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running a 383 with 9.5 to 1 and afr heads small cam and a t-76 with 5 lbs right now and planning on 10 to 15 max depending on how much power it makes. I have $59 in a 730 ecm and have a file from a supercharged 355 42 lbs inj that I started with and have been told the timing is way to aggressive for boost so looking to others to chime in and tell me what has worked for them. I was really good with my n/a set up but dont have much of a clue for what boost likes. here is a copy of what is in the car now and I dont hear detonation but the car gets terribly hot under boost and wont recover. but if I drive normal with no boost it is fine.http://www.thirdgen.org/techboard/at...now-timing.jpg
__________________ 1992 formula firebird 5.7 t-top car 383 late model 1 piece rear main 4 bolt roller block comp cams 226 232 @.50 550 lift 112 lobe sep 1.6 crane gold rockers, 42 lbs injectors, billet 58mm tb hsr intake, turbonetics t-76 ceramic bb turbo intercooled probe moleculite flat top pistons,powder metal full floating rods, scat crankshaft 1675 bob weight. 10.5 @ 138 on 6 lbs yikes!!! wait until 12 lbs. no dyno figures yet but car is full weight and some. still has a/c and a huge stereo in it. real street car. guessing over 600rwhp.
Re: looking for boost timing tables to compare to.
At 5psi and 9.5:1 with 91+ octane, I'd think 36 degrees wouldn't be a problem. I was running 36 degrees on 10:1 10psi, but my cam was 246/254 .558/.558. Now I still run 36 degrees with 8.5:1, 16psi, and cam of 264/271 .626/.626.
Re: looking for boost timing tables to compare to.
You can use other $59 bins to compare to, there is a thread on code59.org that is calling for all current bins (I didn't see yours there), and some good examples as well as some questionable ones.
Also comparing stock $58 and $8F might also give you some idea.
Yours is a bit agressive, but if the engine likes it, run with it.
Re: looking for boost timing tables to compare to.
Quote:
Originally Posted by Six_Shooter
You can use other $59 bins to compare to, there is a thread on code59.org that is calling for all current bins (I didn't see yours there), and some good examples as well as some questionable ones.
Also comparing stock $58 and $8F might also give you some idea.
Yours is a bit agressive, but if the engine likes it, run with it.
yeah, good idea. I know when I down loaded a turbo bin. the timing was totally different from what my supercharger liked. turbos make peak boost in places where superchargers make very little. so I run more timing in those places. if your car is running hot under boost and you think its timing, just highlight above 100kpa, -10* and then go try it again. if it doesn't get hot or as hot, your in the right direction.
Re: looking for boost timing tables to compare to.
After reading and replying to this thread, I actually took my own advice, and looked at a bunch of turbo bins.
A bunch of $59 (lots of disparity there, which I guess can be expected), a couple $58, a few $8F, and a couple $31.
They were all quite different in overall shape, but they did seem to share one common trait and that was to drop timing quite a bit above 100KPA, and for the most part level out. Some like $8F had huge dips in the higher KPA regions, but that could have been more of a safety feature, since those cars were ECM limited to 9.5 PSIG were fuel cut was enabled, and this could have been GMs way to keep the engine together, if it were to over boost.
