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Supercharged Supra

cribbj

"Supra" Moderator
Staff member
Made a bit of progress on my supercharger drive setup. The last of the pulleys (the supercharger pulley itself) arrived, and all I had to do is figure out how to adapt it to my supercharger.

So how do we fit this:



Onto this:



Well, we make one of these:



Then it almost turned out as drawn, except my ace machinist missed the note about TAPPING the holes for M8x1.25, so then he had to go back & countersink them:



So here it is, on the ‘charger, and I’m checking belt alignment. For all you real smart guys, yes I know I missed a few pulleys with this belt routing! This is using the stock timing belt just to see how the pulleys line up – and they’re not bad!



Unfortunately, this is about as far as I can go with it this time, as I’m off to play in the sandbox for a month. Next time I’ll get the idlers squared away, and make sure I have all I need to drive it on the dyno.

Still have to get that doggone harness wired, and I have a real mental block about doing that.
 

cribbj

"Supra" Moderator
Staff member
How did you get your motor so damn clean, you could eat off that!
LOL, all it does is sit, that's why it never gets dirty! This is actually just a mockup motor now; it made 498 HP to the engine dyno back in '98, but it has some issues. I haven't figured out yet if the block's deck height is too short, or too much material has been taken off the heads, but it's a real bear to get the timing belt tight, and the tensioner requires shimming. Until I get interested enough to figure out where the issues are with it, I'll just continue to use it for mounting parts and experimenting with things.

My good motor has been sitting patiently at the engine builder's shop since late 2009, waiting for me to get this supercharger drive finished and the silly harness wired up. Then we expect to lay down some serious power with it. We should get this puppy finished by this summer.
 

Zuffen

Super Moderator
Staff member
John,

Are you planning on an idler below the supercharger?

Doesn't seem a lot of wrap even for a cogged belt.

You're mighty talented at swapping from Imperial to Metric dimensions and back.

It's going to sound wicked. The belt will be banging away and the supercharger howling like a cat on heat.

You'll need that big stereo.
 

Cobber

New Member
What stops the supercharger pulley spinning on the front of the supercharger? Just the tension on the M10 bolt or is the adapter a press fit on the shaft as well?

Another step closer.
 

scotturnot

Member
Looking good John, I was just in Houston, I should have tried to set somthing up to come see this thing. Just remember when its dyno time, I may need to make a road trip.
 

cribbj

"Supra" Moderator
Staff member
Looking good John, I was just in Houston, I should have tried to set somthing up to come see this thing. Just remember when its dyno time, I may need to make a road trip.
Scott, you should have let me know you were in town! The Fcar was running really well too; we could've gotten in a few hot laps of the 610 loop!

What stops the supercharger pulley spinning on the front of the supercharger? Just the tension on the M10 bolt or is the adapter a press fit on the shaft as well?
Andy, it's just a friction fit - I was amazed when I took it apart and realised there weren't even any shear pins coupling the two sides. This is supposedly how all the Opcon Autorotors are setup.

John,

Are you planning on an idler below the supercharger?

Doesn't seem a lot of wrap even for a cogged belt.
Rod, definitely at least 1, and possibly 2 idlers below the supercharger. As you know, the usual UZ setup is to put one between the P/S pulley & the SC and call it good, but I've seen some recent setups where guys put another between the SC and the A/C pulley, and that makes a lot of sense to reduce the belt flap on that side.

You're mighty talented at swapping from Imperial to Metric dimensions and back.
The machinist made the same remark :D. I did the same thing on a drawing I gave him for a ring nut wrench that I had him make for the Ferrari, and he missed a dimension or two on that one too.

Next I need to figure out whether I'm going to try to run this setup as is on the dyno, or pull the P/S pump & A/C compressor off. I suppose on the P/S side I could simply pipe a loop from the pump output back to the reservoir, but the fluid is probably going to heat up a bit from being pumped, even though there's no pressure. I really want to try to keep the P/S in place 'cause it'll help with the belt angle going to the first idler. Otherwise, I'll need to go through some gyrations with relocating the alternator, and I may not be able to use the stock tensioner if I do that. Better if I can just figure out how to keep the P/S pump there. Maybe put a little cooler in the circuit temporarily?

The A/C compressor pulley "should" be happy just sitting there and freewheeling, sorta like another idler, because the clutch won't be engaged, so the compressor itself won't be turning?

Thoughts?
 

JustenGT8

New Member
That's looking very serious John :)

I think the PS pump will be fine just on recirc...it's not doing any 'work' so won't get very hot.

Just on the belt path. Run the standard idler puller just below the SC (see my pics). I modded mine so it would pivot and i could use it to help set a higher 'base' tension on the beelt as well. If you could fabricate anothjer smaller idler pully to replace the fan pulley it would help as well i think as the belt path would be nicer? You be running thermos anyway so no need for the fan?
 

cribbj

"Supra" Moderator
Staff member
That's looking very serious John :)

I think the PS pump will be fine just on recirc...it's not doing any 'work' so won't get very hot.

Just on the belt path. Run the standard idler puller just below the SC (see my pics). I modded mine so it would pivot and i could use it to help set a higher 'base' tension on the beelt as well. If you could fabricate anothjer smaller idler pully to replace the fan pulley it would help as well i think as the belt path would be nicer? You be running thermos anyway so no need for the fan?
Justen do you have a link to your pics? I'm feeling lazy and not wanting to troll through your 30 page thread :)
 

SC400TT

Moderator
Damned nice set of pulleys there John!! Certainly look like you spent some serious cash having those made.

Ryan
 

JustenGT8

New Member
Justen do you have a link to your pics? I'm feeling lazy and not wanting to troll through your 30 page thread :)
Pics aren't great as it turns out, as none of the engine outside of the bay...i'll check to see if i have any of the belt routing and post em up but suspect not as the belt only went on in the car.
 

cribbj

"Supra" Moderator
Staff member
Bitte schön Neal

No, the idle was still fairly smooth, but that was with an extremely rich carb setup. We'll see how it runs & idles when it's being forced fed by its supercharger, hopefully in not more than a month or two.
 

cribbj

"Supra" Moderator
Staff member
Another piece of the puzzle arrived today, the 350 tooth HTD drive belt. It's 2800mm long x 40mm wide.




Still not much progress on the harness, but the pressure's really on me now; it's the only remaining piece of the puzzle before the engine can run. I can't even blame Dennis anymore - he's finally got the long tube headers finished after three years. That was the last box he had to tick on his side to be done.

I think I'll put one more idler between the supercharger and the A/C compressor, just to ensure there's no belt flappage (is flappage a word?)

The sexy redhead is sitting there in the background, and I just finished its COP conversion which really turned out super and I'll post some pics in my "New Daily Driver" thread. It's now getting its low beams upgraded to HID projectors this afternoon.
 
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