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Oh also what was your rim and tyre size?

If anyone is interested this is how I convert, I'll assume the nismo is 4.4

KM/H x (1000/60)

This gives your speed in meters per minute.

pi x Diameter (in metres)

This will give you the cirucumference of your wheel in metres.

Speed / Circumference

This gives how many rpm of wheel per minute.

Then divide by diff ratio if in 4th.

Edited by Rolls
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Would 18s make it better or worse? Sorry full noob at this shit

I just re did it with 240x40x18 and it is 3955 vs 4010rpm for 110kph

Use these websites

http://www.rkm.com.au/calculators/calculator-circle-sphere.html

another calc

RPM = (diff ratio * (mph * 88)) / (tire circumfrance in inches / 12) * transmission 4th ratio

Edited by Rolls

Just measured on my boost controller and powerfc rpm. Got 3410rpm and 3439rpm hitting 18psi in 4th. Dunno how accurate that is tho lol

Pretty damn accurate I'd say as it is using the CAS and it is low rpm (at high rpm the CAS signal can get inccurate in some cars).

Could you try 2nd gear just out of curiosity? as that is what I think most people are interested in.

Edited by Rolls

Pretty damn accurate I'd say as it is using the CAS and it is low rpm (at high rpm the CAS signal can get inccurate in some cars).

Could you try 2nd gear just out of curiosity? as that is what I think most people are interested in.

Yea I'll give it a squirt tomorrow night haha

If its making that much boost in fourth its not really going to be a whole lot different in second. If anything it wont make full boost as the motor wont have the same ammount of load on it. Its always harder to get full boost in the lower gears.

I would be pretty happy with that sort of response. I know the T78 on our car makes full boost (22-23psi) by about 4500rpm and i built an R32 GTR a few years back that made about 5 psi of boost with a T78 at 2500rpm, full boost (again 22-23psi) by no later than 4000rpm. It was a pretty insane GTR to be honest and a bit of a freak engine.

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