Avoiding KR - Safe 50 trim boost...

[agp03]

Is there a general consensus on max boost levels?

My mods: stg2 ecm/inj, walbro w/o return, AGP FMIC, 3" tbe and cai, SAFC and UEGO w/b.

Appreciate it!

[contraption22]

Every car is different. And conditions are never the same from run to run.

Factors that could determine your max allowable boost in no particular order of imortance:
fuel quality(Octane, age, ethanol content, MTBE content)
fuel mixture
abient temp
intercooler efficiency
compressor efficiency
exhaust backpressure
sparkplug heat range
ignition advance
engine production variances
altitude
barometric pressure

Bottom line, what works for somebody elses car, even with the exact same modifications, may not work for your car.

Monitor your knock with a scanner. Monitor your fuel with a wideband. Inch up your boost a little at a time.

[agp03]

I know that varied mechanical conditions and every environmental condition will affect boost and combustion, I am just looking for a general consensus. C'mon 50 trim guys, help me out. What are you running? Especially interested in set ups similar to mine.

My w/b says I am fine. Do not have a way to detect knock, though, hence my concern. Will an obd 2 scanner work? What do you look for?

Thanks again, and btw I was told from one knowledgeable source that 17psi is about max for a stg 2 setup. I ran 20 at 10.9 on the w/b. Should I be elated or should I be

[contraption22]

Quote: Originally Posted by agp03

I know that varied mechanical conditions and every environmental condition will affect boost and combustion, I am just looking for a general consensus. C'mon 50 trim guys, help me out. What are you running? Especially interested in set ups similar to mine.

My w/b says I am fine. Do not have a way to detect knock, though, hence my concern. Will an obd 2 scanner work? What do you look for?

Thanks again, and btw I was told from one knowledgeable source that 17psi is about max for a stg 2 setup. I ran 20 at 10.9 on the w/b. Should I be elated or should I be

With an obd2 canner you can check knock sensor output, or knock retard degrees.

[j2talc]

just so you know, I run 22psi daily (393hp last dyno) and i see about 4 on the KR

[Turbocruiser13]

But how much of a difference would there be between your RC injectors and his S2s?

[str5010]

The aerofroce scan gauge is awesome for monitoring knock, thats what I use with the uego to watch fuel on the 50 trim. I would assume that if you have the fuel to support it, you could safely get away with at least 18 psi of boost with that AGP intercooler. I was running that with the stock intercooler and only picking up a KR on 2-4 on the scan gauge. With methanol I can now run 20-21 psi and have KR of less than 1. Better safe than sorry though, get a way to measure Knock.

[distinctdev]

Quote: Originally Posted by contraption22

Quote: Originally Posted by agp03

I know that varied mechanical conditions and every environmental condition will affect boost and combustion, I am just looking for a general consensus. C'mon 50 trim guys, help me out. What are you running? Especially interested in set ups similar to mine.

My w/b says I am fine. Do not have a way to detect knock, though, hence my concern. Will an obd 2 scanner work? What do you look for?

Thanks again, and btw I was told from one knowledgeable source that 17psi is about max for a stg 2 setup. I ran 20 at 10.9 on the w/b. Should I be elated or should I be

With an obd2 canner you can check knock sensor output, or knock retard degrees.

incorrect, get a techgauge or an aeroforce gauge

[endlessheart666]

Well so you know, whether or not your you have a rich a/f you can still get knock if you are messing with timing and not fuel pressure too. I can personally attess....10 a/fs and 3kr.

[agp03]

Yes, and thanks everyone for the replies. I don't think that I am messing with timing since my SAFC reads Positive (+) at WOT, and I presume that its all up to the stg 2 ecu at that point. Not sure though and posted another question related to just that. Truly appreciate the discussion.

[SRT4Jon]

On pump gas I run 15-16psi max, I have no need to push it on crap pump gas. I save the big boost for race gas :shrug:

You have to just test it, asking people what their car does doesnt mean jack for your car.

[evo77]

Quote: Originally Posted by agp03

Is there a general consensus on max boost levels?

My mods: stg2 ecm/inj, walbro w/o return, AGP FMIC, 3" tbe and cai, SAFC and UEGO w/b.

Appreciate it!

You say you want to avoid KR but you have no device to measure it. This should be YOUR FIRST PRIORITY if you truely want to tune the right way.

As already mentioned, even if your wideband is showing safe AFR, that does not mean that you aren't getting knock.

Without an Aerforce or Tech gauge, your tuning with only one eye open.

[superfox1]

I run 19psi ..untill I get my leak fixed..then it's going up to 25

[Turbocruiser13]

what are you using for injectors superfox?

[ac_srt4]

with 2 nozzles and 90% methanol, i get 0 knock at 20 psi and below 3 kr @ 5500rpm at 23psi on sunoco 94.

without methanol, knock can go up to 6-10 on 23psi.