IRS Conversion
Moderators: notoptoy, S Allen, Solex68
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st3ph3nm
- Roadster Fanatic
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Re: IRS Conversion
Sounds like fun. There's no reason you can't mock up the geometry with cardboard and pins, and see how it all moves. Also, I highly recommend Carol Smith's book, "Tune to Win". Really good summation of suspension setups, without being extremely dry and technical.
SR311-01113 U22
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fj20spl311
- Roadsteraholic
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Re: IRS Conversion
Paper?....just put the numbers a free online rear suspension simulation
Phil
67.5 SRL311-00148 Blue (FJ cruiser VOODOO Blue)
67.5 SPL311 FJ20E teal SDS EFI
69 SRL311 SOLD
19 Raptor SCAB
67.5 SRL311-00148 Blue (FJ cruiser VOODOO Blue)
67.5 SPL311 FJ20E teal SDS EFI
69 SRL311 SOLD
19 Raptor SCAB
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dbrick
- Roadster Fanatic-Site Supporter
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Re: IRS Conversion
What about the front end? Get a rack and pinion to work and THAT would be a useful fabrication exercise, although there are some things in the way like the crank pulley and most of the crossmember. Maybe a V6, shorten the engine length and shoehorn a steering rack in there.
Dave Brisco
Take my advice, I'm not using it"
66 2000 The Bobster
64 1500 in pieces for sale
1980 Fiat X1/9
2009 Volvo C-70
08 Expedition EL, STUPID huge but comfy
1962 Thompson Sea Lancer, possible money pit
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fj20spl311
- Roadsteraholic
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Re: IRS Conversion
Maybe a rear rack will fit.......
Phil
67.5 SRL311-00148 Blue (FJ cruiser VOODOO Blue)
67.5 SPL311 FJ20E teal SDS EFI
69 SRL311 SOLD
19 Raptor SCAB
67.5 SRL311-00148 Blue (FJ cruiser VOODOO Blue)
67.5 SPL311 FJ20E teal SDS EFI
69 SRL311 SOLD
19 Raptor SCAB
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pebbles
- Roadster Fanatic-Site Supporter
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Re: IRS Conversion
This is kinda slick
http://community.ratsun.net/topic/7446- ... op-secret/" onclick="window.open(this.href);return false;
http://community.ratsun.net/topic/7446- ... op-secret/" onclick="window.open(this.href);return false;
David
"When we were standing next to the motor while on the dyno, and the motor hit VVL, eyes went watery.."
"When we were standing next to the motor while on the dyno, and the motor hit VVL, eyes went watery.."
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Mattk
- Roadster Nut-Site Supporter
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Re: IRS Conversion
So I've been toying with the idea of doing an IRS in Roadster. What I've been looking at is a rear sub frame out of a miata, either with a miata LSD or a toyota LSD (as I'm am still trying to figure out how to shoehorn a 3sge Beams under the hood).
My thinking is to cut and narrow the sub frame around 8-9 inches (wheel offset may play a role in determining width). Also this allows for some freedom in mounting the sub frame up into the roadster in a manner that would allow the suspension to sit at the factory (Mazda) ride hide but still having a lowered roadster...hope that make sense.
I've been building and sketching some models and have found that the geometry change is, surprisingly, not as dramatic as I expected. Also since I'm not planning on racing the car the suspension need not be super precise. I have downloaded a couple of the free/trial versions of the suspension software but haven't screwed with them yet....maybe I might should possibly do that!
Anyway one last observation is that with a IRS you maybe, might be able to put wide or deeper wheels in the rear as you will not be dodging leaf springs...but again just a maybe!
Cheers
Matthew
My thinking is to cut and narrow the sub frame around 8-9 inches (wheel offset may play a role in determining width). Also this allows for some freedom in mounting the sub frame up into the roadster in a manner that would allow the suspension to sit at the factory (Mazda) ride hide but still having a lowered roadster...hope that make sense.
I've been building and sketching some models and have found that the geometry change is, surprisingly, not as dramatic as I expected. Also since I'm not planning on racing the car the suspension need not be super precise. I have downloaded a couple of the free/trial versions of the suspension software but haven't screwed with them yet....maybe I might should possibly do that!
Anyway one last observation is that with a IRS you maybe, might be able to put wide or deeper wheels in the rear as you will not be dodging leaf springs...but again just a maybe!
st3ph3nm I totally agree!!!st3ph3nm wrote: My last point is a little tongue in cheek, but if you're going to make the "perfect" modern roadster, why the hell would you put an SR20DE in it? Shouldn't you at least use an SR20VE? Or a 3SGE Beams? The SR20DE is great bang for your buck, but it doesn't make it onto my list of all time great engines.
Cheers
Matthew
MattK