Cheap IRS

[Dieselbikin]

Has anyone used the rear subframe/suspension out of a Miata? They are common, inexpensive, mostly self contained.

 

[wehrme]

Haven't heard of using a Miata, but have seen a couple that used Pontiac Fiero's.

 

[jiggseob]

I've just scrounged a complete irs from a 90 Subaru Justy

IRS includes a structural crossmember, diff, diff-mount crossmember, halfshalfts, hubs, struts, drum brakes with hyd slave cyls and cable e-park-brakes, coil springs, struts, trailing arms, trailing arm mounts, sway bar and mounts.

Wheel bolt pattern is 4x100, which is VW, Toyota, Honda, Acura, and others. Should be easy to find wheels, I will try to find a 5spoke alloys to match my front Honda Comstar.

Took about an hour to take it all off the car, including spinning out and hacking out a welded nut inside a unibody cavity.

I have two CX500 Hondas, one will be losing its swingarm and rear wheels. I hope I can fabricate a frame that can bolt on, so if I hate triking, I can unbolt and go back to tipping over.

The Subaru Justy before disassembly was 58 inches wide at the outside of the tires, so I may not even narrow it at all. The car had 60 hp, and put most of the power out the front wheel drive. The rear diff is the tiniest car one I've seen, but I hope it will hold up to the massive power and torque of the bone-stock 35 year old CX500.

The Justy coils will be too much, I may try cutting them, or go to scrapyard and scrounge an active suspension compressor from a Merc-Lincoln, and do airbags in place of coils.

My first trike build of any sort, I'm trying to figure out posting a pic of the scrounged irs sitting in the back of the pickup.

Any advice? One of the Strilchuks (Lehman connection) are neighbours here, advises me to make it as low as is practical. And then he laughs and wishes me luck.

 

[Gorilla]

IRS includes a structural crossmember, diff, diff-mount crossmember, halfshalfts, hubs, struts, drum brakes with hyd slave cyls and cable e-park-brakes, coil springs, struts, trailing arms, trailing arm mounts, sway bar and mounts.

Wheel bolt pattern is 4x100, which is VW, Toyota, Honda, Acura, and others. Should be easy to find wheels, I will try to find a 5spoke alloys to match my front Honda Comstar.

Took about an hour to take it all off the car, including spinning out and hacking out a welded nut inside a unibody cavity.

I have two CX500 Hondas, one will be losing its swingarm and rear wheels. I hope I can fabricate a frame that can bolt on, so if I hate triking, I can unbolt and go back to tipping over.

The Subaru Justy before disassembly was 58 inches wide at the outside of the tires, so I may not even narrow it at all. The car had 60 hp, and put most of the power out the front wheel drive. The rear diff is the tiniest car one I've seen, but I hope it will hold up to the massive power and torque of the bone-stock 35 year old CX500.

The Justy coils will be too much, I may try cutting them, or go to scrapyard and scrounge an active suspension compressor from a Merc-Lincoln, and do airbags in place of coils.

My first trike build of any sort, I'm trying to figure out posting a pic of the scrounged irs sitting in the back of the pickup.

Any advice? One of the Strilchuks (Lehman connection) are neighbours here, advises me to make it as low as is practical. And then he laughs and wishes me luck.

Welcome aboard. No advise but it sounds like a nice project. If possible keep us updated.

 

[diver]

IRS includes a structural crossmember, diff, diff-mount crossmember, halfshalfts, hubs, struts, drum brakes with hyd slave cyls and cable e-park-brakes, coil springs, struts, trailing arms, trailing arm mounts, sway bar and mounts.

Wheel bolt pattern is 4x100, which is VW, Toyota, Honda, Acura, and others. Should be easy to find wheels, I will try to find a 5spoke alloys to match my front Honda Comstar.

Took about an hour to take it all off the car, including spinning out and hacking out a welded nut inside a unibody cavity.

I have two CX500 Hondas, one will be losing its swingarm and rear wheels. I hope I can fabricate a frame that can bolt on, so if I hate triking, I can unbolt and go back to tipping over.

The Subaru Justy before disassembly was 58 inches wide at the outside of the tires, so I may not even narrow it at all. The car had 60 hp, and put most of the power out the front wheel drive. The rear diff is the tiniest car one I've seen, but I hope it will hold up to the massive power and torque of the bone-stock 35 year old CX500.

The Justy coils will be too much, I may try cutting them, or go to scrapyard and scrounge an active suspension compressor from a Merc-Lincoln, and do airbags in place of coils.

My first trike build of any sort, I'm trying to figure out posting a pic of the scrounged irs sitting in the back of the pickup.

Any advice? One of the Strilchuks (Lehman connection) are neighbours here, advises me to make it as low as is practical. And then he laughs and wishes me luck.

