My final gear swap project - Page 7 - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

Mixlplix · 10-07-2013, 10:34 PM

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PantsDants · 10-11-2013, 04:26 AM

Update: Looks like I'll be dropping my car off in the evening this Sunday, and hope to have it back on Monday or Tuesday.

Once I've got it back and have driven it around to get a feel for it, I'll post my impressions on it. You know, provided that it actually installs cleanly, which I'm fairly confident it will, given the think-tank that is this forum. I'll clean up the first post here to include what was actually used in the installation so others going forward have a recipe to follow. I may consider making another thread specifically as a guide to what is needed to do this, hopefully as a sticky.

Mr. · 10-11-2013, 09:22 PM

Picture pleaseeee.

PantsDants · 10-15-2013, 05:28 AM

Starting day 2 without the car; theoretically I'll get it back later today. Of course I HAD to pick the busiest damn diff shop in the state. Good excuse to work from home though! Haha

Fast_Freddy · 10-15-2013, 05:54 AM

Working at home while the rest of us wait patiently for updates = FAIL

It's this or FI for my FRS. Despite adding 25-30 whp my AT FRS still bogs badly on initial WOT. The serious lack of torque would be fine if I had a clutch to slip but in lieu of that I need some wheel spin and the leverage to get it. Looking forward to good news.

PantsDants · 10-15-2013, 11:06 PM

SUCCESS!

Everything went together very smoothly. The only minor hiccup we ran into was that the IS300 carrier has axle stubs on it (the big wheel looking things on the sides) and the FR-S version does not. The IS300's axles are shorter and actually bolt onto these, whereas the FR-S axles just shove straight into the carrier. The spline pattern on the FR-S axle is identical to what's on the axle stubs though, so it's just a matter of popping them out.

As for my impressions of driving it, I can't give a full review just yet. Since the gears are brand new, they have to be broken in for a few hundred miles before I can really get on it. Just from babying it on the way home though, the only way I can describe it is that it feels like there's just less resistance to accelerate. Like the engine had been walking around with weights on and it just took them off.

I can't detect any gear noise coming from the back. Also the speedo is still dead on and the transmission shifts where it used to. Just higher revs while cruising on the freeway now, (sitting at almost exactly 2500 rpm when going 65) which on the stock exhaust is not any louder than where it was before. So far so good! I'll add more after I can have some real fun with it. I guess this was a complete success!

Now about those 3.9 gears... Who wants them?

Captain Insano · 10-15-2013, 11:09 PM

Great news! Let us know how it feels once broken in.

Mr. · 10-15-2013, 11:10 PM

Thank you.

nos145 · 10-16-2013, 12:02 PM

Quote:

Originally Posted by PantsDants

SUCCESS!

dear sir, what RPM is 75 mph at? That's my average cruising speed on hw. im just thinking how this will affect my fuel consumption.

Another questions i have... what do you think would be the effect of having similar set up and then having a turbo on top of it?

Thank you very much

37 · 10-16-2013, 06:55 PM

Quote:

Originally Posted by PantsDants

SUCCESS!

...
Just from babying it on the way home though, the only way I can describe it is that it feels like there's just less resistance to accelerate. Like the engine had been walking around with weights on and it just took them off.

Nice! That's an accurate way to describe the effect. Glad to hear the 4.88 (most likely) turned out to be the right ratio for you. Keep us posted.

Quote:

Originally Posted by nos145

what do you think would be the effect of having similar set up and then having a turbo on top of it?

That's a bad idea. If anything you would want taller gears with a turbo, not shorter. Shorter gears + turbo means you'll have traction issues in gears 1-2-3 above and beyond what you might already have with a 3.9.

Get the turbo first and decide if you have traction issues down low. If you do then that's when you should consider changing your final drive with a taller (not shorter) ratio. However, if you have an automatic then I doubt you'll want to change anything since your transmission already makes the overall ratio taller.

SportInjected · 10-16-2013, 09:14 PM

Awesome! Now, who's the best person to talk to at weir about acquiring the right parts?

Thank you for being the guinea pig for this, your efforts are much appreciated.

PantsDants · 10-17-2013, 04:43 AM

Quote:

Originally Posted by nos145

dear sir, what RPM is 75 mph at? That's my average cruising speed on hw. im just thinking how this will affect my fuel consumption.

Another questions i have... what do you think would be the effect of having similar set up and then having a turbo on top of it?

Thank you very much

Hit 75 briefly on the freeway just for you, it looked to be just under 3000 rpm. Keep in mind this is on the automatic transmission, and I didn't stay there for any appreciable length of time so it may actually be slightly lower than that at cruise.

As for a turbo setup, @37 is absolutely right. You'd want to go taller. It will both help with traction on the low end, and let you stay in each gear longer so you stay in boost. Now if you had something like a centrifugal supercharger that ramps up with rpm, then a lower final drive does make sense, because you get up to max boost faster. This may be the route I go if I decide to go FI.

@SportInjected, I'm going to make a more concise thread with all of the pertinent information in one post, so be on the lookout for that in a bit.

PantsDants · 10-17-2013, 05:54 AM

The final "recipe" for this swap can be found here: http://www.ft86club.com/forums/showthread.php?p=1275527

uncivilised · 10-17-2013, 06:29 PM

Thanks for this guide,

Trying to find a spare 86 lsd carrier for a decent price was difficult. As soon as you mention 86 the price is in the thousands lol

I have sourced an is300 lsd for a good price and I have some 4.55 diff gears to go into this, cant wait lol.

