All fair questions. Before I bought this kit, I looked at a bunch of dyno graphs (of AP2's) and mistakenly assumed that a Novi 1200 @12 or 14 psi would make adequate torque down low on my AP1. If I'd known that wasn't the case, I would have gone Rotrex (KW or TTS) or GT3076R (Ptuning). I didn't, so now I'm just trying to make the best of my second multi-thousand-dollar FI investment in this car.

I like the feel of a turbo spooling, but I think I like even more the way the SC just makes the car instantly fast. The 3.6" pulley already makes the S2000 a rocket at high rpm; I just want a bit more down low. I also have tons of fun turning wrenches, changing stuff, and re-tuning to see what happens. So this is a fun way to mess with the car.

When I ordered the 3.2" pulley from SOS a couple weeks ago, I specifically asked them why the 3.2" was the smallest they offered for the AP1. They said that was the smallest pulley that worked on the Novi 1200 for the AP1 (9k redline) without belt slip, and it's nowhere close to over-spinning the blower. I have not done the math to confirm this, though I probably will one day out of curiosity. Meanwhile, all of the other pulleys have produced lower boost pressure on my car than I expected.

- The 3.8" was rated at 14psi, but made 12 on my car.
- The 3.6" was rated at 15.5psi, but made 14.4 on my car. It made 14 on another AP1 that had full exhaust mods.
- The 3.2" is rated at 18.5psi. I'm guessing I'll see 17 - 17.5.

So, I'm only going to blow off 3-4 pounds of boost, and only at high rpm. I very rarely spin the motor anywhere close to redline, so 99.999% of the time I won't use the BLV. But I'll have more low end & midrange, which I'll use and enjoy every day. And if this isn't enough, I'll pester 928 Motorsports about getting their upgraded impeller working for the Novi 1200.

 

lower boost- have you done a valve adjustment lately?

 

Yes, just a couple months ago before I installed the SOS kit. The clacking noise at idle was driving me nuts!

 

Interesting. So you are running a 3.2 inch pulley now. I would be deeply concerned with belt slip. I haven't had any issue with it out of my Paxton Novi 1000, but the Jackson Racing M45 4-rib supercharger on the Mazda Miata, belt slippage became an absolute nightmare. This scared me out of superchargers for a long time, but I learned my lesson. If it has anything to do with Moss (Jewry) Motors, just walk away cause everything they touch turns to unreliable crap.

So let me ask you this? Generally speaking, how does the Novi 1000 compare to the Novi 1200? I thought they were similarly the same, just one was an updated design...

 

1200 moves quite a bit more air I believe. 1000 is the older comptech kits if I'm not mistaken. Makes the least power from all the centri blower kits.
1200 is a big upgrade from the 1000.
I am also planning to up my boost to probably 15 psi or so. Hoping for no belt slip. So far none at 12.

 

you had issues with your M45? Thats strange becuase I never had any issues with My M45 SC'ed B20 and I ran a 2.8" pulley...was the blower bracket shimmed correctly?
I gave up on it due to it maxing out at 200whp.

Novi1000 and 1200 are night and day different.

Novi1000= 800-850 CFM's and the 1200= 1150 cfm's. The 1000 will maybe get you in the 400 whp and the 1200 in the 500-500 whp. I know im at 520whp.

TO- try a 3.0 Richard Pulley...my 1200 slips all the time with the 3.0 SOS pulley but I think its due to me being out of adjustment for my tenisoner.

 

Dyno results are in! But they require a bit of explaining.

1. We again ran out of time on the dyno and did not dial in the BLV. The 3.2" pulley made ~15.5psi. As far as I can tell, the BLV did not blow off even though I had loosened it a full turn before we put it on the dyno. Still too tight... Yes, 15.5psi is way high for the street, so I will probably go back for another touch-up tune to cap it at 14.

2. The low rpm and midrange difference is very evident (and a lot of fun!) on the street. Anybody with a Novi 1200 should go buy a 3.2" pulley NOW. You won't regret it! We also lowered VTEC to 4,500rpm (was at 5,000 rpm previously) and it feels great when it kicks in.

3. At 14.4psi I made 340whp. At 15.5psi I made 377whp. Not a bad gain. Then we bolted on the CAI I had made, just to see what it would do. How does 421whp grab you? 44whp from a CAI? That's crazy, but it happened. I'll go into more detail in the CAI thread so we can all debate WTF happened, but I wanted to give a basic explanation of the numbers here.

SOS kit CAI thread

Dyno results:



Torque & boost curve, so you can see there was no belt slip and the BLV still didn't open:


Anyway, sorry for posting all the pics of my BLV and so many dyno charts without providing any actual dyno results of how the BLV works! I don't mean to be such a tease.

 

That sucks about the boost valve, but way to go with that CAI

 

Keep in mind that since your power curve drops off at the top end of the trq curve from bleeding boost, you wont have a tendency to get as much belt slip. Belt slip is caused from the acceleration of the motor in its peak power, the belt cant keep up with the acceleration demands, if you reduce the boost/power your belt wont get the "shock" it would normally if you were to let that 18psi fly, yes your still spinning the blower at the same speed regardless of bleed off, but blower speed isn’t what’s causing the slippage, right. Not sure if that makes sense. All I’m getting at is don’t let SOS dictate what pulley to run because of traction issues, they aren’t considering what your doing, they havent any experience with what you are doing. Run the smallest pulley and bleed off where you start to notice belt slip if you want the fattest power curve you can get. If you bleed off right before you deem what rpm you begin to slip on th edyno, set the blow off right before that and you should make that boost all the way to redline with no slip. If you can make 14psi at 6500rpm, that would be pretty fat.

 

damn you guys have me thinking twice about my previous opinions on ever getting another centrifical s/c after the vortech i had on my 00 civic si . i recently sold my turbo kit b/c of turbo failure and didnt want to spend anymore money at the time. the BLV is besically a wastgate????? what kind of boost are you guys seeing at 3500 and 5000 rpms with a max psi of 15 give or take??