Builds 550hp 2JZ 1978 RN28L Build (3 Viewers)

[ntsqd]

Pretty common in the world of LoCost 7's to use a McPherson strut donor front suspension and cut the strut down, weld a plug into the top of it, and then use an SRE or captured SB for the the upper spindle/upright joint in a fabricated upper A-arm. I can see using FWD suspension stuff like mod'd as one option for the front drive of an AWD lay-out.

Another would be first gen 4WD S-10 uprights, unit bearings, etc. Not sure that those have large enough OEM rotors, and I sure wouldn't use those calipers, but the rest of the knuckle assembly is viable. I'm told that those unit bearings are used in some of the desert racing buggy rear swing-arms. If so, they ought to be a decent size & strength.

Taco uprights are really tall, and I'm not sure if they lend themselves to mods easily.

 

[snivilous]

Pretty common in the world of LoCost 7's to use a McPherson strut donor front suspension and cut the strut down, weld a plug into the top of it, and then use an SRE or captured SB for the the upper spindle/upright joint in a fabricated upper A-arm. I can see using FWD suspension stuff like mod'd as one option for the front drive of an AWD lay-out.

Another would be first gen 4WD S-10 uprights, unit bearings, etc. Not sure that those have large enough OEM rotors, and I sure wouldn't use those calipers, but the rest of the knuckle assembly is viable. I'm told that those unit bearings are used in some of the desert racing buggy rear swing-arms. If so, they ought to be a decent size & strength.

Taco uprights are really tall, and I'm not sure if they lend themselves to mods easily.

I'll probably just design it and have it machined since I think it's fun and cool going down that route. This is the knuckle I designed for my buggy a year ago, and would like to follow a similar path on this truck. Then I can easily add all the features and geometry I want.

 

[cruisermatt]

Just now seeing this. Fun project and looks like you are learning a lot.

What’s the reason for such a big tire on the rear, just looks? Have you tried a 225 or 235 Mickey Street R? I have gone really fast on those at around this weight/HP.
Also, Id recommend going about double the size on the IC just based on the looks of that one.
Do you have enough IO to do IAT and MAP sensors pre and post IC?

Too late now but a stock Fox rear goes into these trucks really easily and would be super strong and probably a $200 or less axle. I have a 1JZ 79 Corona project I am
working on and was hoping the rear axle would hold up for a little bit until I put a Ford rear in it, those cars are 4-link though.

 

[snivilous]

Just now seeing this. Fun project and looks like you are learning a lot.

What’s the reason for such a big tire on the rear, just looks? Have you tried a 225 or 235 Mickey Street R? I have gone really fast on those at around this weight/HP.
Also, Id recommend going about double the size on the IC just based on the looks of that one.
Do you have enough IO do do temp and MAP sensors pre and post IC?

Too late now but a stock Fox rear goes into these trucks really easily and would be super strong and probably a $200 or less axle. I have a 1JZ 79 Corona project I am
working on and was hoping the rear axle would hold up for a little bit until I put a Ford rear in it, those cars are 4-link though.

The big tires are just for traction, it spins in 2nd with the current tires still. I was concerned they'd look a bit weird, which is why I didn't push to a wider tire, but it's still traction limited right now. I had looked at the Mickeys since they would hook better, but from the reviews I saw the Nittos were a lot more friendly if I got caught in the rain--like have a chance of making it to the next exit instead of instant death

I completely agree on the IC, this is a cheap $100 one I grabbed that fit. My plan is to build a custom one that is full width and has outlets going straight back. The only reason this one is so narrow is the room needed to fit the two 90deg boots. I have not thought about measuring MAP pre intercooler, but I do have a couple ports left I can get data from if I wanted. One of my friends was suggesting measuring turbo rpm too, and I've also thought about measuring oil temp.

 

[cruisermatt]

I wouldn't waste your time on turbo RPM at all in a car like this, but IAT and MAP pre and post IC is good useful data. That way you can have a good idea of exactly what you need to change, or if you really need to at all. The other thing is once you have that data you can just leave the pre IC sensors in place and use those wires for other sensors, it's not like that data is going to really change later.

As for the tires, yeah they are going to spin, you are on the street, pretty much anything is going to spin on the street over about 400whp and stick shift.
When do we get to see it make a real pass on a drag strip?

 

[snivilous]

I wouldn't waste your time on turbo RPM at all in a car like this, but IAT and MAP pre and post IC is good useful data. That way you can have a good idea of exactly what you need to change, or if you really need to at all. The other thing is once you have that data you can just leave the pre IC sensors in place and use those wires for other sensors, it's not like that data is going to really change later.

As for the tires, yeah they are going to spin, you are on the street, pretty much anything is going to spin on the street over about 400whp and stick shift.
When do we get to see it make a real pass on a drag strip?

