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Tuning my PE table for 3.4" pulley

97AutoXVette

97AutoXVette

New member
Hey guys, I am going to be putting a 3.4" pulley on my car in the near future. With that, I am wondering what to put for the AFR adder vs. TPS for the new pulley setup.

I currently have stock PE tables and the stock 3.8" pulley.

Anyone have any good suggestions? Also, what else would you modify (which tables) and how with a 3.4" pulley?

Any good formulas you may want to share would be great!

Thanks!
 


I never touch add vs tps.

I only adjust add vs rpm table if needed.

You can either leave the stock PE table of 12.3-12.4 plus the ADD vs RPM to bring it down to 11-11.5 afr or you can zero out the adder and set PE to 11.4 all way across. Having a wideband can help make sure you are really seeing that.

The stock tune already runs it slightly rich, so you really don't have to mess with it much. Unless you start seeing problems.
 
Fivefingerdeathpunch said:
I never touch add vs tps.

I only adjust add vs rpm table if needed.

You can either leave the stock PE table of 12.3-12.4 plus the ADD vs RPM to bring it down to 11-11.5 afr or you can zero out the adder and set PE to 11.4 all way across. Having a wideband can help make sure you are really seeing that.

The stock tune already runs it slightly rich, so you really don't have to mess with it much. Unless you start seeing problems.
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Thanks for that info. Def. helped. So, I will not have a wideband hooked up for the time being. I will just be monitoring my KR and Fuel trips real time to get an idea (hopefully that is safe enough).

Would you recommend changing the stock PE table or the "Add vs. RPM" table? Either one yield better results or easier in your opinion?
 
SnowFlake said:
I'd advise against playing with fuel tables before being able to monitor things on a wideband.
Click to expand...

That's fair. But how safe is it to run a 3.4" pulley on an otherwise stock tune? Will the MAF do a good enough job adjusting the fuel as needed for the added air at a given RPM with the smaller pulley and more boost?
 
It's pretty forgiving.

Just scan with you laptop and see if anything jumps out at you, if so just stay out of boost or swap back to stock pulley.

If you are installing headers, takes some runs with just headers added and see the difference in what the car does.
 


Sounds like a good approach. I will be doing the exhaust work soon so I can get some scans after that and see how everything is looking.

Then I can do the pulley swap and check again. if I don't get any KR and timing seems fine, maybe I can leave it as is. I still need to look into how the MAF readings tie into the AFR.
 
Bumping this up. What would you guys recommend for PE table? better to zero out the adder vs. time vs. RPM and modify the PE base target? or better to leave the target somewhat stock and modify the adder?
 
Zero out isnt really a great option. . I woulf just see what you need to change and fix it.. stock tunes are rarely wrong.
 
I wonder why they have the table set up that way. I personally would just want my AFRs to be low to mid 11's all the time.. Not sure if there is really much to be gained with the adder table asside from adding some safety margin for people who live in WOT with their right foot all the time.
 
They run it that way to keep it safe.

Not everyone drives the same nor in the same place on the planet.

They want to it get richer over time because heat builds up in the cylinders as time goes on. There is more to it than just that, but thats something I don't care to get into.
 


interesting... that being said, and based on your knowledge, think I should leave the adder table alone and just adjust the base PE table? Just trying to get a few opinions and try some things out to see what gives me the best (and easily modifiable) results
 
97AutoXVette said:
I wonder why they have the table set up that way. I personally would just want my AFRs to be low to mid 11's all the time.. Not sure if there is really much to be gained with the adder table asside from adding some safety margin for people who live in WOT with their right foot all the time.
Click to expand...

*thumbs up*
 


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