550hp 2JZ 1978 Hilux Build

Just outstanding!

 

I don't know what is more work, building the truck or your detailed write ups ! GREAT JOB on both

 

First tuning session is done!



Threw the seats in yesterday and then checked some things and got gas and got her warmed up and dude remoted into the computer and spent a half an hour or more adjusting things and then we spent over an hour just driving around and adjusting everything. The biggest thing I actually notice is the off idle throttle response, which before was really laggy and now is super snappy and makes leaving from a stop easy and smooth. For the WOT tuning at the end I had to do it in 4th gear since 3rd was spinning the tires (while rolling, with the differential welded). It took me a bit to actually get high enough in the rev range to be useful since the truck pulled so insanely hard that when I felt like it was time to shift we were only around 5000rpm. Finally I got the balls to hold it a bit and got shy of 6000rpm, and the limiter is at 7500, and before 6000rpm we already making too much boost and hitting the boost cut.

As I expected, even with screwing with the wastegate it can't bypass enough air to calm it down. What dude suggested is to mount the wastegate directly to the exhaust housing, since the exhaust flow is directly inline with the wastegate it will give it a lot of control versus being mounted at 90deg off of the header. Plus what's nice about this setup is I don't have much room for a wastegate beneath the turbo, and the exhaust has the front three and rear three cylinders group together and then combine at the turbo flange, so I'd have to run dual wastegates or do a lot of work to get one wastegate to bypass all the cylinders, or have some cylinders with less exhaust pressure than others. Mounting the wastegate directly to the housing fixes all the issues that had stopped me from getting an external. He also recommended the Summit one which is only $100 and is an exact copy of the Tial 44mm one. This picture is how I'll setup the wastegate:



We also talked about tires, he recommended I get the tallest tire possible and that (which I don't quite follow) is more important than the tire width for traction. He said if I can fit a 27 or 28 that will hook a lot better than the 26" tires the truck currently has. He recommended the Mickey Thompson ET or the Nitto 555 which are a bit more street friendly. I'll probably go with the 555 since I've seen people recommend those, and probably run a 28" and he said like a 265 would work well. He said that's what he has on his 900hp Supra and he's able to get traction in 2nd, of course I don't have any weight out back but if I can have full throttle on tap and not be terrifying in lower gears than 4th that'd be great! I also have a boost controller I already bought, so I'll get that wired up with the new wastegate and we can then set boost limits in the tune depending on a bunch of parameters, so we could limit boost to keep it from spinning at lower speeds.

There's still a decent bit of tuning left, I'd guess we're at 80%, and the next thing is for me to get the boost under control. But otherwise it's running like an absolute champ, really responsive, and a ton of fun! The sound deadening seemed to help quite a bit, but it's still pretty loud but I don't think any of it is from the exhaust, mostly wind and firewall noise. The alignment we did is absolutely TRASH. I take the thing out to start tuning and the steering is so fucking twitchy and floaty. I don't know if the steering is just totally worn out, or the alignment we did is actually just that bad. I kind of suspect it being so toed in before made the tires preload the steering so the sloppiness wasn't noticeable, but it's hilarious how excited I was about finding the original alignment being so bad and yet there's a chance it was intentionally bad and that made it good hahaha



Oh and another thing I found, the alternator cable was hanging low. It turns out it wasn't even connected! The end of the wire was just flopping around and the nut was still connected to the alternator! Hopefully that's the only thing I failed to hook up. I got lucky it wasn't sparking around since that huge wire goes straight to the battery! Besides that quick fix, after tuning we threw the hood on and took the truck to dinner to give the wife a ride.



Definitely needs a bigger intercooler, it looks pretty retarded. But I think the Hilux is properly back and better than ever, and hopefully next week can get a bit more tuning and some fatty tires and really see what this little missile can do!

 

The little hilux that could is really fucking going to!

 

Oh Yeah! Fill the whole front end with a huge intercooler.

 

Taller tire has a longer contact patch in the direction of travel aka straight line. Wider tire only has a wider contact patch side to side.

 

It would seem like contact patch is contact patch, and grip would only care what the contact patch area is, not what the orientation is

 

Well,,,,,,,, that was a nice read. You have spent some hours on this project and it is showing. That is just going to be a beast once you get everything dialed in, WHAT A HOOT!!!!
That motor in that little ole truck, it must pull on and on and on for a good bit. Maybe at some point you might get a video of that thing taking off! HA!!!
I do believe that might be fun to drive!!
It is nice seeing it come together. Thanks for posting.

