WHYTLIE

Hello all, hopefully somebody can explain this to me better.

I'm installing an MSD Start/Retard box on my '96 Z-28 to use with nitrous. I've already got the MSD 6AL and appropriate MSD harness. I bought this box off a friend who bought it off E-bay with no instructions. It didn't work on his car so I sent it to MSD and they sent me a brand new box. I went online to MSD instruction download, but the only Retard box they have on there is the 3 step retard. I called MSD tech and got directions on how to install it (what wires go where.)

Also the instructions for the 3 step retard box state that just by hooking it up, it will retard your timing by 4* right out of the box and that you need to adjust for that. So I asked him if the same is true for the normal Start/Retard box. He said he was pretty sure, but not positive.

Does anyone know if this box will retard my timing 4* right away even when not activated by the nitrous kit?

Second, how can I check to see if it is affecting my timing? I figure I would notice a HP loss on a dyno with 4* retarded timing, right? So I could dyno and check the hp difference with the box hooked up and disconected?

My main dilemma is that the pcm will be calling for XX amount of timing, but the Retard box changes that at the coil/opti so the pcm will never know the difference, right?

I hope I was able to be clear about all that, and thanks for any and all help you can provide.

Highlander

If it does retard, just retune or reprogram and add the 4º to the tables and the ENGINE, which is the one that matters, will not notice anything...

But be careful... and add it little by little...

You will notice a performance loss because 4º is a lot...

WHYTLIE

Well that is just it... I don't know if it DOES pull 4* of timing, so I was trying to figure out how to check that.

And if it does I would of course add 4* more timing back to my tables to bring it back to stock. Then put a retard pill in for the amount of nitrous I will be running and all should be happy

But I am still wondering if anyone else has run into this issue yet? Or if they know if this box does pull 4* of timing out?

Camaro_SS/R

Hi Brian,

I definitely don't think that is the case. The kit should come with 4 retard modules for 0, 2, 3, 4 degree that you can plug in. This is the degree of timing that will be retarded when activated either by your nitrous solenoid activation or however you set it up. I had used this for my NOS setup in my old supra and it worked fine.

Here is the instruction for you http://www.msdignition.com/pdf/pn8982.pdf

It should only retard either 10 or 25 degree (you select) on cranking then this retard is turn off when you hit 1300rpm. There will be no more retard until you activate it either high speed at 4000rpm, when ignition is on, or by your nitrous solenoid activation.