cam advance or retard and afr ???

475wildey · #1 07-04-2007, 10:49 AM

does anyone know would retarding cams from +4 deg to straight up be enough of a change to require a retune or what effect it would have on afr ???

Totenkopf · #2 07-06-2007, 08:00 AM

assuming you are efi for a moment, dialing the intake valve opening event back 4* can have an affect. The reason is, we don't get to change the time at which the injector opens. We only can control the pulse width or duration that it is spraying. After the cam timing change, the right thing to do is to put it back on the dyno and see if it responds to probing for more power. If you see a positive response from some initial changes to the map versus the first baseline runs, it makes sense to proceed with redialing in the driveability and WOT stuff. As you would suspect, there are a lot of factors involved with whatever your specifics are in the engine build you have.

475wildey · #3 07-06-2007, 08:53 AM

Thanks for yer responce makes very good sense and yes it is efi

#4 07-12-2007, 06:45 PM

Well I dont like to step on toes HA HA yea right. Any way if you alter the cubic inch size of the engine with the sert it will start to spray the injector earlier than with a smaller injector. This info was passed on to me by Reggi @ R&R. He has done tons of work with the sert and stock ECM . I have tried it and it does work. So say you have a issue with the injector staying on too long and you figure out that you are spraying onto a closing or closed valve. By increase the size it will spray earlier. You will have to remap as it also will feed more fuel as you telling it that the engine is larger than what it is. It is a little trick that can sure some tuning issues. As well playing with injector size.

FXDRYDR · #5 07-13-2007, 06:55 PM

Quote:

Originally Posted by 475wildey

does anyone know would retarding cams from +4 deg to straight up be enough of a change to require a retune or what effect it would have on afr ???

Dunno 'bout retarding 4 degrees. Saw 4 retarded doofs around here somewheres... just sayin'.

Rock · #6 07-13-2007, 06:58 PM

Quote:

Originally Posted by FXDRYDR

Dunno 'bout retarding 4 degrees. Saw 4 retarded doofs around here somewheres... just sayin'.

You look so cute in your avatar. This is a tech thread, u know.

475wildey · #7 07-13-2007, 10:17 PM

I guess yer just all retards

475wildey · #8 07-13-2007, 10:18 PM

Quote:

Originally Posted by HDWRENCH

Well I dont like to step on toes HA HA yea right. Any way if you alter the cubic inch size of the engine with the sert it will start to spray the injector earlier than with a smaller injector. This info was passed on to me by Reggi @ R&R. He has done tons of work with the sert and stock ECM . I have tried it and it does work. So say you have a issue with the injector staying on too long and you figure out that you are spraying onto a closing or closed valve. By increase the size it will spray earlier. You will have to remap as it also will feed more fuel as you telling it that the engine is larger than what it is. It is a little trick that can sure some tuning issues. As well playing with injector size.

Thanks Steve