Advice Needed from 6.7 Cummins Experts...

[SVTXTC]

Asking for a friend.....

2016 RAM 3500 SRW with a 6.7 cummins with the AISIN transmission. D3leted with a Rac3m3 tuner.....4 inch turbo cat-back exhaust. AFE intake. Banks Intercooler. Lowest possible power tune at 60+HP. The truck has 99k miles and has developed a nasty exhaust manifold leak that permeates the cab. Looking for suggestions on the best replacement two or three-piece exhaust manifold upgrade so this does not happen again.

The diesel shop recommended if my friend wants to replace the turbo....now is the time to do that because its free labor because of the exhaust manifold replacement. What turbo would you recommend?

Currently....my friend is looking at a BD steel multi-piece exhaust manifold upgrade. Would you do this and keep the stock 99k turbo or upgrade?

Thoughts on replacing the stock turbo with a Fleece Performance Cheetah 63mm or 64mm turbo? It's currently hitting 33psi in boost with the stock turbo. There are no head studs done. The diesel shop refuses to install head studs without pulling the head and resurfacing it. I know many other replace the head studs one at a time and others seem to be ok. The shop he uses refuses to do this head stud install. This truck is used daily for towing enclosed trailer and towing an open car trailer. More power is always nice....but more concerned about reliability. Please advise. Thanks guys.

 

[AustinSN]

I guess I could be ignorant on these engines, but even a 7.3 you'd never bother replacing a turbo unless it was bad for just a 60hp tune.

A quick search shows some 6.7s pushing more than 550whp on stock turbos. 100k miles isn't much for a diesel turbo, I would save the $3k personally.

 

[Tractorman]

Look up Tater Bilt turbos on facebook. But unless he wants big power, I would just stick with the stocker charger for now.

 

[venmos1]

whats the cost for replacement when it does fail? This truck going to be kept long term? Seems pretty common knowledge that the stocker vgt is going to fail at some point. I vote second gen swap time!

 

[SVTXTC]

I guess I could be ignorant on these engines, but even a 7.3 you'd never bother replacing a turbo unless it was bad for just a 60hp tune.

A quick search shows some 6.7s pushing more than 550whp on stock turbos. 100k miles isn't much for a diesel turbo, I would save the $3k personally.

There isn’t anything wrong with the stock turbo. When you choose the exhaust manifold, you are presented with all kinds of options for mounting different turbo upgrades. It seems like the appropriate time to do it is all.

 

[SVTXTC]

Look up Tater Bilt turbos on facebook. But unless he wants big power, I would just stick with the stocker charger for now.

I’ll check him out. Thanks! He would like more power but doesn’t want to hurt the 6.7 on the stock head studs with 34+ psi.

 

[SVTXTC]

whats the cost for replacement when it does fail? This truck going to be kept long term? Seems pretty common knowledge that the stocker vgt is going to fail at some point. I vote second gen swap time!

The labor for the exhaust gas manifold swap is $1100. A turbo swap would be free and would save $1100 in labor again in the future. It will fail at some time 100%

The upgraded turbo would be $2300-$3500.

The diesel shop also tunes the vehicle. It will need a tune revision for the new exhaust manifold. The turbo would be tuned for free as well at the same time for added future savings

 

[SVTXTC]

Picture of the beast!

 

[AustinSN]

The labor for the exhaust gas manifold swap is $1100. A turbo swap would be free and would save $1100 in labor again in the future. It will fail at some time 100%

The upgraded turbo would be $2300-$3500.

The diesel shop also tunes the vehicle. It will need a tune revision for the new exhaust manifold. The turbo would be tuned for free as well at the same time for added future savings

A few things to chew on.

A manifold is going to be more labor intensive than the turbo. Reading on various forums, book time for a turbo is anywhere from .9 hours to 1.7 hours but most guys say there is no way and it's at least 3.5 if you know what you are doing. Assuming $140/hr for labor (about what it is around here), if they are charging him $1100 for a turbo swap, they are trying to get 8 hours for it.

I'm seeing quite a few guys get over 200k miles out of the stock turbos (especially deleted trucks), seems like most of the time it's a failed actuator, which some mechanics fix that as opposed to replacing the turbo.

Kind of surprised they would want to retune the truck just because the manifold is different (flows slightly better I imagine), I can see it for a max power situation, but for a 60hp tune it's a little odd to hear that.

