I've heard that with a N/A build in the 11+ range (93 octane) it may be necessary to retard timing on the dizzy to prevent knock and increase reliability (but I've also heard that this isn't necessary until 12+...)???

Also, with a 75 wet shot, Zex recomends a 4 degree retard.

My question is - With an 11:1 CR and a 75 wet shot would I be safe setting my dizzy to 12 degrees and leaving it at that?

I ask because I don't want to invest in a system (ie M.S.D.) just to retard timing when on the bottle if it's not completely necessary.

Additional info that might be helpful in answering this question - Engine is 11:1 CR D16Z6 fully built... forged internals, upgraded cam, springs, retainers, valves, port, polish, etc, etc... Using Uberdata for management (unfortunately they don't have nitrous retard yet... that I know of.) Can't really think of anything else that might be helpful, though I'm sure there is...

 

Bump... c'mon peeps, at least a simple yes or no answer.... I searched on this already and couldn't find anything.

 

12 degrees should be just fine. I'm running stock timing right now on my 12.1:1 Comp LSVTEC, 93 pump gas. Retard to 12 and use some NGK plugs with a heat range of 7 or maybe even 8 in your case. The MSD system is worth it... you're not losing power off the bottle with retarded ignition.

 

The problem with retarding your timing that much is the off the bottle performance loss. Since you're only on the bottle about 1% of the time, the engine performance will suffer the other 99% of the time. I run a Hondata system that automatically pulls whatever amount of timing I want when the nitrous is activated and runs full timing when off the bottle, works great. If I were you I'd invest in at least an MSD system that will pull timing when nitrous is running or switch to a management system that will do it for you like Hondata.

A 4 degree retard should be fine with your setup as long as you know you've got good air/fuel/nitrous ratios when spraying. Proper heat range plugs are important too for those track days.

 

Yeah, I knew that there would be an "off the bottle" penalty for having ignition retarded that much, but I'm trying to decide if that drop in power is worth the hundreds that an MSD setup would run me.

How much of a loss can I expect from a 4 degree retardation off the bottle, and how much do the MSD systems that would help me with this cost? (I've looked and I can't find one...)

Oh, and thanks for the info so far.

 

I found with my B16 that the initial throttle tip in was poor on just a 2 degree retard, a 4 degree retard made my car feel pretty gutless off the line. For the hell of it you could always go out and retard your timing 4 degrees and see what it feels like and then return it to stock. I think you'd have to look at something like the MSD digital 6 type ignition system. I know they are more than a standard MSD 6A box but not sure on the pricing. Check them out online and see if it meets your needs and what the cost would be. Ultimately a Hondata S200 system with nitrous control may end up being the cheaper/easier route to go.

 

Thanks. Appreciate the help, just what I was looking for.