yea ive done the search, but im still a lil confused. will i see a power increase. i know it wont be much but will it with a stock fuel pump? im not about to pull that tank just yet. if i put an AFPR on my setup (see sig) will i see an increase?

 

If you aren't running a little on the lean side you won't. It's more of a tuning tool, not a power adder. I personally believe that it's one of the more useful tuning aides, If you're running nitrous or a turbo, it's a must have. I use the BBK piece for the 305 TPI, slightly modified. When you start messing with timing and fuel pressure, chip tuning, breathing modifications etc. It's good to have one to get it dialed in properly. I'd like to see someone dyno the fuel pressure range the way they did for the V8, who knows, it may add power by itself, I dunno. I know that after a few of my mods, I got one, upped the pressure, and had better top end power.

 

ok, im running on the rich side for now so ill hold off on that. im just looking for anymore power i can get before i have to start dropping $$ on my turbo (gonna start shoppin for parts in a month or two)
i wanna get as much as i can out of it this summer, just for a lil more fun at the strip.

 

You'd have to put an air/fuel gauge on the car, and then go for a WOT run. At WOT, the computer goes into Power Enrichment (PE) mode, and stops checking the oxygen sensor. So after adjusting the AFPR, when you do the WOT run and check the gauge, you're reading the actual "result" of the increased pressure.

Daily driving won't help you tune an AFPR b/c the computer would be adjusting everything. The a/f gauge would really be showing the result of the computer's work, not the result of AFPR tuning.

And remember, you do make more power when you run slightly lean- but it increases the possibility that you'd burn (melt through) a piston... especially if you add nitrous!

So you'd need some more airflow mods (like a cam or headwork) to be running lean enough that you'd need extra fuel pressure. Hope that makes sense

 

What Tom said....and to tag onto it, you can't do what he said with a normal O2 sensor. You'd need a wideband for any sort of REAL tuning.

If you're running RICH already, and are using a stock fuel pump, a stock regulator, and stock injectors...I'd say you've got a problem. Maybe some bad injectors or a busted regulator diaphragm, you might have some ignition problem. I don't see any reason for you to run rich at all on stock fuel pressure unless there's some other problem causing it.

 

Wideband, eh? How much does -that- go for? Can it be used with the stock computer?

And for that matter, would it make more sense just to weld on another bung (what a word!), and keep both oxy sensors on there?

 

ok for running rich, i think part of my problem was 16* timing and a dirty o2 sensor (caused from the 16*) i set it to 12* and replaced the o2. i am running the 3.4 17lb injectors thought, so they arent stock.
and as far as i know, a wide band goes for about $500. a friend of mine bought one for his custom turbo sunfire(pretty bad a$$ too)

 

Yeah, they're pretty expensive as drdave said.... I'm surprised you don't know about this Tom! Little behind the curve?
The stock O2 sensors are total garbage. They're really only capable of saying "you're lean, you're stoich, or you're rich." They don't know HOW lean or HOW rich you are, only that you ARE lean or rich. They're not accurate and they're not sensitive by ANY means. I can run so rich that I barrel black smoke running down the interstate when it's cold out...and the O2's still say I'm just fine.

Widebands are capable of picking up ACCURATE ratios....they CAN tell you how lean or rich you are, that's why people use them for tuning. They REALLY help turbo guys too, since A/F ratio is super important for them obviously. A lot of dyno shops will screw in a wideband into your stock O2 sensor bung when they go to dyno-tune your car, so they can see what's happening with the air/fuel ratio.

Seeing as how expensive widebands are, I wouldn't weld in another bung and use it full-time. I would use it only when you needed it, as a tuning tool. Because if you fouled out a wideband...well, that just sucks. Can you say second mortgage?


And to drdave: 16 degrees of timing? I hope you were running 93 octane! That's quite a substantial amount of base timing. Ok, I can see how you're running rich now too. Those 3.4 injectors flow more than the stock 2.8/3.1 injectors, which I *believe* are 15 lb/hr. So, maybe an AFPR wouldn't be a BAD choice, since your delivery system isn't stock. You could try reducing it down by maybe 2 lbs and see what happens if nothing else solves your problem.

 

i was running 89 octane, no noticable problems at 16*. now that i set it back to 12* and new o2, it seems a bit better, but still more than it should be. i may look into one.

 

I should have noted that the kind of timing you can get away with will have a close relationship to your compression ratio. Along with some other stuff too complicated for me--like if they're aluminum or cast iron heads, the combustion chamber shape, blah blah blah. Being able to run 16 degrees on 89 octane....I'd guess you've got maybe 8.5:1 or so compression....am I close? lol....

Hey, an adjustable regulator never hurts as long as it's set right. I would also note that you will FEEL more power by leaning it out, but carefully check your plugs when you start cutting back pressure. Cause even though it may feel like it's running better, lean will destroy things. Rich will only destroy spark plugs, catalytic converters, and O2 sensors pretty much.

 

Damn, $500? That's why I don't know about them. Aren't Ford oxy sensors better? I had heard something about our oxy sensors not being accurate, but I didn't know it had to do with the range- I just thought they "incorrect" like factory gauges can be.

Hell I think for $500 you can get one of those exhaust gas analyzers....

 

Check out the LM1 from Innovative Motor Sports:

http://www.innovatemotorsports.com/

About $350US with a sensor. There have been some group purchases for this unit (including on the DIY PROM) board which lowered the price.

For tuning a WB is worth it's weight in gold.

There is also a kit available as shown at www.diy-wb.org. The sensor costs a little more for that unit though.

RBob.

 

3.4 engine should be 9.5:1 compression
3.4 injectors should be 17lbs.

My 3.4 swap was/is running a bit rich also. I figured I had just smoothed out the air passages to much

I may see about dropping down to ford 16lb injectors, then get a afpr and keep cranking it up to make it right.

I like the dual o2 sensor idea To bad I ditched the 3.4 manifolds Anyone got a set laying around?

 

Wow.

Hey could this just be done with reading the spark plugs?

Er, nevermind... that'd be hard to do after a WOT run (shut the car off immediately? Haha)