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Discussion Starter #1
Hi guys. My type r came with a reciept from area Motorsport to show it's had a rebuilt box with m factory diff and a different final drive ratio.

Im just trying to work out what my final drive actually is compared to a stock fn2.

In 6th gear cruising at dead on 70mph, my rev counter shows about 3450rpm

Is this standard?

Could somebody with an fn2 let me know their rpm at 70 when cruising in 6th.

Regards

Matt
 

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3500 rpm sounds correct.
CTR will do about 20mph per 1000 rpm in top gear.
obviously this reduces as you get to the top of the rev range since we don't top out at 160 mph
 

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Had a look when out in mine last night, pretty much bang on 3450rpm at 70mph.

Mine's a completely standard 08 FN2 for reference.
 

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If it's a standard box then the rev needle should match the speedo needle if that makes sense? If it does then it's an OEM final drive.
 

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Discussion Starter #9
If it's a standard box then the rev needle should match the speedo needle if that makes sense? If it does then it's an OEM final drive.
Not quite sure what you mean?

My car doesn't have a Speedo needle, just a digital gauge on the top of the dash
 

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Discussion Starter #10
The invoice suggests it's an mfactory race pack 1 lsd.

It says on the invoice

Mfactory race pack 1 lsd
Used second gear
Honda mft 2 litres
Exedy clutch kit
Matching 4.7 crown wheel
 

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The invoice suggests it's an mfactory race pack 1 lsd.

It says on the invoice

Mfactory race pack 1 lsd
Used second gear
Honda mft 2 litres
Exedy clutch kit
Matching 4.7 crown wheel
Unless I'm missing something none of this would affect gearing. The LSD will help massively in corners but the ratios remain unchanged.
 

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Discussion Starter #13
The invoice suggests it's an mfactory race pack 1 lsd.

It says on the invoice

Mfactory race pack 1 lsd
Used second gear
Honda mft 2 litres
Exedy clutch kit
Matching 4.7 crown wheel
Unless I'm missing something none of this would affect gearing. The LSD will help massively in corners but the ratios remain unchanged.
Would the 4.7 crown wheel not affect gearing when standard is 5.06?
 

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Yes, that would raise the gearing by 5.06/4.7 = about 1.077:1
so 3450 rpm should become 3204. If my maths is correct.
 

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Discussion Starter #15
Hmm, starting to wonder if the previous seller replaced the box with a different one and sold the good one in order to make more profit.

If there any way I can see if the m factory diff is actually in there?
 

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Discussion Starter #17
I've been told to put it in first gear and with both wheels off the ground turn a wheel and if the other wheel goes the same direction it means the diff is installed.

I'm assuming clutch will need to be down for this test
 

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Hi guys. My type r came with a reciept from area Motorsport to show it's had a rebuilt box with m factory diff and a different final drive ratio.

Im just trying to work out what my final drive actually is compared to a stock fn2.

In 6th gear cruising at dead on 70mph, my rev counter shows about 3450rpm

Is this standard?

Could somebody with an fn2 let me know their rpm at 70 when cruising in 6th.

Regards

Matt
Unless the dash/ecu has been reprogrammed following the gearbox change, 70 will appear at the same rpm as everyone else. The only way to tell is to compare your displayed speed with a GPS speed - and you'll also find that there is quite an overread for <08 cars. Tyre wear and sizing has a factor to play in this too but as a general guide check out the following,

Calculated speeds and rpm:

5.062 FD, 70 mph @ 3610 rpm
4.7 FD (EP3), 70 mph @ 3352 rpm
5.46 FD, 70 mph @ 3894 rpm - common upgrade, typically alongside a long 6th gear.
5.46 FD & long 6th, 70 mph @ 3477 rpm
5.84 FD, 70 mph @ 4165 rpm
5.84 FD & long 6th, 70 mph @ 3719 rpm
 

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I've been told to put it in first gear and with both wheels off the ground turn a wheel and if the other wheel goes the same direction it means the diff is installed.

I'm assuming clutch will need to be down for this test
I think this won't work because the MFactory is a Torsen diff which acts like an open diff until it senses torque. I have an MFactory Racepack LSD and both wheel turn the opposite direction.

The only sure fire way to tell if you have an LSD or not without taking the gearbox completely out is to pull out the driveshafts.

Or go round a roundabout really fast and hang on for dear life. If you understeer into the trees, you have no LSD.
 

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Discussion Starter #20
Hi guys. My type r came with a reciept from area Motorsport to show it's had a rebuilt box with m factory diff and a different final drive ratio.

Im just trying to work out what my final drive actually is compared to a stock fn2.

In 6th gear cruising at dead on 70mph, my rev counter shows about 3450rpm

Is this standard?

Could somebody with an fn2 let me know their rpm at 70 when cruising in 6th.

Regards

Matt
Unless the dash/ecu has been reprogrammed following the gearbox change, 70 will appear at the same rpm as everyone else. The only way to tell is to compare your displayed speed with a GPS speed - and you'll also find that there is quite an overread for <08 cars. Tyre wear and sizing has a factor to play in this too but as a general guide check out the following,

Calculated speeds and rpm:

5.062 FD, 70 mph @ 3610 rpm
4.7 FD (EP3), 70 mph @ 3352 rpm
5.46 FD, 70 mph @ 3894 rpm - common upgrade, typically alongside a long 6th gear.
5.46 FD & long 6th, 70 mph @ 3477 rpm
5.84 FD, 70 mph @ 4165 rpm
5.84 FD & long 6th, 70 mph @ 3719 rpm
Interesting

I tried the GPS Speedo app on my phone and when at 70 on the dash, my phone app read dead on 70 also.

The car was mapped with ecutek last year so could this have been sorted at the time of mapping?
 
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