 

Following

 

This thing is awesome! The only thing I have to add is to pair those halo headlights with an LED Toyota Emblem

https://floatingcentercaps.com/prod...oma-2018-2023-tundra2018-2023-prado2018-2023/

https://www.youtube.com/shorts/2vjJGTQziFo

 

That would actually be kind of cool. I don't know, is that getting too ricey

Funny enough those emblems cost almost the same as the original style Toyota emblem I was going to get which as usual can only be sourced from Thailand for $100+

 

Not until you put underglow on it! Also needs a roof scoop lol

That vintage Toyota Emblem does look cool!

 

took me a moment to realize why that emblem looks familiar. reminds me of a key fob. Now that'd be really cool to turn it into! You know...depending on the actual dimensions of the thing. Could always scan and 3d print it smaller i suppose

 

You forgot the spoiler

 

That looks cool. You should hang it on a fat gold chain around your neck.

 

Tire and wheel selection time! I didn't realize car tires are so insanely cheap, maybe I would've bought tires earlier hahaha. It's like $1000 for a set of nice tires and some cheapo wheels. I can only buy two 40s for that price

I did some measuring, and then said if we have the tools we will use the tools!



After scanning the front and back wheel wells and adding a bunch of reference geometry...



I was able to do a 3D sketch and (at least in the front) cycle the suspension. The below probably makes minimal sense, but it's showing the suspension hub points at the scanned full droop, and then full bump at full left and full right turn and straight ahead. If you want to play a puzzle you can try to identify what is happening



I then modeled up a tire that I can adjust the wheel and tire dimensions and mated it to the hub points. And for reference, the driver's side with the tire still installed matches pretty well to the CAD for the clearance on this zerk with the stock tires:





From here it's easy of just modifying the wheel and tire dimensions and see what fits! Here's the stock wheel and tire, which is a 205/75r14.



Since I didn't model the individual suspension components, at the full bump position we are mainly looking at the tire to fender and inner wheel well clearance, which even on the stock tire at full bump is very close:



The stock tire would theoretically even hit the fender at full bump and turn:




Trying a 245 wide tire up front, and we have similar contact as the 205 but even happening at right turn now:



Though the 245 is still clearing the fender at straight bump:



Moving onto the rear which is a lot easier. I did not bother to flex the rear suspension since I don't imagine the axle will experience that kind of loading often enough to matter, and if it does the tire might rub the frame a little and who cares. Below is the stock setup:



Pushing to a 275 which is the only size offered for a r15 for a Nitto 555R, I think this was an 8" wide wheel with 5" of backspace. Measuring the crossmember that sticks through the frame and slightly protrudes we can measure the distance from the side wall, which is at 0.89", and we can see the tire sticks out about flush with the bedside.



As I recall the next photo is at 5.5" of backspace, so we would end up at ~0.4" of frame clearance, and sectioning it we can see the tire is now tucked in from the inboard surface of the bedside:



But we can see the bedside is a little above the tire, so looking at a side view what's it look like...



So a 275/50r15 would fit pretty well regardless of the backspacing. Probably 5" of backspace would do well, that'd give an inch or so of frame clearance, and sit about flush with the bedside. The bedside is also really flimsy and can easily be pushed out an inch if I add a brace on the inside, so that could be done to keep the tires tucked under the fenders a little bit if I want.

For the front I need to shop around for sizes. If I go to a larger wheel I'll clear the upper arm more and have more sizes available, but I feel like 15s will look better on this with the tiny tires (already a step up in size from what it has!). I can probably push the tires to 245 wide up front, but I'll have to push the backspacing out to clear the upper arm, and the tires could have contact issues at full bump, but for normal driving and turning appear to be fine. And that's 40mm (nearly 1.5") wider than the current tires, I can always run a 225 or 235 and get more clearance and still be wider up front than I am now. However front tire sizes in 15s that are performance tires (not necessarily drag radials, probably all season performance tires) don't have a lot of options and most are either too short or too tall. Additionally I need to look at how much steering scrub radius I have, which is easy to do since I have the kingpin axis drawn up, so just need to look at the trade of backspacing vs tire size vs clearance vs scrub radius change.


