I know this is going to get a ton of different answers but still wanted to get some input. First off this is my setup:

97 7.3 with ~308,XXX miles
46637 air filter
3" downpipe to 4" straight pipe
200/30 injectors
Hydra chip w/ tow tunes
Turbo exhaust butterfly valve delete
Edge digital EGT sensor installed right at the drivers exhaust manifold elbow
Electric fuel system
4.56 rear gears
35" tires

I tow a 13K fifth wheel and for the most part the truck does well. On flat ground there are no issues and mild grades it pulls pretty well. The one area where I am struggling is EGTs. While I am planning to install an intercooler with upgraded turbo and up-pipes, that is probably not happening until later this year (or as the budget allows). Most of the time, I don't focus much on the EGTs as I don't pull long grades and I know these engines can sustain short bursts over 1300 degrees with no issues.

That being said, when I have to pull longer grades, especially when at altitude, the EGTs tend to climb fast and stay high. This causes me to back off the pedal despite the truck having enough power to travers the hill. For example, last year we pulled the rig up over Donner pass (EB hwy 80). It has a 6% grade for ~30 miles. I had to drop to 2nd gear and hold at about 35mph to keep the EGTs down despite having enough power to drive the speed limit. I tend to try and keep it under 1250 on the longer pulls which means that I have to drop to 35mph or sometimes slower. Now when I say that the temp gets high, I mean in the 1300-1390 range. Some guys have told me that these motors can handle 1600 with no problem but others have said never to let them run more than a minute over 1300. I have never had it over 1395 as my anxiety gets the best of me and I back off the pedal. I can't afford to test these theories and was hoping y'all had some input.

Also will I see dramatic drops in temp once I install the intercooler and turbo setup? Should I consider water/methanol injection? Any input is welcomed!

 

Your anxiety is a good gauge to follow. Who ever said 1600 is wrong, wrong. I pull 18K in my signature and have to back off all the time. Intercooler will only do 100 less temp. EGT's are these trucks biggest problem.

 

I usually try to not go over 1250-1300 if I can. I've searched and like you, heard many varying responses.

 

I have heard that the aluminum the pistons are made of starts to melt at 1250 degrees. So short bursts of 1300 is all I try to do. I read it on the internet so it must be true. LOL

 

Yeah I have heard the same. I have also talked to guys who regularly run theirs at 1400 and claim to have no issues. When I look up the melting point of cast aluminum it says around 1,000 degrees which is substantially lower than the 1200-1350 range these trucks are supposed to "safely" operate.

oldbird1965 I was hoping for more than aa 100 degree decrease especially if I am spending the $$$. There has to be a reliable way to drop EGTs since the newer trucks don't have this issue even with all the emissions equipment clogging up the exhaust pipe.

 

I would be more concerned about rings expanding and breaking off the top of the piston before the piston melting down.

My dead 6.4 would cruise, unloaded, during regen around 1225-1300. Wild, they had super loose rings to compensate.

 

A new turbo will help a lot. I think the two best options are:

a KC drop in with intercooler

a T4 turbo with intercooler.

I think the IC is good for 100-150 degrees depending on each truck’s personality.

I would probably give KC a call and see what they suggest.

 

Funny you should say that because this is the kit I am looking at. I already have the intercooler and plenums, I just need to order this kit and install it. Just don't have the extra $3k lying around.

 

My 97 was horrible to drive empty with rosewood 200/30s, barder diy d66 kit in the turbo, and Tony wild man tunes when I first put it together years ago. It was intercooled. I unhooked my intercooler just to see what it was like and it was much worse to drive.

It is a completely different experience with jelibuilt tunes and a kc s300 style turbine wheel in the barder modded stock turbo.

With your gearing your pickup will be a great tow rig once your get your issues sorted. I don’t know how many degrees you’ll lose with an intercooler but you most definitely need one. You’ll have to decide if you want to drop the $$$ for a t4 kit or not. The general consensus is that the borg sxe turbos are worth the cost of admission. That 364.5 would be a great size for what you have done already. Where you don’t have an intercooler in yet and you need up pipes if there was ever a time to drop $3,000 on the irate kit this would be the time. Kc has fantastic drop in turbos available for us. You will save some money with the drop in, how much depending on what you do for the intake Y and pipes if you go the drop I. Turbo route. I am putting a stage 2 in my 2001 right now.


