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Discussion Starter #1
Im going to use this thread to document my tuning. It will show links between map voltage, timing and knock and hopefully give people a good starting point when tuning. Also if you can provide any additional information please do.

Fuel Setup:
RC 750cc
Aeromotive Regulator
Walbro 255
Greddy Emanage/E-01 With LC-1 Wideband
TechGauge Timing/Knock/o2


What started all of this:
I was at the tracking running 20psi, running 13.0 @ 112.6, The mph was pretty low considering the turbo.

Data for this run:
Knock Retard: 8 Degrees
Map Voltage: ~3.65v @ WOT
AIR FUEL: 10.X falling to 9.X
BOOST: 20psi
Fuel Pressure: 43psi base

In an attempt to lean out the 10:1 afr, more fuel was pulled via the emanage resulting in:
Knock Retard: 11 Degrees
Map Voltage: ~3.5v @ WOT
AIR FUEL: 11.0 falling to 10.x falling to 9.x
BOOST: 20psi
Fuel Pressure: 43psi base


Once i got home from the track, I had a feeling my knock sensor may be messed up, so i zero'ed out my emanage and ran only a 4.0v clamp
Knock Retard: 0-1 Degrees
Map Voltage: ~4v @ WOT
AIR FUEL: 10.x falling to 9.x
BOOST: 20psi
Fuel Pressure: 43psi base


What i see from this is that i need to lower my fuel pressure to lean the car out at this point, pulling any significant more amount of fuel through using map voltage will cause spark knock. I will be trying this at the track tomorrow. Thoughts? :hi:
 

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this is just a thought and a problem i had, the injectors are too big for the boost you are running. i was using s2 injectors with the stock turbo and just seemed i could not pull enough fuel even at 22lbs. this was with w/i as well though. i went back to the s1 injectors and tuning became SOOO much easier. now i can maintain a steady 12:1 a/f across the board. I also have 0 knock and map is clamped at about 4.6 volts..this was monitored on an lm-1 and chrysler drbIII
 

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Discussion Starter #3
srt4fun80 said:
this is just a thought and a problem i had, the injectors are too big for the boost you are running. i was using s2 injectors with the stock turbo and just seemed i could not pull enough fuel even at 22lbs. this was with w/i as well though. i went back to the s1 injectors and tuning became SOOO much easier. now i can maintain a steady 12:1 a/f across the board. I also have 0 knock and map is clamped at about 4.6 volts..this was monitored on an lm-1 and chrysler drbIII
I also had this same issue with s2 injectors on the stock turbo, unable to pull out the fuel without advancing timing too much.
 

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yeap, exactly, i would have to clamp so much the timing would be f'd all up. and i was still seeing 10.8:1 at redline and loosing too much hp. I've yet to jump back on the dyno, but datalogin shows much better results on the road. Last time i dynoed w/ the s2's i put down what is in my sig, and that was with a 12.5:1 a/f dropping off to the 10.8, now with a steady 12:1 i should have picked up a few ponies. why not try some different injectors? Still got the s2's kicking around?
 

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Discussion Starter #5
im going to try lowering my fuel pressure and see how that goes, nope the stage 2's were sold once I got the big turbo.
 

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good plan, but if you see yourself going to low with pressure, keep the smaller injectors in mind. what pcm are you using? stock, s1, etc.?
 

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distinctdev...

How is your fuel pressure setup? Are you running a static system? If not where is your vacuum line running from?
 

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WhatsADSM said:
distinctdev...

How is your fuel pressure setup? Are you running a static system? If not where is your vacuum line running from?
Vacuum line is from the red line (boost only), and its a rising rate 1:1 regulator. What pressure are you running with you vacuum line off?
 

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Check your PMS.

Although your setup isnt bad (the boost only source is a good one BTW). Im surpised that with all your mods and basically a 4.0v clamp you are in the low 10s for AF..
You also have exhuast, FMIC, etc? correct?
 

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WhatsADSM said:
Check your PMS.

Although your setup isnt bad (the boost only source is a good one BTW). Im surpised that with all your mods and basically a 4.0v clamp you are in the low 10s for AF..
You also have exhuast, FMIC, etc? correct?
Yes: agp fmic, needwings dump.

Ill let you know how things go with your advice. Im gonna check my plugs and wires also.
 
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