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Discussion Starter #1
I have switched one of the race bikes to High Comp pistons13.5-1 and changed to a wet nitrous system so we can push it much harder this year. Problem with this platform is there are no options to pull a few degrees of timing for the nitrous. (I do not want to switch to our stand alone ECU on this bike). I think we are nearing the limit of what this motor can give anyway. So I am looking for a bandaid. In general with an all out HC race engine on nitrous, I am theorizing Surface Gap Plugs might help with detonation and melting the electrodes off against not being able to pull 2-4 degrees out. Curious if anyone has some experience or thoughts on it. Always someone out there to detail my short comings 馃榿
 

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Depends on your coils, the Champion A55V is an excellent surface discharge plug, colder than std IIRC, the only issue for me is the cap is solid and not removable so if your coils use the threaded section of the plug rather than the cap you're screwed. I changed from wires with soft boots and large Cu ends on my desmoquattro to stick coils that only use the threaded section so i had to revert to a std type plug, or i'd still be using them.
 

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We used surface gap plugs in our top fuel dragster back in the 80's for exactly that reason. To keep the extended tip from turning into a glow plug, the gap can be adjusted by grinding the tip of the ground bar to whatever gap you see fit IF YOU HAVE THE COIL. TheyThey are set @ 0.32 a stock Ducati coil will have no problem with that nitrous or not. Find a NGK racing catalog (The easiest plug on the planet to read & rolled threads) lookup your existing spark plugs dementions & heat range then find the same dimensions in a surface gap select the COLDEST heat range they have available in your plug (The bigger the number the colder in NGK) if your not able to go at least 5 steps colder find another style that is colder drill & tap your head to make them fit.

May the nitrous gods be gentle on you............................
 

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Discussion Starter #4
Thank you guys I appreciate the inputs. Some great insight and information. Since the nitrous bikes (Aprilla & Suckzooki) will be on the button for 25-30 seconds straight I think the surface gap plugs might help protect the motors without pulling timing. I think it would also be an advantage on the twin turbo Ducati, even though that bike runs full stand alone ECU, so it has boost mapping and timing can be programmed and adjusted per boost levels and by gear. This one is being pushed to the absolute limit, but hopefully not over 馃槼. Especially given my ass in nearly on top of the plenum.

From what I read in your post, you think the coils from a 999 are up to the task? Is anyone aware of a better coil for 999? I worry the oem coils may not be up to the task with raised redline and sustained there, and wasted spark.
 

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鈥05 749R, 鈥89 851/926, 749R/999RS project
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From what I read in your post, you think the coils from a 999 are up to the task? Is anyone aware of a better coil for 999? I worry the oem coils may not be up to the task with raised redline and sustained there, and wasted spark.
I swapped my 999RS "Corse" style rocker covers for the OEM 749R covers so I could run the 749/999 stick coils on a 999RS engine in my 749R. It ran like a champ with the RS surface discharge/gap plugs: 168rwhp on a Dynojet 250i with a conservative 11500rpm redline.
 

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Thank you guys I appreciate the inputs. Some great insight and information. Since the nitrous bikes (Aprilla & Suckzooki) will be on the button for 25-30 seconds straight I think the surface gap plugs might help protect the motors without pulling timing. I think it would also be an advantage on the twin turbo Ducati, even though that bike runs full stand alone ECU, so it has boost mapping and timing can be programmed and adjusted per boost levels and by gear. This one is being pushed to the absolute limit, but hopefully not over 馃槼. Especially given my ass in nearly on top of the plenum.

From what I read in your post, you think the coils from a 999 are up to the task? Is anyone aware of a better coil for 999? I worry the oem coils may not be up to the task with raised redline and sustained there, and wasted spark.
I don't know anything about surface plugs but do you have links to details on the twin turbo bike or the one you're talking about here?
 

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Discussion Starter #7
There are no links to the Twin Turbo bike. It is my personal LSR bike I am running this year on FIM world records. Here are a couple pictures of it during construction. What would you like to know?
1002684
1002685
 
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