SN-93

[83gt_sn93]

Hey everyone. Just a question, my car has a MSD Digital 6. It has the option of a timing retard for nitrous and I was using it until i could afford a MSD Boost retard. Well now I have the msd boost retard installed. I am running a carb'd application and have 38 deg of timing at 3000 rpm. Now under boost how much timing should I be taking out of it. My paxton is putting out 7lbs of boost at 5500. I dont rev it past there anyways. Also keep in mind my engine was built with 8.5:1 compression and I do have an adjustable fuel regulator that is boost referenced. The car seems to work great but seems to struggle a little over 5000rpm. I am going to play with the jetting a bit. I do have a CSU carb so I am sure that is not the issue. Any help would be appreciated.

Also to give you guys and idea, I added an oil cooler and had the impeller jet hot coated (www.fireballcoatings.com) and I couldnt touch the blower before after driving it because it was so hot, now I can put my hand on it all day long. I did have to shim the impeller but it was no big deal. Just thought I would put that out there.

Thanks,

Randy

[pavement pounde]

Thanks for the info Randy
What would be the benefits of coating on the impeller ?
I think with boost retard it is wise to start with full retard and then while testing go back 1 degree until a knock is heared and the go up 1/2 degree.
But I am not sure about it

[speedytang]

Final timing should be at 19 degrees at WOT. So you need to remove 2.5 degrees for every 1 psi. If your engine is having problems at over 5000rpm you are either blowing out the spark (Plugs should be at .032) or the carb is either to lean or rich. Do you have a wideband? If no wideband taking the car upto the surge and shut the car off and check plug #7 and see its condition. This will tell you your fuel mixture.