300/440/550 Tapered nozzle boring on a 550sx question??????????

[splitlaneslikemoses]

How much should I bore my nozzle on a 91 550sx w/ reed motor? I've never done this. I'm gonna send it to Zero soon and need to give him a number. Also, I'm sending him my flywheel and was asked if I want the ring gear drilled? Do I want this done?

Any info would be great? Thanks......

 

[cabatema]

Check out group k (www.groupk.com) these guys sound like they really know what there are doing. They have done extensive testing on everything from pipes, carbs, porting, cyl matching, flywheel lightening and nozzle boring. A lot of good information there if you take the time to read it. I'm sure if you contacting them they would be able to give you there recommened nozzle boring specs based on your set-up. Plus I heard there prices are pretty reasonable.

 

[Conquistador]

I have a JRE tapered bore nozzle, definitely noticed some bottom end improvement.