7.69in from powerhead gasket.
7.69in from powerhead gasket.
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is the e-tec one a bit too fat at the top though ?
the volume of the e-tec looks miles bigger from the pictures than a similar one for sst motor like heavy kevi makes.
it only has to be a couple of mm in each direction and it will be miles out.
any dimensions of this one ?
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Please dont think I knocking you mike, I am not, I am
just trying to clear something up.
if this exhaust is going on a longshaft that has a different adaptor plate thickness I believe ( could be wrong , again ) wouldn't the tuner length need to be different yet again
especially if running on a fishing boat .?
I understand this is correct length on a short mid for v bottom, but if fitted on the longer 20 inch mid what should the length then be ?
I ask as its dealing with a totally different gear ratio and going inside the longer bigger can,
Most people doing the tuner mod will be running the short mid and the 1.86 ratio on race boats rather than 20" with 2.42 on a average speedboat/fishing boat.
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No problem Phil. Im going to guess here but I think for best engine performance the tuner length to powerhead should be maintained. For a 20 " would usually be on a larger boat that would require more bottom end power to get it up. If your application only runs 6200, my pipe numbers are to short. I know those numbers are great for running 7400. You do not want to run over 7800 in any application. You can't get a Jet to turn those rpms. Typical longer pipe gives you more low end power, but can limit the top rpm ability. As you shorten it to get higher rpms, you will loose bottom end power, The torque peak is moving up. You have to decide what your application can tolerate. Hope this helps.
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close enough to "modify" it is tapered
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Ive spun mine 7800 with stock tuner. Boat went 57.5kn. It doesnt need to be cut at all if you dont like.
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If you can pull a good prop load at 7800 rpms, I would agree don't shorten it. With the longer pipe it will, get on plane better and have more low end power with the long pipe. you may want to bring your rpms down and try bigger prop yet. I could see that working in drag applications. There it's all about acceleration, over reving out the back door does not matter as much.
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