CLOSED Group Buy: TRD/ Magnuson 4.0 Supercharger Quickchange Pulley Kit

Josh at Pulleyboys is getting me straightened out. Sending my pulley back in for another.

 

https://www.instagram.com/p/BdYw1eeF_K-/?taken-by=billdacat8

Got two more done this weekend. @XPOTRPR & @racebug68 came up yesterday morning and we went to work. Josh’s fought us like crazy. I finally had to get midieval on it to get it to let go. He’s got more details here. XPOTRPR build & BS

Travis’ was an interesting challenge since it wasn’t actually installed in a truck. At least not in a conventional way. So, we ended up sourcing an intake manifold, bolting it down to a shipping pallet and then bolting the blower to that. Worked out pretty well. That pulley came off easier than any others that I’ve done. Was super easy. New hub slid on beautifully. The modded pulley press tool worked like a charm.

Now that all the local guys are taken care of, I’ll be selling the snout cutter and press tool. If anyone needs them, let me know.

 

Huge thanks to Jake ^^^

Truck runs great.. still need to do a couple more maintenance items (replace fuel filter, replace s/c coupler, replace seal), but super happy with how it's running.

 

Can you all do me a favor an measure the ID of the pulleys you have on the shelf for me? I have a 2.5" and 2.8" pulley, the 2.5 fits real nice on the hub. Screws only function to hold it there. the 2.8 is really loose though, putting those 5 tiny screws in shear force to hold the pulley concentric on the hub with belt tension. I am emailing Josh at pulley boys... the conversation isn't going well. He said all pulleys put the bolts in shear force, and that all 2.8 and 2.7 pulleys measure large. But that doesn't make sense with what Jake, Josh, and I found. We found that all the smaller pulleys fit tightly on the hub other than my 2.8, making it seem like that one was out of tolerance.

2.5 = 1.129" or so
2.8 = 1.137" or so

Josh said the 2.7 pulley is 1.136".

Can you guys give me some measurements with your calipers of the ID, helping me determine which ones are the outliers?

Thanks,
Travis

 

@racebug68 Weird they are giving you issues. I just sent a picture of my Boogered 2.6 with a description of what was wrong, and they sent another one right out.. like they knew they had a "bad batch". Wondering if they are getting a lot of reports and trying to push back on some. Not saying that's right at all.. it should get taken care of. Just wondering why they are giving you grief.

 

I am also trying to find that out. Seems really like a design flaw if he says they are all supposed to be lose and rely on those tiny screws in a shear force situation to hold it concentric with belt tension and easily 10,000 blower rpm.

I sent him measurements and he is responding in 1 line useless emails things like "they are all like that". Like what I say? Our experience was that they weren't all lose on the hub, we had to cool the hub before all the other pulleys would even slide on... which is how I think it should be, and the screws only function is to hold the pulley onto the hub, not 'locate' the pulley on the hub...

 

The design acts like a hubcentric/ lugcentric design similar to our hub/ rims design, The stress in this case is mostly seen on the press on design, but the bolts ensure that the pulley stays on evenly and correctly on the hub. I am a little behind the loop here on your issue, but what is the issue here? This design is not like the URD press ons.

 

I see what you mean, I stopped working on it since the design and issues really bugged me so the truck and supercharger got covered for now. I just did some quick research on the ZL1 quick change upper pulley and they use 10 bolts to drive the pulley onto the hub and then there's two thread holes to extract the pulley from the hub when switching sizes. It be press fit, not hand fit, or loose in some cases.

 

The pulley should fit snug on the hub, one should locate the other and the small screws should hold it in its place. That is how it works with my 2.5, and how it was with the other peoples pulleys that I have first hand knowledge of. but my 2.8 pulley fits very loosely on the hub, like almost 0.010" loose, meaning the tiny screws will have all the force exerted by the belt on them in a shear configuration. Not good. And pulley boys is not being useful, saying things like "all of the 2.8" pulleys are like that, there will be shear force on the bolts in either case, the pulley isnt pressed onto the hub, if you dont like it send it back." I disagree, and although there is no press fit on the pulley to hub, a clearance of 0.001" or so means that there is effectively no movement to be considered shear on the screws themselves.

I would happily send it back if I could get one that was correct. but apparently all the 2.8's are like that? I asked him to measure a 2.7" and it was 1.1.36", almost the same as my 2.8. Hoping some of you can measure and post the ID of your pulleys so I can get a trend of what is what, without relying on the questionable responses from pulley boys. They have an incentive to not tell me the truth...

