Converting 202 to DIS

[inj gtr202 Profile]

A little trick I used to do with very large profile cams, was lean mixture and higher timing. Example, a 308 Holden large solid profile. 15:1AFR and 30 degree timing in those areas. There's some BIN's of mine like this in the custom tune area. That does smooth them out as they're not producing torque when set like that.

I've just ordered a remote IAC Mount to try and sort this out.

I'll start a new thread with Log files etc.

At the moment the timing is around 20 at idle with an afr of about 13.5 at idle.
I've got the closed throttle table timing set to increase as the vacuum drops to try and catch it after a rev.

I'll try leaning in out a bit more and bumping the timing up in the meantime.

[Dylan Profile]

Agreed, IAC is a must.

[vlad01]

Can leaning them out and higher timing in some of the cruise areas help with emissions on a big cam?

[Dylan Profile]

Makes a big difference to plug life on a 5 litre.
But the standard ignition system lacks on anything with higher compression as well. Ignition upgrade and a leaner idle and light load areas makes a world of difference to driveability and plug life.

[vlad01]

In turn emission would benefit heaps too! The headers, and cat won't be glowing red all the time

Also the engine will last longer as the walls aren't being bombarded with unburnt fuel and soot.



I think I leaned out my red car idle AFRs slightly as a warmup transition somewhere tipped it over the edge when cold due to being too rich, it would always abruptly stall when idling.

[v6bucket Profile]

Nice HP out of that cam. I found that using 25° to 30° at idle helped with the idle on a 262° Camtech cam, which has already been mentioned.
vlad01, I'm sure he hasn't got a cat to worry about.

[vlad01]

I meant more the headers glowing, which I found happens at just above idle on my VP when the fueling was too rich, more spark timing helped a little but fueling was the biggest factor by far.

I had the same problem when installing ecotec green 777s into my VP shitbox without adjusting the tune and it was running 12-15% too rich. It incinerated the paint off the chassis rail, the clutch fork cover melted away, cable was bare rusted metal by that stage and lots of other stuff burned too. Leaned it back to the correct values and nothing else changed and the exhaust temps were completely solved.