Couple of questions

[1968Droptop]

If you had a n/a engine tuned perfectly, and just added a supercharger, wouldn't the jetting stay the same ? Just more air moving through the carb, but the mixture would still be correct ?
I'm running 96's, and it seems to be a little fat. Currently have NGK racing #8's. Was playing with the idea of going one range hotter to #7's. I know hotter plugs can equal detonation. Not sure if I want to go a tad leaner on the carb, or hotter on the plug ? Suggestions ?

[jrork]

Bouncing it up to the top for a buddy.
Besides, this boat has a regoddamndiculas blower surge. LOVE IT! Drop dead gorgeous bad azz boat Droppy has......

[DMOORE]

Don't go hotter on the plugs. 8's are where you want to be. I've read before that some setups will actually need to go leaner after a blower install. Every engine is different. Is the motor fat at idle or WOT?
Darrell.

[jimsplace]

The general consensus has been to jet up about 4 initially, increase squirter size about 4-5. Some feel this will put you on the safer side, but not too far off. Being lean with a supercharger is not part of the "lean and mean" status. Being lean is just expensive, and you get to try over.
I have been told, I may end up with the same jetting as naturally aspirated, but I haven't got there yet. I am still working on that part.
At idle it wanted to run rich, but it is idling good now.

[1968Droptop]

Thanks for da bump Johnny Show :D. It's fat at idle for sure, leaving a lot of black chit on the back of boat after a day of boating. I know I need to get it to the dyno over the winter.
I was just wondering out loud about plug heat range vs. jetting. I was also wondering out loud about my jet size, as a buddy is running 92's on his 521 BBF (n/a tunnel ram w/ Dominators).

[atxwrangler]

FOR WHAT IT'S WORTH I'M RUNNING86'S/ 93'S! NOT MUCH SURGE AT ALL :mad: ,PLUGS LOOK JUST RIGHT! :)

[ghittner]

Don't know about Washingtons pump gas but here in Ca it is impossible to jet by looking @ plugs. With the additives we have here, I was 10 jet sizes too large in the primaries and 8 sizes too large in the secondaries and the plugs were bright white!:eek: The only way to be sure here in the Bulls*it GREEN states is to purchase an A/F ratio meter. I bought the new NGK Powerdyne tool for $225.00 and it's the best,most fun, most usefull tool I've ever purchased. With todays fuels, this is the only way to tune. Now I know I'm right on! 11.3 @ WOT and 12.0 @ cruise. I also have a pyrometer that runs about 1400 Deg. Oh yeah, I surge 50-100 RPM. No soot, no fouling and I run the coldest range available in the plug that fits my Canfield heads. I'm running a 498 w/ 8:1 compression, B&M 420 w/ dual 750 DP's jets are 73's and 83's, 10 Pds boost. Crower cam W/694/723 lift and 267/276 duration @ 50. Hope that helps....

[1968Droptop]

I'm running 96's. I know an A/F gauge would be nice, but not gunna happen with my exhaust
http://i134.photobucket.com/albums/q90/DaytonaTunnel/CIMG0286.jpg

[Shadow1]

The LM-1 is a nice wide band oxygen sensor and it can store up to 40 minutes of run time so you can download it on your computer later on and watch the fuel curve. It also has a great manual calibration button so you know if it is accurate.

[ghittner]

I'm running 96's. I know an A/F gauge would be nice, but not gunna happen with my exhaust
http://i134.photobucket.com/albums/q90/DaytonaTunnel/CIMG0286.jpg
I have an uncoated, polished, Stainless Marine collector that I had to weld through the water jackets into the exhaust stream. It was actually very basic to get done however with mine, I just had to polish the Stainless back up. Your's would need to be recoated unless you put it where it's hard to see???? The sensor is only in for tuning, you can take it out and plug it when done. :confused:

[cruser]

Drop,
I have the same headers and am kicking myself for not getting the bung welded in when I ordered them. I might just look around for a cheap set of regular headers to put on and tune with. Wonder how much the header differences would effect the A/F.........
By the way, Az is great for boating. They are predicting 81 today and 84 tomorrow at the local lake.

[jimsplace]

1968teardrop
On the surge at idle and running rich. I had the same problem. It takes a little time, but what was suggested to me and it did work.
Turn the idle mixture screw in, the engine will increase in speed, and maybe surge, reduce idle speed with idle screw. Go through this process as many times a necessary to get best idle. Be sure and do all the screws the same each time. Do these steps in small increments.
I am actually 1/8 - 1/4 turn out on idle mixture screws. (my next step is to increase the idle air bleed to get the idle screws back out for a little more wiggle room if I want). Holley told me even the 1/8 out may be a minimum, but it is OK.
I am running a 540 bbc, (2) 1050's, and a 14-71 blower. I was told my carburetors absolutely would not work and I needed different carburetors. The engine idles at 1200 out of gear and 1000 in gear very evenly with no black smoke at idle. It idles as well now as it ever did naturally aspirated.

[ghittner]

1968teardrop
On the surge at idle and running rich. I had the same problem. It takes a little time, but what was suggested to me and it did work.
Turn the idle mixture screw in, the engine will increase in speed, and maybe surge, reduce idle speed with idle screw. Go through this process as many times a necessary to get best idle. Be sure and do all the screws the same each time. Do these steps in small increments.
I am actually 1/8 - 1/4 turn out on idle mixture screws. (my next step is to increase the idle air bleed to get the idle screws back out for a little more wiggle room if I want). Holley told me even the 1/8 out may be a minimum, but it is OK.
I am running a 540 bbc, (2) 1050's, and a 14-71 blower. I was told my carburetors absolutely would not work and I needed different carburetors. The engine idles at 1200 out of gear and 1000 in gear very evenly with no black smoke at idle. It idles as well now as it ever did naturally aspirated.
Agreed, I was told the same, you just need to take the time to understand the surge is from being too rich. I as well am running 1/4 out all the way around and no surge, no soot.

[@theRVR]

1968teardrop
On the surge at idle and running rich. I had the same problem. It takes a little time, but what was suggested to me and it did work.
Turn the idle mixture screw in, the engine will increase in speed, and maybe surge, reduce idle speed with idle screw. Go through this process as many times a necessary to get best idle. Be sure and do all the screws the same each time. Do these steps in small increments.
I am actually 1/8 - 1/4 turn out on idle mixture screws. (my next step is to increase the idle air bleed to get the idle screws back out for a little more wiggle room if I want). Holley told me even the 1/8 out may be a minimum, but it is OK.
I am running a 540 bbc, (2) 1050's, and a 14-71 blower. I was told my carburetors absolutely would not work and I needed different carburetors. The engine idles at 1200 out of gear and 1000 in gear very evenly with no black smoke at idle. It idles as well now as it ever did naturally aspirated.
Glad to hear you and the engine are still happy. :) :)