At the end of the day, it's his truck/wallet, but it just doesn't seem worth it to me. His power is well within the capability of the stock turbo, it sounds like it's still in good shape, and if he does want to push the limits of power there are other parts of the truck that will live a shorter life.

PS Nice ATC I've got a 24' myself.

 

[beau t]

My question would be how much play does the stock turbo have or does he just want to swap it to get more power.

 

[SVTXTC]

A few things to chew on.

A manifold is going to be more labor intensive than the turbo. Reading on various forums, book time for a turbo is anywhere from .9 hours to 1.7 hours but most guys say there is no way and it's at least 3.5 if you know what you are doing. Assuming $140/hr for labor (about what it is around here), if they are charging him $1100 for a turbo swap, they are trying to get 8 hours for it.

I'm seeing quite a few guys get over 200k miles out of the stock turbos (especially deleted trucks), seems like most of the time it's a failed actuator, which some mechanics fix that as opposed to replacing the turbo.

Kind of surprised they would want to retune the truck just because the manifold is different (flows slightly better I imagine), I can see it for a max power situation, but for a 60hp tune it's a little odd to hear that.

At the end of the day, it's his truck/wallet, but it just doesn't seem worth it to me. His power is well within the capability of the stock turbo, it sounds like it's still in good shape, and if he does want to push the limits of power there are other parts of the truck that will live a shorter life.

PS Nice ATC I've got a 24' myself.

Thanks for the feedback! The $1100 includes the exhaust manifold part and hardware etc. It’s a tune revision not a complete retune. Sorry I miss quotes that!

That’s my ATC. I have that and a open ATC 20.

 

[SVTXTC]

My question would be how much play does the stock turbo have or does he just want to swap it to get more power.

Zero play. The truck is used daily for light towing. He put 70k miles on it last year. It’s hard to plan out oil changes and maintenance but it all gets performed on schedule. He did not anticipate having this issue at 99k miles...it sucks for the business to have it down. I guess the question is how long an upgraded turbo would eat the head studs when the factory turbo caused this damage right?

 

[jeffh81]

@Junior00 seems to be pretty damn knowledgeable about Cummings engines. Maybe he can chime in

 

[SVTXTC]

@SID297 What would the 5 star truck guys advise?

 

[beau t]

I guess the question is how long an upgraded turbo would eat the head studs when the factory turbo caused this damage right?[/QUOTE]


i didn't have a good answer for you was just curious if he just wanted more power i guess, does the shop think he's running high EGTs and that what caused it to crack ? its cracked at the EGR runner correct, looks like the bolt could be broke to? I'm curious because a buddy just bought a newer 1 and i will be working on it with him when needed and its nice to have known problems to look for.

 

[me32]

Why not have the stock turbo rebuilt while its out?

 

[SVTXTC]

I guess the question is how long an upgraded turbo would eat the head studs when the factory turbo caused this damage right?

i didn't have a good answer for you was just curious if he just wanted more power i guess, does the shop think he's running high EGTs and that what caused it to crack ? its cracked at the EGR runner correct, looks like the bolt could be broke to? I'm curious because a buddy just bought a newer 1 and i will be working on it with him when needed and its nice to have known problems to look for.[/QUOTE]

my understanding of the issue can best be quoted here “The oem manifold is prone to movement and warping from the repeated heating/cooling cycles that it experienes. This is why most aftremarket companies move to a 2 piece manifold design. I have read more then several owners who have had to replace it with an aftemarket manifold after removing the oem mani because the manifold holes and head studs were not even close to lining up anymore. While it is possible that it is only the gaskets causing your exhaust leak, it is MORE likely that it is manifold movement that is the cause.”

 

[Junior00]

I’ll check him out. Thanks! He would like more power but doesn’t want to hurt the 6.7 on the stock head studs with 34+ psi.

If we were talking a couple years ago I would say give him a try. I have personally seen two fail from him. One could possibly be attributed to overspeeding, but the other was just straight up lack of attention when it was put together. I believe there are better options, for cheaper.

The labor for the exhaust gas manifold swap is $1100. A turbo swap would be free and would save $1100 in labor again in the future. It will fail at some time 100%

The upgraded turbo would be $2300-$3500.

