Community Forums

bigdgr · 12-25-2012, 02:04 PM

Does anyone have actual experience with the MP8 from ts performance on the c7 cat ? It sounds good but would like to hear from actual users. Thanks

aztortuga · 12-26-2012, 09:56 AM

I have had an mp8 installed on my caterpillar c7 in a 40 ft motor home for the last several months. In my trip to Arizona from Oregon this year the mh pulled the mountain passes with much more vigor, had better acceleration, but after 1600 miles of experience I can only see minimal improvement on fuel mileage. I am well satisfied with mine. I did have it set off my in dash engine alarm so had to "turn it down" on the provided control knob. I am concerned about exhaust temp as it is running 1375 degrees easily on long hard pulls with 27.5 pounds of turbo boost. I unfortunately didn't check the exhaust temp before I installed the c7 so can not at this point offer a before and after comparison. Will check the exhaust temp without the mp8 during the next several weeks and report back. I am definitely satisfied with the increased performance but I do back off the accelerator pedal on these long had pulls when the exhaust temps go up.

Mystery · 12-26-2012, 10:05 AM

Who installed mp8?

aztortuga · 12-27-2012, 12:54 AM

Installed the mp8 myself. Not difficult if you have some mechanical ability.

bigdgr · 12-27-2012, 11:00 AM

Thanks Aztortuga. We are going to Alaska this summer and I was interested in increasing fuel mileage and climbing ability in our 05 Travel Supreme 38 DS04. Although several sources say that 1325 EGT is fine in the c7 I would be concerned myself. What were your EGT's on similar climbs before installing the MP8 ? The factory claims no EGT increase which puzzled me. Any updates would be appreciated as I'm unsure which way to go right now. Our mileage runs between 7-5 and 8 pulling an 03 Jeep Grand Cherokee Ltd at 65-70. Thanks again, Darrell

Korryp · 12-29-2012, 09:45 AM

Had one for a few years now. Mileage went up a little but if that is the only reason you are looking at one I'd pass. My coach pulls mountain passes a lot easier and has better torque. I'd do it again.

jauguston · 12-29-2012, 02:05 PM

I have one also. It adds noticable power but if you are looking for more than barely measureable increase in fuel mileage don't bother. There will be a slight improvement but when you find this new found power you tend to use it negating the mileage increase.

1375-1400 degrees EGT with the sensor pre-turbo is safe. The engine has steel pistons rather the more common aluminum pistons in other diesel engines and the steel can tolerate higher EGT.

It is a very easy DIY install. Once you get access to the top of the engine its a 5 minute job. The worst part for me was threading the available 40' controller extension cable from the engine up to the dash board so I could adjust it from the drivers seat.

Jim

Mystery · 12-31-2012, 08:51 AM

Any opinion on decreasing the life of the engine or tranny because of use of the mp8 or other performance chip mods?

ajm12 · 12-31-2012, 09:08 AM

Quote:

Originally Posted by Mystery

Any opinion on decreasing the life of the engine or tranny because of use of the mp8 or other performance chip mods?

The thing I am a little leery about is installing the EGT sensor.

jauguston · 12-31-2012, 10:02 AM

Everyone has a opinion. Here is mine. The Cat engine is a 300,000 mile engine before overhaul. If the MP-8 reduces engine life at all and I don't believe it does if you don't pull it for long periods at a EGT over 1500 degrees it is not going to be by much and the chances of a motorhome getting that many miles in its lifetime are quite slim.

If the transmission is kept at or below 300 degrees fluid temperature measured at the fluid out location you are not hurting it.

Jim

jauguston · 12-31-2012, 10:24 AM

12,

Installing a pyrometer is project that takes some thought and some standing on your head.The sensor should be installed in the exhaust manifold right next to where it and the turbo join. The turbo is dual inlet so you don't want to drill your hole in the center of the manifold or you will hit the divider. The hole needs to be offset to one side a little bit-doesn't matter which way. When I did mine I put the large hose for my Shop-Vac in the exhaust pipe and taped it up to seal it. I put the hose on the outlet side of the Shop-Vac to pressurize the exhaust system. I did that so when my drill went through to the inside of the manifold the pressure would blow the metal chips back up the drill bit and keep from getting any metal chips into the turbo. Worked fine. I drilled and tapped for 1/8" pipe thread. and got a sensor that was 1/8" pipe thread. The Shop-Vac did a good job of blowing the tap chips out as well. Once the manifold is tapped you are 99% done.

Jim

ajm12 · 01-01-2013, 06:43 AM

Quote:

Originally Posted by jauguston

12,

Installing a pyrometer is project that takes some thought and some standing on your head.The sensor should be installed in the exhaust manifold right next to where it and the turbo join. The turbo is dual inlet so you don't want to drill your hole in the center of the manifold or you will hit the divider. The hole needs to be offset to one side a little bit-doesn't matter which way. When I did mine I put the large hose for my Shop-Vac in the exhaust pipe and taped it up to seal it. I put the hose on the outlet side of the Shop-Vac to pressurize the exhaust system. I did that so when my drill went through to the inside of the manifold the pressure would blow the metal chips back up the drill bit and keep from getting any metal chips into the turbo. Worked fine. I drilled and tapped for 1/8" pipe thread. and got a sensor that was 1/8" pipe thread. The Shop-Vac did a good job of blowing the tap chips out as well. Once the manifold is tapped you are 99% done.

Jim

So if I understand you correctly you are blowing into your exhaust pipe and forcing metal pieces back into the hole you drill. My only concern is how do you know all the metal pieces will come out the hole and know back into the engine?

jauguston · 01-01-2013, 09:41 AM

No you do not understand what I wrote. The positive pressure prevents metal chips from dropping into the exhaust manifold. There is a very slight danger that a metal chip from the drill or tap could damage the turbocharger so the positive pressure in the exhaust is just a little insurance that nothing will drop into the manifold. Another way to prevent chips from dropping into the manifold is to fill the flutes of your drill bit and your tap with heavy grease. The sticky grease will catch chips. It needs to be cleaned and regreased several times as you drill and as you tap. If you still don't undertand the process I describe I would not recommend you do it.

Jim

aztortuga · 01-01-2013, 09:49 AM

I have done two pyrometer installs, both as jagustin recommends. I did not use his reversed shop vac method but believe it has merits. I used a new drill bit,a magnet pickup tool and liberal amounts of grease to lube and collect metal particles on the drill and from within the hole being drilled. By the time I had penetrated about 1/2 inch before breakthrough into the manifold, I had removed virtually all of the metal particles. I do not believe there was much to go into the manifold as the drill broke into the interior space. I have not had any problems using this method of going slow, removing particles as I went along, and using care when doing the whole process. It did seem to take a long time to drill the hole but the manifold on the c7 is pretty thick and when you are standing on your head to perform the drilling--well you get the idea.