Drag strip pass will be aways down the road, I've never been on a drag strip but I definitely want to take the truck to one someday! I have a Dragy that I'll at least get some level of data from near the house. I just need it to do a 0-60 better than 4.5s so I can at least say it's faster than my Tundra, but I have a feeling that will be hard to pull off before the AWD!

 

[snivilous]

(PART 1) Been a fat minute since I did anything to the Hilux, after the last 3rd member broke life got busy with other stuff. In the past few weeks I've been chipping away at the truck since it needs to vacate the lift.

First my 9" housing from Quick Performance showed up.

I also got joints from Summit Machine who are local in Utah. I've wanted to run these joints for a long time, originally wanted to run them on my buggy. They are not cheap though, but if I did one end fixed and the other adjustable then the price was about the same as running all adjustable heims, and since you really only need to adjust them once that seemed fine. These are their "small" joints. They are rebuildable and greaseable and seemed like a good option for a street rig to try them out.

Now that I had all the parts, I needed to finalize the suspension design. My original plan was to do a 3-link with panhard, but mounting the upper link was a bit tricky and likewise the panhard had a tight window to operate in between clearing the differential and clearing the fuel cell. Because of that I looked at a triangulated 4 link, which in general I've always been a fan of, and that packaged a lot nicer. I did lots of reading and finally just settled on some parameters to get out of analysis paralysis.

This is where I settled for the baseline configuration. I have 1" of adjustment on the frame side uppers, and 1" on the axle side lowers, so I have 4x different options. All the other locations were just an afterthought of having room to add another bolt hole.

This was all done in conjunction with laying it out in Solidworks:

With all the points setup, I then drew up the bracketry in Solidworks and then exported it and setup the CAM paths for the plasma table.

The axle has an offset diff since the pinion is not centered in the diff, but the pinion is centered with the axle. Because of that the upper link mounts are unique to each side. This is where having the scan was very powerful.

Then off to cutting and welding the brackets together. First weld in awhile looking good!

As time has gone on I've settled on a combination of MIG and TIG for the projects. Some things, like two edges, I can TIG way better than I can MIG weld. But other spots it's way faster and easier to lay it down with the MIG and I can get good welds.

With the brackets done, it was on to prepping the frame. The lower link mounts went in the same vicinity as the leaf spring perches, and those were going to be a bitch to remove and I didn't want to spend days grinding, so I opted to completely cut out the perches and then weld in a replacement plate to get the frame smooth and it worked out beautifully.

Next was to weld in the link brackets.

Axle coming along and has the link brackets all done.

With the axle done, I decided to scan the completed axle and insert it into my CAD assembly to see how the real thing compared to the perfect CAD, which I thought was a fun experiment and yielded some cool results! The green is the new scan, the gray is the previous scan/perfect brackets.

From that I then pulled link lengths from the CAD and started welding the links together. The links are nearly replaceable top to bottom---in retrospect I should've tweaked the design to make them the same length---but the uppers are about 0.75" shorter than the lowers. The links have jam nuts plus an extra 0.25" of threads showing so they can be threaded in, so in a pinch I probably could swap a lower link and remove the jam nut and get it to the correct length to fit the uppers.

I'm using 1.5" x .120" DOM for the links, this should be massively overkill. From some reading a somewhat "large" link for a car is 1.25", so I decided to bump a size over that to be safe. Not a lot of bungs that fit this thread size and tube size, but I got some from WFO Concepts. Essentially everything in the rear is offroad sized hardware, which I think looks cool and I don't want to worry about the rear ever having a strength issue again.

 

[snivilous]

(PART 2)
With the rear link components done, I hung the housing so I could figure out how I wanted to do the shocks.

With the shock position and length figured out, I ordered some Viking coilovers. From what I've read they are a spinoff from QA1 and most people like them. They are also wickedly cheap! These are their mid tier valving setup that's a bit more performance focused than their pure comfort lineup. These are 5.75" stroke, have compression and rebound adjustment, and cost $275 a shock! Got a whole coilover for the price of a bump stop on my buggy.

I didn't get any pictures of the coilover mounting, but pretty simple brackets. The axle has a boxed in tower that hangs down pretty far, the front fuel cell crossmember has some little tabs come off. This leaves everything mounted below the frame so if I want to add a floor in the bed it can still be flat. With the coilover mounts done I painted the axle.

And then today finally mounted everything!

You can see the remnants of an original crossmember which sat too low for the upper links at full bump. I'm not worried about deleting it since the fuel cell crossmember which I added to the frame is only a couple inches behind it.

I fought with the rear brakes a bit, and you have to completely disassemble the parking brake drum to get the axle shaft retaining plate in place from what I could figure out. That seemed like a huge pain in the ass, so I deleted the whole parking drum brake assembly to simplify things. I can't actuate the parking brake right now anyway, and having the axle shaft be quick to pull out is a much higher priority than a dedicated parking brake.

