I like this IRS design!!!

[85 Cutlass Brougham]

I was reading through Hot Rod's IRS suspension guide and looking at all the aftermarket kits available, and this one really impressed me. It is NOT a Semi-Trailing arm design like a 60's Jag, Vette, BMW or Datsun 510/240z. Most of the aftermarket street rod designs copy the early Vette or Jag IRS, which uses the halfshafts as the upper control arms rather than a dedicated arm. This is less than ideal for a number of reasons that should be obvious. Can I afford it right now? No. But I will post it here for the benefit of the forum and for comments. The only thing I didn't like is the lack of inboard brakes, but the really cool coilover placement seems to preclude that as an option.
http://www.team321.com/321HotRodIRS/321HotRodIRShome.html

Also note the 2 joints in the lower control arms. It seems to me that this may be to impart a passive 4 wheel steering geometry such as that in the Porsche 928.

 

[jonnyslick]

Yeah that's very cool ... they have a great website too. What's the suggested MSRP on those (I didn't see it on the site unless I overlooked it).

 

[jonnyslick]

😳

Nevermind I did over look it. So it comes out to around $4,500 with all the trimmings and work ...

 

[85 Cutlass Brougham]

But you could do it cheaper if you got the center section from a junkyard yourself. Still, it is about $1,000- $2000 more pricey than a beefier axle, bigger brakes and tubular uppers and lowers for a standard G body rear suspension. If I had a real job I would be real tempted to buy one. They list the price with everything as around $3900, which is not all that bad when you consider what you are getting. If you get your own center, you could probably knock $400 off the price. However, I wonder what I could build something similar for myself. 8.8 center section, transverse leaf spring instead of the coilovers, etc. I may try to design one in a year or two when I get that far in my engineering classes. I would also do inboard brakes to remove unsprung weight.

Another cool thing about this design is the motion ratio that the inboard coil overs allow for, which permits much greater travel in the suspension, thus keeping the wheels planted through a larger range of travel. I post this sort of thing hoping it does the same for others that it does for me: Foster thought about different ways to use technology.

 

[andrewmp6]

Only irs i seen i liked was the c5/c6 that ones not bad but id never have a irs again after that 240sx i had it had traction problems bad.

 

[midwestls]

Yeah, I got one just like it on mine. (If only........) :lol: But personslly, I had a 240sx and many Cougars, including a supercharged 90 XR7 I have now and I luv IRS. Nothing comes close to ride quality. As far as traction, my 240 liked to hop, but my XR7 launchs hard and stright

 

[2000.malibu.ls]

I get that far in my engineering classes

what kinda engineering classes are you refering to? Im a high school student looking into engineering for colledge so that why Im asking 🙂

 

[85 Cutlass Brougham]

As of now, I am doing my math and science basics (at SPC) before trying to get in to the local state university (USF) for their Mech. Engineering program. I am taking Calculus with Analytical Geometry I, and intro to Chem with lab this fall. As for what the courses are called, I will find out after my transfer in 4 semesters. I still have 2 more Calc courses after this, and then Differential Equations. For Science, I need Physics I and II as well as Chemestry I and II, both with labs. Right now, I am enrolled for 9 credit hours between the 2 classes and the lab, with a cost of around $1,000 for the semester including books.

As for the 240 problems, the problem is that the stock bushings are rather soft and let everything move around too much. It is a good design, but it does benefit greatly once you spend some cash on stiffer parts to replace the stock ones.

 

[2000.malibu.ls]

hm ok sweet Im looking into ucf, Im surprized you dont go there? I am wanting to duo major in mechanical and aerospace.

 

[andrewmp6]

I had the metal bushing in the sub frame metal diff bushings and the control arms from spl parts.My problem was my rb25det i had in it