I also did some research about the tire diameter vs width discussion, and while larger tires do appear to have a traction increase it wasn't super conclusive. I suspect some of it is due to the increase in radius, ie lower force output at the ground due to the larger lever arm reacting the axle torque so tires would slip less regardless if the contact patch was the same. Though on that note the contact patch should also increase since the radius on the tire is larger (hertzian contact patch effectively). With all of that said, from what I read it wasn't enough of a difference to really be noticeable, so I think I will probably stick with the ~26" tire size since I don't want this to look like a gnarly drag truck with huge tall tires in the back. I'd rather have a fairly square setup, not that that will happen, but just to keep the front and rear tires similarly sized so it looks more balanced and discrete.

I thought all of this was cool to show off! If anyone has suggestions for tires or wheels or anything I'm all ears. Though I'll probably buy wheels and tires tomorrow. Right now thinking the Nitto 555R2 in 275/50r15 in the back, not sure about the front but something in the 225-235 wide r15 and 26" tall range. And then thinking of just some cheapo black steelies, can't get too nice on the wheels when the body looks how it does hahaha

 

Love this project! What filler are you thinking for the wastegate to turbo housing weld? Ive had good luck with 309l on clean cast.

What scanner are you running? Solidworks still makes me want to throw things so its a ways off, but someday.

 

So you're a turbo guy, too?

 

Just a guy, playing a guy, disguised as another guy.

I just like cool stuff.

 

Hadn't thought about the filler much, I had been kind of leaning towards 309 but wasn't super concerned since it's only thermally loaded and easy to access.

The scanner is called an Einstar and was $950. It works awesome, and certainly takes a bit of screwing with in Solidworks to play nice but isn't bad once you accept that 99% of things are reference geometry. If it makes you feel better, Solidworks will always want to make you throw things if it's not randomly crashing or telling you a mate is impossible for no reason, is it even CAD?

 

I will now forever patiently await the day you announce your intentions to turbo your tundra.

 

I ordered some tires and wheels. Front tires are some random Coopers meant for classic muscle cars it seems, 235/60r15 I want to say. Extremely limited tire selection for 15s, and I thought a 17 would just look dumb on the truck, so the Coopers seemed like the only tire within a range that look halfway decent and coincidentally was the size I wanted. The front tire size I currently have that's 26" tall is actually quite a bit larger than factory tires, but I didn't want to drop sizes since I want to lower the truck an inch or two (maybe...) and still have some amount of ground clearance, and lowering it with the tires would look weird. The new front tires will be over an inch wider than my current ones so hopefully look decent. For the rears I got 275/50r15 Nitto 555Rs, which are also 26" tall tires and drag radials. These will be like 3" wider than the current rear tires. I debated going to a taller tire, but after reading I didn't think it'd give much advantage and I don't want it to look like a drag car with massively tall rear tires, which is why I kept the front and rear the same diameter so from the side it'll look pretty discrete. For wheels I got some cheapo steelie 15x8s, again to keep it discrete, plus I'm sure I'll eventually change the wheels and lug pattern and these cost $50 a piece. All in with mounting and balancing I think will run $1300, and the tires should show up tomorrow and the wheels I got yesterday.

I got the Summit wastegate in and got to work integrating that into the turbo housing. I started with milling out a pocket on the exhaust housing.



Then fit up a 1.75" tube and welded it on.



If this doesn't bypass enough air I don't know what will! This is looking down into the exhaust manifold, so the air will want to flow out the wastegate more than it'll want to go anywhere else.



I also welded the wastegate port inside the turbo (that I spent all the time machining out before) and sealed up the wastegate hinge location.



With the hood closed the wastegate still clears by an inch or two also.



Next up was the wastegate dump. Initially I was going to have it dump into the fender well, but after watching some videos and hearing how loud it is I decided I didn't like that idea. It just seemed kind of hack and janky, and I'm already worried about how loud the truck is. Granted, the wastegate opening noise will only be at high throttle when it's already loud, but if I ever put a muffler on the truck or want to quiet it down more then the wastegate is just one more thing adding to the noise. I do love some good engine noise, but I don't want to draw attention and be obnoxious like a lot of exhausts are. So with that in mind I integrated the wastegate dump into the exhaust.



And it turned out pretty slick I must say!



It wasn't too bad, the biggest annoyance was now the downpipe has to come out through the front of the engine bay, so I had to spend more time beating the shit out of the exhaust to get it to fit going forward. It wasn't too bad, but didn't go as smooth as I thought.

I already had a boost controller solenoid waiting for this, so I pulled the wiring harness apart and ran the wiring for that which was straight forward. This was my initial setup for the hose routing.



