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  #1  
Old 10-06-2018, 04:05 PM
v8volvo v8volvo is offline
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Location: Montana, USA
Vehicle: '86 745, '83 764
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What will count in the real world for a vehicle like yours is not how much peak power you can make but how much you can continuously USE without burning the motor up. Can you use all the power of the stock engine for extended periods of time currently without coolant, oil, exhaust temperatures getting out of control?

Doubling the stock hp as some folks have achieved in a lightweight car that mainly gets used for commuting and an occasional brief stomp on the accelerator for fun is one thing and even a heavily modified engine could potentially live a long and reliable life with that kind of use. But put that motor in a heavy vehicle, load it up, start rolling up a mountain pass on a warm day and hold the pedal to the floor for more than a few seconds and things will not go well for very long unless you have done major additional supporting work to the cooling system that will enable you to throw off all of the additional excess heat generated by increased HP. More power always equals more fuel which equals more heat.

Anders is the one to listen to on what is a reasonable and reliable power goal for these. But again max HP is has no meaning in a vehicle like this if part of the power band is off limits to protect the engine.

I would start by assessing where you stand now in terms of cooling capacity. Without making any changes to increase power, are you able to take your truck as it is today and drive up whatever is the longest and steepest grade you'd like this truck to be able to climb, in warm weather, with your foot against the floor the whole way, and have the critical engine temperatures stay safe? Most cars and trucks that came with this engine cannot do this even at the stock power level without significant work to bring the cooling system up to the task.

If your truck can, then you have headroom to make more power and use it. Otherwise, though, your effort will be wasted when you back off on the hills to keep it from melting down. Make your first task keeping the stock engine cool at full load by beefing up the cooling system, then see where you are able go from there. New clean radiator, new 80C thermostat, big intercooler, and big external oil cooler will probably be the least you need to do. Radiator size upgrade or an additional aux radiator are almost a guaranteed requirement for more power, and might be needed even just for the survival of the stock setup when working hard depending on what kind of weather you want to run in.

Sweet looking truck, welcome to the forum.
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86 745 D24T/ZF 345k lifted 2.5"
83 764 D24T/M46 155k
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  #2  
Old 04-13-2019, 07:24 PM
mammothvw mammothvw is offline
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Join Date: Sep 2018
Location: california
Vehicle: VW LT 45 4x4
Posts: 2
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Sorry for the late response and thanks for all the replies and messages. I've had a lot of brake and non engine issues and the LT has been stagnant. Most of the "truck" turbo diesel engines available in America I've looked at are too tall for the LT. Going to mess with the pump timing and maybe swap the turbo after checking what the current boost is.

No cooling issues currently and at the rate of this build I won't be over 6500 pounds for awhile.
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  #3  
Old 04-27-2019, 01:27 PM
Uberhare Uberhare is offline
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Join Date: Jun 2013
Posts: 8
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First you will want to add an intercooler if not already installed.

Second, you can increase fueling and boost encrichment.

3rd, install a manual boost controller to increase boost

4th, Block off the overboost valve on the intake manifold. It pops around 12 psi.

I had the cold size of my turbo oversized when it was rebuild.
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  #4  
Old 07-02-2020, 10:58 PM
RedArrow RedArrow is offline
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Join Date: Jan 2013
Location: New York
Vehicle: 1986 Volvo 745 TD
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Quote:
Originally Posted by v8volvo View Post
What will count in the real world for a vehicle like yours is not how much peak power you can make but how much you can continuously USE without burning the motor up. Can you use all the power of the stock engine for extended periods of time currently without coolant, oil, exhaust temperatures getting out of control?

Doubling the stock hp as some folks have achieved in a lightweight car that mainly gets used for commuting and an occasional brief stomp on the accelerator for fun is one thing and even a heavily modified engine could potentially live a long and reliable life with that kind of use. But put that motor in a heavy vehicle, load it up, start rolling up a mountain pass on a warm day and hold the pedal to the floor for more than a few seconds and things will not go well for very long unless you have done major additional supporting work to the cooling system that will enable you to throw off all of the additional excess heat generated by increased HP. More power always equals more fuel which equals more heat.

Anders is the one to listen to on what is a reasonable and reliable power goal for these. But again max HP is has no meaning in a vehicle like this if part of the power band is off limits to protect the engine.

I would start by assessing where you stand now in terms of cooling capacity. Without making any changes to increase power, are you able to take your truck as it is today and drive up whatever is the longest and steepest grade you'd like this truck to be able to climb, in warm weather, with your foot against the floor the whole way, and have the critical engine temperatures stay safe? Most cars and trucks that came with this engine cannot do this even at the stock power level without significant work to bring the cooling system up to the task.

If your truck can, then you have headroom to make more power and use it. Otherwise, though, your effort will be wasted when you back off on the hills to keep it from melting down. Make your first task keeping the stock engine cool at full load by beefing up the cooling system, then see where you are able go from there. New clean radiator, new 80C thermostat, big intercooler, and big external oil cooler will probably be the least you need to do. Radiator size upgrade or an additional aux radiator are almost a guaranteed requirement for more power, and might be needed even just for the survival of the stock setup when working hard depending on what kind of weather you want to run in.

Sweet looking truck, welcome to the forum.
What an amazing reply! This belongs to a 'forum sticky' for all the horsepower dreamers. Very very true points for everyone.
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