Id luv to see a picture up of it

 

[stacebg]

IRS includes a structural crossmember, diff, diff-mount crossmember, halfshalfts, hubs, struts, drum brakes with hyd slave cyls and cable e-park-brakes, coil springs, struts, trailing arms, trailing arm mounts, sway bar and mounts.

Wheel bolt pattern is 4x100, which is VW, Toyota, Honda, Acura, and others. Should be easy to find wheels, I will try to find a 5spoke alloys to match my front Honda Comstar.

Took about an hour to take it all off the car, including spinning out and hacking out a welded nut inside a unibody cavity.

I have two CX500 Hondas, one will be losing its swingarm and rear wheels. I hope I can fabricate a frame that can bolt on, so if I hate triking, I can unbolt and go back to tipping over.

The Subaru Justy before disassembly was 58 inches wide at the outside of the tires, so I may not even narrow it at all. The car had 60 hp, and put most of the power out the front wheel drive. The rear diff is the tiniest car one I've seen, but I hope it will hold up to the massive power and torque of the bone-stock 35 year old CX500.

The Justy coils will be too much, I may try cutting them, or go to scrapyard and scrounge an active suspension compressor from a Merc-Lincoln, and do airbags in place of coils.

My first trike build of any sort, I'm trying to figure out posting a pic of the scrounged irs sitting in the back of the pickup.

Any advice? One of the Strilchuks (Lehman connection) are neighbours here, advises me to make it as low as is practical. And then he laughs and wishes me luck.

.



see no reason it wont work.... before you get too far into it i would suggest checking the gear ration on the bike an the miata,, got into trouble w that a while back... bike was 2: something an the car was 4.11 i had to find some monster tall tires to make it work
not positive but if you cut springs i think it makes them stiffer

 

[jiggseob]

pics of the irs on the back of my truck

Here are pics of the irs assembly, still all dirty, on the back of the truck

Ratio of Subaru diff is 3.70:1 Ratio of CX500 final drive is 3.09:1 (11/34). So I will have to select as tall tires as is possible to keep my hwy revs down.

The Subaru setup is 53 inches wide at the hub-faces.

As it sits, the coils are fully extended, so the suspension is all jacked up way higher than one would want it to run. I'll have to find a way to squat it down, by shortening/cutting the springs, or by changing the springs out for some sort of airbags. Maybe getting several fat girls to sit on it ??

 

[jiggseob]

Strut top mounts

Yes, it would have been ideal if the crossmember had included top strut mounts; I will have to frame that up. The struts hold the knuckle vertical, so I will have to provide an inch or so of for-aft and side-to-side slotting of the mounts to provide adjustment of camber and trailing arm angle.

I'm hoping to be able to stay low-tech and use the provided drum brakes. I even managed to take off the flex brake hoses, recently replaced by the previous owner of the Justy.

I find parts such as the struts a little difficult to source. Not many Justys came to Canada.

 

[diver]

I like it . looks like a real nice set up

 

[stacebg]

Here are pics of the irs assembly, still all dirty, on the back of the truck

Ratio of Subaru diff is 3.70:1 Ratio of CX500 final drive is 3.09:1 (11/34). So I will have to select as tall tires as is possible to keep my hwy revs down.

The Subaru setup is 53 inches wide at the hub-faces.

As it sits, the coils are fully extended, so the suspension is all jacked up way higher than one would want it to run. I'll have to find a way to squat it down, by shortening/cutting the springs, or by changing the springs out for some sort of airbags. Maybe getting several fat girls to sit on it ??

ratio is pretty close
wasnt that lucky to find one that low... didnt really look
i did find with the tall tires an stock drum brakes, brakes were lame at best subie is light so back brakes are also "light" ....now you put tall tires on makes em worse... ended up cutting the drum part of and making aluminum spacer / adapter and putting disc brakes on it... that fixed it

 

[Trike newbie01]

How did this turn out for you? I have been thinking about using a rear out of a 99 outback but gear ratio is 4.11 and bike is only 2.66 so may use some other rearend if i can find one cheap enough.

 

[jiggseob]

Side tracked... house projects, kids, etc

My IRS setup, and my CX500 are sitting in the shop, looking at each other, and thats about it.

I did go back to the bush where the IRS donor car was, and body-sawed the lower rear body-pan, including all of the rear suspension mounts. I may use that body-pan as the bottom, and then box-in the top. No need to fabricate the frame-up of rear suspension mounts, just use the box-in framing of the top to brace up the pan. The body pan is form-fitting on the IRS, and when I box over it, there will be a lot of storage space inside.

The kids have both moved out, so there is hope....

Jiggs.

 

[TORKER]

I know this is a few years old, but have there been any work/progress on this? I am using Miata parts on my own build.

TORKER.