Supercharger Rebuilding

Does anyone have experience with going through a supercharger rebuild? I know there is a good bit of info surrounding oil changes and coupler/snout rebuilds, but I am more focused on where the power gets made in the case. I have reached out to a few service providers and received quotes and information all over the place.


Some vendors offer rotor coating and internal case coating that claim to improve tolerances (and increase boost) while some say the only option is to replace the rotors with factory units (at a significant extra cost). The claim for rotor replacement only is that only Eaton can properly coat and maintain tolerances on the rotors.


Some vendors offer porting while others say it is not possible or advantageous to do so.


I have about 115k miles on my charger and was considering going with a full rebuild in order to prepare for the next round of upgrades, and as preventative maintenance. I have received quotes as low as $1100 and as high as $2400.


I really am not adverse to a higher cost, but want to ensure that the work is done properly and can get me to my end goal of 600 hp/tq at the wheels.


Looking for feedback from those that have gone through a “full rebuild” and can address the following points:

• Rotors coated (yes/no):
• Rotors replaced (yes/no):
• Case machined (yes/no):
• Case ported (yes/no):
• Case coated (yes/no):
• Boost before and after (psi, if known):
• Vendor used:
• Cost (inc shipping):
• Turnaround time:
• General feedback:

 

@ViktorG is going through a major build right now and might be able to help. If not @dirtydeeds is usually go to guy for SC ?'s

 

Following

 

I haven't had a supercharger rebuilt, but I'll give you some general thoughts from my experience with these superchargers/engines.
I've used 3 different TRD blowers on my Tundras. The first one I bought new, and the rest were used.

The new blower was on my big off-road truck and put out 6 PSI stock (at 3500 ft elevation), 8 PSI with the blower pulley upgrade and 10 PSI with both pulleys upgraded.
On 6 PSI, the motor spun a rod bearing and was replaced under warranty by Toyota.
I put 2 pulleys onto it afterwards to max out the boost.
On 10 PSI the second motor melted a hole in a piston, but the S/C was OK.
I replaced the block (out of warranty) and took the crank pulley off.
On 8 PSI one of the rods broke in the third block, sending shrapnel into the S/C, toasting it.
I put the fourth motor into it and returned the truck to being naturally aspirated.
It's been fine since.

On my race truck, I installed a used S/C that I found on Ebay.
That supercharger had absolutely no coating left on the rotors, they were bare aluminum.
It put out around 5 PSI.
I bought another used blower with all the coating intact on it and the boost went up to 6 PSI.
Adding a crank pulley bumped it to 8, and the 2UR-GSE throttle body took it up to 9.
Afterwards, I had a custom 50mm blower pulley made, and now it hits 13-14 PSI.
The built block is still holding that + a 100-150 hp shot of nitrous.

I would suspect that re-coating rotors that are still good is unlikely to add more than 0.5 PSI since the difference between good coating and no coating at all is about 1 PSI.
I would also suspect that a stock bottom end would not last very long at 600 whp/tq.
I don't think that porting the S/C would add much because the stock throttle body is the biggest restriction on the inlet side.
As far as vendors, I would trust Magnuson above any other rebuilder since they actually manufacture the blower.
I've heard a few stories about issues with Jon Bond rebuilds over the years.
If you are thinking about spending $2400 on a TRD S/C rebuild, you might consider putting that money towards a brand new $6000 Harrop.

That's all I have for feedback.

 

There ya go @swank501 hope his input helps make your decision

 

Thanks for the information!
Did you have any type of specification or document go-by when disassembling or reassembling the supercharger? Most of it looks pretty straightforward, but i hear the rotors must be "timed" to spec or the performance and life will suffer. Anything worth noting on that?

 

I’ve only had the intercooler out and drive snout off, I’ve never removed or disassembled the rotor pack itself.

 

After some thought and consideration, i am taking the cheap approach on this for now. Charger is coming off. I will put in a new coupler, change the oil, change some O-rings, and do a thorough inspection. I got one of the new upgraded couplers from SCOL that just released.

If i see anything crazy while it is off, then i will go deeper.

 

Charger came off for a quick refresh and back to business. Nothing unusual. Looked pretty good for 120k miles. Bearings seemed solid still. Slight coating wear on the peaks of the lobes. Something worth noting on the oil change. SCOL recommended time not break the case cover and to just drain from the plug hole. Bad advice. It will not drain from there since it is designed to retain most of the fluid. The back of the case must be popped off and resealed for a proper oil change.

 

It won’t easily pour out, but normally you would use a big syringe with a flexible hose to suck the fluid out so that you don’t have to open the back of the rotor pack.

 

Yeah you could probably do that if you had the equipment. The way the back of the case is designed, you can pop the oil cover off without disrupting the rotor case. I was fully expecting the oil to come out the way SCOL recommended. None came out. I thought the case was dry until I popped the cover off it came pouring out.

 

A couple things that gave me some headache on the re-installation was the trio of vacuum hoses on the snout and the fuel injector rail rear spacer on the passenger side.

The vacuum hoses were a real pain to reconnect since the crossover casting for the coolant plumbing is right in the way. I really wish i had connected the hoses before installing the charger. That or does anyone know of some type of 90 degree adapter that will install over those hose stubs?

The injector rail spacer on the passenger rear was a real pain as well. its already a pain just to reach back there to place it on the head, but to wedge the rail in that tight space without misaligning or knocking it over is a real challenge. Wondering how some of you guys handled that? I eventually got it, but knocked off the back of the engine a couple times and prob spent ~30 minutes (cumulatively) searching for the thing when i did.

 

Both of the things you mentioned are a struggle. The hoses are a pain to reconnect and the rear rail spacer is a real b**ch. I've dropped it a couple times in the past as well.

 

Would you know the part number for that spacer? Id like to have one as a backup for next time i do this job. The first time i dropped it, i found it pretty quick, but the second time it was really hiding well and thought it was a goner. That is definitely a show stopper if it is lost.

 

23891-38020

 

How long did the SCOL coupler last you? Just curious as I'll be going this route as well for replacement due to some rattle.

 

I had the high speed lab machine and rebuild mine…

 

Not sure if i understand the question? it is still installed and working fine

 

Ok, thanks. I was just wondering if the SCOL coupler ever began to make the rattling at some point after it was installed or if it's held up fine.

 

This is obviously a way old thread and OP had already done the service, but just thought I’d post this interesting snippet from Brian from Superchargers Online which is who I would trust with a rebuild if needed.