I been messing around with my timing, right now its at 10 BTDC w/ the EST wire disconected. Its running pretty good at 10* but im wondering if it should be advanced even more. Setup is a 355, HSR, vortec heads, and LT4 hot cam. I've heard people are running 14* on these HSR motors. Shoiuld i keep advancing and see if it doesnt ping? It would back fire through the intake at 6* so it was too retarded at stock specs.

 

I am running 12 on my stock 305 and it works fine. I run 93 octane.

 

all motors are gonna be different. are you tuning the chip at all?

base timing doesnt really matter too much if your gonna change timing in the chip thru the spark tables. My 383 i have set to 10 base and make changes thru the tables.

IF you got a mail order tune, what base timing did you tell them to set it at? Or what did they tell you to set it at?

If your on the stock tune and your trying to get an idea what it wants, play with 8-12. I dont think you'll need much more than 8-10 for base.

 

i got the car like that it was a mail order chip i believe if i can locate the receipt maybe it might say what timing it likes. Also what fuel pressure are you guys running??

 

i just run about 40psi with vacuum connected at idle... which is 46 psi disconnected

 

38-44 for mine.

 

same ? about timing, im in the last stages of firing up my car after the hsr swap all i need is a chip, what would i need to set my base timing, im also installing a nos kit maybe a 100 shot, would timing be affected with the nos

 

im running 14 btdc on my timming. mail order chip. 48-50 fuel psi. with kirban adj reg.... 355 hsr lt4 hot cam 113 vette heads..
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with nos i think you need to run lower timeing. and more fuel..

 

i have 24# injectors, i have the fuel pressure at about 46psi. The base timing is 10* BTDC. Should I keep bumping it up?

 

If you are going run NOS , then you should do it properly and have a retard setup for when the NOS is on only .
Otherwise you are running your engine retarded most of the time to save it when you do spray or you risk blowing it when you spray if running timing to suit normal NA driving

 

100 shot doesnt really need timing pulled. i'd only pull 2 degrees and run a step colder plug.. still will work good n/a but better on the spray

 

The mags have run timing up at 12 and 14 degrees, beyond that, the car slowed down.

 

I've got the car set right at 14 right now seems to be running good and pulling real strong now, don't think im going to go any higher than that. I tried setting it at 12 and it had a small pop through the intake and less throttle response. Had to re-lower my idle but i think its running good right now. Running 93 octane, going to see if it pings on regular.

 

I found the receipt for the LS Racing chip and emailed the guy at lsracing and he said to set it at 6* and FP at 48#s, I did and it seems to be running good now, I realized that it only pops when the est is disconected, when you plug it back in, the timing gets way bumped up. I had my base at 14* (EST unplugged) before and i took it to the track and it ran really slow like a 9.6 (also was my first time driving and tire spin) and I got a code 43 going down the track (too many knock counts/too much timing) so im going to see what it runs now.

 

What exactly is a mail order chip and how much are they and where can i get one??

 

i got mine from lsracing.com but they stopped doing them i think it was like 120 bucks. question is your 14 base timing WITH the EST unplugged? B/C i've found the proper timing with the EST unplugged is way too retarded and then once you plug it in mine advances to like 16*

 

That is correct ; you set the base timing and then the computer adjusts it once the EST is connected.It is impossible to adjust with EST connected.

 

well when i first fired up my motor I wasn't aware of the est, I did adjust it to like 8* advanced but i wondered why the timing light would bounce by 2*. Motor ran way too retarded. Turned out when i found out about the est and unplugged it it now read 8* retarded.