PDA

View Full Version : Converting RTP to MCX


Roonie's
04-10-2008, 09:44 PM
I did site research and have not found this question asked or answered anywhere. Is it easy to convert an RTP motor to an MCX motor with a simple intake manifold exchange? Can you get the 40 more horses from this swap alone? I assume the better fuel mapping and air flow is through the new intake which accounts for the 40 horses increase as it is same platform everywhere else.

What does the intake manifold cost? A new gasket and manifold is an easy HP increase if this is all it takes.

Hopefully someone can answer this question who is smarter then me.

03 35th Anniversary
04-10-2008, 09:48 PM
You would also have to do something with the ECM, wiring and maybe the cam and heads.....

trickskier
04-10-2008, 09:49 PM
I did site research and have not found this question asked or answered anywhere. Is it easy to convert an RTP motor to an MCX motor with a simple intake manifold exchange? Can you get the 40 more horses from this swap alone? I assume the better fuel mapping and air flow is through the new intake which accounts for the 40 horses increase as it is same platform everywhere else.

What does the intake manifold cost? A new gasket and manifold is an easy HP increase if this is all it takes.

Hopefully someone can answer this question who is smarter then me.
Well it won't be me..................I don't think it is a simple as just changing intake manifolds..........:confused:

JerryS
04-10-2008, 09:49 PM
One thing that comes to mind right away is the ECM programming. I'm assuming the RTP is MEFI 5 as well, but it would have to be reprogrammed by Indmar I'm sure. I doubt both engines have common mapping etc. Is the exhaust the same between RTP and MCX?

Where's engine nut, he'll know.

ShamrockIV
04-10-2008, 09:51 PM
sounds expensive to me!!! like new boat expensive!!

Roonie's
04-10-2008, 10:00 PM
One thing that comes to mind right away is the ECM programming. I'm assuming the RTP is MEFI 5 as well, but it would have to be reprogrammed by Indmar I'm sure. I doubt both engines have common mapping etc. Is the exhaust the same between RTP and MCX?

Where's engine nut, he'll know.


I forgot about the ECM programming and is a big question ?. Could be as easy as hooking up a computer to it for reprogram maybe?

I am guessing they have common mapping and the increased fuel mapping is due to the better intake manifold and longer rails used.

The exhaust for 07 has the CAT on the MCX and not the RTP but that is not a big deal as that wouldn't necessarily have to change. I think all other exhaust components are the same. All just guesses on my part so I was hoping someone who knew could chime in.

TMCNo1
04-11-2008, 07:35 AM
Just put a "Tornado" in your air cleaner! All that extra horsepower and increased gas mileage, it's so simple!

bigmac
04-11-2008, 08:58 AM
Depending on the boat and its age, it may very well end up being cheaper to sell the boat and buy another one with an MCX.

djhuff
04-11-2008, 09:04 AM
The throttle body is different as well.

I agree that it would be cost prohibitive.

east tx skier
04-11-2008, 11:00 AM
Just pick up a can of red engine paint. That's pretty much all it is.




/I keed. I keed.

JimN
04-11-2008, 11:09 AM
Throttle body, intake manifold, a set of 8 injectors, fuel rails, some kind of adaptation for the fuel line (TBI to MFI), ECM recal and other wiring harness changes. The parts alone will be in the $1K range. I'm not sure they have a program for the TBI with CAT and O2 sensor, so those should probably be removed.

JimN
04-11-2008, 11:11 AM
"Just put a "Tornado" in your air cleaner! All that extra horsepower and increased gas mileage, it's so simple!"

You forgot about the magnets that clip around the fuel line- they're supposed to add 20% to the gas mileage by aligning the molecules.

Yeah, right.

Roonie's
04-11-2008, 11:25 AM
Throttle body, intake manifold, a set of 8 injectors, fuel rails, some kind of adaptation for the fuel line (TBI to MFI), ECM recal and other wiring harness changes. The parts alone will be in the $1K range. I'm not sure they have a program for the TBI with CAT and O2 sensor, so those should probably be removed.


I figured it wasn't as easy as it sounded. I actually like the RTP power and have no regrets but if it was an easy 40 hp add on I would have considered it. I have been watching too much horsepower TV on spike on the weekends. They make changing out the stuff look easy. It sounds cost prohibitive at this point. Thanks for the input.

edit; The 07 RTP is not carbureted TBI it is an MFI system I believe.

Hollywood
04-11-2008, 11:30 AM
40 hp from an intake swap alone would be a miracle.

JimN
04-11-2008, 11:49 AM
OK, I'm not a MC tech anymore and haven't worked on anything newer than '01 but I was thinking that anything with MFI would be more than 310HP.

