TRD/ Magnuson 4.0 Supercharger Tips, Tricks, and Mods

80 ft lbs of constant spring tension always changing dynamically as the truck runs is a lot to ask of a pulley bearing. By converting to the double bearing roller it further increases pulley stability and allows the belt to ride on a more centered surface over the stock design, thereby evenly distributing pressure on the idler lessening the load on both bearings as they roll about.

There are two things stopping us from running double bearings on everything, physical space, and practicality. That plus the other idlers in the system do not see the consistent physical shock that the tensioner assembly sees as you rip through the RPM band downshifting and upshifting.

The LFP pulley is 50mm, where as the OE pulley is 52mm.

 

Can the OEM pulley be put on the Roush, like any reason why not? Hard for me to conceptualize one pulley seeing any more shock or load than any other pulley in the system. belt tension is the same all the way around, and load is determined by how much wrap on each pulley there is. As long as nothing slips, should be the same shock loading?? But anyway, I'm not saying a double bearing unit isn't better. Have we seen failures of the OEM tensioner pulley bearings? Maybe there is a load/force situation that I don't understand and beefing up the tensioner pulley is needed.

Is the physical dimension being smaller a benefit? like in clearance to other things? The OEM size pulley would technically be better when using a smaller blower pulley on an OEM belt length, with no additional wrap mods, no?

 

I’ve been running the stock pulley on rousch tensioner with 2.5 pulley for a while now.

 

Never heard of any TRD blower whining at idle before. Is that even possible at 700rpm? Are you sure that sound isn’t coming from an idler bearing going bad.

 

You are putting 80 ft lbs (Roush) vs what used to be 40 ft lbs of tension (OE tensioner) on a bearing and spinning it to neighborhoods of 12-15,500 RPM. You want all the relief you can get and if there is a double bearing unit available, it is known to fit, and the community has documented the work involved to make it fit, why not do the extra bit work to put it on if you have the means and resources available to you to do so?

Static pulleys and bearings rolling in one fixed location are different from a pulley/ bearing which is always bouncing around. There is a reason Cobra owners have bent, snapped, and/ or twisted their tensioner assemblies. Those things move around a ton, so yes, there is shock load being placed on them.

There haven't been failures of the OE pulleys as they are simply just a pulley (to my knowledge), but the bearings have eventually given way. I have also heard of idlers exploding before under normal use, but that's just a general thing not specific to any vehicle. You can run the OE unit as is on the Roush without any additional mods to my knowledge. If you want to cheap out, be my guest, I'm not here to chastize anyone for their decisions and I'm not here to tell you how to spend your money, nor trying to make money off of you, but I'm telling you from my findings I found boost to stabilize after switching from the single to the double bearing unit all other variables remaining equal. Those with analog boost gauges will not notice it as much as I have since I run a digital.

It would be good to have him throw up a video of the sound.

 

That's beautiful

 

Any other takers on this one? This has been kicking my ass for a long time now...

@Lucario Runner suggested pulling the UCON. Any other ideas while I am going after this misfire?

Honest to god feel I like selling the truck when I start it up with this.

Thoughts on what is a good compression test kit for what is probably a one or two time use?

 

Let’s just say, I’d be shocked if it wasn’t the Ucon creating the problem. If you still have 455s than it’s an easy 5 minute trouble shoot to rule out.

 

I would kill the UCON as well. Lucario is on to something there.

You've done the fuel pump, plugs have mostly been ruled out and you are running lean at 15-16 AFR for no detectably good reason. It almost sounds like a poor running condition due to the tune in the UCON. At 45K you should have NO issues with that engine whatsoever.

 

It’s crazy to me how people always first think it’s the Toyota engineering that’s bad and not the aftermarket device they just installed. Especially tuning

 

Agreed. Aftermarket is always so hit or miss. Sometimes it takes what is already there and improves on the baseline item, other times it just takes what is already there and makes a crapshoot worth of issues which can make for a very difficult time diagnosing the very issue it created.

 

Who wants to try to stop me from getting a second car?

I am in the soft search for a Pontiac G8 GT sedan...

Mods I plan to do if I get it?

- TVS 2300 or Harrop TVS 2650 blower
- Cam
- HP Tuners tune
- OTR intake
- Corsa mufflers
- Full suspension

Give me some reasons why I should NOT get one. I know I hate GM, but GODDDD do I miss that classic cammed pushrod sound at idle.

 

OK There was a lot of cursing on my part when I put that thing in, no room to work, super tight connections... If I pull the UCON out I am probably going over to HPTune.

Just to be clear, it is only lean while the misfire condition is in. Once it clear I am a good 14.7ish, then pig rich when I stomp it.

 

Help me out here - What are you referring to about the 455s? It's been a couple years since I didi the install - what am I forgetting?

 

Wouldn’t stop you. I really like the chevy SS sedan.

 

So you have a lean misfire... Intermittent at that too, and happening only when cold, like it's an electrical issue.. hmm... That sounds like faulty circuitry to me to be honest, but that's just my opinion. I would start with the UCON for sure then. Now that HPTuners is here there is no reason to not cross over to the dark side. It retains full OE PCM functionality so all controls are native to the vehicle itself which is always a really good thing.

The injectors.

If the issue does wind up being injectors I have the OE orange 455s right here next to me.

That's one HOT car as well. Very potent.. I would shoot for one of those but they are still very pricey while the G8 GT has become very affordable in the recent years.

 

I both love and hate that I feel like a noob wrencher when I am in this group. You guys are next level and there is a lot to learn (and money to spend) here.

 

But if you really want some reasons. Our roads and highways are shit and the car will fall apart with any kind of stiff street suspension.

 

This place is like a horrible support group where the support group themselves are the enablers of you spending your money further fueling your desire for more speed vices. Lol.

We are like Tacomaworlds tribe at this point. A clan if you will.

 

Ahhhh. Got it. Yep, still got them. Honestly between pulling the SC, replacing the injectors, doing a reinstall, pulling the UCON, testing, and then reversing again. I'll just pull the UCON and go over, as you said, to the dark side... It was pretty damn tempting anyway once I started reading the HP Tuner thread.