[Longboarder]

What up guys.

So after replacing the standard 96mm pulley that comes in the 625 kit to a 92mm pulley and increasing my rev limit to 8,600 RPM, my car felt fantastic. But I didn't gain much peak power in doing so, even though boost increased from 5.0psi to 5.7psi. Peak RWHP increased from 567 (STD) to 573 (STD).

The 92mm pulley gave me the same ratio for boost as the pulley system in the 650 kit, but my boost is still low. Why? Who knows at this point.

Regardless, since I was already needing to run higher octane than what we get here out of the pump in Cali, I was justified in upgrading to the 650 "kit" from ESS...which in addition to the new pulley system, provides for more fuel (larger injectors) and a revised tune. The tune is the key here, as the increased injectors allow for more fuel on the top-end and gives ESS the ability to "fine tune" at the top of the rev range. It also give me more peace of mind given that we are at the limit of what the S65 is capable of in stock form and I don't want to even run lean on fuel.

So what happened? Well, I dyno'd at EAS again and peak power, on average, increased by about 20 as compared with the off-the-shelf 625 kit. So it does what it's marketed to do. The peak power (on my highest dyno runs) achieved on the 625 kit was 567 vs 583 with the 650 kit, however what was apparent was that the 650 kit on the dyno was much more stable and consistent. My dyno's with the 625 kit were subject to more volatility/wider range of discrepancy.

I'm not posting any dyno's in this thread - I will do that later once my new water/meth kit gets installed.

What I wanted to share is my "seat of the pants" impression because there is a significant difference in what I "feel". A la my subjective review.

Even before the car fully adapted to the new 650 tune, I felt a significant increase in "pull" above 7,000 RPM when I first took it for a spin. Not just a little...but a lot. With my prior set up, there was at times, a transition of acceleration at 7K, which I described to others as similar in feeling as what is felt on a sport bike which provides accleration boost at a particular transitory RPM (usually above 8K RPM)

Now, this acceleration transition is consistent and just violent. Perhaps I'm desensitized to how fast the car accelerates below 7K, but below 7K, the car now comparatively feels slow. I know it's not slow because the dyno graphs prove that I'm making just as much power as before (with the 625 kit, upgraded 92mm pulley and 8.6K RPM limit) below 7K. But at 7K, f*ck. I'm telling you the transition makes me loose my stomach every time.

We're entering the dog days of summer here in SoCal so no Airstrip events for a while. But I'm looking forward to the next one coming up in about 3 months to see what I can do with the new top end power.

Be back soon with dyno/technical info.

Cheerz.