TRD/ Magnuson 4.0 Supercharger Tips, Tricks, and Mods

Where did you get that

 

From the mad scientist machine shop laboratory of @Roostfactor

 

This^

 

Good shit!

 

Thanks!

 

I wouldnt say everyone is or isn't. I also think people might be getting some slip and not realize it. It's not like you are building boost and then the belt slips dropping boost to 0. It's more intermittent and progressive than that.
The problem is we only have a 5 rib belt to grip an already small pulley at 3". This is with the correct belt wrap of 190° as guided by the idler pulleys. This give a total belt to sc pulley contact area of about 5".

Once you start going smaller with sc Pullies, you not only lose belt contact area from the smaller pulley alone but also due to the position of the non adjustable idler pullies.

Some info...at a constant 180° of belt wrap, pulley contact area is as follows:
3.0. pulley 4.71"
2.85 pulley 4.47"
2.7. Pulley 4.2"
2.5 pulley 3.9"

That is almost an inch less contact area on the 2.5 pulley vs the 3.0 and that is not taking into consideration the extra load (hp) required to drive the sc with the smaller pullies installed or that you get less belt wrap the smaller the pulley.

What the belt wrap mod does is restore some of lost belt wrap which brings the belt to pulley contact surface area closer to stock.

 

I may need one of these..

 

Just let me know.

 

Sounds like someone was doing their homework on these pullies!

 

I'm a nerd, I like data!

 

Rob the man getting me the hookup on the throttle body. I better see some more acceleration!

Speaking of acceleration, an A5 driver appeared stunned to see me sitting on their rear bumper when they made the big move on the freeway here in Dallas...and tried to get away, but didn't...

 

The Gates rep was just in my office and yes, the racing blue is now the RPM series.

 

Is there a 5-rib belt in the right lengths?

 

not at the moment. Just a 6 and an 8. But I was successful in cutting a single rib off of the 6 rib.

 

Part number?

 

And what length?

 

Stock belt length is 69.5?currently running 2.7" pulley

 

In stock length only, not the 1" shorter belt.

K050705RPM is the part # for the standard 70.5 belt

Stock is 70.5, 69.5 is the shorter belt which is exactly like using the stock belt with a 2.5 pulley.

 

Are you running the injectors that came with the SC? I'm so rich with the 2.825 that I think the 2.7 should work w/o the 7th injector.

 

@Roostfactor Wonder if a larger overdrive pulley helps with belt slip? I hear you with it being intermittent though. I noticed my continental belt slip a little when first installed but stopped after a couple days of repeated WOT Like to see a picture up close of these gates rpm belts. A blue SC belt would be pretty cool though