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Wanna raise the rev limiter, Do i need new Valve springs?

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Old 07-07-2013, 02:20 PM
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Simon da Silva
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Default Wanna raise the rev limiter, Do i need new Valve springs?

Hey Guys. This winther im gonna build a NA setup for my 350z..

Current items in stock are the following.

Tomei Poncams 264-10.8mm G2 Camshafts
Wiseco 11.1:1 forged piston kit
Eagle forged connecting rod set
Fujita Intake pipe and open filter
AMS Lightened Pulley KIT
Nismo CopperMix Single Plated Clutch Kit
Lightened Flywheel Kit balanced to Clutch
Motordyne Plenum Spacer

I'ld like to be able to raise the rev limiter a bit, so im guessing im needing some new valve springs. Anybody got some recommendation on what to go for? and is this needed if i wanna do 8,5k RPM or something like that?

Thank you.
Old 07-07-2013, 02:29 PM
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2004Black350z
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I rev 9k. Stock. Also what is nismo coppermix clutch kit? Never heard of them
Old 07-07-2013, 02:39 PM
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Steve-O Z33
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If you're doing cams, go ahead and do valve springs.
Old 07-07-2013, 04:13 PM
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Classy
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The harsh reality is that the VQ doesn't really make power past 66-6800 rpm unless it has something pushing the power there. Your cams may push it towards the 6800 mark but I doubt any further, I think your stock valve springs will be fine for a rev limiter at 7000. But really after that, yes you will need some better valve springs.

Just to let you know my experience, I had a N/A motor much like you are planning with bigger cams than the ones you have and I didn't make power to 7000 much to my dismay
Old 07-07-2013, 04:18 PM
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terrasmak
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Your going to need a bigger throttle body too, if you want to rev high.
Old 07-07-2013, 08:56 PM
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TuckerE36
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Originally Posted by terrasmak
Your going to need a bigger throttle body too, if you want to rev high.
Well good thing that 75mm Big Bore TB just came out!
Old 07-07-2013, 10:49 PM
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Simon da Silva
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Originally Posted by TuckerE36
Well good thing that 75mm Big Bore TB just came out!

Link?
Old 07-08-2013, 08:22 AM
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terrasmak
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Originally Posted by Simon da Silva
Link?
https://my350z.com/forum/showthread.php?p=10163611#post10163611 here you go
Old 07-08-2013, 11:59 AM
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binder
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I would never run higher lift or longer duration cams on stock springs. They aren't very strong and will allow the valve to float causing premature wear. I know of a few running 7100 with stock valve springs and I wouldn't expect it to fly apart but it will wear much faster than with proper spring tension.

I use fererra dual spring setup and rev to 8500. I also have titanium retainers to reduce some of the weight and add strength since the cams are spinning fast.

It would probably be wise to replace the valves, valve seals and have new valve seats cut to give you the best performance unless your heads are under 10k miles.
Old 07-08-2013, 01:58 PM
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Classy
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Holy crap binder, do you really run to 8500?!? That is insane, I couldn't imagine how that would sound
Old 07-08-2013, 03:19 PM
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binder
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It sounds good! I actually haven't run it up that far in a long time. I'm just not out enough with the car to need to plus i had a turbo failure and haven't finalized this current tune. It's impossible to get stuff done now that I started my new office.
Old 07-08-2013, 03:26 PM
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Classy
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I really wanted to crank some RPM's after my motor build, something I never got to do, back on track, I think binder has shown what you need OP
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