You're right, I was (but not now, I hope) confused :o So, on the supercharger side you have a jackshaft pulley, an idler pulley and the supercharger pulley. Correct? Thanks for the Gates info.

Yes, you got it. I considered doing what Topgunz did and change the SC a little smaller and then up the idler pulley in size but I stuck my hand down in there and there is only the width of my pinky finger between the current idler and something else...I am a little nervous of the larger idler rubbing against something. I need to take a closer liike.

Since I already have the 2.87 supercharger pulley I went ahead and ordered the larger idler pulley that tbatt showed. Since my sc isn't installed yet I don't know if I'll have the same clearance problem you have. I'll know in the next couple of days. Hopefully I'll make the power numbers I want with the a2a kit and e85 where I won't need to upgrade the pulleys. I'll find out on Tuesday when it goes in for tune.

Hey, I'm sorry to bring this back and for missing this info earlier, but if I drop down to the smaller 9lb serp-side pulley, do I need get a larger idler pulley than the one that came with your kit? I'm having boost issues and everything trends correctly until top end, where I think I'm getting belt slip, but I can't hear it. I had no belt slip and expected boost with the 8lb pulley, but I'm now losing boost top end after switching to the 9lb pulley. I didn't change anything else other than replacing the serp-side pulley with the smaller one. Is this where I messed up? Thanks!

9lb pulley on stock system .. belt slip?
 

I have a stillen sc with stock 8lb pulley no other upgrades. I want to upgrade to a2a and add 9lb pulley . Can I just take up the slack with the tensioner as stated on z1 and concept Z website or will it have slip?

Has anyone done this and have some input of this ? Thanks.

Who installed it? Very first thing you should do is go make sure the key is in there. I can totally see it having enough friction to grab until a certain point then without a key it lets go and free spins the pulley.

With the T batt mod there should be zero slip. I have sold many SC kits that does not include that mod and they do not have slip. They use my personal anti-slip pulley mod but it is no where near as aggressive as the one you have.

Most of the slack will be taken up from the auto tensioner. You may experience a little slip but not much. If you upgrade to the Si trim impeller you will have a higher chance of slip due to the fact that it creates more drag on the supercharger which ties all the way back to the serp belt.

I can get you my kit with my anti-slip pulley I send with my full supercharger kits as pictured below.

http://www.the370z.com/members/topgu...6-grip-mod.png

Thanks Topz ,
Not planning to do the Si upgrade. But I do like that anti slip setup , not sure why stillen didn't have that in the first place lol.

I know this is an old thread being revived but I’m in the market for some pulley upgrades. I also am confused on the pulley sides. Maybe someone can point me in the right direction. Currently running the V-3 SCi with TopGunz A2A Kit.

I plan on doing the 928 SuperVortech upgrade. Right now only have the Stillen 9lb pulley that only gives me 8.76psi at 7300rpm. I replaced it as advised by Stillen back when I was on Stillen Kit before TopGunz made his kit available. (Refer to attached pic). Apparently the pulley that was there before was color Blue and I was told by Stillen at the time that the Blue pulley was their 8pb pulley that came with the kit (which only gave me 6/7psi). Reading this thread got me
confused as to whether this was the right pulley i replaced as recommended by Stillen back in 2015

What pulleys would any of u gents recommend with the 928 SuperVortech upgrade and what kind of boost increase would each or any of the pulleys u all recommend actually deliver. 928 is advertising their upgrade to be capable of 72k RPMs and running at 60k + RPMs all day.

My car with the 928 super vortech, 9lb pulley, 3.47 jackshaft pulley sc side and 3.00 sc pulley made 16.4 psi.

With the 928 impeller and the 9lb pulley I bet you see closer to 11 psi. Also, if I remember correctly, the 9lb pulley is a 2.87. You can measure your's to verify what you have.

Maybe should mention what else you modded to fit the 3.47" and 3.0" pulley on the SC belt side. IIRC you needed pulley spacers of a certain size and needed to change the idler pulley on the SC side as well? To make this combination work or no?

And that you have a turbo guard instead of the K&N air filter to be able to make the 16.4 psi, since I'm not sure if everyone is running with a turbo guard or not.

The spacers you can get from 928 for less than $30.00. Those have nothing to do with boost levels as he was asking about.

My car made over 10 psi with the Si sc, 9lb pulley and stock filter. That's why I believe he will make over that with the 928 upgrade.

But yes, when I went to the 3.47/3.00 combo I went to the turbo guard.

My car also made 12.86 psi with the stock Si sc, 9lb pulley, stock 3.2 jackshaft pulley, upgraded 2.85 sc pulley and stock filter.

For 62k+, you will be dealing with belt tension and slip when putting the K$N filter on. :D

Go to the Vortech website and buy their "high traction" pulleys. I did that for my two SC-side pulleys. I went 3.15-3.00" with the larger tensioner pulley

What’s recommended if you already have a Stillen high boost pulley?