And after lots of driving and fucking with things and talking to the tuner and more screwing around and trying tons of spring and no spring combinations on the wastegate, it was still making 20+ psi of boost and going insane!



And just to fast forward trying everything I could possibly think of, with the last thing being I had the boost line from the turbo running to the bottom of the wastegate to try and open it and nothing else connected, and with a single 6psi spring I was still making insane boost. I couldn't figure it out, and then it occurred to me maybe the turbo boost port wasn't actually doing anything and there's no real way to test that... So I moved the boost reference line from the turbo to the MAP sensor line and all of a sudden it only makes 6psi! I may have gone to all this work for no reason, the boost port on the turbo was never flowing any boost! I think the stock wastegate may have been totally fine even!

On a stock turbo there's some actuator thing that connects at the turbo boost port, and I had a plug I put in there since I wasn't (originally) actively controlling the wastegate. That plug had this nipple thing that stuck into the cavity with some O-rings, and I had removed the O-rings but it seemed like air could flow around that nipple. Well needless to say it couldn't, I think some air could flow since it wasn't seal, but not enough air to actually actuate the wastegate or at least not fast enough. This was easily solved by removing that nipple on the plug with the lathe.



And voila, after that I put in the 12psi spring setup into the wastegate and she makes 12psi! And the boost controller can ramp up boost now! I did a drive messing with the boost control in the ECU a bit, and it works great now. The boost controller is commanded open via PWM and that then directs boost to the top port on the wastegate which tries to close the valve, so if the boost controller isn't working no air is directed to the top and the springs open at 12psi with the boost going only to the bottom of the wastegate to try and lift the valve open. In the tune I now have it setup so at ~3psi the boost controller turns on and opens all the way, so the wastegate is fully closed to spool the turbo as fast as possible, and then the duty cycle decreases (ie lets the wastegate valve open) as rpm and/or boost increases to keep it tame. So at 6000rpm the wastegate is fully open, and at ~15psi the wastegate starts to open to prevent the boost from overshooting. My basic boost map so far has resulted in it staying shy of 20psi which is what we want for pump gas! After all this time, I finally have control of the boost the truck is making! And you might think with how much excess boost it seems capable of the turbo is probably slow, but it's in boost almost instantly, and even at mid throttle over 3000rpm it'll be making like 10psi and the truck usually cruises around at 2500-3000rpm to begin with, so it's actually really responsive. There's a second maybe of lag if the turbo isn't spooled up at all, but like in 1st or 2nd it hits really fast and really hard. So hard that today it was spinning tires in 4th gear!



And you might be thinking wow that's a lot of power for that little truck. And it was.



I let my neighbor drive it, bad idea in retrospect, or I should've been more firm about not pushing it very hard. At 80mph in 3rd gear, I think maybe the 3-4 shift, the yoke sheared off the diff.



And that was pretty terrifying since first it slammed all over, then got spit out, and we're hauling ass in a little truck with no ABS. But everything ended up fine. I think when he shifted it shock loaded it and sheared it off, since obviously the truck had been fine prior to that and I had given it lots of full throttle beforehand but it was always a pretty slow shift and at not on the power letting the clutch out. You can only go so far and so fast in this thing before slowing down, so I had never tried to really haul ass--it's not built for speed but for accelerating!

Luckily we weren't far from town, so my wife came and towed us back.





I've probably mentioned it before, but a larger axle has been a plan for a long time. I don't have any misconception about what a Toyota 8" can handle, I just didn't expect it to die so fast. I just wanted to drive it a bit with boost before going to the next stage of the build!



With that said, my plan is to just swap another carrier in or regear this one. I think even with the fatty tires it can handle the power as long as it's "gentle" (at least relative to today). Like get into gear, then give it power, don't try and slam through the gears at 7000rpm. I will eventually do a Ford 9" probably since there's lots of support and gear ratios, but that will involve finding or narrowing a housing, may as well link it then, it just snowballs fast and I haven't even completed the engine phase of the build so one thing at a time. This truck is meant to be fun, not eternally being worked on. And once I get another 8" diff, it's just fixing the driveshaft and a coolant leak, so probably end of the week she'll be back together.

The driveshaft beat up a lot of things, but the only real carnage from it was the coolant hardline got hit and that cracked a weld which is why all the coolant was on the ground. I think the engine was fine, it was turned off pretty soon after we pulled over.



The hardline should be connected to the bracket up at the top of the tube. Somehow the outside of the hardline got hit.



