more boost *update

[cdssolara]

I think that I'm going to try this mod before attempting to relocate the knock sensors. I recently got an OBDII scan tool that allows me to clear the codes, in addition to reading them. Once I cleared the codes, and then pushed the car until I got a CEL, I noticed that the only code I'm now getting is the knock sensor for bank 1. I had previously seen codes for both bank 1 and bank 2, but maybe the bank 2 code had been in the ECU for a long time, and had simply never been cleared. Anyway, I repeated the test by clearing the code again, and then trying to get another CEL. When it happened, the code again is only for a bank 1 knock sensor malfunction. From the manual that I have, it looks like bank 1 is the rear bank (closest to the firewall), so maybe now all I have to do is make this wiring fix.

Carlo, that's great news and in line with what we've discussed. I realy think this will help you (and others). My bet is you can't hear ANY knock either can you? By the way, what OBD-II scanner did you get?

By the way, great pics George and thanks for posting them Ron. -JoeB

Joe, no I don't hear any knocking, and neither did the guys at the performance shop when they did the dyno tune. The scan tool I got is from Car Codes, model ISO. It paid for itself after 2 scans, and it's great for clearing the codes. I'm sure there are other features that I haven't tried yet. Is this the model that you have? I think Ericsol uses it, as well.

[JoeB]

Carlo, I have that one too. I've had it for a while and it does a TON of stuff! Maybe more than you've seen so far. I talked to the guy that wrote it for an hour. I am pretty good with software and could get through the general stuff on this but found some of the more involved things to be difficult to figure out. I also bought the software for Digimoto. It has a very easy to use interface and I like the graphs. The cable from Car Codes works well with the Digimoto software. It would be really helpful (and I'd buy it) if there was a good tuning guide that explained how to use this software to tune the car. Especially if it included the Split Second R4 software. -JoeB

[cdssolara]

Carlo, I have that one too. I've had it for a while and it does a TON of stuff! Maybe more than you've seen so far. I talked to the guy that wrote it for an hour. I am pretty good with software and could get through the general stuff on this but found some of the more involved things to be difficult to figure out. I also bought the software for Digimoto. It has a very easy to use interface and I like the graphs. The cable from Car Codes works well with the Digimoto software. It would be really helpful (and I'd buy it) if there was a good tuning guide that explained how to use this software to tune the car. Especially if it included the Split Second R4 software. -JoeB

Joe, I'm sure that you're right about it having features that I am not aware of. I will send you a PM to discuss it so that we don't get too off topic here. Thanks.

[Fletch]

I did the rewire this afternoon in anticipation of my 5.5 psi pulley. FYI, it can be without removing glove box, very tight quarters though, would not recommend it.

From the seat of your pants dyno, it seemed to have better response even with 4psi. Air temp is still quite cool around here so maybe I was just getting on it more.

[Fletch]

Finally got the 5.5 psi pulley on this afternoon. The results were great, a lot more low end torque, full boost came on around 3400RPM and the supercharger sounded meaner.

Well, I took a buddy for a ride to show him the new power and the car went into limp mode, then the CEL came on. I did an ignition cycle, the CEL was still on but it wasn't it limp mode anymore. Then I got on it again and it was back in limp mode.

I'm pissed, I don't want to go back to stock pulley after feeling the 5.5psi. By the way, I did the knock sensor rewire, guess it didn't work for me.

What DTC does the ECU send for a knock sensor fault? I'm gonna try to see if my mechanic can check the trouble code for me tomorrow morning.

Another weird thing, my stock pulley said 3.4in on back. I though stock was supposed to be 3.2". Does anybody know off-hand.

[808Camry]

Try do the ECU wiring mod to the other wire. Maybe you did the wrong one or the one that doesn't apply to your problems.

[Ragtop George]

Fletch;

I remember reading somewhere that during the supercharger development, TRD was using 3.4" pulleys, but decided to change to 3.2" to increase the power. So they machined down the 3.4 to 3.2, but didn't change the stamping.

George

[EricSol]

P0325
Knock Sensor 1 Circuit Malfunction

P0330
Knock Sensor 2 Circuit Malfunction

[JoeB]

Fletch, have you done anything to adjust the fuel mixture? If not, I'd strongly recommend it. 3.2" = 4psi. Great info George, I never heard that. -JoeB

[cdssolara]

I agree with JoeB to an extent. What other mods have you done for fuel delivery? Even if you have an S-AFC or other fuel controller, you'll probably still run somewhat lean without a higher flow fuel pump and injectors. If that's the case, you're probably going to get code 0330, which is for bank #2. If you did the wiring mod described, that will only help if you're getting code 0325 for bank #1.

George's point is correct. My stock pulley also says 3.4, but I remember reading something about that being a mistake, and that it's actually 3.2.

[Fletch]

Thanks for all the replies. My mechanic cleared the P0325 & P0330 codes with his ODBII scan tool and I went home and reversed the way I had wired the knock sensors. Now, I have the bottom sensor wire (pin 28) spliced into the top sensor (pin 27). This is the opposite of how I understood the directions but I drove around hard for about 45 minutes, going to redline several times and I haven't got the DTC again. I'm keeping my fingers crossed that this does the trick 'cause the extra boost is great and I don't want to go back to 4 psi.

I run Amoco 93 all the time, I don't have an air/fuel piggy back and I'm running stock injectors and fuel pump.

Are there any aftermarket injectors or is our only option NA Supra?

[JoeB]

Fletch, check out the injectors and drop in Walbro pump at URD. http://www.urdusa.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=PERF -JoeB

[Fletch]

The good news is the knock sensor rewire is preventing the engine codes. However, the car doesn't feel nearly as quick as it did when the pulley was just put on. I think it's a combination of
1) I'm getting more used to it
2) Ambient temperature is up to 70 degrees or so instead of 35 earlier
3) The ECU has adjusted the timing

Thinking about disconnecting negative battery cable overnight in hopes of ECU resetting itself. Will that work though?

[Ragtop George]

Fletch;

Yes, disconnecting the battery will reset timing to nominal. I will also reset your fuel trims as well. I found my car got a bit faster after a couple of days after I did my rewire, and since the power was unplugged from the ECU during the rewire everything was reset. I assume it was the fuel trim that got dialed in better that increased the power.

The increased ambient temperature does make a big difference, I have really noticed that.

George

[Fletch]

Never disconnected negative battery cable, no need. It's been warm/cool, warm/cool for the past several weeks and from a seat of your pants dyno standpoint, ambient air temp plays the biggest role for performance. The next biggest thing that hinders performance is having a passenger along, specifically 200+lbs dudes. Except for long trips, I try to keep 1/2 tank or less, 18 gallons of gas weighs a lot.

Overall, very pleased with the 5.5psi pulley, no plans for fuel upgrades. Brakes next, possibly clutch if it starts to go.