Builds Isuzu 4BD1T Lexus LX450 (Land Cruiser) Build (1 Viewer)

[Wheelingnoob]

Nice clean fab work Jerms. That down pipe is a bugger with that darn bolt there. Ive dealt with that before and it's like being stuck between a rock and a hard place. I too have wondered about flex braided pipe and exhaust brakes. Figment for mine on my Bj would be a lot easier if it could hold pressure, then the braided section could go just about anywhere. Do you plan on insulating the intake pipe? I could see that thing grabbing quite a bit of heat as well. Do you think you could put a section of corrugated or something on your intake? I know corrigated sounds awful, but I worry about that pipe and your air filter can with all the engine movement. It's going to fatigue something. Looks great!

Thanks! Im quite happy with how it turned out. Yeah the bolt the starter and the engine mount where all conspiring against me for a bit. I have room for a 3.5" pipe just not when you need to sneak it by all this stuff. I just don't have room for the bends and there radius.

I have a feeling the bradded flex i have would handle it for a year or more but would fail at the worst time. Im going to try and sneak the exhaust brake under the starter then the flex. I want to have the flex within a few pipe feet on the engine.

I may try and insulate the intake but in the past I have seen very very little drop in intake temp post intercooler. Not enough to justify the cost to get it ceramic coated.

Yeah Im worried about that as well, I need to find a 3" diameter corrugated rubber coupler that is soft enough to flex but not collapse under boost. I think if anything will fail its the fender well its bolted too.

 

[doug720]

Looks great!

On the SS flex joint, on the NPR I bought, the factory exhaust brake was located after the flex section. The exhaust brake was hung with exhaust hangers and fairly solid, so the SS flex was upstream and showed no signs of distress. The truck had the stock exhaust and around 140K miles for reference.

I originally set my intake from the air filter can to turbo inlet with hump hose joints and solid pipe like you have roughed in. After running for a short time, I to was concerned about the vibration on the air filter housing and mounts.

I ended up using the stock Toyota rubber/plastic accordion type flex hose. I have nearly 25k miles on my swap now and no intake hose issues. You can see mine in my swap thread on page 15 post 300.

I also ran my exhaust like you did when until I swapped turbos. I had no issues with heat on the alt/vac pump, dip stick, etc. There seems to be enough airflow to keep the exhaust surface temps low enough to not cause issues on my mine. But I run max 16-18 pounds boost on a 4BD2, so yours maybe different.

After the turbo swap, I ran the exhaust over the top of the starter to the firewall and down and followed it down to connect to my existing exhaust at a 3 bolt flange. It was a little tricky to make the down pipe this way, but it is much cleaner and I do not have to remove the exhaust to change the starter or alt.

Keep it going like you have been, and it will a driver soon!

Cheers

Doug

 

[Wheelingnoob]

Looks great! On the SS flex joint, on the NPR I bought, the factory exhaust brake was located after the flex section. The exhaust brake was hung with exhaust hangers and fairly solid, so the SS flex was upstream and showed no signs of distress. The truck had the stock exhaust and around 140K miles for reference. I originally set my intake from the air filter can to turbo inlet with hump hose joints and solid pipe like you have roughed in. After running for a short time, I to was concerned about the vibration on the air filter housing and mounts. I ended up using the stock Toyota rubber/plastic accordion type flex hose. I have nearly 25k miles on my swap now and no intake hose issues. You can see mine in my swap thread on page 15 post 300. I also ran my exhaust like you did when until I swapped turbos. I had no issues with heat on the alt/vac pump, dip stick, etc. There seems to be enough airflow to keep the exhaust surface temps low enough to not cause issues on my mine. But I run max 16-18 pounds boost on a 4BD2, so yours maybe different. After the turbo swap, I ran the exhaust over the top of the starter to the firewall and down and followed it down to connect to my existing exhaust at a 3 bolt flange. It was a little tricky to make the down pipe this way, but it is much cleaner and I do not have to remove the exhaust to change the starter or alt. Keep it going like you have been, and it will a driver soon! Cheers Doug

Thanks Doug,

I have seen your intake and like it, i remembered from your swap the talk of vibration with the first one you had. Ill look into alternatives in the 3" flex range.

