance reasons I had to remove the guide pulley sub assembly below the main supercharger pulley as my pullers claws did not fit. My 'forged' Harbor Freight puller ended up shearing off the claw end of the tool in a dramatic catastrophic failure under load. Fortunately the claws were reversible, so I reversed the puller claw and tried again. This was like playing Russian roulette except you keep pulling the trigger knowing it is going to go off. Again it sheared off the other forged claw sending steel parts flying at great speed under load. Frustrated with POS tools I went to Sears and bought a beefy ratcheting Craftsman puller rated at 5 tons. It was pricey but I knew it would do the job without question. It also had better designed claws that did not have the clearance issues of the HF puller. The Craftsman puller screw was too long to put a socket wrench over the end of the puller once it was installed, so I had to get creative and remove the upper radiator shroud to make room for the tool and use the locking crescent wrench extension method to break the pulley free. The Craftsman puller made quick work of the pulley. Quality tools are worth it every time. Unfortunately the removal damaged the OEM pulley by warping it at the claw points. Meaning I was now past the point of no return.

Removal of guide pulley sub assembly:


Craftsman puller vs catastrophic failure of HF puller:


Removing OEM 3.0 pulley:


Pulley removed:


Step 5
The URD instructions state to boil the pulley to heat it up so the center hole expands allowing it to be installed on the supercharger shaft. As heat is transferred to the supercharger shaft from the hot pulley and the pulley cools down it will permanently mount to the shaft. It is critical to get the pulley fully installed before this happens. To make the install easier, I would strongly suggest baking the pulley to obtain a higher temperature as other members have done. I set a toaster oven right next to the truck to minimize transfer time and baked the pulley for an hour at a setting of 300 degrees. When checking the pulley temperature with my IR temp gun it read 340 degrees. So much for accurate toaster oven controls but figured the extra heat couldn't hurt.

Step 6
Assemble and grease the URD tool. Make sure to insert the threaded nose piece with the allen key side going into the tool. So when it gets stuck in the SC snout after you remove the tool you can use an allen key to remove it. I greased the full length of the tool, the bearings, washers and threaded nose section to make the install as easy as possible.

Assembled URD pulley install tool:


NOTE: the threaded nose piece should NOT be fully installed into the tool. Because the supercharger nose is tapered to allow the seating of a pulley removal tool, the entry area is not threaded. This means the threads must extend further into the supercharger nose to bite. I threaded mine into the tool all the way and then into the SC nose. Half way through the install I sheared the threads out of the SC nose due to inadequate depth and the tool came apart under load and was scattered everywhere inside the engine bay. Worst thing possible in a time critical install. Probably would have been SOL if I hadn't heated the pulley in the oven and instead followed the instructions to boil. Fortunately was able to remain (semi)calm and locate all the parts, to reassemble the tool and carry on. I would suggest installing the threaded nose piece into the supercharger snout first, then once the pulley is held in place install the tool onto the threaded nose piece.

Step 7
Installing the pulley is not an easy task. Lube the SC shaft with conventional motor oil as instructed in the URD instructions. It is a good idea to practice the install execution with your friend using the factory pulley as you will only get one shot at the install. Using heat protective gloves remove the pulley from the oven, place in position, place strap wrench over pulley, and insert install tool. You can place a wrench over the end of the pulley installer and lock it against the battery if you have a wrench long enough, reducing one job needed on the install. Then have one person hold the strap wrench on the pulley while the other person cranks on the nut with an open ended wrench as quickly as possible. Do. Not. Stop. It will be moderately easy at first then increase in difficulty as the shaft heats up and the pulley cools off till it is permanently mounted. It is extremely critical that you get it all the way on before this happens. My install went horribly wrong as mentioned above, but I was still able to get it on, though at the end of the install I was using my full body weight to force the pulley on against its will. The tool is designed in such a way that you cannot over press on the pulley, it will stop when seated flush.

URD pulley install tool installed on supercharger snout (picture is post install for illustration):


Wrenches on URD pulley install tool (Picture is post install for illustration, missing strap wrench on pulley):


Step 8
Drink a beer and relax knowing you didn't royally screw this up (hopefully).

Step 9
Repeat step 2 to ease the tensioner on the SC belt and while holding in that position reinstall belt over the new pulley. Double check the belt routing to make sure it didn't come off anywhere else while not tensioned.

URD pulley installed and belt reapplied:


Step 10.
Fire it up and enjoy the extra boost!

Final polish step needed is to find some orange torque seal and dab the pulley to shaft interface like the stock one had so it does't look like the pulley was ever removed. Comparing colors to other members with superchargers there seems to be many colors used, so an exact match is likely not necessary, just an approximation.

Driving impressions: Boost comes on sooner and is more responsive. Most noticeable off the line, the truck pulls harder across the entire RPM band. My poor KO2s will pay the price. Unlike other naturally aspirated products that may claim a peak HP increase, the boost increase across the RPM band results in noticeable power increase everywhere, not just near redline. Assuming a good install, the $200 spent on the pulley and install tool provide a good performance return for the cost, especially compared to the base price of the supercharger. I scored my pulley from another member on TW so it only cost me $100 instead of $150.

I highly recommend this product for anyone with the supercharger, especially given the price. It feels as if it should have come this way from the factory. As was put in another thread, the supercharger wakes up the Tacoma. The 2.85 pulley wakes up the supercharger.

 

Random question, you wouldn't work in Redmond near willows and 95th would you? Seen a truck like yours in that business park

 

Actually my Girlfriend used to, so my truck would be there periodically. My wheels are pretty rare, makes the truck easy to spot. And of course the occasional stop at Black Raven Brewery.

 

What about the step where you get a new custom dyno tune to allow for the increased boost... Are you just going to drive it on the incorrect tune? Do you have a way to accurately measure the A/F ratio?

 

You can't tune it, it's locked by Yota. The flash it with a premade tune when the SC is put on. There are very qustionable piggy back tuners/ECU etc. It was only the pre 2009 that you could tune.

 

BTW, nice writeup OP. This needs to be stickied in the performance section.

 

Good question. The factory supercharger reflash tune is able to accommodate the increase in boost as it is pretty rich. A/F gauges are a very good idea. Had it not been for seeing several other members on this forum do it first with their A/F results remaining safe I would have definitely done an A/F as well. However that does raise the cost of this mod significantly.

 

im thinking bout doing this soon.
sounds like it worth the time and money

 

I'm sold !!!!! Been waiting for a good write up on this and "Crash" comes through again.........
Ordering parts now. -30 here today. Wish I was installing during this temp.

No A/F gauge for me yet but do have a boost. So I'll let you know the difference with the gauge readings.


Thanks Crash

 

I should mention URD recommends

AMPRO T74193 Heavy Duty 3 Jaw 4" Gear Puller

AmPro #T74193 3-jaw puller in the instructions, if you are looking for something less expensive than the Craftsman unit. Although the reviews state that it also broke on first use. I'd rather just buy quality one time.

 

Good writeup and great looking truck. Working with interference fit stuff is always a pain.

I'd bought some torque seal couple weeks ago in orange from Amazon that looks close to what you had when dry. http://www.amazon.com/Aircraft-Tool...F8&qid=1455514025&sr=8-3&keywords=torque+seal

 

I've been running the 2.85 pulley for over a year now, and it definitely wakes the supercharger up.

 

I second the "sticky thread" vote.

 

Mods are welcome to move and sticky-ify.

 

Looks good but one suggestion I would make is where you talk about heating the pulley up in the oven to above the temperature it would reach boiling: this is one of those instances where more isn't necessarily better. In fact, the increased temperature can actually be worse for this application. I'll explain. Boiling the pulley will get to about 210deg (varies depending on elevation and a few other things... water boils at 202deg where I am for instance) which will cause the ID of the hole to increase ever-so-slightly which is the goal. The more you heat the metal the less this happens (up to the point of deformation anyway but we're a ways from temps required for that) so your return on investment as it pertains to the ID diameter wanes significantly. In and of itself it wouldn't be a big deal either way another hundred degrees or so but there's another element to this install and that's the pulley output shaft on the s/c. The ideal way is to cool that puppy to get it to contract ever-so-slightly (which you mentioned is why you did the install in the dead of winter) so that the two slight variations will assist in pressing one onto the other. As you press the pulley on there's a heat transfer that occurs and this is why time is of the utmost importance during install and why you press and don't stop until the pulley is seated because that's when bad things happen. The higher the temp of the pulley the more heat radiates into the output shaft which causes whatever you do to cool it to be reversed more quickly. In other words, heating your pulley to 350deg or 400deg won't really help the ID of the pulley that much more than the 210ish degrees but it does give off MUCH more radiant heat which not only makes it more difficult to handle but will transfer even more heat to the output shaft which will cause it to expand while pressing it on. You didn't have a problem because there's a lot of factors involved and I'm trying not to get overly technical with the explanation but to be safe I would modify this how-to to not discuss super-heating that pulley as it will likely cause more issues for others down the road and it's not likely that anyone would benefit from that variance from the installation instructions that the manufacturer provides.

