Rick's not happy with just putting the SC on like it comes out of the box. He just HAD to change the pully from the 5" in the kit to a 4", which of course yields more boost. [edit] This install also has the A/A intercooler. [/edit]

This is not a bad idea since the '04 has a lower redline and won't develop as much boost as the earlier years. But being the cautious guy he is, he wanted to get it dyno'd ASAP to make sure it wasn't running too lean. He had Balanced Performance install an exhaust bung so he could get the A/F readings.

Good thing, because once in VTEC the A/F jumped up to over 13:1, even hit 13.5:1 some of the time. Below VTEC it was great, but above 6k rpm it instantly went lean. I think he was running about 296 RWHP at a guess-timated boost of about 7psi (judging from the MAP voltage). At this point the injectors were hitting 72% duty cycle.

After some "modifry" work we were able to get the A/F into "happy land" and at the same time saw RWHP go to 310. Not too bad for an afternoon's work and half a dozen dyno runs.

I'll be making the "A/F tweek" permanent this week so he'll feel comfortable using VTEC all he wants. Here's the "before & after" plots (stock vs SC).




And here's the final run with the A/F tweek. We were doing this manually, so I missed hitting it right at VTEC. You can see where the A/F starts to rise but is quickly brought back into range once I hit the switch. Adding the extra fuel caused the injector duty cycle to run up to just over 80%, but that's not a problem.



BTW Rick - I'm 99% sure the issue with the AC is the wrong wire. I verified in the manual that the ACC wire is for the compressor, and it's a red wire, the color I remember they tapped into. There is no red +12v wire on the ECM, they should have used a black/yellow.

Which means it's no problem driving the car, just don't use the AC.

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Wow! I'm jealous. Nice job guys. Can us future FI Atlantans use your assistance in the upgrade Modifry? So Does this mean you both are coming to the Dragon?

 

Bob and Bob,
Thanks for EVERYTHING!
( I sure am glad you didn't use the tranquilizer gun on me I hear the headache afterwords is a B!otch.)

Still up in the air for the dragon.

 

WOW! 310 rwhp! Congrats!

Rick, you have any other mods besides the Comptech?

Modifry - What are you using to adjust the A/F ratio? V-AFC?

I was aiming for the 295 rwhp Comptech claims. I planned on using the 6lb. pulley when I install supercharger. I might go ahead and just order the smaller pulley if your not having any problems with it.

Can you tell me where you ordered your smaller pulley from?

Thanks

 

congrats man! 310hp at the wheels

 

[QUOTE]Originally posted by OyATL
WOW!

 

Are you using a variable resistor on the IAT line?

 

Not exactly.

Here is what we did during the dyno runs.
This method does not cut the IAT wire, which I preferred when testing on somebody elses car. The object was to pull the IAT voltage closer to 5v by using the resistor connected to +12v. During the dyno runs IAT was about 1.9 volts, to get the A/F ratio down to 12:1 we had to force it to 4.5 volts. I was manually activating the switch which is why the A/F chart shows the lean bump where I hit it slightly after VTEC.

For a more permanent hack, I would do this:

In Rick's case his lean condition was only during VTEC, and was very flat, so the simple fix is to connect a relay to the ECM VTEC output and use it to insert a resistor in line with the IAT sensor to cause the IAT voltage to go up to 4.5 volts. I don't know how big this resistor needs to be because I've not done it yet.

This is not a perfect fix. During cold weather the A/F will rise a little because the air will be denser, but I don't know how much it will change. Modifying the MAP signal would be a better all-around approach but with the SC the MAP is already clamped at maximim and we can't go any higher without risking a CEL.

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What did he just say?

 

He's tricking the computer into thinking the intake air temp is colder than it actually is. The computer then adds more fuel. Jackson Racing uses something very similar on there SC kits for Civic's and Integra's.