Thanks, Travis

 

1.136 for the 2.8 pulley
1.131 for the 2.6 pulley

On my hub the 2.6 fits cherry and has to be dead straight, the 2.8 just falls into place. Also I pushed my hub .215 passed flush with the hub to line up the pulleys.

 

thanks for the feedback. I am concerned about those 2.8's, the added clearance means the bolts have to take all the stress. And there are just 5 5mm stainless screws... hardly seems reliable.

Can anyone else measure a 2.8, and also a 2.7 pulley?

 

Can some others get a pulley ID measurement for me please?

 

Well, I just heard back from Josh Cook, of Atkins Rotary Specialties / Pulley Boys. Not good news. If we are to believe his statements, the 2.5 and 2.6 pulleys have an ID of 1.128 inches, whereas the 2.7 and 2.8 pulleys have ID of 1.136 inches. That perfectly correlates with the fact that the smaller ones fit nicely and the larger ones fit loose.

I don't know if that is measured or design spec. We have already seen some tolerance on the IDs, as measured in this discussion. I am not very comfortable with the 0.008" slop being taken up by the 5 tiny screws that hold it on. Am I being overly pessimistic? How do you all feel? Who is actually USING their 2.7 or 2.8 pulley? Any issues?

Thanks,
Travis

 

Just use the 2.5

 

You are probably just being over pessimistic.

 

LOL, could save myself $80 by sending the 2.8 back...

You are running a ucon though, no fair. Who else besides OP is using a 2.5 with a TRD flash?

 

get the 2.6.. happy medium

 

I am with the bully dog tune and cold winter weather to keep things cool for now. Have colder plugs, bigger coolant reservoir, higher flowing coolant pump and a battery relocate in the works and am waiting for OVtune to get a self tuner available so I can upgrade the tuning.

The 2.5 pulley is too fun to let go of so I'm throwing more money at her.

 

Is there a heat issue you are trying to combat? Wondering why you need more flow from the coolant pump and a bigger reservoir.

I'd like to have an idea ahead of time what kind of changes I should expect with a 2.5 or 2.6 pulley compared to a 2.8 or even stock 3.0. Anyone notice pinging? Anyone data-log and see the injector pulse-width go to the extreme with the injectors supplied in the SC kit? Any visible signs of running lean (AFR meter)? Any overheating?

I'll have to investigate the OV tune more. Seems like lots of folks talking about that in one way or another. Previously, was set on either a TRD tune or a UCON,,, obviously a price difference there though!

And what should I expect with the transmission. Mine has a lot of miles on it now, would like to do at least a full flush and some performance fluid in it. I don't plan to race it or go to redline with it regularly, and hoping to maintain smooth shifts for comfort in off-roading and traveling to the off-road destinations. So likely NOT do a shift kit? Or should I expect to burn things up by having it still shift sluggishly with the added power? My truck is extremely heavy and the SC is mainly to regain some torque lost to all the weight.

thx for your inputs!

 

From the OVtune thread

On the stock TRD tune and 2.85 pulley peak boost AFR was 12.3+, lean enough to cause detonation.

I noticed it only takes about 3-4 runs before the supercharger is hot enough that the ECU will start to pull out timing. This is also when fueling will start to be all over the place, because of maps that control fuel compensation to air temperature. (fixed)

Overall thoughts :

After hearing the engine with my Det ears today I would personally recommend against running smaller pulleys on a stock TRD tune unless you have additional cooling mods to keep the superchargers cooling system from getting hot, and or higher octane / methanol. You might be okay with 93 and a 2.85 on stock ignition, but there is simply no way 2.55+ stock ignition and 91 octane is safe.

Sorry typing from my phone and it is being stupid.
Coolant lines to the TB isn't the issue. It is that the stock heat management system for the TRD supercharger is not designed for higher than stock boost.
We have seen this exact same issue on the new twin turbo Infiniti, you get 2 good runs and it's boiling hot.
A very large heat exchanger upgrade on those cars will allow you to bump boost up 10psi and no overheating intercoolers.

I took a good look through the components today. The stock exchanger is a decent size if the supercharger peak output was like 5psi, not working hard.
But 8+ psi is pushing the boundary, larger exchanger and even larger resevoir, upgraded pump would do the job perfect.
Or a larger / more efficient supercharger.
An option I spoke with the owner of this truck today about would be tapping two holes into thesupercharger heat sink cover and have water methspray right above the internal heat exchanger. ( for a 2.55 pulley )