The reason I ask about your fueling setup is because I personally had an issue where a 340 LPH pump was overrunning my stock FPR and causing my base fuel pressure at the rail to be 63+ PSI. My tuner didn't know this the first time I tried to get the car tune and he had a hell of a time because it seemed like he was running out of injector up top. So he just played it really conservative and thus I ended up with really low numbers on my first go. After I installed a fuel pressure gauge on the rail I realized I had an issue. Ordered an AEM FPR to dial back the base fuel pressure to the standard 43-45 PSI and all was well after that. Car acted right up top, plenty of injector duty cycle left, able to go more aggressive on the timing, and ended up with 393 WHP at 16 PSI on a Novi 1220 (which flows less than your Novi 1200).

Now, my issue was because I was using a 320 LPH pump with the stock regulator. Your 255 LPH pump might not have the same issue since it flows less and the stock FPR can likely keep up with that flow without the base pressure rising. Only way to be 100% sure is to get a fuel pressure gauge at the rail. Not saying that its necessary or that its what's causing the problem. Just something to think about.
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Thanks for the info, anything is helpful! I've never heard of a 255 having that issue and my tuner didn't mention the duty cycle or anything but I'll look into it.
Still super confused why im not making more power lol. Thinking of every possibility.
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Junky pointed out your missing boost. I'd chase that down first. I'm still not sold 220 readings are good. Mine always belted out over 260ish when I tested it.

 

The reason I ask about your fueling setup is because I personally had an issue where a 340 LPH pump was overrunning my stock FPR and causing my base fuel pressure at the rail to be 63+ PSI. My tuner didn't know this the first time I tried to get the car tune and he had a hell of a time because it seemed like he was running out of injector up top. So he just played it really conservative and thus I ended up with really low numbers on my first go. After I installed a fuel pressure gauge on the rail I realized I had an issue. Ordered an AEM FPR to dial back the base fuel pressure to the standard 43-45 PSI and all was well after that. Car acted right up top, plenty of injector duty cycle left, able to go more aggressive on the timing, and ended up with 393 WHP at 16 PSI on a Novi 1220 (which flows less than your Novi 1200).

Now, my issue was because I was using a 320 LPH pump with the stock regulator. Your 255 LPH pump might not have the same issue since it flows less and the stock FPR can likely keep up with that flow without the base pressure rising. Only way to be 100% sure is to get a fuel pressure gauge at the rail. Not saying that its necessary or that its what's causing the problem. Just something to think about.
[/quote]

Thanks for the info, anything is helpful! I've never heard of a 255 having that issue and my tuner didn't mention the duty cycle or anything but I'll look into it.
Still super confused why im not making more power lol. Thinking of every possibility.
[/quote]

Junky pointed out your missing boost. I'd chase that down first. I'm still not sold 220 readings are good. Mine always belted out over 260ish when I tested it.
[/quote]

Apparently, my boost gauge showed 14 at redline. My girlfriend was looking as I was going WOT on the highway. Still trying to figure it out though. Haven't ruled out anything for sure yet. And thats very high compression, most people seem to get near what mine was at, around 220.

 

May be helpful if you could post the dyno graph.

Or just call me curious.

 

#3 valve and guide were bad leak down you could hear hssss and not any from the others. #3 was 195lbs, others were 215-ish lbs
Autowave did the work pulling apart. New supertech dual springs and keepers, one new valve, new guides, grind all the seats
re assemble. install a Exhaust cam key -2˚ (Sideways) new 3.8" SC pulley, re dyno at 382whp

GL

 

So update: decided to pull the spark plugs out to do one last compression test and maybe regap the plugs and this is what they look like:



They are really black on the thread. Its been just under 2 weeks and I bought them brand new. Stock gap. Is that normal for being boosted?

Also, new compression numbers are different than when I did it before adding on the supercharger. Only like 3 months or so back, it was 220-230 across the board. Now its 210, 180, 210, 210. What could've made it change so much? Idk why cylinder 2 is so low compared to the rest when they were all good before. Going to do a leak down soon. Any input? Thanks.

 

Are you using the same gauge? I recently did a series of compression tests and in short, observed a huge variance between 3 different gauges. One gauge was reading in the 150/160 range. I determined it was the gauge as I performed a compression test on another s2000 and observed the same results using this gauge. Another gauge yielded readings in the 260 range and one was even lower at 130 (I'm assuming there was some sort of leak). Make sure you're using the same gauge.

 

Yes, I've compression tested my car about 5 times now and all of it has been done by borrowing autozone's tool and it's all been the same brand, OEM. Compressions always been around 225 for all 4, except now for an unknown reason.