FAQ: I've had some common questions asked, so here are the answers
Q: How loud is it, how insulated is the vehicle? A: There is a video on YouTube of the inside at idle with the door open, but it might be hard to compare relative volumes. I used 5 gallons of acoustic deadening from Second Skin, it's a spray/roll on polymer. I also added 4-5 gallons of a thermal block coating that has ceramic micro beads to keep the cabin temps insulated. Also by Second Skin, IIRC it's like $87/gal. These are through out the tub and doors. I then added silver backed fiber insulation where I could fit it, then installed a whole new Mass-backed Carpet kit throughout. I then replaced all the door and window seals that were old to help seal out the road noise. I'm pretty positive you won't find another 4BT swap that has gone to this effort for sound, as just this required over 120+ hours by me. No shop could ever justify the time needed. It is as quiet as you can ever get inside of a mechanical injection rig. That being said, I've owned a GX470 and LX450 and they are obviously quieter in stock form. Side benefit is that the cabin is also insulated very well. I also have a UV & Infrared blocking tint that reflects most heat from the glass ($700 for tint).
Q: I heard 4BTs vibrate a lot? A: As for vibrations, I added a silicone Fluidampr Harmonic Balancer and along with a slightly higher idle, it doesn't vibrate like most most 4bts.
Q: I heard 4BTs are slow? A: As for highway driving: it's certainly not a speed demon, but I've had it over 90mph with no vibrations. The turbo and gearing are really set-up do go 70-75mph or less, like most 4speed autos, its sweet spot is around 60MPH for max fuel efficiency. Given the weight of the vehicle, it is surprisingly fast. The turbo starts to pull around 5psi until 22psi max. I've driven an OEM turbo diesel 1990 1HDT 80 series and mine is significantly faster. You won't win any drag races, but it gets out of its way pretty well for highway on ramps. It has minimal turbo lag compared to an HX35, which is the OEM turbo for Cummins.
I'd urge you to come drive it, if you are interested. There isn't a good way to compare it to another Landcruiser, as there isn't anything else like it.
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