Glad to hear the flex can withstand the exhaust brake I can now put the flex in a much nicer area. The exhaust brake its self I think will go back along the side of the transmission.

Also good news about the parts withstanding the heat. I really have no option with the exhaust, no room over the starter. I could run it beside and out the wheel well but then its a lot more bends and heat issues to deal with. Plus I have a lot of brake lines in the way there.

Thanks for the input its much appreciated.

 

[Dougal]

Hey just letting you know. There's some guy on 4btswaps.com who is building one *exactly* the same.

For your intake pipe. I'd support it above the engine with a bracket off the throttle support bracket, break it just after that corner and run two hump hoses between that and the air-box.
Should provide enough compliance and stop stuff touching.

 

[Wheelingnoob]

Hey just letting you know. There's some guy on 4btswaps.com who is building one *exactly* the same.

For your intake pipe. I'd support it above the engine with a bracket off the throttle support bracket, break it just after that corner and run two hump hoses between that and the air-box.
Should provide enough compliance and stop stuff touching.

Intresring! Ill need to check it out

Good idea on the intake and thats what I plan to do. I got a better hump hose today that is a tripple hump hose and its softer as well.

No updates today got some more parts and picked up the intercooler. Then worked on my brothers truck getijng it finished up for a day trip this weekend.

...via IH8MUD app

 

[GLTHFJ60]

Hey just letting you know. There's some guy on 4btswaps.com who is building one *exactly* the same.

Yes sir. For a while I thought they were the same truck.

 

[cody c]

I'll ask him for you.

Today I spent the morning at my buddy's fab shop bending up new end tank sections to plug the holes left from cutting the old out let and inlet off. Worked out good and hope to have it welded tonight or tomorrow. I am just having then weld on a 2.5" straight so I can connect with a 90* silicone coupler. I also fashioned a flow distribution divider for the inlet, this will direct half the flow coming into the intercooler up into the top of the cooler. Problem with it just going straight in is you have 1/3 to 1/2 the core doing 80% of the cooling. This will send half the air up into the top 1/2 of the intercooler allowing it to do its share of cooling. Sorry no pictures of that part today, when I pick it up I will get some pictures.

I then went back to my shop to work on a few other things.

I started with the PS resivor and where to mount it. I decided on mounting it beside the fuel filter on the old fan shroud tab.







Worked well there and I was able to bend the pump feed to an angle that allowed me to get a clean run of the hose from the rez.

I then hooked up all the pressure lines for it.





Fits like its made to go here.

I also removed the brake lines that run right up the to the front of the engine bay.

Much more room for intercooler pipes now.



Then I hooked up the FJ80 throttle cable from cruise to throttle. Had to make a tab for it but turned out good I think.



Both cables hooked up and when I push the peddle I move the throttle now so that was easy.



Lastly the kick down cable attchment, same thing here needed to make a braket to hold the cable. I had modified the factory Isuzu arm to take the cable end a few months ago.



Works great.

Tomorrow I hope to have the intercooler back and start work on the piping.

Whats the gauge in the last picture? It looks so cool I'm going to have to find a reason to justify putting one in my hilux.

 

[Wheelingnoob]

Yes sir. For a while I thought they were the same truck.

They just maybe......

 

[Wheelingnoob]

Whats the gauge in the last picture? It looks so cool I'm going to have to find a reason to justify putting one in my hilux.

That is my mechanical oil pressure gauge, its not ideally located for reading oil galley pressure but its visible and I can still get an overall oil pressure.

 

[Wheelingnoob]

Ok short day today.

Worked on down pipe and exhaust today. Started by adding a 2.5-3" cone adapter for the jump to 3" pipe. I was originally going to put the V band right there but I realized it would eliminate any chance of removing the starter. So I moved the V-band about 6" down and in the middle of a bend.



