Build Lexus LX450 Cummins 6bt/NV4500 swap

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No doubt the IATs will drop with the IC on the highway. There's no need to even measure it in this application... question is did you need those lower IATs to get you over the mountain passes at 60mph? or did you just need to tune your pump or turbo a bit better? It's simply a function of adequate power with the least complexity possible, in my view. All the IC does is densify the air so you can feed the motor more fuel and it can then make more power. If you don't need the extra power, no point in running the IC. If you need or want more power, then run an IC and track the temps so if you then desire, you can install a more efficient IC and so on... My point is simply that with a good running hot air 6BT, I'd bet you'd be more than happy with the power and ease of service.

I know, questioning the standard line of thinking is such a PITA! :)

I'm not saying that I would not ever add an IC to one, but it would totally be for purposes of trying to build a 13 second 80 or something hilarious like that.lol... These things haul ass with the 6BT and no IC. As CJ would tell you, there's room for days in my engine bay and that's darn nice when something goes wrong... and it always does.

Good point CJ on the 60mph and gearing. It's at 70+ that the 3.54s really shine...

OK- Sorry for the thread jack. Just thought it worth hashing out a different line of thinking since you're embarking on the build...

-Phil
 
Thank you for the input and ideas, they are all good and have marrets. Do not hesitate to toss them out. The intercooler thing is intresting, I will have to think about it.

There are two other Lexus LX450 locally with or in the progress of swaping 6bt's into. One is intercooled and the other is a 90 6bt non intercooled so will be intresting to see there results. Both are almost identical other wise, nv4500's ect.
 
The VE motor will feel like a slug until the spring and fuel pin are replaced, and the screws are turned. After that is done correctly, it will haul.
 
turbophil said:
The VE motor will feel like a slug until the spring and fuel pin are replaced, and the screws are turned. After that is done correctly, it will haul.
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Yeah they both have VE engines, the intercooled one has a pin and gov spring. I believe the other is all stock.

I plan to just keep mine stock for now since it's already running 55hp more.
 
That 55hp makes a huge difference. I think your set. I would only do the AFC spring for quicker boost. I went from 15-18max boost to hitting 25-30 in 4th and 5th gear pretty much instantly.
As for inter coolers I'm glad I did mine. I have enough hills around here where it helps and it adds a bit of mileage. Enough Cummins conversions added them afterwards to make me feel good I did it before. Off-roading it doesn't matter either way. EGT temps are non existing going that slow in low range.
 
Do you think that added boost was from the spring or the fuel plate though. They need the fuel to make the boost a jump of that much boost means there must have been added fuel through out the RPM range.
 
maybe this explanation will help understand fueling?

There are 2 sources to control fuel with these Bosch pumps. both are some what independent and build on themselves. If you would hook an air source to the AFC it would fuel and increase the RPM proportional to pressure just like the throttle/governor arm (gas peddle).

1st input: is the throttle. which on these is a governed based fuel system so your input is related to desired output RPM. The difference of the actual RMP vs input is how hard it fuels to get to the output.

2nd is the AFC (boost): the fuel pin-VE or Plate-Ppump is additional fuel available based on boost This adds to the primary throttle input.

so if you disconnect the AFC you can still build boost but as the RMP increase the boost falls off. by loosening the spring your able to add additional fuel at lower RMP's achieving more boost without adjusting max fuel rate. if you maximize boost with the AFC spring adjustment with out smoke is the key, and your boost falls off at WOT more than you would like that's when it's time to add more overall fuel with the fuel Screw-VE or sliding the plate-Ppump. Adjusting max overall fuel will change the Boost AFC rate as well and will likely need tightened up, the VE is more prone due to using pressure as the control for max fuel as it's primary, The Ppump relief valve can be switched out with adjustable but not as common for normal everyday use.
 
another way of thinking about it is adding HP/Boost at the lower RPM changing the power curve. you might have the same peak but you have more available power, more area under the curve when needed. that's where the efficiency comes from in diesels.
 
Thanks, much more clear now. My Isuzu 4bd1t only has a max fuel adjustment so this is all new to me.
 
Anyone used the Ford F800 accessory mount? Looking for alternatives or other options. I did not receive an alternator or AC compressor with mine. So if I can run a 22SI alternator and a medium duty AC compressor maybe that is better?

