From knowing nothing to having a Thunderbird supercharger on an m20b27i

[agent]

How'd the video on your phone cone out Jacob? I, uh... *ahem* tried not to talk all the way through it.

[Sideways87]

I'm compiling a parts list now of things I need before I do it again!!!

Sent from my SM-N900V using Tapatalk

[Ether-D]

Thank you Zach! That was so much fun guys. Cain't wait to do it again.

[Sideways87]

Autocross Video

[Ether-D]

I right like the door handles too.

[Ether-D]

A/C Schnitzer inspired pin stripe.

Quint, what size are your pulleys?

[Q5Quint]

take your top off.
Show me them pin stripes.

Now I am trying to figure out some crazy tensioner situation, but I should have like 50%+ wrap without it. I went with the custom pulley but added in a vgrove for the ps, but in doing so had to delete the stock mechanical fan because of it pushing it all forward.

[Ether-D]

I got off my ass and put the 3.73 lsd back in today. I was kinda nervous about it. I was afraid it would lose all the big balls. It's just fine. It seemed to sustain more boost. I saw it go over 7psi (barely) for the first time ever. I reckon I might even get back some MPGs. I got 20 mpg last tank.

Also re-did my pin stripes in an A/C Schnitzer sort of tribute in burgundy. I think it's titties.

[Lithium]

I only have 50% wrap on the s/c pulley. I added more tension to to the belt and it didn't change it a bit. I was thinking about trying a 7 rib belt. Only problem then would be that I'd have 1 1/2 ribs not touching the crank pulley. But since it's likely the s/c pulley is slipping, it could still benefit me about 14% more gription.

I made my own crank pulley by using a six rib pulley we had lying around in a box of junk and making the inner part to bolt onto the crank and welding them together. (See Piks) it really helped / now I need to find a 7" 7 rib pulley & do the same to add more boost.

[Ether-D]

I only have 50% wrap on the s/c pulley. I added more tension to to the belt and it didn't change it a bit. I was thinking about trying a 7 rib belt. Only problem then would be that I'd have 1 1/2 ribs not touching the crank pulley. But since it's likely the s/c pulley is slipping, it could still benefit me about 14% more gription.

[Lithium]

Tensioner

- It usually always slips on the blower pulley.

My SC pulley is from an early Supercoupe (I think)
SC pulley diameter is 3.15" - crank is 5.5" - Making 5.5PSI on my M50
(Next I will got to 7" on the crank pulley & hope for 10.5PSI)

Have a look at my photo below.
Things that worked for me is having about 65% wrap around the SC pulley - using the tensioner position to increase wrap - my tensioner is manual & I preload it up with a jack - if I can turn the belt more than 90 deg it's too loose - I have about 8/10K on the belt. I have adjusted it a couple times & it's not slipping yet.

I hope this helps.

[Ether-D]

Belt slippage is likley the cause - I am running a six rib belt with a manual tensioner + huge tension & it works great. (M50 + Eaton M90)
Boost stays consistant all the way to Redline.

When I started out I thought my engine was sucking up the boost @ high rev's but it was just belt slippage.

I hope this helps.
Tim.

Yep, it is slipping. I was watching closely today and as soon as boost starts to drop, I can hear some squeekage. I had convinced myself it was the alt belt because before I put the sc on, it would start slipping at high rpm. I also have a manual tensioner, but with normal tension on the belt.

Tim, on yours, was it the sc pulley slipping or the crank pulley? I have pretty good wrap on both. Also, what sc pulley is on yours? Mine is off of a later model supercoupe so it's the biggest one that fits this m90.

[Lithium]

slip

I may after I get another DD, but for now, this one has plenty of power. Also since it builds the boost up to 7 and then trails off, doesn't that mean I'm already in the "efficiency island" of the m90? I feel like if I pulley it up, it would just make more boost earlier and trail off earlier. Or am I just witnessing my engines' volumetric efficiency by way of my boost gauge?

Belt slippage is likley the cause - I am running a six rib belt with a manual tensioner + huge tension & it works great. (M50 + Eaton M90)
Boost stays consistant all the way to Redline.

When I started out I thought my engine was sucking up the boost @ high rev's but it was just belt slippage.

I hope this helps.
Tim.

[Ether-D]

Quint, that looks great! How did you possibly keep power steering (sarcasm font needed)? Go get it bro!

[Q5Quint]

Me this upcoming weekend: