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Looks like the BRZ dash lights up red with the km/h not being illuminated (but present).

Also the fuel gauge is slightly different, GT86 says "R" and BRZ "E" from what I can see.
 

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Discussion Starter · #8 ·
55 miles a day before I go anywhere. Usually dual carriageway, but I'm using a lot of alternatives when I'm not on school run duty.

Everything seems to holding together and bedding in nicely. I'm on my phone at he moment, with its stupid keyboard. I'll happily expand on my thoughts a bit later if anyone's interested.
 

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Yes, many many times at the weekend when driving around Croft Circuit trying to keep up with all the modified race cars (and not succeeding!).


Although, my racing instructor later recommended that the car would be best changing gear nearer 6k revs as he thought there wasn't any extra power after that.
Edited by: herit86
 

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Discussion Starter · #14 ·
Scratches head....
Touch wood (not like that!) It hasn't missed a beat so far. Except for running out of washer fluid due to no warning lamp (read idiot lamp as someone else suggested they should be called!).
Tyres hardly seem worn even with driving it as err... would be expected. I'll dig out my depth gauge and measure them as someone's bound to ask.
Its been on trips to Isle of Skye, Isle of Man (topical after fifth gear's article the other night and highly recommended!), Wales.... On my own, full of family (toddlers in the back), mates to very local pub....

Go on.... let's call it question time, I'll see what I can answer.
 

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GT86Owner said:
A chap on the FT86 club posted wheel torque in each gear. for 1st, 2nd and 3rd you are best taknig it to the red line. With 4th and 5th you should change up at 7k.

The engine should produce the same torque at a given speed whatever the gear in (apart sometimes from low-loaded gears, like first, and more relevant on turbocharged vehicles).
 

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gt_sjo said:
GT86Owner said:
A chap on the FT86 club posted wheel torque in each gear. for 1st, 2nd and 3rd you are best taknig it to the red line. With 4th and 5th you should change up at 7k.
The engine should produce the same torque at a given speed whatever the gear in (apart sometimes from low-loaded gears, like first, and more relevant on turbocharged vehicles).
Wheel torque is the same when crusing in say, 4th or 6th at 60MPH. However the torque the engine is outputting will not be. it will be doing more rpms in 4th and outputting less torque accordingly.

When your boot is down the engine torque is divided by the gear box ratio. So when you shift up to 5th from 4th before 7krpms, torque will drop, unless like you say on some turbo'd engine torque output is higher at low rpms in which case wheel torque may be sustained or boosted.

Torque of the FA20 drops off quite quickly after 7k to the point where you will have more wheel torque in 5th than in 4th past 7k rpms.





Edited by: GT86Owner
 

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That's somewhat correct, with some assumptions. The transmission doesn't divide engine torque, it multiplies it.

I'd be surprised at 60mph if 6th gear is providing more 'wheel' torque than 4th. 6th gear will be doing about 2000 rpm!
 

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gt_sjo said:
That's somewhat correct, with some assumptions. The transmission doesn't divide engine torque, it multiplies it.

I'd be surprised at 60mph if 6th gear is providing more 'wheel' torque than 4th. 6th gear will be doing about 2000 rpm!
Well it divides or multiplies depending on the gear. 4th is 1:1 anything below is multiplying anything above is dividing torque.

In 6th the ratio is 0.767:1 wheel to engine or a ratio of 1.3:1 engine to wheels.
Torque 150lbft/1.3 = 115blft at the diff axial.

In 4th the ratio is 1.213:1 wheel to engine or a ration of 0.824:1 engine to wheels.
Torque 150lbft/0.824 = 182blft at the diff axial.

I ahvent bothered to add differential gearing as it constant.
 

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4th gear on the manual transmission isn't 1:1. Only 6th gear is less than 1.00.

Your calculations are not relevant to your previous statement about being in 4th or 6th gear at the same wheel speed. Your numbers above claim 150 ft-lb of torque, but of course this amount of torque is not available everywhere in the engine's power band.


Torque appears to drop by about 20% from 6500rpm to 7500rpm. It'd be pretty straight-forward to put some in-gear acceleration numbers into a spreadsheet to make this discussion data-driven.
 
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