to address the low end debate, why not add gears to help? i'm already 4.77s which will be over kill after my SOS kit gets installed, but some 4.44s would be a nice addition to a SC. its just an idea though.

 

I 2nd that. I plan to do 4.44s or 4.57s with a reinforced diff, probably after I replace my clutch. 4.77 for a supercharged car is too much IMO.

 

With your goals in mind (stock clutch, no stand alone,stock fuel pump,stock injectors etc) I would go with the base line sos kit. I would also just leave the kit like it is with the 1220 blower, its a great blower and will meet your power goals (and some). As far as the low end, there isnt gonna be a huge noticeable gain, but it will be some gain. The best way i can discribe it is......stock power band on steriods lol. If you want to keep the baseline kit, like jack in the box said, gears would give you that low to mid range push with the charger (I also agree 4.44s would be my choice). With that said, your car will NOT be a slug with the baseline sos kit and stock diff.

As far as install, if you have some car guys (s2k guys or just guys that can wrench on cars) i would offer them some beer and food to help ya with the install (spend the install money on 4.44s ) . It is a really fun install imo, and will teach ya alot about the kit. The instructions were one of the many things that pushed me in the direction of the sos kit. They tell you where every nut, washer, bolt, line etc goes, hands down the BEST instrucions i have seen for any kit(pictures for every step). The guys at SoS will also answer any questions you have and service is second to none!

I have a SoS stage 2 and i love it! It is a blast to drive, hope some of this helps. If you were local i would gladly help with the install and give you a ride in my car.

Keep us posted on what you go with!

 

Yea, the SOS was a pleasure to install for the most part. VERY good instructions. Making the fuel pump fun is impossible, though...it's only 2 hours though (easier if you remove the seat and sit on the console).

I took 22 relaxing hours to do it. That's lots of water breaks and lots of me spinning the blower with my hand going "wwwsssshhhh"

On their FVM and VTEC...I'd say your argument is yes and no.

If you FLOOR it, the VTEC transition is around 4700 and it wakes up at that point (though it is a smooth transition). If it's partial throttle, it still seems to be 6K, so in that situation it is a slug (relatively) and then wakes up at 6K. Below 3K, there's SOME improvement, sure, but it's still slow...you'll be disappointed if you think the low end character is going to change dramatically.

Overall, I'm very satisfied with the SOS kit, and I still haven't worked out all of my problems. My AFR spikes up after 7K (but only a little). SOS has been very helpful. Still, while I'm limited right now to 7000RPM or so, it still makes 240hp on a Mustang dyno (4psi, +50 from stock).

I'd also recommend getting a fuel pressure gauge (a cheap one to check that the pump is working right) and a wideband O2 sensor/gauge package. Otherwise, they will be verifying AFRs using an O2 sensor on the tailpipe, which is NOT an optimal solution at all as it is less accurate.

 

LOL, i lost it at spinning the blower with my hand going "wwwsssshhhh"

 

, nice cover up

 

Excellent points, all. It depends a lot on how you drive, and what you want. I'm stuck putting around in Atlanta traffic and rarely get the chance to turn the car loose, so the low end matters a lot to me. Plus all my previous cars were V8's (LT1 for 8 years before the S) and I had the Greddy turbo kit for a while too. So I came into S2000 ownership thinking the missing low end was something that needed to be fixed, and the Greddy kit really fixed it. At any rpm, stomp the gas and the turbo just hurls the car forward, sucking you back into the seat. (Then it runs out of breath in VTEC, leaving you wanting more. That's why I got rid of it.)

So... My priorities are very specific, and my opinion is just one data point. I'm just saying that compared to other cars, and compared to other kits, any low-end or midrange improvement the base SOS kit delivers is miniscule by comparison. But if you've already driven one and liked it, then you already know it'll satisfy you. That's the best advice any of us can give you - go drive or ride in several boosted S2000's to make sure you know what you are, and are not, getting. Riding in a KW AP2 was a real eye opener for me, but I already had the SOS kit installed.

My car has been boosted for maybe 13 months now. Greddy for most of that; SOS for the last few months. I couldn't possibly imagine going back to NA now; I'm addicted. I'm running the Greddy E-manage Ultimate so that I can pass Atlanta OBDII emissions, and it works great. Hondata is a better OBDII-compliant choice than the EMU from a tuning standpoint, but I just kept the EMU from the turbo kit to save cash.

 

D00d - love this My wife is currently debating COLORS for the "custom finish" so that she's invested in the process and feels that she's partially spending the cash!

Gotcha. It is a bit different than I was expecting, but still better than a 6k power on with a 9k power off that comes up a lot quicker than I'm used to.

