just wondering how far i can go with the timing, i called SDPC and they suggested 10*base. Of course I tried for more, I had it as high as 14* and didn't hear any pinging. It's now at 10 but felt alot stronger with more. Is the higher number safe? thanks for any help. Also, as I read the posts I see people get upset when the "search" is not used, hope I'm not going against the grain here help using this option would be appreciated as well

 

Hook up a scan tool and see what kind of knock counts you're getting. The knock sensor system in your car will probably prevent you from hearing any knock at all but it still may be happening. Once the KS hears "knock" it pulls enough timing to quench the detonation and then pulls some more timimg for good measure. I noticed in a previous thread that you're using Vortec heads. They don't like a whole lot of timing from what I understand.

I can gaurentee that nobody will run the "do a search" BS here on the Ontario board. If you have a question, run it up the pole. Somebody will answer it

 

woah!!! i'm glad i pulled it back. i was under the impression there would be no detonation with the ks. I have a slight back fire on decelleration and thought it was do to timing. i set it to factory spec and still had the same problem. my cat is gone and most of my pollution controll system and i still have the same prom. could that be the problem?(need calibration for these mods)

 

The settings for the timing has to match the timing of the chip or the chip will give the wrong tming curve

Daz

 

so your saying not to advance the timing with out changing chip? I see in all the mags and hear of people advancing the timing for performance gains all the time. No mention of recalibration. I know from 6 degrees to 10 degrees is a nice diffrence in performance

 

well since you d/c the computer when setting base timing I'd assume it will just give the same curve as before but with +X timing at any given point correct?

 

that's my understanding of how it works. I figured that was considered a free mod. I noticed when i did play with the timing you have to set the tps as well and you know about disconnecting the computer so i would recomend bumping it up to 10*. i read in 1 magazine article they bumped it as high as 12*on a stock 350 tpi. it's a noticable diffrence. you can feel the power increase. I'm no mechanic and up until now alls i had to go by is what i read in GMHTP and magazines of that nature

 

Acceld Z does make a very valid point tho. Your knock sensor may very well hear knock long before you do and retard timing so for best results a scan tool would be the only way to know 100%. But of course you could always run the car down the track also or possibly feel the gains via SOTP in some situations.


EDIT: Why would the TPS need to be adjusted each time you change your timing?

 

I'm not sure what all goes on exactly but when you bump the timing up your idle revs a little higher as well and I like mine sitting around 700 where it sounds mean so i set everything again and the tps was always out a bit. I've bean told its important for that sensor to be dead on so i always check it.

 

idle is set via the IAC... if your tps is off after you just set it a day or week or even month ago its probably on its way out and needs to be replaced would be my thinking on that. I dont see any reason the tps will change when you adjust timing.

 

I think when i set my idle back down and reset the IAC it was the next step to follow(TPS) I played with it alot last season. since i left it at 10* I havn't had to touch it. thanks for the tip. i have another TPS laying around so I think i'll change it. just to be safe.