I bought a 2007 Silverado 2500 eclb with a 8'' fabtech lift. The pyro wasn't working when I bought it but I recently replaced the probe. The truck has stock gearing with 35 12.50 17s as well as Fab Four bumpers, Warn winch, dual cp3s, built trans with a 1056 and a 66mm Danville turbo. My EGTs are at about 900 in fifth gear at 65mph. I run it in fifth cause it's better on fuel and EGTs are lower than in sixth. My tuner told me that's about as good as it will get. I'm curious as to what other guys are seeing with their lifted trucks. I am also wondering if the front bumper is hindering the air flow and causing it to run warmer than a stock bumper would.
Lifted truck EGT temps
- Thread starter TQMONSTR
- Start date
My truck ran hotter trans and engine wise with the stock plate on my fab fours. I cut a 4x16 hole out and put mesh it to cool it down. The winch is blocking airflow but its not gonna affect egt's. Gearing will help, as they will take some load off the drivetrain.
I realize gears would help with acceleration but I don't see how they would help on the highway. I'm at roughly 1650 rpm in 5th at 65 mph which I think is the same rpm I would be at in 6th with stock size tires. I was told the EGTs are high cause the load on the truck is high. I understand that but my old truck (05 ccsb) ran the same EGTs towing 10000lbs as my new one does empty.
Gears does not just help with acceleration but it does take the stress off the transmission and the transfer case. I'm running on 37's and I cruise 800* at 65 mph in 5th gear with nearly no boost. It doesn't get over 1000* on a grade 7 to 8 hill. I'm sure your truck can be tuned a bit better to control the egt. 6th gear does hurt alot but once you regear it to 4.56, it will act like it is in 5th gear and you will be able to use 5th gear better for towing wise. My 5th gear at 65 mph is too low for towing (1650 rpm) and a bit too high in 4th gear (2400 rpm). The 4.56 gearing will help with all around driving for the 6 speed guys. 4.10 for the 5 speed guys who are running 35" to 38" tires.
Like others have said.. It's not "bad" but not "great" either
Sweet spot for most the trucks is 1800-2100rpm my avg egt is 800° loaded with avg hieght load(under 5' tall on yhe deck) and rolling ~30,000lbs at 68-70mph
Under 1800rpm egt, engine oil temps and eventually ECT all go up to some extent or another and I'm using more fuel to do the same work
Sweet spot for most the trucks is 1800-2100rpm my avg egt is 800° loaded with avg hieght load(under 5' tall on yhe deck) and rolling ~30,000lbs at 68-70mph
Under 1800rpm egt, engine oil temps and eventually ECT all go up to some extent or another and I'm using more fuel to do the same work
What if you pick up the speed a bit so your RPM is higher? What are your EGT at 1800 rpm?
Maverick Max XRS
570 Berg.
Maverick Max XRS
570 Berg.
I'm running 4.11's with 35's on my 07 classic with the 6sp Alli, its pretty much like factory ratio's...very little to no "gear/tire related" turbo lag, the turbo doesn't choke out or want to run out longer than the gear and torque always seems to be there when I need/want it...
When I cruise along at freeway speeds, my EGT'S are at about 800* or less...but lets be honest here, I'm not just "cruisin along" very often
Not sure about IAT compared to ambient. I'll have to go visit my tuner to check. Boost while cruising is 4-5 psi. I'm guessing my tune is pretty warm. Probably 550 to 600hp but I haven't dynoed it or ran it at the track yet.
EGT's seem a little high for cruising, and in my tow tunes, I don't see any boost while just cruising...but it also sounds like your truck is a heavy pig with ALOT of added wind resistance too...
Now, in the race tune, I see appx 3-5psi...
So, it would almost seem like the tune you've got is a bit hot for a tow tune...
Single tune? DSP5?
WHO is the tuner?
It is a heavy pig! 8000lbs ish with me in it. No DSP here. Never really saw the point to them.
Yup, that's a huge b!tch!
Weight and co-efficient of drag could definately be playing a role here...gears would ABSOLUTELY help but I wouldn't expect that to totally eliminate your EGT issue
Well, maybe you haven't seen the benefit of a DSP switch BEFORE NOW...?
Hopefully you can see where there is a benefit, now...
Knowing now, that you're running a single tune, I'd say get a switch and multiple tunes...problem solved!
When/if EGT's ever become an issue, twist the knob/key and drop the power level...
Done
I'm running 4.11's with 35's on my 07 classic with the 6sp Alli, its pretty much like factory ratio's...very little to no "gear/tire related" turbo lag, the turbo doesn't choke out or want to run out longer than the gear and torque always seems to be there when I need/want it...
When I cruise along at freeway speeds, my EGT'S are at about 800* or less...but lets be honest here, I'm not just "cruisin along" very often
What gear are you in at 65mph and what's your rpm range?
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
I had EGT that were higher than I thought they should be, probe ended up going bad. New one and it's all good now. They were about 200* high for a long time.
Maverick Max XRS
570 Berg.
Maverick Max XRS
570 Berg.
I would check for boost leaks and get some info on the tune, Timing, Pulse etc... Lower gears will help the same as dropping a gear helps, as some others have mentioned...VVT's run warmer factory, modded ones are going to do the same, drop a 75-80mm big brother on that 66 and watch the egts drop