I just finished street tuning my car and after tinkering for hours i got my afr's to hit solid 12.1 in boost, question is, my timing is at 24* in the last column and im concerned thats a little high, but it runs SO good i dont want to back it off...

plugs look great and i hear no sign of detination...

setup is b18a with 450 dsm inj. and t25 turbo at 10 psi on turboedit...

curious whether this high of ignition advance seems safe at full boost on a small turbo???

 

bump

 

That's on the aggressive side without a dyno IMO. Butt dyno's don't mean anything. Your body really only feels big <U>changes</U> in torque. Take a pull to redline and shutdown the car in the high RPMS. Remove the spark plugs and check where the heat strap is or just take a clear picture.

Backing it off a couple degrees may yield more power/no changes. I doubt you'll lose much power, but you'll gain a lot of safety until you hit a dyno

 

i steped it off through the last few boost columns and in hte end its 20*...

sound better?


i wasnt detinating before so i should be great now... but im worried about my afr now, it was hitting 12.1 before, will it go rich now??? i dont have my wideband around to check afr's...

 

just pulled the plugs and i have a few small specs but not terrible, is 21* going to be backed down far enough?

 

20* is fine. If the AFR changes then do some more tuning .

BTW it's 12:1 not 12.1 (it's a ratio...I know I'm being a ***** )

 

when i said 12.1 i mean 12.1:1 on my plx...


i meant its hitting low 12's...

no problem tho, i turned my timing down to 20 degrees total timing but strangely my plugs look lean???? im gonna check my base timing and see what its at...


i would do some more tuning but my wideband is MIA for today...


Modified by jarvis199 at 7:17 PM 6/15/2006

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jarvis199 &raquo;</TD></TR><TR><TD CLASS="quote">when i said 12.1 i mean 12.1:1 on my plx...
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OK my bad

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jarvis199 &raquo;</TD></TR><TR><TD CLASS="quote">

no problem tho, i turned my timing down to 20 degrees total timing but strangely my plugs look lean???? im gonna check my base timing and see what its at...

i would do some more tuning but my wideband is MIA for today... </TD></TR></TABLE>

After shutting down in high RPMS? If so get a wideband on there ASAP. If it's getting leaner that means you're making more power, remember there is a direct correlation between fueling values and power.

 

ok, so i retarded the timing on the map that i had tuned using a widband... and had hit hihg11's to low 12's on the wideband, took that same map and took out 2* total timing, tapered it so that it was a smooth transition, and ran it, and the plugs looked ok, ran it at the track with 19* total timgin wtih the same fuel maps as before and the plugs were black and it ran like shat...

so i think im going to go with my tuned fuel map, plus about 22* of total timing, and run with it till i can get my wideband back, at 24* i didnt HEAR any audible detonation, and i have a very quiet exhaust, but that doesnt mean that it WASNT doing it... so does 22* total timing at 11.5 psi in my turboedit map seem alright??? im at 28* at 0 vac and its tapered down from there...

last week at the track it ran 9.1 spinning the whole track, tonight with the new ignition map it ran 9.3 and lost 3 mph and didnt spin anything but 1st and wheelhopped like a SOB in 2nd...

any tips would be good, if i had my wideband id just turn it to 22* (seems like a good round number) and tune the afr, but i dont have it, and ive got to stick to my tuned fuel map...

for reference, my plugs on the 24* map had maybe 8 or 9 very light specks on the center of the plug, the ground strap was tan and grey mixed with the timing mark about 1mm toward the threads from center...

this all sounds like jibberish to me now, im thinking about it too muhc... now someone has told me that you can run up to 30* total timing with my setup, i think ill stick with 22-24... any tips/flames/hate mail would be awesome...

 

Is your Dizzy and ECU Sync'd correctly?

I wouldn't be surprised if it wasn't...If it isn't your Timing Tables wont show the actual timing #.

 

yea they are fine, 16* base timing... well my maps are showing 16.50* on idle vac but im sure that half degree isnt causing this...

 

ttt

 

i ran about 20* total on a 200k mile ls motor all summer last year. 24 is pretty agressive, id go to the 20-21* range for 10 psi. its better to sacrifice a few hp to have your motor stay together

 

awesome, im sitting at 22* right now and it feels ok, but ill proly back it down to 21 and see how it feels...

