GPRXP Vigilante Waterbox and exhaust system

[Hydrotoys]

TDR at

http://www.bansheedepot.com/default.asp

and ask for the conversion waterbox for a gpr with the rxp engine.

Part number is "MC1"

TDR RACING
1821 S.W. 7th Ave.
Pompano Beach,
Florida 33060
Ph: 954-784-0020
800-321-6354
Fx: 954-784-0109

You will also need the Riva 1300 free flow hose. Jerry sells it in his online store, or at any Riva outlet.

http://www.4-tecperformance.com/index.php?main_page=product_info&cPath=16_22&products_id=125

You will need to cut your J-pipe below the weld, and rotate the J-pipe. Make sure the lower water hose doesn't contact the SC.

[Hydrotoys]

Good question by RX951...

Why won't the stock rxp waterbox fit in the GPR?

[Hydrotoys]

MC1 waterbox....feet not included.




Painted with aluminum primer and krylon textured paint.



What the system looks like installed in a GPRXP. Note, that the battery can go in three primary locations. As shown, over tunnel, or behind waterbox.


Overtemp sensor shown. Yamaha waterbox tie down shown. Suggest using a high quality clamp on top of waterbox, since hose seems a little loose.

[JFizzleJR]

..

found the answer to my question

[Hydrotoys]

Yup. Just remember the Riva's and RR's are all much smaller holes. So you are going backwards to use those fittings.

[JFizzleJR]

you mean going backwards in the exhaust restriction department, right?

I'm just looking for something as quiet as possible without losing performance. "stealth mode"

[Hydrotoys]

Well, neither is that quiet. I've heard plenty of RXP's with the transom mount. The stock exhaust may be noisier..

Another option, is to go with the stock GPR exhaust and the plastic sound restriction box that comes with it. You should be able to squeeze the IC under it, and the battery behind the waterbox. You don't need the Riva hose, and usually can find the stock hose and plastic resonator on here.

[addicted]

What about the stock gpr water box and SS? I think it would run near silent and backpressure should not be a problem because both engines are very similar in size, but the 4 stroke fires 1/2 as many times at a given rpm. A custom J pipe would be needed, but what is the point of the J shape anyway?

Mark, I know we discussed this, but figured I post to generate some ideas.

[Hydrotoys]

Kill the jpipe. Re-do a pipe within a pipe similar to the J-pipe, and have it shoot back to the stock gpr waterbox. Of course you need to redo the front of the gpr waterbox as well.

The gpr waterbox is well made, and is very huge in comparison. I don't know if the interal backpressure is more or less. Consider sending one to danny, and see if he can flow it for you.

[Hydrotoys]

I just got off the phone with them. They are running about 3 weeks out!

[jeffsntx]

I just got off the phone with them. They are running about 3 weeks out!

Thats why I am going to try to make the RXP box work with a few modifications.

[Hydrotoys]

If you have a good aluminum welder available in your area, no reason it wouldn't work. The RXP boxes have a history of blowing apart. Like Mike suggested above, you would be better off converting a GPR box for reliability sake.

After spending 3 months designing this box, I've been pretty happy with the TDR one. I just wish I could get it faster.

[jeffsntx]

I do know someone that is an awesome aluminum welder. I have the inlet and outlet removed from the box right now. I need to set the engine in it and get it it aligned to have the new pipes welded in it. I figured that removing part of the baffle in the box and making the outlet larger it would reduce the back pressure and help reduce the risk of blowing it apart.

[Hydrotoys]

Not sure. So many have blown out, I'd be careful with that one. I got plenty of gpr waterboxes if you need some for tinkering.

[jeffsntx]

After spending 3 months designing this box, I've been pretty happy with the TDR one. I just wish I could get it faster.

Mark, I am getting VERY close on my second conversion and am trial fitting everything while waiting on Ted to finish my drive shaft. The TDR box that I bought from GP1500SC is WAY off on the outlet diameter. The outlet on the box is probably 1/2" smaller than the free flow hose that I have. Is this common or what? Maybe TDR phucked up when they built this one? I havent pit my micrometer on it but the outlet on the box is the same diameter as the GPR exhaust outlet in the hull. This is just my luck.