This section of exhaust will probably have to get spliced out. It looks fine from the wrapping, but there's probably an inch deep sharp dent under it. The tube got absolutely crunched, to the point of being bad enough to need replacing I think.



And then the driveshaft!



The ends and yokes all appear relatively fine. I'm hoping I can give the driveshaft shop the two halves and they can salvage everything and just retube it. Hell they could even cut it down and sleeve over it since only the centered is messed up.

And that wraps up the past couple days! Tomorrow should get the tires and wheels mounted, and hopefully drop off the driveshaft. Need to find an 8" diff but apparently my neighbor knows a guy selling one or two for $250, maybe they're even geared better than my diff. I think I should have it running again in a couple days, hell maybe I can meet with the tuner again before the end of the week! At a minimum the engine is running absolutely fantastic and stoked to get the boost under control finally. The rear end exploding is a shame, but should be a relatively cheap and easy fix all things considered, and time to keep an eye out for a 9"!

 

Moral of the story don't let your neighbor drive

 

Literally I was telling my wife how I can have a switchable boost map so the truck can be in low power mode if I want to let someone else drive it, but we concluded that's kind of pointless since it's adding features purely to limit people I don't trust, so probably shouldn't let those people drive it to begin with

 

That's why you should enjoy it first, too bad it happened. Oh well!

 

DANG!!!!

Holy Moly! :$&?!$!!!

 

Bluetooth drive shaft mod... Nice.

 

Keep in mind yours is a 7.5" and like 50 years old lol. To upgrade to an 8" i think you'll need to swap the whole axle housing since the 8" is 30 spline axles and 7.5" is 27 spline. Worth it for the strength increase but I think it might be wider too.

Side note, you should become a writer with these novels you post on here haha great updates as always!

 

I picked up an 4cyl 8" diff last night, which from what I can tell matches up with the one I have. I guess the 7.5" diff has an 8 bolt pattern and the 8" are 10 bolts. The good news being the truck should be back together by the end of the week and really just waiting on the driveshaft for most of it. Bad news is nothing will be upgraded I've been looking at Ford 9" stuff and it's crazy how cheap it is compared to the offroad stuff I'm used to. A custom built housing with shafts is a $1000, a normal diff is like $600. Add in brakes and other stuff and you're in $2k for a brand new axle ready to rock. Course if I'm doing that then add in the cost of links and coilovers and really probably in the 3-4k range all in.

I am already shopping for that stuff, but still want to go ahead with fixing what I have so I can finish getting the engine tuned and have the drivetrain in a "completed" state before taking the truck under the chopping block again. Buy everything I want and have it in a pile ready to go so I can swap it over a week with minimum down time.

 

Too bad I can't take it for a rip since we have the meat!






















I think it looks good, and lowering it an inch or two eventually will be perfect. The rear needs the rear lower fender and a bumper to cover it up a bit more, but I can't complain at all! I do plan to push the rear fenders out by an inch or so with a bracket coming off the frame, and might try to flare the fronts out a little bit too. The rear tires aren't quite as wide as I was expecting due to the wheel, and the fronts are a bit wider due to the wheels. I'm stoked though! The rears are ridiculously sticky just rolling around the shop and mounting them. Both front and rears are right around 25.5" tall, the rears just seem small in the photos from the lack of tread--which I don't understand how you get very many miles out of something where the tread depth at full tread is about the same as a normal tire when it's on the wear bars... Like if these wear down until the tire is completely smooth is fine to still run them? I don't understand!

Got the rear diff swapped out too.







New diff got welded up, and before putting it in I adjusted the side adjusters a bit since it feels AWFUL. And I went full adjustment in both directions and it didn't feel any better, so I just set it to the factory backlash spec.



Once installed... it feels EVEN WORSE. It is insanely notchy feeling, and even sounds bad just spinning. I don't know what happened to this thing. I even thought about trying to get a pattern off of it, but I said fuck it I don't want to know how bad it is and I don't plan on tearing it down and setting it up properly. Hopefully some gear oil on it makes it not sound terrible, so the bet is what fails first, the pinion shearing or the gear teeth getting wiped out?!

At least it's easy to pull and everything is lightweight so not a bad job. At this point I'm just going to try and be somewhat gentle to it and cross my fingers it can live long enough for some 9" parts to show up, since how it feels has if anything accelerated my want for the new axle, and I really don't want to spend more money on this tiny axle!

I also dropped the driveshaft off to get retubed. Next up will be fixing the coolant line and the squished exhaust section!