How high has the bar been raised?

1slow370 · 02-07-2014, 03:27 AM

Ok I am NOT worried about my oiling system, so how fast can i spin her before i get valve float? I think i saw sharp by coop was at 8500 till he blew but that was with boost and not enough fuel. I know 8100 has been done for a while till the pump blows, and i think zelminator had mentioned 8300 before. Oil pressure and consistant supply won't be an issue, nor will exploding pumps so whats up? I am also going to call JWT and see what they say, wether i should be worried about bearings, piston speeds, or valvetrain first.

Megan370z · 02-07-2014, 06:24 AM

the intake valve spring are much stiffer than the exhaust valve spring .
I dont remember the number but they are in the book.

Im sure they are good up to 9000 but the exhaust one, I wouldnt go higher than 8300-8400.

I tried ordering those intake valve spring but Nissan didnt want that.

If you need a side by side VHR Vs HR .. look at this.. I should have put the spring rate too..
but only the VHR intake valve spring are stiffer .. everything else has the same the spec.

DIGItonium · 02-07-2014, 09:37 AM

Quote:

Originally Posted by Megan370z

the intake valve spring are much stiffer than the exhaust valve spring...

I'm curious... have you considered dual valve spring setup? Ferrea only has them for the VR38, though.

fuct · 02-07-2014, 08:18 AM

is there a good amount of usable power in that higher range?

FPenvy · 02-07-2014, 08:26 AM

i have mine set for 8K redline since i got tuned last march. not sure if that helps your research or not lol

critical · 02-07-2014, 09:49 AM

i wouldn't want to be a test dummy for this

megalapagas · 02-07-2014, 02:09 PM

I woukd agree aswell being at 8k but of course having a good Fuel and Oil pressure but isn't that risky business even raing the rev limiter to 8k??....*In for Updates*

FPenvy · 02-07-2014, 02:13 PM

Quote:

Originally Posted by megalapagas

I woukd agree aswell being at 8k but of course having a good Fuel and Oil pressure but isn't that risky business even raing the rev limiter to 8k??....*In for Updates*

my rev limiter is at 8k but it's not like i sit there and hold it at 8k lol i may kiss that here and there when drag racing. but i DD mine so i typically i'm not hitting the rev limiter driving to work.....unless i'm late

megalapagas · 02-07-2014, 02:26 PM

Quote:

Originally Posted by FPenvy

my rev limiter is at 8k but it's not like i sit there and hold it at 8k lol i may kiss that here and there when drag racing. but i DD mine so i typically i'm not hitting the rev limiter driving to work.....unless i'm late

LMFAO yea I understand xD I didn't explain myself correctly and yes I would agree as mines a DD aswell and well what were your gains at the drag strip + what were your jumbers on the dyno with your rev limiter at 8k?

FPenvy · 02-07-2014, 02:30 PM

Quote:

Originally Posted by megalapagas

LMFAO yea I understand xD I didn't explain myself correctly and yes I would agree as mines a DD aswell and well what were your gains at the drag strip + what were your jumbers on the dyno with your rev limiter at 8k?

numbers listed in the sig. i got the dyno sheet saved somewhere i'll have to find it. i really dont think they even cracked 7600 when dynoing it if i remember right. i could be wrong though.

edit: checked my sheet they took it to 7800. then the data stopped. kinda seems to drop off power wise past about 7400 though. maybe he was backing off then as well.

TerribleONE · 02-07-2014, 03:11 PM

Quote:

Originally Posted by FPenvy

numbers listed in the sig. i got the dyno sheet saved somewhere i'll have to find it. i really dont think they even cracked 7600 when dynoing it if i remember right. i could be wrong though.

edit: checked my sheet they took it to 7800. then the data stopped. kinda seems to drop off power wise past about 7400 though. maybe he was backing off then as well.

I have yet to really see anyone pick up any power by going to 8k. I really dont see what the big fuss is about with raising the rev limiter.

megalapagas · 02-07-2014, 02:28 PM

I just saw your signature and your numbers *Facepalm*

megalapagas · 02-07-2014, 03:54 PM

That's a Great point! I hate when it bounces causing my next gear to be on the low rpms -.- ...will take note on that though to mantain power.

Jordo! · 02-07-2014, 04:08 PM

There's an early "soft" rev cut on OEM tune (fuel based, goes overly rich), I believe, to make the hard rev limit (ignition cut) put less strain on the motor.

You'll see little "divots" in the dyno graph as you approach rev limit on a factory tuned motor, just before the OEM ignition cut.

I'm intrigued by where this all goes, but I am guessing either a seriously ported and polished head and/r different IM will be needed to really capitalize on the higher rev limit.

On a related note, will the VVEL maps (if untuned) be able to extrapolate beyond, say, 7800?

Would love to see someone with stiffer valve springs and a massaged head/IM combo (and, I guess a VVEL tune plus different exahaust cam) push it into the 8+ K range. If torque didn't drop off, that would be a seriously powerful, screaming to redline VQHR.

This is all pretty uncharted territory, at least as far as I know, so looking forward to more details as this comes together

FPenvy · 02-07-2014, 07:02 PM

Quote:

Originally Posted by Jordo!

There's an early "soft" rev cut on OEM tune (fuel based, goes overly rich), I believe, to make the hard rev limit (ignition cut) put less strain on the motor.

You'll see little "divots" in the dyno graph as you approach rev limit on a factory tuned motor, just before the OEM ignition cut.

I'm intrigued by where this all goes, but I am guessing either a seriously ported and polished head and/r different IM will be needed to really capitalize on the higher rev limit.

On a related note, will the VVEL maps (if untuned) be able to extrapolate beyond, say, 7800?

Would love to see someone with stiffer valve springs and a massaged head/IM combo (and, I guess a VVEL tune plus different exahaust cam) push it into the 8+ K range. If torque didn't drop off, that would be a seriously powerful, screaming to redline VQHR.

This is all pretty uncharted territory, at least as far as I know, so looking forward to more details as this comes together

The soft cut you mentioned is what I touched on earlier. I didn't like being somewhat close to 7400 and it cutting some power. Once I raised mine when I got tuned I love that there's no interference from the ecu now.

02-07-2014, 03:27 AM	#1 (permalink)
1slow370 A True Z Fanatic Join Date: Aug 2009 Location: In the D Posts: 3,732 Drives: v8 74 260z ;) Rep Power: 7251	How high has the bar been raised? Ok I am NOT worried about my oiling system, so how fast can i spin her before i get valve float? I think i saw sharp by coop was at 8500 till he blew but that was with boost and not enough fuel. I know 8100 has been done for a while till the pump blows, and i think zelminator had mentioned 8300 before. Oil pressure and consistant supply won't be an issue, nor will exploding pumps so whats up? I am also going to call JWT and see what they say, wether i should be worried about bearings, piston speeds, or valvetrain first. G37sHKS likes this. __________________ ANSWER PRICE LIST Answers - - - - - - - - - - - - - - - - $0.75 Answers (requiring thought) - - - - $1.25 Answers (correct) - - - - - - - - - - $12.50 Last edited by 1slow370; 02-07-2014 at 03:29 AM.

02-07-2014, 06:24 AM	#2 (permalink)
Megan370z A True Z Fanatic Join Date: Oct 2009 Location: Canada Posts: 1,156 Drives: 370z Rep Power: 24	the intake valve spring are much stiffer than the exhaust valve spring . I dont remember the number but they are in the book. Im sure they are good up to 9000 but the exhaust one, I wouldnt go higher than 8300-8400. I tried ordering those intake valve spring but Nissan didnt want that. If you need a side by side VHR Vs HR .. look at this.. I should have put the spring rate too.. but only the VHR intake valve spring are stiffer .. everything else has the same the spec. __________________ Megan Journal Click Me ....................One Man Team Motorsport Click Me Last edited by Megan370z; 02-07-2014 at 06:27 AM.

02-07-2014, 09:49 AM	#6 (permalink)
critical A True Z Fanatic Join Date: Oct 2012 Location: Washington Posts: 1,252 Drives: 09' 370z 7AT Rep Power: 16	i wouldn't want to be a test dummy for this luigi90210 likes this. __________________ Quaife w/ gears \|Stillen Gen 3\|SOLD FI Resonated Test Pipes \|SOLD FI 18'' \| 25row Stillen Race \| Progress 35mm/25mm sways \| Swifts/Koni\|Volk G25's\| Stoptech SS lines\|\|SPL Front/Rear Arms\|

02-07-2014, 02:09 PM	#7 (permalink)
megalapagas Enthusiast Member Join Date: May 2013 Location: McAllen,TX Posts: 457 Drives: '10 370Z Tour A/T Rep Power: 12	I woukd agree aswell being at 8k but of course having a good Fuel and Oil pressure but isn't that risky business even raing the rev limiter to 8k??....In for Updates __________________ GTM 34 Row Oil Cooler \| K&N Drop Ins w/ Z1's Post MAF Tubes \| F.I Non-Res'd 2.5" T.P w/ CF CBE \| Axis Wheels \| Piecing together My Own Custom T4 Top Mount Single Turbo Kit Still in the works \|

02-07-2014, 02:28 PM	#12 (permalink)
megalapagas Enthusiast Member Join Date: May 2013 Location: McAllen,TX Posts: 457 Drives: '10 370Z Tour A/T Rep Power: 12	I just saw your signature and your numbers Facepalm FPenvy likes this. __________________ GTM 34 Row Oil Cooler \| K&N Drop Ins w/ Z1's Post MAF Tubes \| F.I Non-Res'd 2.5" T.P w/ CF CBE \| Axis Wheels \| Piecing together My Own Custom T4 Top Mount Single Turbo Kit Still in the works \|

02-07-2014, 08:18 AM	#4 (permalink)
fuct A True Z Fanatic Join Date: May 2009 Location: Sugar Land Posts: 3,692 Drives: 97' Ranger :) Rep Power: 24	is there a good amount of usable power in that higher range?

02-07-2014, 03:54 PM	#13 (permalink)
megalapagas Enthusiast Member Join Date: May 2013 Location: McAllen,TX Posts: 457 Drives: '10 370Z Tour A/T Rep Power: 12	That's a Great point! I hate when it bounces causing my next gear to be on the low rpms -.- ...will take note on that though to mantain power. __________________ GTM 34 Row Oil Cooler \| K&N Drop Ins w/ Z1's Post MAF Tubes \| F.I Non-Res'd 2.5" T.P w/ CF CBE \| Axis Wheels \| Piecing together My Own Custom T4 Top Mount Single Turbo Kit Still in the works \|

02-07-2014, 04:08 PM	#14 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 418	There's an early "soft" rev cut on OEM tune (fuel based, goes overly rich), I believe, to make the hard rev limit (ignition cut) put less strain on the motor. You'll see little "divots" in the dyno graph as you approach rev limit on a factory tuned motor, just before the OEM ignition cut. I'm intrigued by where this all goes, but I am guessing either a seriously ported and polished head and/r different IM will be needed to really capitalize on the higher rev limit. On a related note, will the VVEL maps (if untuned) be able to extrapolate beyond, say, 7800? Would love to see someone with stiffer valve springs and a massaged head/IM combo (and, I guess a VVEL tune plus different exahaust cam) push it into the 8+ K range. If torque didn't drop off, that would be a seriously powerful, screaming to redline VQHR. This is all pretty uncharted territory, at least as far as I know, so looking forward to more details as this comes together __________________ Enjoy it. Destroy it. Last edited by Jordo!; 02-07-2014 at 04:11 PM.

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