Very close to the tie rod at full bump. I'm going to lower the bump stop another 1/2" and clearance the pipe a bit. I could not get it any further away with out running into clearance issues somewhere else.



V-band placement here it allows easy removal of the down pipe to allow removal of the starter.



Got it snaked around the sway bar mount and bell housing.



Then down the transmission to the flex pipe.



From there I will build some exhaust mounts and put in the exhaust brake about 11" back from the flex where I have room to mount it. Its big and surprisingly heavy.



That's all for today.

 

[Polar Bear]

Your clearance at full bump made me think of the guy I saw at the mud drags. Big power and too much motor movement put his exhaust into the tie rod and steered him out of control, rolling the rig.

In retrospect he could have probably just gotten out of the loud pedal but he panicked, and things went pear shaped.

At full bump I doubt the two would contact for more than a brief moment, but it's something to keep in mind.

 

[Wheelingnoob]

Your clearance at full bump made me think of the guy I saw at the mud drags. Big power and too much motor movement put his exhaust into the tie rod and steered him out of control, rolling the rig.

In retrospect he could have probably just gotten out of the loud pedal but he panicked, and things went pear shaped.

At full bump I doubt the two would contact for more than a brief moment, but it's something to keep in mind.

Yes I am hoping to have 3/4" clearance when done. The engine also will pull the exhaust up and away under power so I should be fine. I cant see being at full bump for any more than a moment at a time and even those are few and far between. I do not jump, race or otherwise drive at excessive speeds off road. There will always be a time when I do not see a cross ditch and hit full bump but I can count on one hand how many times that had happened.

Its always in the back of my mind as I built this that us why its got no springs or shocks and it at full bump.

Thanks for making sure though and thanks for the story.

 

[Polar Bear]

This is what I love about your build- very well thought out.

Please continue with the daily dose of diesel cruiser porn :-D

 

[Fromage]

Intakehoses.com has rubber hump hoses that are very flexible. They would be perfect for that air intake pipe (not for boost applications).

This is looking good. I used the same method for looking at clearance at full bump and there were a few parts that were close. I haven't had any issues. I think that with any type of HD lift, it's uncommon that the front suspension would go to full bump on both sides at the same time. Even with a snowplow hanging off the front of mine, I have never come close.

I think you will like the lockup in several forward gears.

 

[doug720]

I tried using very flexible double hump hoses on swap. I did not feel they allowed enough movement between the heavy engine and sheet metal air filter canister. On mine, when the engine was shut down, it shakes fairly hard. It shook the housing and mounts pretty hard and looked like it would damage the canister in short order, so I went with a flex hose.

On the bump stops, keep in mind that when the vehicle flexes or hits a bump hard enough to contact the stops, the rubber stop will compress. I found this on mine also, even though I extended my stops, when I flexed it hard, a tang on the Isuzu motor mount would contact part of the diff pumpkin. It took me a while to find what was happening, as when flexed and stopped, no contact, it only hit when moving.

Also, the Isuzu motor mounts are fairly soft and allowed more movement than I expected. When the 4BD2 is making power in low gears, it twists quite a bit on the mounts. When combined with some suspension flex, I found the 3 bolt exhaust connector would vibrate on the bottom of the body. The connector was a good 2" away from the body when everything was static.

Looks good as usual Jeremy.

Doug

 

[Wheelingnoob]

Intakehoses.com has rubber hump hoses that are very flexible. They would be perfect for that air intake pipe (not for boost applications). This is looking good. I used the same method for looking at clearance at full bump and there were a few parts that were close. I haven't had any issues. I think that with any type of HD lift, it's uncommon that the front suspension would go to full bump on both sides at the same time. Even with a snowplow hanging off the front of mine, I have never come close. I think you will like the lockup in several forward gears.

That is actually where I got my hoses from. I have the rubber hump hose and its very stiff. Its cold but only -3c and the hump is almost rock hard. I cant imagine how hard it would get on some of our winter trips.