The tops of the coilover where the adjustment knobs are is very easy to access. These shocks have 20+ adjustment positions, and by position 5 they are already wickedly stiff. I'm worried even the softest setting might be too stiff for how lightweight the truck is, we'll see when I drive it and do some launches. Worst case I'll tear them down and revalve them, or for how cheap they are just buy some of the comfort lineup.

This is roughly ride height, which is where I wanted it to be. This is with zero preload on the springs, just kissing the spring collars at full extension. This ends up with 2.75" of up travel, and 3.0" of down travel. This is with a single 150 lbf/in spring as I recall.

I am so stoked how it's turned out, it looks absolutely nasty. I saw a mini truck at a car meet a few weeks ago with a similar four link, but I think he just had bushings on both ends with small tubing. The links on this look like she means business, and having the huge billet ends on top of the axle was just coincidence but is pretty cool!

And that wraps up this update, I wanted to post all the pictures before I get too many. I'm on the books for the driveline shop, that's probably two weeks out. Both coolant lines are welded up, one is installed and the other needs some mounting brackets added. The exhaust I haven't touched. Couple other minor things. Truck should be ready to rock by the time I get the new driveshaft, and hopefully (knock on wood) is bulletproofed enough to handle the power for awhile!

 

[snivilous]

Yesterday finished up the cooling lines and tackled the exhaust. I ended up cutting down the passenger side coolant hardline so it would line up with the softline a bit better, and then cut and welded new brackets to locate the hardline where I wanted. For the exhaust I ended up replacing nearly everything with the exception of right next to the front V band and the outer foot or so where it curved into the bedside, only because I didn't have any more curved exhaust pieces to make a new tip. I ended up splitting this section of the exhaust that goes from the in front of the transmission crossmember all the way to the back, into two sections with another V band. The front section is just a 4ft straight piece effectively and ends right before the rear of the cab. This makes putting everything together a lot easier compared to last time trying to snake the exhaust around the coolant lines, bedside, above the trans crossmember, and into two exhaust hangers. The rear section curves up at 30 degrees right into a Vibrant resonator muffler thing, and then does a normal 90deg turn into another straight and out the bedside. This is a fair bit simpler than the previous setup that did a funky compound curve to clear the battery. I'm hopeful the resonator muffler thing quiets it down a bit, I'm fine with the truck being loud at full throttle, but right now it's too loud for me just cruising around--like I wouldn't take the dog with me ever in the truck. We'll see if it does much if anything, of course most reviews are how it's loud compared to whatever other system people had, not people going from straight piped to adding this muffler. It's also pretty small so I don't have high hopes, but you can only fit so much without looking weird or getting crazy.

Today I screwed around with the front suspension, and got it mostly together then pulled parts of it off again to change my plan for it. After some measuring I should be able to fit the same Viking brand coilovers the rear has without really any modification. The front shocks don't seem to be blown, they still have nitrogen in them, but they are really soft. Additionally the stock spring setup is a complete pain to install, it's like 4" too long, so it's really awkward to get the spring in. The best method seems to be unbolting the LCA from just about everything and then compressing the spring, then jacking the LCA up to bolt it to the frame---it's a cluster and sketchy at best. I'm hoping by shoving some coilovers in it will make installation of the spring less sketchy, plus have compression and rebound adjustment and be able to dial it in for the increased weight of the motor.

My current conclusion, maybe coming full circle, is that the LCA is bent. I measured stuff AGAIN and the UCA all seems to be in the right spot, and the LCA mounts seem to be in the right spot, but the LBJ is 1+ inches rearward from where it should be so it has to be the LCA is bent. I think I will just fork over the $100 for the one LCA on eBay (even though it's way grosser than the one I already have) and see if that fixes the alignment. I'm also going to order a proportioning valve, AN3 brake lines to replace the rear brake lines, and then some other components to refresh the front right while I have it totally torn down. Now to wait for parts!

 

[gnob]

nice job on that exhaust.

 

[snivilous]

nice job on that exhaust.

Thanks! Getting better each time hahaha! I do like the exhaust work, I cut a bunch of 15deg pie cuts and then it's just puzzle piecing it together to go where you want, tack it with the MIG, then finish it off with the TIG which I've gotten to the point 99% of it is just running over it and fusion welding since the fitment is dialed. It's a lot faster than the first times I was figuring it out!

 

[gnob]

Thanks! Getting better each time hahaha! I do like the exhaust work, I cut a bunch of 15deg pie cuts and then it's just puzzle piecing it together to go where you want, tack it with the MIG, then finish it off with the TIG which I've gotten to the point 99% of it is just running over it and fusion welding since the fitment is dialed. It's a lot faster than the first times I was figuring it out!

this is how i did my 3.4 crossover. all day project.