I do like the simplicity of the diesel adapters accessory kit tho. Just looking at options.
 
Wheelingnoob said:
Anyone used the Ford F800 accessory mount? Looking for alternatives or other options. I did not receive an alternator or AC compressor with mine. So if I can run a 22SI alternator and a medium duty AC compressor maybe that is better?

I do like the simplicity of the diesel adapters accessory kit tho. Just looking at options.
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Never looked into. How is it different? Anything has to be better than trying to get a replacement from DA. I'm on phone call #7 this week so far trying to get a spare thermostat housing. He updated it and looks to be a much better design than the first one.
Will you run an AC up in Canada?
 
Wheelingnoob said:
Anyone used the Ford F800 accessory mount? Looking for alternatives or other options. I did not receive an alternator or AC compressor with mine. So if I can run a 22SI alternator and a medium duty AC compressor maybe that is better?

I do like the simplicity of the diesel adapters accessory kit tho. Just looking at options.
Click to expand...

I have seen that setup, but haven't plunked down the money to run it. I'm running the factory dodge cummins accessories on my 4BT.
 
Mr Cimarron said:
Never looked into. How is it different? Anything has to be better than trying to get a replacement from DA. I'm on phone call #7 this week so far trying to get a spare thermostat housing. He updated it and looks to be a much better design than the first one.
Will you run an AC up in Canada?
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The issues your having are my main concern going that route.

The Cummins F800 braket moves the AC compressor above the water inlet. The alternator still sits on top.

We still get warm summers up here, my igloo melted last Sumner :( lol. I also plan to travel to places like moab, death valley and other warm places in it.
 
Wheelingnoob said:
The issues your having are my main concern going that route.

The Cummins F800 braket moves the AC compressor above the water inlet. The alternator still sits on top.

We still get warm summers up here, my igloo melted last Sumner :( lol. I also plan to travel to places like moab, death valley and other warm places in it.
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I'm still rocking no AC. It works half ass so I just don't bother but I usually don't use the AC in any vehicle if I'm alone. I like windows down no matter what temp.
 
Mr Cimarron said:
I'm still rocking no AC. It works half ass so I just don't bother but I usually don't use the AC in any vehicle if I'm alone. I like windows down no matter what temp.
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I'm Canadian so usually when it gets above 16c (60f) I start to melt.

I actually use my AC far more in our winter living on the coast here we get a ton of rain and it's much easier to keep the windows clear with the AC drying the incoming air.
 
I gotta agree with Turbophil, been looking for an 89-98 6bt and plan on piping mine straight to the snorkel.

Can't wait to see your build play out as I'll be using it for a template for mine and surely a lot of others will too.

You should start a Patreon page, I'd donate to the cause for inside info and insight.
 
Well today I spent part of the day getting the Isuzu back together. I plan to get it loosely assembled so I don't forget where stuff goes then tow it back to my garage for storage till I'm ready to start the Cummins swap.

I also spent some time testing and checking things on the 6bt. The fuel shutdown solenoid works, tested. The glow screen works too. Pulled the inlet elbow and the inlet manifold or what ever it is called on a Cummins is clean. The fuel heater is toast, the top part is melted. I'm going to remove it from the system anyways.

For fuel heat when needed I may just add a fuel heater to my racor fuel water separator.

The HX35w appears to have been damaged in the accident I can't tell if the compressor cover or backing plate is bent causing the compressor to rub on it or if the shaft is bent. I need to dig into it a bit more. If it's not too bad I'll rebuild it. It will forsure need a rebuild kit and a compressor wheel so far.

That's all for this weekend.
 
I call it intake manifold but I see most others say intake horn.
Didn't you rig up a timer on your Isuzu glow plug system? Are you going to do the same with the grid heater?
 
Mr Cimarron said:
I call it intake manifold but I see most others say intake horn.
Didn't you rig up a timer on your Isuzu glow plug system? Are you going to do the same with the grid heater?
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Yeah, it looks like most the intake chamber is in the head area. Anyways it's was nice and clean no rust or other build up no oil at all in the intake horn or build up on grid.

I never hooked up the glow system on the Isuzu it never needed the help of glow right down to - 10c last winter.

I do plan on using the timer I got to controle the grid heater. I think for simplicity I will wire the two grids together.
 
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