4.08 gears and Lightened Flywheel

Zensation

True but half The idea behind reducing the weight of the flywheel is that more torque will reach the wheels due to less rotating mass on the crank. Its just that most of the losses from crank power to wheel power occur in the gearing of the transmission itself. And your right the throttle response increase is due to the same reason because there is less weight on the crank. I notice it if the clutch is pressed the engine spools up quicker but again if im driving the time it takes to go from 2000 rpm to 7000 rpm probably hasnt changed. Idk for sure bc i havnt clocked it. All i really noticed is its sometimes annoying to start moving from a stop.

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370z NISMO 0675 327 rwhp 280 rwtq - sold.
FD RX7 single turbo 508hp - sold.
Lexus IS-F 5.0L V8

Zensation

^ quoted your wrong post oops lol

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370z NISMO 0675 327 rwhp 280 rwtq - sold.
FD RX7 single turbo 508hp - sold.
Lexus IS-F 5.0L V8

Chuck33079

I would assume the amount of power difference you'd see from a lighter flywheel would get swallowed up by dyno variation and air temp/density.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

Zensation

Yeah thats very true. Are you still glad you swapped? Since there was no track performance difference at the drag i can find no real way to validate the purchase. If my clutch is in i can rev faster but i dont notice a difference while racing so i ask myself is it worth it all the time. Eapecially at rush hour lol.

__________________
370z NISMO 0675 327 rwhp 280 rwtq - sold.
FD RX7 single turbo 508hp - sold.
Lexus IS-F 5.0L V8

Chuck33079

I like mine. The throttle response is markedly better now vs stock. I'd do it again. I'd probably go lighter since it's loud as hell now and I can't see it being too much worse. Is it worth doing if you've got a healthy stock clutch and the CSC hasn't failed yet? Probably not. If you're opening the transmission anyway? Sure.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

Roddy1

Thanks for the replies, any word on the gears?

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2011 370Z, 6-Speed Manual, Sport Package. - K&N Drop ins | Top Speed Axleback | H&R Spacers SOLD
2009 G8 GT, 6.0L LSX V8, Rotofab Intake, ARH Long tubes, SOLO exhaust, VMS Tune - SOLD

ka24king

I agree with chuck on that if I take my tranny off again I'm going light as possible. Even with my steel south bend clutch flywheel it's really loud so if the noise is there might as well take full advantage.

ka24king

I'm in for info on gears as well

GSS138

I am looking at doing 4.08 gears when I do my LSD install soon. There seems to be some concern on it affecting syncro rev and I have been trying to get a straight answer about it before I pull the trigger and buy them.
But in theory and based on my tracking experience, I rarely see above 130 MPH on the tracks I do. Most of the time is spent between 3-4th gear, which would mean two things for me going to 4.08 gears:

1. I will have to shift a lot more.
2. I should gain a lot of my usable power band and should see a lot of benefit in terms of creating a "quick car" vs a "fast car"(high top speed).

For road racing, a quick car is always preferred to a car with high top end, unless you are doing circle track or topping out a lot in 5th(which I am not).

For drag racing NA, I would think the 4.08 gearing would be a huge improvement, but I don't drag race so I am just speculating.

So once I can get some solid feedback on the syncro rev problem, I am going to decide to buy them or not myself.

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Current Mods: Vorpal Weapon +5.

Roddy1

Good point on the Sync Rev. Hadnt thought about that.

__________________
2011 370Z, 6-Speed Manual, Sport Package. - K&N Drop ins | Top Speed Axleback | H&R Spacers SOLD
2009 G8 GT, 6.0L LSX V8, Rotofab Intake, ARH Long tubes, SOLO exhaust, VMS Tune - SOLD

bleunetizen

I just ordered os giken lsd and only reason why I have not gone with shorter FD is the synchro rev too.. hopefully uprev can figure this out?

Zensation

You will lose syncro rev functionality. When you go to down shift the rev match will be off by a couple hundred rpm. There is no way to get around this currently. In order for the rev match to work properly a constant hard programmed value for each gear is coded somewhere in the ecu. Since your final drive changes with a 4.08 swap your overal gear reduction changes and the constant coded value in the ecu is then wrong. Is it physically possible to change? It is if someone knew how to access the info in the computer. To my knowledge no one has been able to even find it much less modify it and this is the only thing that held me back from a 4.08 swap. I was so close to pulling the trigger but theres just something about knowing that a feature on my car doesnt work correctly whether i need it or not.

__________________
370z NISMO 0675 327 rwhp 280 rwtq - sold.
FD RX7 single turbo 508hp - sold.
Lexus IS-F 5.0L V8

Eclipz

EcuTek is working on making synchro match work on 4.08 gears. I don't know if they finished it yet though

Zensation

Yeah but theyve been working on it for years. I hope they make some progress soon.

__________________
370z NISMO 0675 327 rwhp 280 rwtq - sold.
FD RX7 single turbo 508hp - sold.
Lexus IS-F 5.0L V8

Chuck33079

Visconti claimed it was already possible with Ecutek, but there's been so much BS about ecutek it's damn near impossible to separate fact from fiction. SRM would overshoot the target rpm on the throttle blip, right? Hardly the end of the world if that's the case.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent