An Rx8 Eccentric Shaft?!?
02-07-2008, 09:39 AM
#1
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Join Date: May 2007
Location: Lompoc, Ca
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Ok... running around the net... I dropped into atkinsrotary.com (bump to atkins rotary...) (better make that two...) and I was running around the site and ran into an rx8 eccentric shaft...
Wait a second... this actually fits in a 13b?!? and it weighs a half pound less than the 13b eccentric shaft? Ok... two questions...
1. Will this effect emissions? (I am in california... what else do I need to say)
2. Will this improve things for response/speed?
My jaw needs to make new residence off of the floor...
Wait a second... this actually fits in a 13b?!? and it weighs a half pound less than the 13b eccentric shaft? Ok... two questions...
1. Will this effect emissions? (I am in california... what else do I need to say)
2. Will this improve things for response/speed?
My jaw needs to make new residence off of the floor...
02-07-2008, 08:15 PM
#5
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Join Date: Feb 2005
Location: Kissimmee FL.
Posts: 1,579
the renesis in the rx8 is a 13b. the e-shaft will fit just fine. but you will need to get the rotating assembly balanced to match.
this is from Mazdatrix.com refering to the RX8 shaft into a earlier 13b.
*These shafts are .6lbs. lighter than the earlier 13B shafts. The main journal diameters are approximately one-half thou smaller, and there is a one-half thou taper in the rear main journal.
*If using the RX8 rear gear in an earlier 13b engine, you must add sealant where the rear gear o-ring WOULD be. There is no groove to hold the o-ring because the Renesis engine mounts the o-ring in the side housing rather than on the gear. We recommend using Hylomar, but a THIN layer of silicone sealant will also suffice.
lightening the weight of the rotating assembley will slightly increase HP but will decrease torque. RPM's will rise faster and smoother. IM not 100% sure. but i seriuosly doubt it will effect emissions.
the main benefit to me anyways is, its new. not 15-20 years old used part. and its cheaper!!! go with the rx-8 stat. gears too. also cheaper plus stronger.
this is from Mazdatrix.com refering to the RX8 shaft into a earlier 13b.
*These shafts are .6lbs. lighter than the earlier 13B shafts. The main journal diameters are approximately one-half thou smaller, and there is a one-half thou taper in the rear main journal.
*If using the RX8 rear gear in an earlier 13b engine, you must add sealant where the rear gear o-ring WOULD be. There is no groove to hold the o-ring because the Renesis engine mounts the o-ring in the side housing rather than on the gear. We recommend using Hylomar, but a THIN layer of silicone sealant will also suffice.
lightening the weight of the rotating assembley will slightly increase HP but will decrease torque. RPM's will rise faster and smoother. IM not 100% sure. but i seriuosly doubt it will effect emissions.
the main benefit to me anyways is, its new. not 15-20 years old used part. and its cheaper!!! go with the rx-8 stat. gears too. also cheaper plus stronger.
02-21-2008, 10:44 PM
#7
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Join Date: May 2007
Location: Lompoc, Ca
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so in theory if someone got the bright idea to get a 13b with said stationary gear, stationary gear, and lightened rotaries... with a twin turbo setup... it could possibly equal some very... VERY evil things? Dare I ask what possible horsepower gains could be had from a set up like that in a 13bTT?
02-22-2008, 08:14 AM
#8
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Join Date: Feb 2005
Location: Kissimmee FL.
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im guessing that your new to rotarys. and cars in general.
you'll soon find out that the whole "twin turbo" thing isnt so great. most people use a single turbo and get much more power. having to spool up 2 turbos takes some effort. especially with rotary engine since your doing this with one rotor for each turbo.
and yes, there will be a slight power gain from having the lightened E-shaft. and its always good to have stronger stat. gears. but its not going to be something amazing. the real gain using the rx8 internals (to me anyway) is the parts are brand new. and the gears can handle more abuse.
example: 79-80 12a's where 100hp at the flywheel 81-85 12a's where 101hp to the flywheel. only internal difference i seen where the rotors where slightly lighter.
not much of a difference.
you'll soon find out that the whole "twin turbo" thing isnt so great. most people use a single turbo and get much more power. having to spool up 2 turbos takes some effort. especially with rotary engine since your doing this with one rotor for each turbo.
and yes, there will be a slight power gain from having the lightened E-shaft. and its always good to have stronger stat. gears. but its not going to be something amazing. the real gain using the rx8 internals (to me anyway) is the parts are brand new. and the gears can handle more abuse.
example: 79-80 12a's where 100hp at the flywheel 81-85 12a's where 101hp to the flywheel. only internal difference i seen where the rotors where slightly lighter.
not much of a difference.
02-22-2008, 02:08 PM
#9
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Join Date: May 2002
Location: California
Posts: 22,465
Originally Posted by krazy13' post='895079' date='Feb 21 2008, 08:44 PM
so in theory if someone got the bright idea to get a 13b with said stationary gear, stationary gear, and lightened rotaries... with a twin turbo setup... it could possibly equal some very... VERY evil things? Dare I ask what possible horsepower gains could be had from a set up like that in a 13bTT?
neat thing about turbos, is that you dont have to spin the engine faster.
most of the updates on the 13b have been to bring it up to the racing engine spec from 1980, ie the newer engine have things like hardened stationary gears, lighter rotors, higher oil pressure etc, just like the race engines.
if you're not revving over about 8000rpms, more of that stuff isnt too important. and with a turbo you can set it up to make power around 7k, in which case you dont need to get fancy with the block...
although if you need an eshaft, might as well get a newer lighter one
