Engine/Transmission (1994 - 1998) Is my timing too advanced?

[JGheen]

So I have been trying to figure out why my EGTs climb so slowly now with te new EDMs and timing adjustment. I hav figured that my timing is set between 15 and 16*, but not sre cuz of the variances I got but according to the dial indicator I never got above 5. 6mm lift reaching TDC, so it as to b close to 16 and definatley around 15.

Anyway, does that much timing really decrease the EGTs like so? I only see maybe high 1300* when hammering on it, but can see higher when hammering on it from second gear instead of third. BTW, when is a good time during acceleration to rate my EGTs? Full, hard accel from a dead stop or just a couple gears of full fueling? I have always been confused about this.

Smoke is still there, obviously from the pics I posted, but it clears up good after 2K rpm. I won't have time to double check the timing setting till this weekend, but what do you guys think from my exhaust temp data, too cold? Cruising down the freeway I am still getting 750-950*F, please let me know if there is any other data you would like to hear to determine if the timing is advanced too much.



Thanks guys,



Joe

 

[JGK]

Joe,



On mine, when I roll it on it in 4th or 5th and let it run out, I'll see the boost go to about 40 lbs then stop. As the acceleration continues the temps will climb right up to 1300* then really take off. I believe what is going on is the waste gate is opening at 40 lbs but the pump is still fueling. Since the turbo is no longer adding air to burn the fuel, temps take off.



I don't worry about this too much because I rarely ever drive like that (doin' over 100 when this occurs, so if you try this, find a wide road with no traffic and lots of room to run!).



So if you want to see what your turbo is doing vs fueling and EGTs try this. Might have a friend along to help watch the road while you're looking at guages.



Of course, a better way would be to strap it to a dyno.



I don't think you have to worry about too much timing regarding EGTs. Excessive timing will generally be more of a problem with regards to getting it to run right at low revs and excessive cylinder pressures. But we're talking above 20* timing. Mine is set at about 16. 5* and I like it there. I think what you're seeing is the benefits of the EDMs and turbo. Enjoy!!!



-Jay

 

[JGheen]

Thanks Jay, that is what I was thinking as well about low rev running. I would think if it was too advanced it wouldn't even fire or at least be very tough to hold and idle. I was also curious about the washers I used with the injectors, they were definately thicker than my stock washers, but being copper, they crush down pretty good when torqued so maybe my spray angle ended up just fine and I am just paranoid about it.

Well, I guess I will just check my timing again this weekend to verify and also use the dropped valve method for finding TDC.



Joe