Mines a 400,40" compared to your 39", not far off.

 

You simply need more tension. If you've got the CT kit use a pry bar on the pulley wheel.

I've used a 3.0" without any problems. Also change your belt if it's old.

 

i use 390s on my 3.0

 

Belt is brand new and the CT tensioner has been modified as above so has good tension .. Anymore and it will snap or break the blower i bet!

I think it's a case of the additional torque being produced now that is causing the slippage. The belt is also new so I think it's still stretching out.

ASP has the 8/10 rib pulleys on file plus the spacers required to make it work so I might go this route depending on what the shop decides to do with the setup.

 

Is your set up 6 rib?

 

It's stock so yeah I think so..

Oh and hello from New Zealand!

 

i've decided to get the 8-rib belt set up. Going to order the pulleys from ASP, had a lot of guidance from 99SH who's done this and the 10-rib (cheers man!). Going to take this opportunity got get an additional 1psi more boost too. I currently run a 6.5"/3.6" set up (will be for sale soon)

The parts i'm getting for this are:

- 6.6" crank pulley
- 3.5" blower pulley
- 7mm aluminium spacers x4
- Goodyear 4080400 (40') and 4080407 (40.7") belt
- Dayco 89016 idler pulley

I'm hoping this finally sorts it out!

 

What are the 4 spacers for? Going from 6.5 to 6.6 and 3.6 to 3.5 just seems to close to where you started out. If both pullies are larger you will get more traction.

I went from 3.2 and 6.0 inches to 4 and 7.5 inches for larger size and then added two more ribs.

[attachment=98547:IMG_0617.jpg]

 

Since you're running air to air you should get a much bigger crank and up the boost. Try a 7inch mate! Going up 0.1 of an inch seems silly.

 

The 4 spacers are for the additional offset generated by the two extra pulley ribs.

I want to go 6.6 so I'll still have easy access to my belt without taking pulleys off or interfering with the water pump.. I was also getting about 17.5psi with the existing setup and don't really want to go much higher.. I'm still running 10.7 JDM compression too!

7.5" is massive!! How heavy was that pulley and what problems did you have to overcome with the belt to get that to work??


EDIT: Now you've got me thinking about a 7.5/4.4 or 7.5/4.2 combo.. That would give me about 1-2psi extra and probably a lot better grip, especially with 8ribs.. What issues does a 7.5" crank pulley bring? Does it interfere with the water pump pulley or does it just make getting the belt on and off a pain??

Also i'm estimating a 43" belt is needed for this, is there a mathematical formula?