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986Jim · 03-31-2006, 08:08 AM

Okkk.. I wasn't sure how you were going to do the trans/rear end.

An adaptor plate with a custom clutch will work good. I made an adaptor plate for an Miata to run a full RX7 tranny rear end and drive shaft shop axels. We cut it from 1/2" aluminum and used threaded ARP bolts to each point.

THe clutch was a Miata flywheel and pressure plate with an RX7 spline in the miata disc. It was a pretty trick setup and held together well. The Miata made 476whp with a 50trim and spray, on 110octane. Pretty cool setup and the RX7 trans and rear end with a Kazz diff held up for 200+ passes down the track ~ 11.2-11.4.

My question would be then, I wonder how a 2.5L trans / axel setup would handle an LS1. The LS1 makes a lot of torque where the trans on the boxster is only technically designed for 200-220ft/lbs vs say 400. If you were to dump in a Quaife or Kazz it might work, then half shafts would become the next problem.

Another problem is the limited bellhousing size on the Boxster, again you will be stuck with a small sized clutch (whats the boxster? 225mm or so ish.. vs say 300? in an ls1?) which will take a lot of abuse from that motor.

03-31-2006, 08:08 AM	#45
986Jim Registered User Join Date: Feb 2006 Location: Toronto Ontario Posts: 291	Okkk.. I wasn't sure how you were going to do the trans/rear end. An adaptor plate with a custom clutch will work good. I made an adaptor plate for an Miata to run a full RX7 tranny rear end and drive shaft shop axels. We cut it from 1/2" aluminum and used threaded ARP bolts to each point. THe clutch was a Miata flywheel and pressure plate with an RX7 spline in the miata disc. It was a pretty trick setup and held together well. The Miata made 476whp with a 50trim and spray, on 110octane. Pretty cool setup and the RX7 trans and rear end with a Kazz diff held up for 200+ passes down the track ~ 11.2-11.4. My question would be then, I wonder how a 2.5L trans / axel setup would handle an LS1. The LS1 makes a lot of torque where the trans on the boxster is only technically designed for 200-220ft/lbs vs say 400. If you were to dump in a Quaife or Kazz it might work, then half shafts would become the next problem. Another problem is the limited bellhousing size on the Boxster, again you will be stuck with a small sized clutch (whats the boxster? 225mm or so ish.. vs say 300? in an ls1?) which will take a lot of abuse from that motor.