Also, when I went to my local Autozone/Pep Boys to borrow a couple pullers (mine was too large to clear the snout) I ended up taking both the 5-ton and the 3-ton puller with me and I was glad I did. The 5-ton seemed much nicer but it also had a clearance issue and the 3-ton not only cleared but was more than adequate for the task at hand. I'd suggest getting your hands on more than one puller before you start so you can use whichever ones works best while working and not having to leave to get another one or ordering one online and being down for a week or more until it arrives for those who don't have more local options.

 

Here is my stock pulley, other Cobra owners call it a "wagon wheel"... Mustangs get re-tuned when changing pulleys... I did not realize it was unpossible to custom dyno tune a Tacoma, that is really surprising. Most Cobra owners change out the pulley for a smaller one I choose to keep my Cobra stock because it is fast enough for me, smaller pulleys lead to belt slip, smaller pulleys detract from resale value (generally speaking), and smaller pulleys require a custom tune (generally speaking depends on the size and existing mods). And yes, I know my Cobra engine looks awesome... Its the 303 Aerospace

 

Valid point regarding to much temperature difference would just lead to accelerated heat transfer and therefore be counter productive. After talking to others that had done it via boiling and baking and had better success baking, I went with the baking method. While mine got a bit hotter than I intended it too, it was supposed to be 90 degrees over URD instructions. @12TRDTacoma

Regarding the pullers, a 5 ton is definitely overkill. But it will definitely get the job done. I linked to the Craftsman one I used that has low profile claws that fit nicely behind the pulley, though the length is a little long but manageable. I can say for certain this puller works for this task.

 

For what it's worth, I did this install too and boiled my pulley. Not only am I about a mile above sea-level making my boiling water temp about 10deg lower than most people on this forum reading this but I did it in the middle of summer and the temps in my garage were approaching triple digits. I had no issues at all and just made sure as soon as I started I kept going until it was seated and didn't stop. I really think that's the most important part of the entire install. I doubt anyone's mean temperature difference spread will be closer than mine even following the instructions to the letter so I doubt many (any?) would actually benefit from an increased temp of the pulley as it applies to this installation. I really don't see it helping and I'm afraid it could end up hurting someone's install based on the science which is more likely the more extreme the temperatures get.

 

Look in all truth I have attempted the different methods twice over. And within those methods I found that the most consistent way was to bake it rather than boil it. Why because the baking method provides an even temperature to provide the slight expandature that is needed to fit it on the blower. Boiling works but you gotta be quick to install it and upon the pulley up to temp. We are talking about billet aluminum, and honestly, it is much more resilient to warping than you would think. As for heating it up, as long as you are not scorching it with a torch to attempt to expand it, you will not warp it by any means. For insurance purposes of ease of installation you should apply some anti seize and before you do so, you should make sure that the output shaft is as smooth as possible, even if that means sanding the shaft with some 1000 then stepping up to 2000 grit sandpaper.

 

I didn't say warping was a danger at these temps and even said it wasn't really worth mentioning since we were a ways from temperatures where that would be a concern with the type of metal we're working with. Removing material by sanding also isn't necessary if you follow the installation instructions URD includes. Once you remove material you can't add it back. Again, not worth the risk. Sure, 9 out of 10 times you'll probably not cause any issues but if you're that 1 out of 10 person you're going to be SOL for following these 'advanced' installation instructions. I followed the basic installation instructions that URD includes to the letter and had zero problems. They work fine. The only time I have EVER heard of someone having a problem was when they didn't follow the instructions exactly and stopped or did something different.

Again, his post is fantastic and very descriptive. I was just warning about suggesting that people heat their pulley to hotter temps than the manufacturer states because the science doesn't support this as helping and could more likely do harm than good. He didn't have problems but that doesn't mean that someone else couldn't and if they didn't follow the manufacturer's instructions they're SOL.