a stock Comptech w/ aftercooler should make 290-300 whp. Without the aftercooler it should still be at 280 whp. There is something wrong with those numbers...

 

Are you sure you don't have your numbers backwards? Without the A/C, the blower should be able to push out almost another psi of boost. Nevertheless, yes, I agree something is wrong with the OPs results. Like I said before, 5 psi seems too low with or without A/C. I think he needs to look for a leak in the plumbing or in the bypass valve or a slipping belt.
I've witnessed the following:
AP1 with Comptech kit BEFORE the introduction of the A/C was later modified with the A/C. The boost pressure was about 5.9 psi, so it's likely that it was pushing about another psi before the A/C went on. WHP was around 270. Comptech installed a smaller pulley to offset the lost boost due to the added volume of the A/C. Boost pressure went up to 6.9 psi and whp jumped to 290.

 

you are right, it should be more with the non-aftercooled one but the non-aftercooled one should start losing power after a couple of runs since it will get hot real easy. don't you think aftercooled one should produce more power at the end? that's why i wrote the numbers like that

 

I don't believe it would. The aftercooler has always been considered as "insurance" and not a performance enhancer, so long as the kit is kept at stock boost. Only when the owner begins to tinker with boost to bump the HP up dramatically does the A/C come into the equation.
Remember, Comptech was running these kits without aftercoolers for years and producing eye popping performance. They were designed to run non-aftercooled from the start. As many, many owners discovered, adding the aftercooler to an existing kit lowered HP because boost was lost. In the stock kit, boost is far more important than a "cool" intake charge when it came to making power.
Even though 6 to 7 psi can add another 70 to 100 whp to an AP1, that kind of air compression doesn't produce enough heat to adversely affect the safe running of our engines UNLESS something goes wrong with some part of the system and that's where the insurance part of the equation comes in.
Don't be fooled into thinking that just because one of our cars has an A/C, that it should be a "monster". Look at the overall picture. Would you be in awe of a car just because it's got HUGE rear tires and a loud exhaust?

 

Mugen and Comptech exhausts are completely worthless... that's why you didn't see any gains. The Mugen header makes some nice midrange gains but they typically are +/- 3 hp on the top end. I haven't seen dynos for the Comptech header.

That's exactly what I was talking about. You've been around for 5 years and you've tried the parts that have been out for forever. The reason people say "the S2000 is maxed out from the factory so mods don't do anything" is because the bolt on parts that have been made have been pretty worthless up until a year and a half ago.

My header is one of the top 2 or 3 horsepower producing headers out there, and my T1R 70mm single outlet exhaust is #1. AJ racing dynoed them together and got 218 rwhp untuned. There is plenty of power to be made in the S2000 from bolt ons, you just have to look past the stuff that's been around for years and look at the awesome parts available now.

 

The biggest benefit from the Mugen exhaust is weight saving. While the T1R 70mm might make more peak power, it is obnoxiously loud and could be embarrassing on a daily driver.

 

There is definitely something wrong with those numbers in the 250 hp range.......myself and a fellow s2k member just got done installing a comptech SC/w Aftercooler on a bone stock AP2....only addition was 4.57 gears(which won't change HP #'s).....nothing else and it put down 303 HP /193 tq @ the wheel on a very accurate Dynojet with the A/F ratio at 13.0 to 1 at 8200 rpm(fuel cut) and the correction factor at 1.01......we did tighten the belt before it went on the dyno as i noticed it had loosened slightly since driveing around for a few days after the install.....i suspect you have a loose belt 1st.....2nd possibly a boost leak....and 3rd why is your A/F ratio so rich at redline.....mabey becuase of a drop in boost....when in fact the management is expecting full boost and its not getting it......Comptech said the tune for a stock pully should be in the high 12 to 1 range and if it starts creaping up in the 13's to shut it down....ours ended up perfect...and the stock exhaust/cat seemed to work just fine...Good Luck!

 

dyno peak #s dont mean to much from dyno to dyno. Make sure your consistent with the one you go to.

Yes hot weather does affect #s. I dynoed bone stock in the low 190s. Bolt ons high 190s. With A SC and bolt on I was about 275 rwhp. I added test pipe and dynoed 279 but I was veyr lean 13s 14-s. I then richened her up and what is unbelivable is my power wnet up and I got 286 rwhp. Didnt know richening could gian you power..........All those dynos were done on a cool day 50-60 degrees,

Sat, I dynoed and this time 86 degrees outside and sunny day (very hot for Seatle) I was without a test pipe and I also leaned it out a little more. I had also driven on the freeway for about 40min to the dyno place. The dyno had a small fan and first pull was 261 rwhp..........second pull right after was 248 . I jsut said screw it. I can't belive how much heat can affect supercharges who run pretty hot already.

My AF was pretty good for the 1st run at 261, dippe dinto the 13s slightly then back to 12s and 11s. The 2nd run was pretty rich as it was probably 11-12s the whole time due to it being so hot.

Tonight I also riched her up just a little more as I dont want to see any 13s. Ran really strong when racing an AP2 tonight.

If I went back on a cool day I'd probably be at 275-280 so don't worry about it. Akso the brand new kits from Comptech run you at 5.5 PSI.

Also a Test pipe to me isnt worth it. Didnt gain me to much HP and leaned me out by one point.

 

...or you could stop spending thousands of dollars to gain 5whp and do one of the 2 things that will get you real HP in the S2000: Go FI or build/stroke your motor.

 

^ You don't get it do you? The J's header and T1R70mm (which cost 2000 together) add almost 20 hp to the wheels. Where did you get the 5 whp number? Oh, you made it up. I've never seen you in the JDM forums. If you keep up with the new bolt ons that are coming out you realize that there is a lot of potential to the car while N/A. If I dyno'd on a cool day I'd end up around 230 rwhp - 30 horses or so over stock.

...but I have a supercharger coming to me in the next week or two so now I'm shooting for 310