4.556 final drive with TRD gear ratio change - good or bad idea?

[GT86_PRAGUE]

Originally Posted by rx3

That's a good point.
We have to get the car inspected every 2 years and usually they take it on a very short test drive and this is where they could notice it. But this really depends on the person who's driving it.

Which country?

I would like to see an technician who could tell I have lighter flywheel and too short final drive. Yes, if he drove stock GT86 he would definitively tell that your is odd especially if you have stacked some drivetrain mods, but you can then use some excuses like different ECU (if it is legal), better exhaust, intake, lighter wheels, Natural 100 or any usable bullshit. They are not used to these cars. Anyway, you dont have any friends there?

[rx3]

A German speaking country.

I agree, it's unlikely that they would notice. Although 5.13 could be stretching it.

These inspection bureaucrats aren't anybody's friend. They just stick to the law or whatever they believe the law is.
One also has to wonder about what law-makers were smoking when the came with some of the ruling. For example, the law also says that the top speed of the car cannot be reduced. Which is kind of ironic because if you were caught driving at that top speed you'd be sentenced to jail for at least 6 months and lose your driving license indefinitely.

[GT86_PRAGUE]

Originally Posted by rx3

A German speaking country.

I agree, it's unlikely that they would notice. Although 5.13 could be stretching it.

These inspection bureaucrats aren't anybody's friend. They just stick to the law or whatever they believe the law is.
One also has to wonder about what law-makers were smoking when the came with some of the ruling. For example, the law also says that the top speed of the car cannot be reduced. Which is kind of ironic because if you were caught driving at that top speed you'd be sentenced to jail for at least 6 months and lose your driving license indefinitely.

I dont want to have 5.1 on autobahn, 4.67 is a stretch on long/fast trips. Depends also on your current exhaust setup. My car is almost too loud, I will probably be deaf in a year or two, so I may upgrade again to 5.1. Also consumption would sky rocket against stock.
And I am not sure if stock axles can hold increased torque with stacked mods.

So lucky that we eastern Europeans have a friends who know a friend and if you have money many things are possible...
But we cannot get larger wheels or GT wing if they are not TUV approved.

[rx3]

Why did you choose to go to 4.67 and why the switch to 4.88?

(In our slaloms we often need to use 1st gear. So, a shorter ratio would possibly make the first gear unusable.)

[GT86_PRAGUE]

Originally Posted by rx3

Why did you choose to go to 4.67 and why the switch to 4.88?

(In our slaloms we often need to use 1st gear. So, a shorter ratio would possibly make the first gear unusable.)

I wanted 5.1, I like extremes but this seemed to much extreme, I drive on a highway too. So I decided for 4.88 but Weir didnt responded to my mails and ordering 4.88 from Japan was too expensive mainly due to shipping and import duties. So I ordered Mfactory 4.67 from UK where it was reasonably priced. They dont have higher ratio there.
Now I have it for 3 months and I feel from the beginning this is not what I have expected, I wanted more. So 4.88 seemed perfect again. I had to call Weir multiple times but in the end I got it and it was even cheaper that Mfactory. I sold 4.67 to a friend, so it was not that bad financially.
I will pick up my car tomorrow and hope that 5% extra will be worth this hassle.
4.56 is the cheapest, but you have to consider big amount of labor involved for a tiny bit of change. Than this doesnt make much sense (at least for me). I had changed FD (4.67: -14%) and LWFW (TRD -40% weight) at the same time and I immediately wished I went for more. On the highway it is a different story especially with laud exhaust, so 4.88 seems perfect again. For mortals 4.67 is fine and only a bit peppier than 4.56.

[GT86_PRAGUE]

Originally Posted by rx3

Why did you choose to go to 4.67 and why the switch to 4.88?

(In our slaloms we often need to use 1st gear. So, a shorter ratio would possibly make the first gear unusable.)

I need 1st only twice per 1 run, but I also changed headers last week to Nameless, so I dont have cat and car pulls like a train from 3800rpm. So I am very interested how this will be on track, but I am counting on Cusco cross mission set to fix these issues if needed. Also I will switch to E85 next week, so I expect more low torque and I might not use 1st gear at all.
I have a thread about that:
http://www.ft86club.com/forums/showthread.php?t=94450

[GT86_PRAGUE]

Originally Posted by rx3

Why did you choose to go to 4.67 and why the switch to 4.88?

