DARKmj16

iTrader: (6)

its a 92 Camaro 305 tbi (t5 in, came factory with auto) and I need to set timing and am wondering what is the best * everyone has had best performance from?

browsing tho posts im seeing a lot of 4* and 6* advance, so would it be safe to assume that's the idea timing?

also when the timing is sat what should it idle at warmed up? browsing tho some more posts, seems lik 500-750, so 650 would be idea?

Mailbox Hunter

Per the stock sticker on the hood, it says to use 6* timing.

Personally I have my engine modified a bit, but I still find 6* to be what I need. Tried 8* once, and it didn't work out to well, 4* seems to low IMO, but I guess certain setups require different needs.

As for as idle RPM's I can even be certain. I feel like a lot of factors come into play, mine set for 600-700, but on cold starts I see upwards of 1000-1200 until the engine gets a bit warmer, then it settles.

DEFINITELY 6* THOUGH.

DARKmj16

iTrader: (6)

ya going tho posts looks like I cant adjust idle on the 92, all ecm. but I will set at 6* and go from there.

any one care to add? seems odd the stock timing would be best.

btw its factory motor, nothing special about it.

Mailbox Hunter

When I had my stock 305 engine (rest its soul... in hell) I ran it at 6*. Even now that I moved into my 350TBI (cam, intake, chipped, exhaust (when I had it...)) I run 6*. The IROC hood I bought for my RS has the stock sticker that reads 6*... so I have no clue what car that came from, but 6* all around for me.

I mean I'm curious to what other people run, don't get me wrong, I just conformed to the norm =D

82tarecaro

iTrader: (4)

I just set my Crossfire to 10 degrees. I like it so far, but I haven't had it like that for long. Crossfires also are supposed to be set at 6 degrees BTDC as per the manual.

DARKmj16

iTrader: (6)

10* wow. but doesn't crossfire operate a little different then TBI? so wouldn't that mean the * would affect it differently?
but still something to try thanks.

actually heres a parameter, I don't want spark knock (as im told that's what the noise I hear is called) I prefer to run 89 but lately have been forced to 87.

Tuned Performance

iTrader: (92)

Set it to tdc with the est disconnected. the ecm will advance the timing based on coolant temp and rpm vs map kpa.

DARKmj16

iTrader: (6)

you again! lol but I now how to do the timing but that brings up a good question, does the ecm advance the timing by a set amount (say 14* from where ever the base timing is) or does it always go to the same * of advancement? (say always goes to 20* advance regardless of base timing)

Tuned Performance

iTrader: (92)

The ecm just know a starting point and in this case its zero just a reference point. It really depends on how warm the engine is and the map reading but you might even see it 30kpa and 18 degrees advanced.

82tarecaro

iTrader: (4)

Crossfire is nothing more then a dual throttle body TBI system. The thing that might differentiate it is that the Crossfires had a bit more aggressive cam then the later TBI systems. Also, I swapped in an even more aggressive Crane cam years ago, which might make the engine like a bit more timing then stock. I have driven it the past week at 10 and I am unsure if I will leave it there. It seems to run fine, but I get a little bit of run on every now and then when I shut it off. Also, with the AC on, temps were creeping up over 200 degrees on an 85 degree day but I am suspicious of the fan clutch and will be replacing it this week for a heavy duty unit.