Thinking about throwing in a s475 with .90 housing in my lb7? Wanna keep the stock sticks in for a bit! Anyone have that same setup and not like it?
So wouldn't be practical to dd?
With a delicate right foot it would be driveable. Couldn't mash it from a stand still or tow with it though.
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Put the 475 over the stocker have the best of both
Would it be harsh on the rods?
I have been running a s475/83/.90 for years. With 40 overs. I DD the truck and tow heavy....
...Egts stay right at 1000° pulling up hill....
Why is everyone afraid of EGTs lately? I run a "smaller" turbo (S371) and an aggressive cam, so I run up hills at 1200-1350°F empty. Throw a trailer on and typically I'll have to drop a gear and get into the powerband (2200+ RPM), but EGTs still stay 1100°+. Have run this way for years, nothing ever melts...
I consider 1350°F safe for a long time (10+ minutes), just watch your coolant temp. I don't mind hitting 1400° for short bursts up hills, and have never had any problems. I start to get nervous above 1400°, even for just a minute. If in doubt, drop a gear to get the airflow up where the larger turbo is more efficient.Wow i need a 0.90 housing... I run at 800-1000 at mid throttle just crusing down the highway.
Dave... even downshifting so like 2200+ rpm, with enough throttle to not be embarrassingly slow i was seeing 1300-1400... is that "safe"??
It is all in the tuning. It can be done safely, but you can't go max effort tune for sure. Any good tuner (ATP, Kory, etc, etc) will be able to keep your engine together with compounds.Would it be harsh on the rods?
I consider 1350°F safe for a long time (10+ minutes), just watch your coolant temp. I don't mind hitting 1400° for short bursts up hills, and have never had any problems. I start to get nervous above 1400°, even for just a minute. If in doubt, drop a gear to get the airflow up where the larger turbo is more efficient.
The fact that your coolant and trans temps were climbing that quickly kind of implies something isn't right with your setup/driving. You shouldn't unlock your torque converter when towing, it just adds heat. I have found that with a trailer, 5th gear unlocked is the same RPM as 4th gear locked, but produces way more heat. If needed, you can drop another gear. The Duramax will pull all day at 3200 RPM, just get crap mileage.
Engine coolant temps can be addressed a number of ways. James (Chevy1925) has posted his adventures in controlling ECT with big power and heavy loads.
Why is everyone afraid of EGTs lately? I run a "smaller" turbo (S371) and an aggressive cam, so I run up hills at 1200-1350°F empty. Throw a trailer on and typically I'll have to drop a gear and get into the powerband (2200+ RPM), but EGTs still stay 1100°+. Have run this way for years, nothing ever melts.
Heck, cruising level highway at 80 MPH puts my EGTs at a hair over 900°, and I run that for 4 hour stretches.
To the OP, you can run a S475 on stock fuel, but EGTs will be higher than stock, lag will be WAY worse, but you can tow if you want to. You will need gauges, and will need to watch them, but it can be done.
Wow i need a 0.90 housing... I run at 800-1000 at mid throttle just crusing down the highway.
Dave... even downshifting so like 2200+ rpm, with enough throttle to not be embarrassingly slow i was seeing 1300-1400... is that "safe"??
I consider 1350°F safe for a long time (10+ minutes), just watch your coolant temp. I don't mind hitting 1400° for short bursts up hills, and have never had any problems. I start to get nervous above 1400°, even for just a minute. If in doubt, drop a gear to get the airflow up where the larger turbo is more efficient.
The fact that your coolant and trans temps were climbing that quickly kind of implies something isn't right with your setup/driving. You shouldn't unlock your torque converter when towing, it just adds heat. I have found that with a trailer, 5th gear unlocked is the same RPM as 4th gear locked, but produces way more heat. If needed, you can drop another gear. The Duramax will pull all day at 3200 RPM, just get crap mileage.
Engine coolant temps can be addressed a number of ways. James (Chevy1925) has posted his adventures in controlling ECT with big power and heavy loads.
It is all in the tuning. It can be done safely, but you can't go max effort tune for sure. Any good tuner (ATP, Kory, etc, etc) will be able to keep your engine together with compounds.
EGT's usually dont coincide with ECT. you can have 1000 degree EGT and still get 240 coolant temp. when i pull hills during the summer im generally at 1100-1200 for long periods of time like dave said but i can hit 240* coolant temps fast. thats in 4th gear, 2600rpm, and 55-60mph with 15k. but when its 40-60* temps out side, i can pull the very same hills in 5th gear, 1100egt, 70mph and coolant never goes over 220* with 15k on the back. i can drive it significantly harder in the winter than the summer just because the outside air temp will actually knock temps out of my cooling system. its an eerie feeling seeing 45psi of boost, being in 5th gear and hearing that turbo whistling harder than hell as you pull that much weight up a hill during the winter time.
with the boat you posted, you should be able to pull that grade for that long at that egt and air temp without issue. really, you should be able to knock it down a gear with that light load and be even less egts. the higher rpm will also let the fan draw more air in and keep temps at a better level too. engine will be working easier as well.
Why is everyone afraid of EGTs lately? I run a "smaller" turbo (S371) and an aggressive cam, so I run up hills at 1200-1350°F empty. Throw a trailer on and typically I'll have to drop a gear and get into the powerband (2200+ RPM), but EGTs still stay 1100°+. Have run this way for years, nothing ever melts.
Heck, cruising level highway at 80 MPH puts my EGTs at a hair over 900°, and I run that for 4 hour stretches.
To the OP, you can run a S475 on stock fuel, but EGTs will be higher than stock, lag will be WAY worse, but you can tow if you want to. You will need gauges, and will need to watch them, but it can be done.
So should I run something smaller you think? I never tow anything, hell I don't even have a hitch... got rid of it when I did my roll pan and never bought the big Chevy hitch they sell, anyway Maybe something smaller but still in s400 or what about s369? Don't want to trash my rods just yet, need the trucks internals to last a little bit longer.