10-11-2013, 09:22 PM	#87
Mr. Supra Senior Member Join Date: Oct 2012 Drives: AE86 & BRZ Location: Merica maryland Posts: 877 Thanks: 717 Thanked 491 Times in 288 Posts Mentioned: 38 Post(s) Tagged: 2 Thread(s)	Picture pleaseeee. __________________ Build Thread YouTube Channel IG - Fwankyhong Subscribe

10-15-2013, 11:10 PM	#92
Mr. Supra Senior Member Join Date: Oct 2012 Drives: AE86 & BRZ Location: Merica maryland Posts: 877 Thanks: 717 Thanked 491 Times in 288 Posts Mentioned: 38 Post(s) Tagged: 2 Thread(s)	Thank you. __________________ Build Thread YouTube Channel IG - Fwankyhong Subscribe

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10-07-2013, 10:34 PM	#85
Mixlplix Banned Join Date: Sep 2013 Drives: 2013 FR-S Location: Earth Posts: 39 Thanks: 0 Thanked 9 Times in 6 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Subscribe

10-11-2013, 04:26 AM	#86
PantsDants Senior Member Join Date: Jul 2013 Drives: Scion FR-S A/T, Whiteout Location: Seattle Posts: 334 Thanks: 57 Thanked 221 Times in 90 Posts Mentioned: 16 Post(s) Tagged: 2 Thread(s)	Update: Looks like I'll be dropping my car off in the evening this Sunday, and hope to have it back on Monday or Tuesday. Once I've got it back and have driven it around to get a feel for it, I'll post my impressions on it. You know, provided that it actually installs cleanly, which I'm fairly confident it will, given the think-tank that is this forum. I'll clean up the first post here to include what was actually used in the installation so others going forward have a recipe to follow. I may consider making another thread specifically as a guide to what is needed to do this, hopefully as a sticky.

10-15-2013, 05:28 AM	#88
PantsDants Senior Member Join Date: Jul 2013 Drives: Scion FR-S A/T, Whiteout Location: Seattle Posts: 334 Thanks: 57 Thanked 221 Times in 90 Posts Mentioned: 16 Post(s) Tagged: 2 Thread(s)	Starting day 2 without the car; theoretically I'll get it back later today. Of course I HAD to pick the busiest damn diff shop in the state. Good excuse to work from home though! Haha

10-15-2013, 05:54 AM	#89
Fast_Freddy Senior Member Join Date: Jul 2012 Drives: Passat Location: East Coast Posts: 626 Thanks: 331 Thanked 188 Times in 130 Posts Mentioned: 6 Post(s) Tagged: 0 Thread(s)	Working at home while the rest of us wait patiently for updates = FAIL It's this or FI for my FRS. Despite adding 25-30 whp my AT FRS still bogs badly on initial WOT. The serious lack of torque would be fine if I had a clutch to slip but in lieu of that I need some wheel spin and the leverage to get it. Looking forward to good news.

10-15-2013, 11:06 PM	#90
PantsDants Senior Member Join Date: Jul 2013 Drives: Scion FR-S A/T, Whiteout Location: Seattle Posts: 334 Thanks: 57 Thanked 221 Times in 90 Posts Mentioned: 16 Post(s) Tagged: 2 Thread(s)	SUCCESS! Everything went together very smoothly. The only minor hiccup we ran into was that the IS300 carrier has axle stubs on it (the big wheel looking things on the sides) and the FR-S version does not. The IS300's axles are shorter and actually bolt onto these, whereas the FR-S axles just shove straight into the carrier. The spline pattern on the FR-S axle is identical to what's on the axle stubs though, so it's just a matter of popping them out. As for my impressions of driving it, I can't give a full review just yet. Since the gears are brand new, they have to be broken in for a few hundred miles before I can really get on it. Just from babying it on the way home though, the only way I can describe it is that it feels like there's just less resistance to accelerate. Like the engine had been walking around with weights on and it just took them off. I can't detect any gear noise coming from the back. Also the speedo is still dead on and the transmission shifts where it used to. Just higher revs while cruising on the freeway now, (sitting at almost exactly 2500 rpm when going 65) which on the stock exhaust is not any louder than where it was before. So far so good! I'll add more after I can have some real fun with it. I guess this was a complete success! Now about those 3.9 gears... Who wants them?

10-15-2013, 11:09 PM	#91
Captain Insano Senior Member Join Date: Sep 2012 Drives: 2014 Jeep Wrangler RubiconX Location: Midwest, USA Posts: 1,282 Thanks: 110 Thanked 292 Times in 224 Posts Mentioned: 7 Post(s) Tagged: 0 Thread(s)	Great news! Let us know how it feels once broken in.

10-17-2013, 05:54 AM	#97
PantsDants Senior Member Join Date: Jul 2013 Drives: Scion FR-S A/T, Whiteout Location: Seattle Posts: 334 Thanks: 57 Thanked 221 Times in 90 Posts Mentioned: 16 Post(s) Tagged: 2 Thread(s)	The final "recipe" for this swap can be found here: http://www.ft86club.com/forums/showthread.php?p=1275527

10-17-2013, 06:29 PM	#98
uncivilised Member Join Date: Oct 2012 Drives: 86 GT Location: australia Posts: 74 Thanks: 31 Thanked 27 Times in 20 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Thanks for this guide, Trying to find a spare 86 lsd carrier for a decent price was difficult. As soon as you mention 86 the price is in the thousands lol I have sourced an is300 lsd for a good price and I have some 4.55 diff gears to go into this, cant wait lol.

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