Lifted truck EGT temps

[Ridin'GMC]

Well, first off I gotta say I've got pretty Killer tuning from Mark B

6th gear @ 1850rpm appx 65mph egts will be about 650-800* usually closer to 800* but here in the PNW youre pretty hard pressed to find a road that doesnt change elevation, so I attribute the slightly warmer egt's to variation in grade and for some reason....I swear there's more roads going uphill than down, lol

Im almost always in my built trans race tune and I have 60 over injectors, but that really shouldn't mean a whole lot...

At 70 I'm running about 2000rpm and egts are pretty much unchanged...

Now if I roll into the throttle to start up a hill of course everything changes...these numbers are flatland only references...

I will say that if I wanna go 60mph, and stay in 6th gear, RPM drops too low, around 1400(? Never really paid any attention) and EGT'S will rise if the trans doesn't downshift...they'll get to and hover between 900* and 1000* just to stay at that speed in 6th

But really, it takes an effort to keep it in 6th @ 60mph, the trans doesn't like it much and it will want to downshift with the slightest exaggeration in throttle input

ARE you POSITIVE you are in 6th gear at 1850 rpm cruising approximately 65 mph? From my calculation by using a gear calculator your information is skewed. Even I know by cruising my own truck with 37" tires and 3.73 gears, it still doesn't sound right.

The information you gave me at 1850 rpm using 4.11 gears, at 65 mph you would be in 5th gear, not 6th. IF you were in 6th gear at roughly 65, you HAVE 4.65 gears at 65 mph. If you are positive you have 4.11 gears at 1850 rpm, then you are in 5th gear. Which makes sense why you were lugging your engine in 6th gear because the rpm is right about that low at 60 mph with 4.11 gears. At 1850 rpm in 6th gear with 4.11 gears, that puts you at 75 mph, 5th gear at 65 mph.

The difference in rpm from 3.73 to 4.11 in 5th is roughly 170 rpm and 150 in 6th, not much of a difference. 3.73 to 4.56 is a 360 rpm difference is 360 in 5th and 300 in 6th. Now in 5th gear using 4.56 gears with my 37" tires at 65 mph (actual measurement is 36") put me at nearly 2000 rpm which is perfect for towing wise and 6th gear is 1700 rpm, perfect for cruising. Which is why I said 4.56 is perfect for 6 speed guys running 35-37" tires because it gives us better driveability and is within the peak torque rpm range for efficiency.

 

[TQMONSTR]

Do any of you know how much cooler my truck would run with a hot side boost tube and a high flow Y bridge with a cold side tube? Has anybody installed the TowFlow up pipes and noticed a drop in EGTs? I'm not sure if an aftermarket intake would help. I'm still running a modded stock one with a k&n filter.

 

[Ridin'GMC]

I doubt any of those will benefit that much of a reduction in EGTs. I would suggest you try to get the tune more refined. My truck weighs as much as yours does and I live in hilly conditions and don't really have an issue with extreme EGTs. Try a different tuner to see or have your tuner refine it.

 

[TQMONSTR]

I'm not sure I have an EGT issue. I thought they were higher than they should be but after the responses I've gotten from other forum members they don't seem too bad. I would absolutely love for them to be lower but they are what they are. I will get my tuner to have another look at my tune and see if he can get them any lower though. I'll just have to live with them until I can get rid of this lift.

 

[TQMONSTR]

thought I'd update this thread since I've added some parts. Found out my autometer gauge was doing funny things so I had some Isspro gauges installed. I also had a Profab shorty Y bridge and tow-flo up-pipes installed. EGT's are now 600 cruising in 5th at 65mph give or take. Before I installed the new parts I always let the truck cool down to 400 before I shut it off. Now it cools off way quicker and I never have to wait for it to hit 400. My max EGT is also down too. Before it would max the 1600 gauge at 140kmh(85mph). I had the truck up to 190kmh(120mph) and the gauge stayed at 1350. I"m not sure what helped the most, and to be honest I don't really care, but I'm very happy with where my EGT's are now.

 

[cdbright]

wow , i can p[eg mine at 1600 at WOT , but that is in my high tune and SOCAL diesel has some hot ones :woott::woott: , but she sure hauls the mail:thumb::thumb::thumb: