So I got the new pulley and belt but I did notice a few cracks in the belt on the supercharger side (I believe called the jackshaft side). I did order a couple of new belts for that side as well. Just wondering if there was a way to get to the tensioner from the underside of the car or does the supercharger have to come out in order to replace that belt? Any suggestions are greatly appreciated. Thanks

The easiest way to get to the tensioner is from underneath the car

Aaron, have you had a chance to mock up a front bash bar?

I have not. The fast intentions bar fits up perfect though.

So I got the 9lb pulley on with the roller back in the right spot, replaced the OEM tensioner and installed the new belts. No evidence of anymore belt slippage but still only getting about 10 psi of boost. Did a boost leak test and found a few loose clamps that were losing a little air. Tightened all of those. The only other leak I found was at the Mass air flow sensor. Extremely slight leak due to a stripped bolt. Will have that taken care of once I get it back to RT Tuning. At this point I'm wondering if it needs a new tune due to the pulley change. Any advice always appreciated.

I would for sure get a retune with a pulley change, you'll be making more boost earlier in the rpm range and also more boost overall, throwing everything off. Fix all the air leaks before really concerning yourself with boost numbers. Also, try a pull with that prefilter off just out of curiosity, I've heard those can be hit or miss. For reference I make 15psi with that tiny k&n motorcycle filter.

DrBacon - You make 15 psi with the K&N installed? That's seems really impressive. What are your mods?

Proper belts and belt tension. Unlike a turbo a supercharger is literally mechanically connected to the engine, it will always try spinning at a certain rpm relative to engine rpm, thus moving a constant amount of CFM. The belts are the weakest point in the chain and usually the limiting factor.

The K&N filter is restrictive, but not in the sense that people realize. That filter when clean is capable of flowing enough air to support 15+ish psi of boost but it takes more work for the engine to suck the air through it creating a greater parasitic loss on the engine. When there's more drag it usually ends up in belt slip and thus lower boost, if you can properly tension and use the right belts that slip is reduced/eliminated. This is why you see people gain boost going from a filter to a turboguard, it's not because the filter isn't capable of flowing the air but rather because the drag is reduced so the belts are no longer slipping.

You can have a filtered car and a turboguard car with the exact same setup make the same boost, but guess what? The turboguard car will always make more power since it isn't working as hard to pump the air. Boost numbers don't mean everything.

Thank you for the explanation

This is true to an extent. SOHO and I believe even the Ace kit was offered with a turboguard not because of belt slip. They were offered because more airflow equals more power. A good example is the attached dyno sheet. While my car was on the dyno, I had one run done with a turboguard and one with the NGR screen which has smaller mesh than the turboguard. You can see that with the NGR screen it lost almost 1.5psi and a little over 30 whp. There was no belt slip. It was due to air restriction.

But, parasitic loss definitely plays a part too, that's why superchargers can actually be harder on a motor than turbochargers. The motor has to work harder especially when you start getting into the higher boost levels

I didn't go into much detail but that was effectively my point when I said a clean k&n filter is capable of flowing enough air to support 15psi given all belt slip is eliminated. Clearly that mesh screen you used couldn't flow enough air to support the desired boost. As the k&n filter becomes dirty and airflow is restricted one of two things will happen, the belts will either begin to slip as the drag on them is increased or you will simply lose boost. It seems around the 6 month mark with fairly often driving is when the filter needs to be replaced or cleaned to prevent that.

I have a turboguard on the car at the moment but I've never checked what peak boost it's making, I would assume it's still probably about the same.

You could be right about the k&n being capable of supporting 15 psi. My car made close to 11 psi with it and the 9lb pulley. Once I started experimenting with pulleys I went to the turboguard. One of the reasons I went with the turboguard instead of the filter is how much of a pain in the azz it was to change the filter. I probably should have done a filter vs turboguard test when my car was on the dyno.

I've dealt with the stupid k&n filter for a couple years now and I've had enough which is why I'm running the turboguard at the moment. I finally managed to find a fabricator (after several well known/famous shops said it would be too difficult lol) willing to make me an intake so the car goes in on Friday to get that done.

Post up some pics when you get it finished. Even though I'm going tt, I'd like to see what you come up with

Can someone please correct me if I'm wrong. From some research that I was doing and to the best of my understanding is that a larger pulley will reduce boost psi and a smaller pulley will increase boost psi. So if this is true the 10lb (2.75) pulley would produce more boost psi than the 9lb (2.85). Correct?