TBM cones with OEM pumps and hookers

[Foximus]

The farther you shim it, the less it will immediately load up the pump from your hole shot.

 

[OCD Solutions]

The farther you shim it, the less it will immediately load up the pump from your hole shot.

Gotcha, setback helps load the pump but if the setback loads it up too much for the engine to handle, you can take it back out with shims and find a happy medium instead of a new impeller?

 

[Foximus]

Yes. Talk to art at jetworks.... hes probably one of the only people who does not agree with how Impros sets up impellers. He says even without the additional setback people request, dave cuts them back to far. They load up the engines before they can get on the pipe. I'm starting to agree with him after playing around with mine. I may be ditching my 9/17 hooker for a stock SXR impeller.... =\

 

[OCD Solutions]

Yes. Talk to art at jetworks.... hes probably one of the only people who does not agree with how Impros sets up impellers. He says even without the additional setback people request, dave cuts them back to far. They load up the engines before they can get on the pipe. I'm starting to agree with him after playing around with mine.

I wonder if he does them that way as a starting point so they have more adjustment than they need without having to be sent back for more? If I thought I wanted 3mm setback but there were guys running up to 7mm then I may ask for 7 or 8mm setback and 5mm of shims.

It may also be to make up for variance between pump stators. :dunno:

Either way, it requires the end user to know more about pump setup than just simply threading the new impeller on and rockin it.

I'll be assembling my Mag pump soon so these details are all very good. I've never played with anything on a pump other than swapping impellers so I'm sure I'll have more questions soon about pump tuning for optimum efficiency, hookup and power delivery.

 

[Matt_E]

Yes. Talk to art at jetworks.... hes probably one of the only people who does not agree with how Impros sets up impellers. He says even without the additional setback people request, dave cuts them back to far. They load up the engines before they can get on the pipe. I'm starting to agree with him after playing around with mine. I may be ditching my 9/17 hooker for a stock SXR impeller.... =\

I have to wonder if that's not a reason for some people's troubles with TBM cones loading down their engines too much. The impeller sits so close to the vanes when it's cutback. Add the TBM cone and you have a higher pressure pump.
Now the engine might have some real problems getting going against that load.

 

[Foximus]

In short I was talking to both Art and Dave, and they both agreed what I was planning was too much, Art HIGHLY recommended agaisnt it and even Dave said that it would be no good...

But with my setup, I've actually given myself the ability to switch between a 650pump and a 750 pump and use the same prop and driveshaft. Since I already have a 6mm cutback on my hooker (which is 6mm more what dave cuts them down as to turn them into hookers in the first place), I can switch it into the 750 pump and result in an EFFECTIVE 12mm of setback and clear everything just enough. Dave said it would ruin my bottom, and art said it would kill about all my pop. Its just far to much load.


And yes I know, very few things are built with anywhere close to that much setback, but you can take it in proportion and make a conclusion.

 

[Waternut]

Either way, it requires the end user to know more about pump setup than just simply threading the new impeller on and rockin it.

There may be quite a lot of truth to that. Dave has been making these props for quite a while and I have just recently seen them advertised on his site. He sold them through PM's, phone calls, and their whole existence was known only on forums.

 

[Big Kahuna]

Yes. Talk to art at jetworks.... hes probably one of the only people who does not agree with how Impros sets up impellers. He says even without the additional setback people request, dave cuts them back to far. They load up the engines before they can get on the pipe. I'm starting to agree with him after playing around with mine. I may be ditching my 9/17 hooker for a stock SXR impeller.... =\

Dave and Tim Bushman did a lot of testing on the SXR's with design, repitching and cutback. Every builder out there does things differently, but for prop questions I would stick with a person who does just that. For Motor questions, I would not call Dave.

 

[Boris]

I'm dying to give a hooker a try, anyone want to let me use theirs ? :439: