Alright, I know these subjects have been beaten to death already but new threads are good right? Anyhow, I'm looking to drop pulley size on the supercharger to either a 3.4 or a 3.5 on my 3800 II SC/five speed swap. I understand that every engine is different so no definite answer exists but I'm looking for some suggestions to my specific situation.

So, going off the research I have done, I'm planning on running a 180 thermostat and autolite 104's. I already have a really open and freeflowing exhaust but haven't done any porting. My intake is also very free flowing and pulls cold air from outside the engine bay. The last piece of the puzzle is that my Christmas present to myself was HPTuner software. I'm still learning how to do the tuning myself but its something that I've really wanted to get into for a long time. So assuming that I become at least somewhat proficient with the tuning, I'm going to assume that I can tune to try and rule out any KR.

With my stock engine and tune I'm only seeing low 20's as far as mileage (sometimes a little worse) so I want to try and improve that as well (though with a pulley size drop I would be happy with a small improvement). This is a daily driver so I'm not looking to do too much more modding to this engine. I'm planning a turbo build next for when I really want more power. I just want a small increase in the meantime to keep myself happy.

By the way, any recommendations for learning how to use the tuning software from those that have gone through this stage before would be appreciated as well. Thanks

I got HP tuners and a wide band about 6 months ago - best money I ever spent.

Step 1. learn how to scan the important vitals to get familiar with the scanner- Keep the 3.8 pulley for now and learn to scan rpm, short & long term trims, timing advance, knock, inlet air temp, collant temp etc. I think you have to do a conversion in HP tuners (on their website in the tips section i think) to get the timing to read in positive numbers - ie 16 degrees advance (instead of -16).

b/t/w I average about 24 mpg in mixed driving with my 3800 Fiero.

It is very important to know if you have any knock with the 3.8 before you start increasing boost.
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87 Formula Clone, 3800SC, 3.4 Pulley, 4T65E-HD, HP Tuners, AEM Wideband, 12.98 at 103.4 1/4 mile, Regal GS Gauge Cluster, S-10 Brake Booster Upgrade.

[This message has been edited by DimeMachine (edited 01-13-2012).]

Drop to a 3.4 as that is what I call stock for the 3800 in the Fiero when a good intake/exhaust is used. I have only had a few swaps leave my shop with the stock 3.8 pulley on. I would not worry with changing to 180 stat or 104s with the pulley drop.as neither are really needed. Cant help on the tuning part as I have not done any myself...Your MPG with the 5 speed should be better than low 20s though.

One easy tip to increase MPG and Performance is to just use the 2004 GTP timing table. However:
Watch KR closely as the 2004 table is a dramatic increase in timing as compared to 97-03.
The increase in MPG will be 2-4 miles with just that change alone.
Also, stay with a larger pulley if looking fo better MPG.

The best MPG I had was with the 3.1 pulley and a tune taylored for economy. I want to say ~26 MPG

[This message has been edited by nosrac (edited 01-13-2012).]

Thanks for the responses so far. I forgot to add....what's the general consensus out there for a good value wideband O2? I see AEM suggested a lot and sometimes Innovate. Forum input?

I am presently getting about 24-25 MPG with a 3800 SC Series III engine, 3.4 pulley, and a five speed Getrag at 73-75 MPH with the A/C running. There are some mods that may decrease MPG such as a VS cam, N* TV, intercooler, etc. but I hope that the new tune increases the MPG as well as power.

Nelson

Stuck between the AEM UEGO and the Zeitronix Zt3. They both seem like decent setups but I think I like the look of the Zeitronix Gauge (Red w/ black bezel) style a little better.

Any opinions on the actual Wideband O2 Kit itself for either of these? I seem to be reading mostly positive reviews for both.

AEM UEGO

Zeitronix Gauge and O2 Kit

[This message has been edited by GraterFang (edited 01-14-2012).]

quote Originally posted by GraterFang: Stuck between the AEM UEGO and the Zeitronix Zt3. They both seem like decent setups but I think I like the look of the Zeitronix Gauge (Red w/ black bezel) style a little better. Any opinions on the actual Wideband O2 Kit itself for either of these? I seem to be reading mostly positive reviews for both. AEM UEGO Zeitronix Gauge and O2 Kit

I researched for a few weeks last summer and ultimately it seemed like most people had good things to say about the AEM - so I bought one. So far it has worked perfect and easy hookup with HP tuners.
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87 Formula Clone, 3800SC, 3.4 Pulley, 4T65E-HD, HP Tuners, AEM Wideband, 12.98 at 103.4 1/4 mile, Regal GS Gauge Cluster, S-10 Brake Booster Upgrade.

[This message has been edited by DimeMachine (edited 01-14-2012).]

quote Originally posted by DimeMachine: I researched for a few weeks last summer and ultimately it seemed like most people had good things to say about the AEM - so I bought one. So far it has worked perfect and easy hookup with HP tuners.

Thanks

Just the kind of reply I was looking for. Anybody else?

I have the Innovate LC-1 because it has 2 analog outputs. One to the gauge and one to the ECM. I think it was the cheapest one at the time. You are supposed to do the free air calibration every 20k miles.

The AEM looked good in your link above. I would ask about the analog outputs. It's one thing to datalog with the wide-band O2 but it's another to have that same fast acting sensor provide your ECM with very accurate information for fuel trim once you go closed loop after tuning (simulating a narrow band). I'm guessing it has 2 or more outputs though. No free air calibration is a plus too.

AEM has a 0-5 v analog output for data-logging with HP tuners, and a serial output for "hyper-termainal" data logging - not exactly sure what that is. I have not found it necessary to use the wideband on 3800 to simulate a narrowband. In a nutshell, I started my tuning process by forcing my PCM to stay in open loop (and disable areas that modify the AFR in open loop) and then I tuned my MAF with the wideband to a point where the commanded AFR is = to the actual AFR. Then as a check, I welded in another bung for my wideband to run at the same time as my narrow band and logged the narrow band millivolts against the wideband AFR to make sure they both were reading stoich at the same time on the log. Then of course you re-enable closed loop so that it keeps the AFR at stoich at part throttle operation. Now, I use the commanded AFR as a guide to where the AFR is - with confidence knowing I have adjusted the MAF freqency so that it is accurate.

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87 Formula Clone, 3800SC, 3.4 Pulley, 4T65E-HD, HP Tuners, AEM Wideband, 12.98 at 103.4 1/4 mile, Regal GS Gauge Cluster, S-10 Brake Booster Upgrade.

I suggest against using any narrowband simulation from widebands... it is typically very messy as the response the pcm on most GM obd2 systems is looking for is very specific.