(In our slaloms we often need to use 1st gear. So, a shorter ratio would possibly make the first gear unusable.)

So, I was on a trackday yesterday with 4.88 installed and man, this is HEAVEN. 1st gear is very short, but they are still usable especially in my city driving, 2nd is reasonable short. I might buy Cross Mission Gears for transmission, but today it doesnt feel like I HAVE TO have them to be driveable.
I cant go full throttle on 1st, I am loosing traction with Hankook RS-3.
Only REGRETS for me are not buying this in first place and not buying shim kit with it.
This and coated headers are the best mods ever.

[Toyota86.ir]

Originally Posted by GT86_PRAGUE

So, I was on a trackday yesterday with 4.88 installed and man, this is HEAVEN. 1st gear is very short, but they are still usable especially in my city driving, 2nd is reasonable short. I might buy Cross Mission Gears for transmission, but today it doesnt feel like I HAVE TO have them to be driveable.
I cant go full throttle on 1st, I am loosing traction with Hankook RS-3.
Only REGRETS for me are not buying this in first place and not buying shim kit with it.
This and coated headers are the best mods ever.

did you ordered extra parts out of weir kit or the weir kit was complete for swap?

how about noise in higher rev?

[Aztec]

Originally Posted by GT86_PRAGUE

So, I was on a trackday yesterday with 4.88 installed and man, this is HEAVEN. 1st gear is very short, but they are still usable especially in my city driving, 2nd is reasonable short. I might buy Cross Mission Gears for transmission, but today it doesnt feel like I HAVE TO have them to be driveable.
I cant go full throttle on 1st, I am loosing traction with Hankook RS-3.
Only REGRETS for me are not buying this in first place and not buying shim kit with it.
This and coated headers are the best mods ever.

Rip gas milage on any long drives
Cruising rpms would be so high

[GT86_PRAGUE]

Originally Posted by Toyota86.ir

did you ordered extra parts out of weir kit or the weir kit was complete for swap?

how about noise in higher rev?

I didnt, thats the regret. They have to made some changes to pinion and made shims for 8mm hole.
What noise? There is no noise if done properly. Only some humming at 190km/h, There might be this humming at corresponding rpms but I dont notice them because I dont drive at constant +-6000 and more rpms on lower gears, I just quickly go thru them and upshift at 7500 to next gear.

[GT86_PRAGUE]

Originally Posted by Aztec

Rip gas milage on any long drives
Cruising rpms would be so high

4500 rpms at 150km/h and 8l/100km. Not bad at all. At least for my standards, its a sport car, not a eco cruiser.

[churchx]

Indeed. Higher rpms are not the only variable impacting fuel usage. After all at lower gearing/higher rpms one need to press accelerator less to get same power to produce same power. So while indeed tallest gears should be most economical, it's not THAT bad fuel economy wise even with different FD. It will be much noisier though so a bit less comfortable for very long drives for many hours cruising at high rpms noise-wise. More engine noise at high rpms almost always gives more aural pleasure and more enjoyment .. if it's not for many hours to live with imho.

[GT86_PRAGUE]

Originally Posted by churchx

Indeed. Higher rpms are not the only variable impacting fuel usage. After all at lower gearing/higher rpms one need to press accelerator less to get same power to produce same power. So while indeed tallest gears should be most economical, it's not THAT bad fuel economy wise even with different FD. It will be much noisier though so a bit less comfortable for very long drives for many hours cruising at high rpms noise-wise. More engine noise at high rpms almost always gives more aural pleasure and more enjoyment .. if it's not for many hours to live with imho.

Actually my highway consumption went down a bit, but slightly up in city. Noise is pretty much the same, you are just revving faster. If you compare noise at any rpms with noise with same rpms from shorter FD it should be the same, but speed would vary. So yes, it is noisier on same speed, but not on same rpms. Anyway, the exhaust is making more noise than dif.

[Falcon]

Whats your RPM @ 100km/h?