mkvamso

iTrader: (2)

I've got an 05 gto with a Maggie mp 122 running 7 psi. It believe it still has stock .83 rear pulleys and a 2.8 front.
I'm running the hd tensioner with a cheap dayco belt and I think it's slipping a little at high rpm.
I checked the torque on the tensioner today and it doesn't break away until 40 lb ft.

I'm wanting to pulley it down a bit but I'm worried that if I do it will definitely slip.
Any advice on how to spin this thing a little higher?

I don't want to take the blower off to overdrive the rear, and I don't really want to buy an 8 rib setup just to see a lb or 2 more boost.

I'm wondering with a better belt and/or tensioner can I run a 2.6 snout pulley or a overdrive crank pulley

soundengineer

iTrader: (16)

if you want to go to a smaller pulley on the supercharger, you will need an 8 rib....
if its already slipping, it will slip more with a smaller pulley on it

theres really not an overdrive crank pulley...you would have to get a custom set of 3 pulleys to add onto the front of your Crank and supercharger, and a custom tensioner as well...
and then basically run 2 belt systems...one system for the stock accessories(basically keeping stock belt routing and tensioner)
and a second one for the special crank/maggie snout/maggie tensioner...

mkvamso

iTrader: (2)

Innovators west makes an 8 inch crank pulley, just not sure if it will help with belt wrap or not

c6matt

iTrader: (1)

...Innovators west balancer is what you need...but it's cheaper to just swap the rear pullies and OD it...and it's free...or just labor...

mkvamso

iTrader: (2)

I don't have a press, and I don't trust any shop around here to do it.
I'm not looking to spin it that fast
Just trying to get 9-10 psi without spending too much more money

mkvamso

iTrader: (2)

after looking for an 8 inch crank pulley for a few days I called asp to see if they make one. I'm sure the ati and iw pulleys are nice but after shipping it would be around 600. Asp said they don't carry them normally but they could make a custom one, ended up being quite a bit less than the other two.
It has to be custom made so turn around isn't that quick but for the price I can't complain

kyoytey1693

iTrader: (7)

If you troll some of the gto forums you can find an IW pulley for cheaper. That's where I got mine. Ebay has some from time to time.

My car makes 11.4lbs of boost on a 2.6 front pulley, stock rears. I am running a Katech manual tensioner and I have it cranked down a little harder than recommended. I hardly ever see belt slip.

There isn't anything available for purchase (that I'm aware of) to grant more belt wrap on the 112/122's.
I would drop the pulley size, get a better belt, get a better tensioner and see what happens.

mkvamso

iTrader: (2)

ended up buying an innovators west 8 inch pulley and a new tensioner.
Haven't noticed any belt slip since the new tensioner but it's been so shitty outside lately I really haven't driven it much.
I'm going to run the 2.8 that's on there and see what it does. If iats are good and there's no belt slip I'll pulley it down some more on the snout.
I've got a 122 but it still has the underdriven rears, with the 8/2.8 I'm shooting for 500+

kyoytey1693

iTrader: (7)

Good luck man! Be sure to let us know your results.

mkvamso

iTrader: (2)

Going to be a little while til it gets dynoed with the new parts.
Going to the track this Sunday to get a good baseline as it sits, motor is 100% stock with a 122 at 7lbs.
After that I'll put on the pulleys and exhaust and see what it picks up. Probably a better indication of power gain.
Supposed to have a dyno day setup for late March, will post some numbers up then

mkvamso

iTrader: (2)

Went to the track on Sunday. With a very small amount of weight reduction my best trap speed was 117 and change.
With the pulley and exhaust I'm hoping to trap 120+, would indicate around 500 wheel or more at its current weight

kyoytey1693

iTrader: (7)

Sounds impressive! Keep us posted.