I hope the Slee 4" springs will prevent it from hitting the bump stops but well see. I can also firm up the shock a bit to help.

 

[Wheelingnoob]

I tried using very flexible double hump hoses on swap. I did not feel they allowed enough movement between the heavy engine and sheet metal air filter canister. On mine, when the engine was shut down, it shakes fairly hard. It shook the housing and mounts pretty hard and looked like it would damage the canister in short order, so I went with a flex hose. On the bump stops, keep in mind that when the vehicle flexes or hits a bump hard enough to contact the stops, the rubber stop will compress. I found this on mine also, even though I extended my stops, when I flexed it hard, a tang on the Isuzu motor mount would contact part of the diff pumpkin. It took me a while to find what was happening, as when flexed and stopped, no contact, it only hit when moving. Also, the Isuzu motor mounts are fairly soft and allowed more movement than I expected. When the 4BD2 is making power in low gears, it twists quite a bit on the mounts. When combined with some suspension flex, I found the 3 bolt exhaust connector would vibrate on the bottom of the body. The connector was a good 2" away from the body when everything was static. Looks good as usual Jeremy. Doug

Thanks Doug. Ill have to play with the intake pipe a bit and see what happens.

I am trying to allow extra room for movement and compression of the bump stops. In a few areas i just have no option its going to be tight. Im tiring to leave 1" on all areas the exhaust could contact. So far the only spot that is close is the sway bar mount its 3/4" away but its in a spot where when the engine torques it will pull the exhaust up and towards it buy the time its moved that 3/4" sideways it will be above the tight clearance.

Im surprised to hear it moves that much i may need to look at different engine mounts. I want smooth running but i cant have the engine bouncing around like rodeo clown as well.

 

[Fromage]

It's weird that those hump hoses aren't flexible, the ones I had were 2.5" and were very flexible. I once used one as a boost hose in a pinch and it blew up like a balloon! Very thin material. It looks like the design is different from one size to another, maybe that's the reason, or they might have changed, it has been 5+ years since I bought them.

My experience is that the looser the engine mounts, the better! I just swapped out the stock FZJ80 mounts for Anchor ones popular for 4BTs and it made a huge difference. On shutdown the whole truck used to bang around, now it's just the engine that wiggles. I have to say that the softer engine mounts made a huge difference in how I drive the truck, I can now lug it at lower RPMs without being annoyed. I'll probably revisit my plumbing now as well since the engine is doing the "mechanical bull". I don't think it is possible to stop some contact in some certain situations. In the end it will all "auto clearance" anyways

 

[doug720]

The Isuzu mounts are great mounts and with the 4Bd's being fairly smooth, at least in comparison to a 4BT, work very well. My swap is most vibration free at any RPM, just shakes some at shut down. I think the stock 60 rear trans mount and Isuzu engine mounts are a good combo and have been trouble free.

My contact issue was in a hard flex/twist in low gear with some power applied, and it was minor, more vibration that hard contact. To correct, I had enough room to move an exhaust mount about 1/4" and all is well.

I'm not saying it's a problem, just keep the movement in mind.

I have found these engines are very quiet and smooth. I never added any sound control and it's no louder than the 2f was. The wind and tires make more sound than the engine does. Most who been in my swap all comment how quiet and vibration free it is.

Quit reading these posts and get back to work!

Doug

 

[mudgudgeon]

Exhaust is looking nice. I would suggest a solid mount to the transmission or bell housing just before the flex joint, then install a much longer flex joint. The flex joint you have may dampen some vibrations, but they allow/absorb very little lateral flex or shuddering.

I built a 4" down pipe and 3" exhaust for my hdj80 and did this. I had some very tight clearances to the chassis, less than 3/8. I used a 14" long flex joint after the transmission, I had no issues with the exhaust contacting the chassis, even with a violent engine shudder at shut down.

The factory exhaust knocked on the chassis at shut down, I was determined my system would not, hence the long flex, and it worked a treat.