 

continuing to tune it based on how it "feels" won't get you anywhere IMO.

set the retard .75*/psi to keep it on the safe side and just tune to a safe AFR. afterwards, get on the dyno in order to see exactly what is happening when your playing with the timing.

 

so in theory i could leafve it at the highest total timing that it isnt detinating at and then tune for afr??? thats waht im getting from this, too much retard will cause high egt's and too much advance will cause detination, so if i find a nice happy medium and then tune for afr i should be fine...

seems most if not all dyno tuned ls turbos are hitting from 20-22* total timing, so ill stay in that range and tune for afr...

 

i guess you could do as you please.

i personally would keep it on the safe side and have more of a retard than anything.

it seems as though your not too familiar with tuning. i would suggest you visit some of these sites and read up some more on how to tune timing and such. there is ALOT more to tuning timing than you think.

Evans Tuning
PGMFI.org

that or take your car to get tuned by someone else.

 

8-9 specs is 8-9 specs too many. I'm sure at 24* you are making great power, but one cylinder may think it's just a little too much and detonate a little. Like you said 20-21* is around average from an LS, but your's may need more or less. I've tuned some that only need 17 at 10PSI. Sounds like 24* is your limit so take out a couple degrees and run at 22*. Run new plugs and check for detonation on every cylinder after some runs.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jarvis199 &raquo;</TD></TR><TR><TD CLASS="quote">thats waht im getting from this, too much retard will cause high egt's and too much advance will cause detination, so if i find a nice happy medium and then tune for afr i should be fine...
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Yep. That nice happy medium is called MBT (Max Brake Torque or I like Minimum Best timing) It's the point whre you've been adding timing and had good gains then all of a sudden you don't gain much more anyway. All it's doing is gain a few HP, but detonation will be creepign up (some cars detonate before MBT though for other reasons). Retarding timing too much would be like 13* at 10PSI and you are really far from that. IMO leave it at 20-21* and from what you've been saying I bet that if you hit a dyno this is going to be the best range . Good luck

 

ive been reading those sites for 2 years now, i understand the concept, im trying to get a decent ignition map without a dyno, and still be safe, so my theory is, if im not detinating then its not too high.. sound right??? ok its a little bit of a weirdidea, but as long as im not detinating and my afr's are good then im ok, and if EVERY turbo ls that i coul find (dyno tuned) is running 20-22* timing, and im not detinating on it, and it feels fast, i think i shold run with it...

i got the afr's dead on wtih 24* timing, but then got to reading and saw that that was a little much, and then noticed #1 had a little pepper onit, so i figured id play with the ignition a little, if i was BARELY detinating on 24* i think 22 shuold take care of it, and im keeping on eye on the plgsu the next few days...

i did 32 passes on that old map at 24* before i noticed the plug was a little touchy, so i know its not detinating too bad, or it would have blown already...

 

You are slightly detonating at 24*...keep that up and you WILL blow the engine.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jarvis199 &raquo;</TD></TR><TR><TD CLASS="quote"> so my theory is, if im not detinating then its not too high.. sound right??
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No, you want the point where complete combustion happens at 15-20* ATDC. At that point you will make the best power. Adding timing may yield a little gain and some actually loose power, but all you really do is get closer to detonation and increase EGT's. For you sounds like it'll happen at 20-22* will be the best, but do what you want it's your car .

 

i understand what your saying, thats why my map is at 21 right now, because thats where it feels the best, and it was slightly det. in 1 cylinder on 24, 23 no det, 22 no det, 21 still feels fast yet is a few degrees into the safe area it feels, if i had a dyno and everything i WOULD do a better tune, but im just trying to get into a nice safe grey area where im not losing too mcuh hp to lack of timing but im not dangerously advanced...

and keep in mind im only about 210 hp at MOST on 10psi on this t25...

so im not looking at a high hp car

 

i just think your missing what im saying, i agree with you, but i cant see taking my timing down into the teens...

if i take my stock map, and then do a -.75* linear retard my total timing ends at 19.38...

so you think 21 is too much???

the way i have it done its a -.60* per psi...

that sound like not enough????

 

I do step retarding becuase at 0-3 PSI you really don't need much in any timing taken out at all. Around 4-6 I take some out and then 7-10 I take some more out. Just stick to 21* I think you'll be fine if you are getting new plugs and checking them everytime