Horsepower TV is supposed to make it look easy- they sell a lot of parts this way. It's done better than the old "Shade Tree Mechanics" and those guys still made mistakes that were left in the show, like the time they installed a power amp and forgot to run the power wire under the carpet and just cut/spliced it. I thought that "fix" was pretty bad, since leaving an insulated butt splice under the carpet with no shrink tubing (or a Heat-N-Seal connector) is going to fail. I don't remember working on a car or truck that never had some water get into the padding under the seats and this is exactly where they ran the power sire.

TMCNo1
04-11-2008, 11:51 AM
"Just put a "Tornado" in your air cleaner! All that extra horsepower and increased gas mileage, it's so simple!"

You forgot about the magnets that clip around the fuel line- they're supposed to add 20% to the gas mileage by aligning the molecules.

Yeah, right.

I'm thinking of going to the flea market Sunday, buy one of everything, get 1010 hp and 79.3 hours/gallon by the time I'm done adding it all on, the way I've got it calculated.:rolleyes: :D And that's not running super unleaded either, nothing but water and tomato juice!

TX.X-30 fan
04-11-2008, 11:52 AM
Just pick up a can of red engine paint. That's pretty much all it is.




/I keed. I keed.



33526



Nice cut Eastie!!! 8p

TMCNo1
04-11-2008, 11:56 AM
33526



Nice cut Eastie!!! 8p


I want one of those Captain drivers hats!:rolleyes: :D The crew always wears white!

TX.X-30 fan
04-11-2008, 11:59 AM
I figured it wasn't as easy as it sounded. I actually like the RTP power and have no regrets but if it was an easy 40 hp add on I would have considered it. I have been watching too much horsepower TV on spike on the weekends. They make changing out the stuff look easy. It sounds cost prohibitive at this point. Thanks for the input.

edit; The 07 RTP is not carbureted TBI it is an MFI system I believe.




I believe the medical term for this would be MCX envy??? 8p



33530

JimN
04-11-2008, 12:09 PM
I forgot about the throttle by wire. That might add ~$50 to the total.:D

trickskier
04-11-2008, 12:09 PM
Just pick up a can of red engine paint. That's pretty much all it is.




/I keed. I keed.
That's CANDY APPLE RED.................. :uglyhamme

Roonie's
04-11-2008, 12:14 PM
I forgot about the throttle by wire. That might add ~$50 to the total.:D

The 07 RTP is also throttle by wire.

Roonie's
04-11-2008, 12:15 PM
I believe the medical term for this would be MCX envy??? 8p



33530



She sure is pretty!

peason
04-11-2008, 12:20 PM
Just what you need - more power in that sweet X2! Maybe you should soop up the John Deere so it can throw all this sucking snow 100 ft!

Roonie's
04-11-2008, 12:23 PM
Just what you need - more power in that sweet X2! Maybe you should soop up the John Deere so it can throw all this sucking snow 100 ft!

LOL now we are talking.

Nitrous anyone?

east tx skier
04-11-2008, 12:39 PM
Throttle body, intake manifold, a set of 8 injectors, fuel rails, some kind of adaptation for the fuel line (TBI to MFI), ECM recal and other wiring harness changes. The parts alone will be in the $1K range. I'm not sure they have a program for the TBI with CAT and O2 sensor, so those should probably be removed.

His is an 07, Jim, isn't it MPI already?

/edit. That already got answered.

east tx skier
04-11-2008, 12:40 PM
33526



Nice cut Eastie!!! 8p

I actually am in as good of shape as that dude. 8p

See, you can get away with posting a picture like that. I probably could not.

Roonie's
04-11-2008, 01:10 PM
So I asked Indmar directly what the differences are and this is the response.

The MCX and RTP start out as the same base engine like you suspected. The intake is the main difference but there are other things as well. The computers that operate the engine ate different which makes the wiring harness different. The exhaust systems on the two engines are also different with the MCX exhaust allowing the engine to breathe easier and perform better. Even just doing the intake might be cost prohibitive. The lower intake retails for 553.00 and the plenum top for 336.75.

sand2snow22
04-11-2008, 01:36 PM
Ah, just drop a crate motor in her like Horsepower TV!

Jerseydave
04-11-2008, 01:57 PM
Changing your prop would "feel" like an extra 40 horsepower

Roonie's
04-11-2008, 02:03 PM
Changing your prop would "feel" like an extra 40 horsepower

Agreed. It came with the 14.5 x 14 OJ so it jumps out of the hole. Indmar also sent me the torque/HP ratio chart comparing MCX to RTP and it as I suspected the real advantage to the extra 40 hp is in the top end of the RPM range. Not something I really care about as I don't barefoot. Both engines are very similar up to a certain point and then the MCX keeps going and the RTP stops at certain RPM ranges.