SoSlo

i broke my first set of ringlands on my boosted b18c

what exactly causes ringlands to break??






Modified by SoSlo at 9:52 PM 6/6/2005

sharkcohen

Poor/lack of fuel management. Poor/lack of tuning.

SoSlo

i was running about 12.5 :1 at 11 psi on a stock block jdm gsr
uberdata on rc 550 cc injectors

wantboost

iTrader: (2)

congrats on popping your cherry

sounds like detonation. was this under wot? long pull or what?

s2kdre

damn thats too lean

0mtber

iTrader: (2)

Could have been anything from bad gas to too much timing, not enough fuel etc.
12.5:1 a/f is a little on the lean side. I always shoot for atleast 12.0:1 on pump

PrecisionH23a

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sharkcohen &raquo;</TD></TR><TR><TD CLASS="quote">Poor/lack of fuel management. Poor/lack of tuning.</TD></TR></TABLE>

Yes... but sometimes older engines are just asking to give. That's why compression/cylinder leakdown tests before tuning are a must.

epic1si

i always try to stay near 11:1 on a turbo car. 12:1 scares me.

PrecisionH23a

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by epic1si &raquo;</TD></TR><TR><TD CLASS="quote">i always try to stay near 11:1 on a turbo car. 12:1 scares me.</TD></TR></TABLE>

lol. 12.0:1 is fine with low boost.

sharkcohen

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PrecisionH23a &raquo;</TD></TR><TR><TD CLASS="quote">Yes... but sometimes older engines are just asking to give. That's why compression/cylinder leakdown tests before tuning are a must.</TD></TR></TABLE>
Very true.

BlackCRX

what would you guys consider low boost tho ??

at what psi/hp do you guys think 12:1 is not enough fuel ??

Tchleung

I always tune mine for 11.5:1 no matter what boost(well around 12.5:1 for 0-3psi) I'm boosting 12 psi

Hayce

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tchleung &raquo;</TD></TR><TR><TD CLASS="quote">I always tune mine for 11.5:1 no matter what boost(well round 12.5:1 for 0-3psi) I'm boosting 12 psi</TD></TR></TABLE>

These numbers seem rich to me.. Im a honda noob (so excuse any dumb questions for a while please and have a B18c turbo. The engine has been dyno'd etc and when cruising it will see around 12.0 - 12.5 :1. When foot is heavily applied it can get down to 10.5 : 1 which is when the plumes of black smoke arrive.

Im getting these number from a apexi t/timer with new o2 sensor.

What sort of afr should I be seeing on a honda? (9.3 psi, 550's)

swlabhot

Regardless of what injectors or boost pressure/turbo you are running, you want to be seeing 12:1 to 12:5 (max!) afr in boost. This is the safe range.

If you are using the 'pencil' type turbo/na timer with the oem O2 sensor to monitor your AFR I strongly suggest that you STOP right now because you gonna blow some **** in no time. The Apexi timer using the oem sensor actually reads richer than it really is so you think you are in the safe range when in reality you are runing very lean. This is from my own past experience. Get a proper wideband O2 to read your AFR if you want to do it accurately and safely.

Hayce

Yea it is the pencil style.. I trust it too much I just thought it must be running quite rich if its putting out black (unburnt fuel) smoke and my back bumper gets soot all over it

swlabhot

The oem sensor does not have the resolution/ capability to read AFR properly. It does not know the difference between 12:1 or 13:1 or 14:1. All it knows about is its either rich or lean in simple terms. So you could be AT 10:1/11:1/12:1 and it would read RICH, likewise you could be at 15:1/16:1/20:1 and it would read LEAN... In boosted motors, you have to be PRECISE in your AFR, just reading rich isn't going to cut it. You get my drift? So you could be running hella lean when you blow **** up or you could also be running hella rich which is also bad as it could cause ring wash....

Simply put you are gambling with your block and a disaster waiting to happen...

Buzzbomb

You said you were running Uberdata, why don't you post your .bin, I'd like to see what timming you were set at. Timming is just as important as A/F.

Like the others said, the A/F looks to be on the lean side, but who knows, maybe it was just some bad gas or one of a hundred reasons.

mrx

Hi,

i don't think 12.5:1 is too lean for his boost. i read somewhere that a richer mixture will prone detonation from a certain point so 10:1 isn't the right choice as well.

i think 12.5:1-12:1 is a good number. 11.5:1 or lower is a bit too rich from what i think.

Best regards
Malte.

tissimo

richer is safer... to a point.. i'd run lower then 12.0.. I tune for 11.5 when I do my buddies b16 turbo at 10-11 psi.. once my supra is done will go probably 11.2-11.0 or so on 18 psi (pump gas).. i'd rahter lose a few hps then dump all that money into a new shortblock..

go even richer (11-10.8) if you do long highway pulls (things start to heat up, richer will help cool it down)

seen4ever

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PrecisionH23a &raquo;</TD></TR><TR><TD CLASS="quote">

Yes... but sometimes older engines are just asking to give. That's why compression/cylinder leakdown tests before tuning are a must.</TD></TR></TABLE>

i will say the same thing, i had a turbo h22a come in a few weeks back, compression was like 170, 160, 140, 170. It was a completely stock h22a, so it shoudl have been in the 200+range. The engine had been hating life as it had went through every imaginable turbo setup there was. It was tuned the safest it could be, but with how bad the crankcase ventilation the engine had (had it setup facotry style) at 10psi on a t3/t61 the rings finally let go. The guy understood that he was pushing the envelope but it did pull pretty nice with its 11.8:1 a/f ratio.

For his engine, it was asking to die, not to mention it had stupid amounts of blow-by, we had to use a hammer to get the oil cap off even.

tthame1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mrx &raquo;</TD></TR><TR><TD CLASS="quote">Hi,

i don't think 12.5:1 is too lean for his boost. i read somewhere .</TD></TR></TABLE>

You read somewhere On a stock motor that is too lean. I personnally like to keep it to around 11.5-11.8. On a forged internal motor 12.5 still wouldnt be safe for a daily driver imo. Keep it 12.1 and under and it will last alot longer.

mrx

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tthame1 &raquo;</TD></TR><TR><TD CLASS="quote">You read somewhere On a stock motor that is too lean. I personnally like to keep it to around 11.5-11.8. On a forged internal motor 12.5 still wouldnt be safe for a daily driver imo. Keep it 12.1 and under and it will last alot longer.</TD></TR></TABLE>

i've read it in "Sir Harry’s Book, The High Speed Internal Combustion Engine" from a friend of mine. But maybe you can explain this with some technical background of whats goin on in the combustion chamber when you run richer mixtures?

in don't think that enrichen the mixture will help to prevent detonations when going too rich and if the totaly over enriched mixture detonates, the explosion will be much havier then with a leaner mixture. i don't want to say that leaner detonations are better but rich as hell won't help in my eyes... but if someone has a good physical explanation ... this is just the moment ;-)

dornon13

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by seen4ever &raquo;</TD></TR><TR><TD CLASS="quote">
we had to use a hammer to get the oil cap off even.</TD></TR></TABLE>

what does this mean... i have noticed my oil cap being rather tight since i have been boosted


Modified by dornon13 at 6:06 PM 6/7/2005

ITR981002

Post your BIN.

tgreaves

I always tune my turbo cars to 11.8:1 - 12:1.. Never had one blow up on me..