timing change impacts to 60' and ET?

Kegracing · 07-19-2015, 03:09 PM

Wondering what timing changes will do to my 60' time and ET? Know every motor is a little different, but just give me your opinions and experience please.

This is a GM ZZ4 - 350 ci crate legal IHRA stocker motor, in a 67 Firebird. Stocker cam. I am currently running 38 degrees, with distributor locked. Usually it has consistent 60' of 1.49-1.51 depending on track condition, bracket racing. Last weekend, hot part of the day, it did spin a couple of times... lot of cars were spinning some, track was hot and sun was bright.

TX heat is just getting hotter, and I want to soften up the 60' a little bracket racing. Thinking about pulling 3 or 4 degrees of timing out of it?

I know testing is best, and only positive way to find out, but also know this is fairly common type combo, and lot of experience on here.

Thanks in advance.

Ken

Stock 412

GTX JOHN · 07-19-2015, 03:31 PM

The timing affects our stocker less than you would think if converter and
gearing are optimal. Our cars 38 to 34 would probably be a hundred or
at the very most 1 1/2 hundred.
I have taken 10 out of our heavy O/SA 318 Wagon (38 to 28) and only
lost 3 (1.57 to 1.60).
I would guess a bit more change if at altitude or bad air.
It might help more to put a hundred or two in your weight box.

Kegracing · 07-20-2015, 09:37 AM

Thanks John. Exactly the type of info I was looking for. I do have some weight I can add, so will do that and maybe a little timing too.

Also, glad to hear you were OK after the fire scare. Hope the damage was not too bad.

Ken

Stock 412

07-19-2015, 03:09 PM	#1
Kegracing Member Join Date: Jun 2002 Location: Red Oak, TX Posts: 441 Likes: 0 Liked 0 Times in 0 Posts	timing change impacts to 60' and ET? Wondering what timing changes will do to my 60' time and ET? Know every motor is a little different, but just give me your opinions and experience please. This is a GM ZZ4 - 350 ci crate legal IHRA stocker motor, in a 67 Firebird. Stocker cam. I am currently running 38 degrees, with distributor locked. Usually it has consistent 60' of 1.49-1.51 depending on track condition, bracket racing. Last weekend, hot part of the day, it did spin a couple of times... lot of cars were spinning some, track was hot and sun was bright. TX heat is just getting hotter, and I want to soften up the 60' a little bracket racing. Thinking about pulling 3 or 4 degrees of timing out of it? I know testing is best, and only positive way to find out, but also know this is fairly common type combo, and lot of experience on here. Thanks in advance. Ken Stock 412

07-19-2015, 03:31 PM	#2
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,732 Likes: 2,798 Liked 2,479 Times in 697 Posts	Re: timing change impacts to 60' and ET? The timing affects our stocker less than you would think if converter and gearing are optimal. Our cars 38 to 34 would probably be a hundred or at the very most 1 1/2 hundred. I have taken 10 out of our heavy O/SA 318 Wagon (38 to 28) and only lost 3 (1.57 to 1.60). I would guess a bit more change if at altitude or bad air. It might help more to put a hundred or two in your weight box. __________________ John Irving 741 Stock 741 Super Stock

07-20-2015, 09:37 AM	#3
Kegracing Member Join Date: Jun 2002 Location: Red Oak, TX Posts: 441 Likes: 0 Liked 0 Times in 0 Posts	Re: timing change impacts to 60' and ET? Thanks John. Exactly the type of info I was looking for. I do have some weight I can add, so will do that and maybe a little timing too. Also, glad to hear you were OK after the fire scare. Hope the damage was not too bad. Ken Stock 412