TRD/ Magnuson 4.0 Supercharger Tips, Tricks, and Mods

2.6 right now, but later today swapping to 2.8 and stock tensioner. I needs all the reliability i can get

Im curious as well now. I've always kept the stock tensioner in the truck as a spare after swapping to the roush. I'm gonna swap them today though and the roush will be the new spare

 

I may do the same and just run the RPM belt as the source of added grip.

 

That was my plan as well. I think i have a stock length rpm belt laying around somewhere

 

For what its worth I’m still on my stealth 2.85 and stock tensioner, just recently put in the timken bearings and rpm belt. The timkens seem to be already letting grease out which has me a bit skeptical at how long they are going to last but hopefully they will be fine.

 

You know mine were letting out a lot as well. I don't know about those Timkens.

 

I just had my belts off to install a Howe power steering pump. I checked out the Timkins I installed 2-3 years ago and no signs of issues. Stock tensioner, 2.5 pulley with a Roost pulley wrap mod. I saw you inquired about ceramic bearings. I had called microblue when I was researching appropriate bearings, they said this wasn't an application for them.

 

For those of you that are looking to this situation and trying to put some thought into how to avoid this situation. I think we all need to be aware that these bearings spin at unbelievably high RPM Like 15,000rpm and up. So just doing original duty is asking a lot out of them. Now when you couple the already high RPM's with significantly higher load (ie aftermarket tensioners) we're creating a recipe for failure. This is also compounded by a single mounting stud that is rather lengthy, and subject to some pretty high loads out away from the primary mounting point.

If you leave everything stock or maybe a pulley swap to the 2.875", I would plan on replacing bearings at 100K miles. If you run additional pulleys for wrap or aftermarket tensioners, I think its advisable to replace the bearings every 50K miles.

The bearings are essentially alternator bearings. If someone else finds a suitable NGK replacement, please post up. For the moment, the only bearings I could find commercially available that met the rpm and grease requirements were the Timkins distributed out of England. I think a set of them were sub $70 including rather prompt shipping. So Aside from the small effort it takes to install them, I definitely think they are worth it.

 

Did your timkens leave out grease? The bottom one next to crank pulley also did it on first start up, I just noticed this top one in the last week or so.


For what it’s worth I had just around 43k miles when the stock super bearings were making bad noises, been on the 2.85 pulley most it’s life.

 

Nope not yet. I'll try to get pictures later. I also got 150K miles out of the original set. Out of curiosity did you have a TRD supercharger kit or the Magnuson kit offered later on? Wondering why your first set went bad so quick.

 

Mine was a magnuson from the group buy. Yeah these bearings literally are only a month old or so. Not sure if I got a bad batch or maybe there was too much grease I have no idea. My truck has seen a fair amount of dirt/water so I just figured that was part of the contribution toward the bearings going bad originally.

 

I just went to go pick up the new Dayco pulley. It really seems close to the original Magnuson one.

The only issue is that it runs a 6203 instead of a 6303 bearing. I'm not sure how I feel about that, I'm sort of wondering if I could do a retrofit to the 6303 bearing using the new pulley, because everything else seems really close. The only difference between this one and OE dimensionally is the OE one is a 75.9mm pulley and this one is a 71.2mm.

 

That newer, smaller pulley is going to spin even faster. If the old one were spinning at ~9300 rpm, the new one will be at 10k…

 

You know that speed for sure? That's pretty flippin' fast man. Yeesh.

 

It's actually a lot higher. What's the crank diameter? 6-5/8" or something like that? Do a ratio to your supercharger idler diameters and multiply times engine rpms.

 

I don't know the speeds of the pulleys, I was just going off the 15k that I've seen recently and just ran a comparison at 10k between those two pulleys you have.

 

My mind is all over the place right now. If one of you guys would be so inclined, that would be awesome.

Actually if I remember right the crank pulley is 6.5"

 

The latter

 

75.9mm/71.2mm=1.066
The larger the circumference, the slower the rpm of the axle.

 

An upgraded tensioner providing MORE tension in order to limit belt slip is definitely the culprit. And physically it makes sense.

 

Overdrive pulley / SC pulley then multiply RPM Redline = your magic number

Yup 6.5” for most of you over drive pulleys