You probably have up pipe leaks if they are original. Your exhaust manifolds could be getting really tired at that mileage also.

whose tunes are you using?

Another thing you’ll want to address at some point is pressure testing your intake and using soapy water to look for boost leaks. If your intake plenums are leaking very much it will make it that much easier to replace them.

~1250 to 1300 seems to be max sustained egts for these engines from what I’ve read over the years. One thing to remember is that sustained heat over miles and miles going up a grade towing is a lot different than hitting 1500-1600 degrees for a few seconds during a full throttle pull empty. Everything inside your engine is going to be hotter when you’ve been holding at 1200 degrees for X number of minutes.

last October we went to southern Utah camping and pulled many 6-7% grades at decent elevation. I was pleasantly surprised how well my 97 did. It was the first time I towed with the new tunes and a clutch that could hold the power the 200/30s are capable of. Jelibuilt daily tune wouldn’t go over 1150 degrees on a grade as long as I had enough rpm to have the turbo lit. Pulled the grades that were straight enough to go fast on in 4th(zf5 trans) at 2500 rpm @60 mph. I tell you this because the 200/30s can be a fantastic towing injector with the right ingredients around them. Here is a picture from that trip. Not sure what my combined weight would be.

 

You can intercool an obs on a budget if you’re willing to source parts from a few different places. I got my intercooler+boots+pipes for $100 at a junk yard. Paid $250 for e99 intake spider, built my own mounts for the intercooler. I ended up buying steel intercooler pipes made for an obs as the ones I got from the junkyard were aluminum and needed a bit more work than I had the skills to do to modify them to work. I can’t remember now what I paid for those pipes, they were built by bar none diesel back around 2014.

 

OP, where are you measuring your egt's from? You get a more accurate reading at the exhaust port vs the turbo down pipe.

 

I have the sensor at the elbow in the driver's side manifold so I am getting accurate temps. I had my mechanic check for boost leaks when he fixed one of my stripped bolts on the up-pipe connection. Everything looked good there and I have decent boost numbers. I can mitigate the temps somewhat if I kick it out of OD on flat ground right before the grade but it doesn't always help. The more I read about this, the more I see that most folks have done intercoolers and are running ZF5s as opposed to the E4OD (which is what I have). I am in no rush to replace the transmission as I just had it completely rebuilt about 2 years ago, but I am definitely leaning towards that alteration in the future. Overall I am happy with the truck and it's capabilities I just want to ensure the longevity of the drivetrain and make sure I am putting my money in the right places with all the upgrades/changes.

 

One more question on this: I unplugged my MAP sensor just for kicks and the truck seemed to have a bit more power and the EGTs seems to be lower. I haven't tried towing with it unplugged as I don't want to risk damage but I thought the MAP sensor just measured boost? My boost is reading the same with it unplugged. I did notice that it had a hard start situation with it unplugged which leads me to believe that I should leave it plugged in.

 

SEEM to be lower? What does your gauge tell you? It shouldn't be a guess. Yes, aluminum melts at 1250*, but remember the AIR is what is being measured, not the temp of the piston itself. A good IC should keep your temps under control with the right setup in other areas. The BIGGEST reason for high EGTs is overfueling. Avoid the temptation to have the biggest injector. Bigger turbo (more air), good IC that moves that air, and an injector that is no more than Stage 1.

 

A couple of thoughts.

i didn’t see you mention bellowed up pipes when you told us your mods? If not you need them. I guarantee they are leaking. Also, your gearing will keep your turbo moving which is good for towing, but the stock turbo probably isn’t keeping up to well. So as mentioned I’d recommend a kc turbo I had one and loved it. 1200 bucks is a lot better in my mind that 3k for a T4 but depends on your preference. I do love the flexibility they provide. Also, who tuned your hydra for your injectors?