timing issues and vortec question

[go_faster]

Ok guys and girls... I went to the track yesterday after doing a vortec conversion on a stock truck. Truck runs fine on the street but at the track it started detonating at the top end of the track and was shutting down. I was looking to base timing but my timing 'tab' is rusty and I can't find zero. Does any one have a pic of a good one? Is zero in the little notch or at the tube piece that is welded to it?

Also the truck has less power now than before the conversion. I simply installed stock 2001 vortecs with the converted intake, no change to push rod length, rocker ratio or cam. Was there someting I should have changed in the valve train geometry? Just doesn't make sense that it's slower.

 

[BoostedSUV]

Re: timing issues and vortec question

You need to retune the truck for the vortec conversion. You can't just bolt the heads on and go otherwise you will be making less power. You probably should have changed the cam as well to match the heads.

The push rod length and geometry are the same so that is not your problem. The problem is not having the correct tune for the swap. The 0 timing mark is the big notch on the pointer...

 

[go_faster]

Re: timing issues and vortec question

thanks. Timing is, and was, set right then. I am on my way to pick up my moats APU1 so tuning is to come. I suspect it is fuel.

 

[cloneman315]

Re: timing issues and vortec question

put a wbo2 and data log,that truck is going to blow up fast!!!!

 

[BoostedSUV]

Re: timing issues and vortec question

I was just going to ask if you had a WBO2 or DM to reference what's happening. I suspect that since the vortecs flow a lot more air you are running lean with the the stock tune.

 

[go_faster]

Re: timing issues and vortec question

I suspect its lean too. I didn't evenmake the full pass and am not driving it till this is fixed. I am doing some datalogging today to see what is going on.

 

[Quickstop [UK]]

Re: timing issues and vortec question

Dude, the heads flow something like 20% better than stock heads so your turbo is flowing way more air in there so you are LEAN.

Your spark retard will have been going nuts prob due to detonation. Did you do any research before you did this? Not being a hater but seems you are surprised.

The cam needs doing, you need to check your valvetrain geometry just in case - were the heads milled at all? If so then you have a higher compression and your valve train may be out.

New cam - yup, need than.

New injectors - if you want to really use those heads then you will need them too.

New tune is the most important thing here and you need a WBO2 for that.

Is it a Typhoon? Your avatar suggests an S10.

Don't drive at WOT until you have done some more things to it dude!!!

Good luck and welcome.

 

[go_faster]

Re: timing issues and vortec question

THanks for the input. I am not driving it at all till this is figured out. The truck is a stock typhoon with vortec heads. S10 in pic is a roots style supercharged smallblock, it has an old school carb which I understand how to 'tune'. Just got an APU1 and am trying to get some information from this thing, I have to admit it is new for me and I am having some difficulty getting it to pull information. I found the proper files and it is getting some information but the packet error count raises quickly and the data is not correct. Is the dashboard on tunerpro supposed to display figures in real time? Seems mine only show on the playback. Any ideas?? Note that I am just trying to get info at this time, no emulation or changes to the chip. I am using the stock code 58 files that I found on code 59 website.

3 bar map and wideband on order, should be a few days.