Here's my many weaknesses showing - AFR= - okay got it - Air Fuel Ratio. Without the AFR sensor, 1) how would you tell and 2) what would the impact be on performance? Are you not making it to 9k due to this issue, or just not getting a good dyno?

For a fuel pressure gauge - that connects to the separate fuel pump for the SC, aye? Since the FP goes under the top, where would I have to route it to look at it for troubleshooting? Ditto for the gauges for the 02 sensor.

Did some initial reading - what do you tap into for the 02 sensor? --- Okay, I think I got it again. The 02 sensor installs (optimally) in an opening after the cat in the exhaust system. That'd require tapping the exhaust system. Alternatively, zip tie it some place such that then sensor can sample the exhaust from the system - ideas on the s2k?

 

No problem, I've been learning as I go, too. I think I was where you are now last week, in fact!

Yes, AFR is Air-Fuel ratio. The SOS SC should run at a relatively low numerical ratio up in the high range (low number = richer, aka more fuel in the mix). Details are in the directions, but the AFR starts out at a high (leaner) ratio, and is supposed to decrease as RPMs climb.

I highly recommend a wideband O2 sensor and gauge (on a stock car this would be a THIRD O2 sensor directly connected to the gauge) mounted via a hole drilled into the manifold (or test pipe if you use one)...BEFORE THE CAT. The AEM one (on SOS web site, but available in many places) seems to be the favorite. Yes, extra gauges are a little "Fast and Furious" but this one's necessary (though maybe not full-time, though I think it should be).

http://www.amazon.com/gp/product/B000CFQM4G

Without that, when you get it dyno tuned, the only thing they can really do to measure AFR is to clamp an O2 sensor on your tailpipe. This is not optimal for at least 2 reasons...lower temperature (O2 sensors read different when cooler), and the air-fuel mix has inevitably changed by the point it reaches the tailpipe. Using this method, my AFR was going over 12:1 (it should be ~11.5:1 or so after 7000RPM). At this point, given the high reading, I decided that I don't want to push the car over 7000RPM until I figure out the issue...or if there even is one. The car will QUITE willingly rev higher than that, though.

I have the AEM wideband O2 sensor and gauge on the way. I will be able to better troubleshoot to see if I have any problems with that. A 12.5:1 at the tailpipe could be a perfect 11.5:1 at the manifold...but there's no way to be sure unless you read at the manifold.

As for the fuel pressure gauge, there's a FAQ in this Forced Induction forum, with a link on a fuel pressure gauge. I got this very same gauge. I don't think this is optimal, but this will be a temporary mounting and will take it off when I verify fuel pressures (there's some concerns the hood could break the gauge, possibly causing a leak...VERY BAD). The forum and guage are linked here:

https://www.s2ki.com/s2000/topic/204...-supercharger/

http://www.amazon.com/gp/product/B000CIKCG2

The fuel pump itself is a drop-in replacement for the stock unit. Hard to reach, but straightforward to put in as it fits in the stock location. No additional modifications needed. Really, for all the whining people do about the fuel pump, I found that the difficulty was overrated. I'd rate it at a 4/10 difficulty. The whole kit was 6/10, maybe 7/10 (10/10 would be rebuilding a transmission).

As to the results in the ~5000 RPM range, I'll give you my results at ~5252RPM, the speed where lb-ft and HP are the same numerically (so if I say 100 that means both HP and Torque). At ~5252 RPM, my car stock read ~107. Untuned, with the Stage 1, it is ~142. My gallery has pics of both charts, and pics of the finished install. The SC dyno is stopping at ~7000RPM, so don't take it as final...it's still a work in progress! At 4000 RPM, it's ~76HP stock vs ~95HP with the supercharger...not a big gain there (torque gains are numerically larger at <5252RPM). It REALLY wakes up when you hit 6000RPM...at that point it is at the power peak of a stock S2000. This is a Mustang dyno, so it will read a bit lower than the typical Dynojets you see posted here. Just so you know what to expect, this will NOT give the car V6 midrange...it will be like getting a displacement increase to approximately 2.6L, though. Up high, you're making LS1 V8 power, though.

The AP1 dyno on the SOS site seems pretty accurate...I'm tracking right with it (a little better actually, on a dyno that reads lower).

Personally, I feel little difference from the driver's seat ( much better, but not dramatic). Passengers swear it pulls hard (and judging by the dyno they are not BS-ing). What I DO notice is how quick it goes through the gears and how fast other cars get left behind

 

Steven, when you say the whole kit is was 6/10, do you mean the supercharger kit? I have heard that fuel pump is a PITA as well as the crank pulley removal, any tips or advice you can give to us?

Thanks!