The diesel shop also tunes the vehicle. It will need a tune revision for the new exhaust manifold. The turbo would be tuned for free as well at the same time for added future savings

May I ask the shop? There is no way I would consider upping the boost with a new turbo without studding and if you’ve never had any problems with coolant loss, over heating, etc. (i.e. the head/gasket is still as it left Cummins) there is no reason studs can’t be installed with the one by one method. The block/head mating surfaces will never be as true as when they left Cummins unless you pull the engine deck the block along with the head. The ARP 2000’s are cheap insurance. With a good flowing manifold, a horn if doesn’t have one already on, and the right turbo he should see drive pressures decrease significantly while spool should still be very quick and overall boost pressures be down as well as egt’s.

If I were wanting more power but still wanting to tow and be reliable, I would go with an S400 honestly. The newest SXE line is very affordable, yet tough enough to fit a daily driver/dedicated tow vehicle. Billet wheels, 360 thrust bearings, there really is no reason to pay $2k+ when these are 98% there for $1k or slightly less from the factory before add-ons.

That said, I didn’t see it mentioned but is he wanting to go 2nd gen style when he swaps manifolds? I personally run an AFE bladerunner but Steed Speed, BD, etc are all good candidates in the 3rd gen style. I see much lower egt’s while towing and playing around, and while there are benefits to a 2nd gen swap, I don’t believe the cost to be worth it unless you’re going all out. With new CAD designed manifolds, they don’t leave a lot on the table. Be sure to use manifold studs, they are well worth it.

I could go on all day, in the end it is all in how he plans to use it that should dictate his choices.

 

[Junior00]

I should have addressed the turbo more as well. Personally, a 63-64 is a little undersized for the 6.7 so it should spool that effortlessly. A 67 is about the sweet spot for all around as it still spools close to stock but will make big power. Biggest thing is getting the exhaust housing right.

I run a 14cm housing with a 71 wheel and it’s a little slow to light on my 5.9 but it keeps my egt’s well in check and by 1600rpm I’m making 10-15lbs depending on load. I had a little over 8k iirc behind the truck going up through the mountains in Tn and never saw over 1150 pre-turbo temps, and stayed in overdrive for the majority of the way except for the switchbacks where I had to downshift. The Aisin will help greatly with that.

For him anything in that range with correct tuning should light and tow very well with correct tuning.

 

[SVTXTC]

If we were talking a couple years ago I would say give him a try. I have personally seen two fail from him. One could possibly be attributed to overspeeding, but the other was just straight up lack of attention when it was put together. I believe there are better options, for cheaper.



May I ask the shop? There is no way I would consider upping the boost with a new turbo without studding and if you’ve never had any problems with coolant loss, over heating, etc. (i.e. the head/gasket is still as it left Cummins) there is no reason studs can’t be installed with the one by one method. The block/head mating surfaces will never be as true as when they left Cummins unless you pull the engine deck the block along with the head. The ARP 2000’s are cheap insurance. With a good flowing manifold, a horn if doesn’t have one already on, and the right turbo he should see drive pressures decrease significantly while spool should still be very quick and overall boost pressures be down as well as egt’s.

If I were wanting more power but still wanting to tow and be reliable, I would go with an S400 honestly. The newest SXE line is very affordable, yet tough enough to fit a daily driver/dedicated tow vehicle. Billet wheels, 360 thrust bearings, there really is no reason to pay $2k+ when these are 98% there for $1k or slightly less from the factory before add-ons.

That said, I didn’t see it mentioned but is he wanting to go 2nd gen style when he swaps manifolds? I personally run an AFE bladerunner but Steed Speed, BD, etc are all good candidates in the 3rd gen style. I see much lower egt’s while towing and playing around, and while there are benefits to a 2nd gen swap, I don’t believe the cost to be worth it unless you’re going all out. With new CAD designed manifolds, they don’t leave a lot on the table. Be sure to use manifold studs, they are well worth it.

I could go on all day, in the end it is all in how he plans to use it that should dictate his choices.

Thank you for taking the time to respond - this is exactly what I was looking for. Can you share a little more information on the one by one method?

The shop refuses to do it even though others do. There have never been any overheating issues and it’s the same way it left the factory. What’s the big deal other than it won’t be factory perfect? It’s still tight and as long as is does not leak it should be fine? What’s the risk for the shop? Would you find another reputable shop willing to do the one by one method? Doing it the other way just seems to be overkill and cost prohibitive even though it’s technically the correct way to do it?