The Power Curve

Dyno Session 1: This dyno run was done at none other than KD Rotary's shop. I was there with some of the guys from my club, who had mostly PFS upgrades. Click here to visit my friend's site that has information on their runs. (And a picture of mine on the dyno.) As you can see my results were great especially for a car with 100K miles (50K on motor). Even Dave said that he was impressed. WOW, that means a lot coming from him! Anyway there are a few things that are interesting to note about this graph. First is that it is corrected for atmospheric pressure (sea level) and air temp. I actually had more power (299 hp) than shown. Another interesting thing is that my power dropped off at the end. Dave said this was due to the restrictions of my stock main cat. I think it could also be heat soak. I deleted my second run for clarity sake but as you can see from the numbers at the top left it was lower. Not only was there no air moving to cool my intercooler but the intake air was also probably being sucked from the engine through the hot intercooler. Lastly is that there is no transition dip in power right before the second turbo came on. This is because I removed the pill in the turbo pre-control hose, which is near the hose for the wastegate. If you want to remove this pill too I warn you that although it merely tweaks the system it can cause the second turbo to over spool in higher boost applications. It also reduces boost on the primary turbo. I am currently running at around 9 psi of boost on the first turbo and around 10.5 on the second. For more in-depth info about tweaking the sequential system check out Wade's web site.

Dyno Session 2: After completing nearly every power upgrade I had planned I decided it was time for another dyno session. I also decided that I would fork over the bones for a before/after dyno of my new high-flow cat. When I was researching buying one I couldn't find this information anywhere. Now my website offers others what I could not find. So here is how the story unfolded. After getting my primary injector seals replaced along with a silicone hose job I took my car to KD rotary once again. The first order of business was fixing the botched silicone hose job another shop performed. (My car was running pig rich after the job.) A few uncrossed hoses later and things were back to normal. They now require a compression test before a dyno run in order to prevent blown engines. My 85K motor produced just under 8s on both the front and rear rotors. This is great considering the miles. Even new engines only get around 8.5. (7s are ok, 6s are low, 5s are guaranteed blown engine time) So my car was strapped down and tested.

As you can see by run number 1 things didn't look good at all. Good enough to smoke just about any Honda but generally not good. The top end was choppy along with low power. Dave suggested plugs and wires and I agreed that bad plugs could cause such an erratic curve. 4 new plugs later and dyno run #2 was produced. As you can see plugs can have a huge impact on power, which is why I am conducting research on various plugs. Basically the plugs I had in my car were not only a little old but were also fouled to hell because of the rich running condition caused by the crossed vacuum hoses. (See how small mistakes can cause big trouble in this car?) Click here for a picture of the fouled plugs.

Next the high-flow main cat was installed and tested. Many people go with mid-pipes (straight pipe with no cat), which will cause a loss on the bottom end but big gains at the top. Personally I didn't want the pollution, the noise, the difficulty with emission testing, the smell and the low end power loss. As you can see I gained about 10 hp at the top end. Things are a little louder but not too bad.

A few notes on the graphs above. The first one is corrected while the second two are not. As the second two were taken on a mild 65-70 deg day the power would have probably been reduced by maybe as much as 10 hp if corrected. This brings my max down to 285 however these runs were also heat soaked runs meaning that my car was sitting on the dyno idling run after run. As noted in the first dyno this resulted in a loss of about 15hp so now we are up to 300 corrected hp. I'm therefore guessing I could see as much as 310-320 rwhp on the street on a cool day. This is equivalent to between 340 and 360 hp at the crank, which is what is the number that's generally quoted in advertising etc. Lastly when comparing the first graph vs. the second two note that the torque scale is different. This caused the torque curve to look very different between the first and second two when in fact they are very similar.

The second two graphs were produced on 10 psi of boost with the following mods. Cat back, high-flow main cat, down pipe, custom intake, intercooler, efini Y-pipe, Pettit ECU and various other minor tweaks.