Hi gang...been a while since I posted. Had a neat experience this morning regarding our infamous Rev Limiters. We all know what happens when we exceed that redline...momentary loss of power and embarrasment sometimes. Staying off the limiter is almost next to impossible when we punch out in the lower gears.....but I was on an approach to the highway..not another car in-sight and I rowed those gears up to just before redline, shifting just before I thought the rev limiter might get me...When I went into 4th I took it up to almost redline and for some reason just kept WOT...the tac did sweep into the red zone and I exceeded 7 grand without the limiter kicking in....I shifted to #6 and let off before entering the highway.

Have any of you folks had a similar breakthrough in limiter free acceleration? Just thought I'd share. I hate that 1st gear, it's too quick.....to the RL.

 

yeah, i think the limiter only kicks in after you're in the red for a second or 2. It's not like an exact stop when your tach shows into the red.

I glanced down and was at around 6700/800 at a shift once and it didn't kick in.

03 6MT coupe, red/willow, premium, aero, splash guards, alum pedals, clear corners, 15% tint

 

Stock tachs aren't always 100% accurate as well, so your tach may show the rev limiter to be higher than it actually is. At 7500rpms mine is off by about 150-200 indicated rpms and I've seen other cars that are worse.


Justin McClanahan
Heavily Modified 95 Infiniti G20
Working on a G35 Project Coupe

 

Sound reasonable.....The tac calibration accuracy could be lacking from real world engine rpm. This was the first time I could actually look down at the tac and see the needle position. When the limiter hits in 1st gear, you don't have time to look.....that needle sweeps into red just too quick.

 

hmm.. i've reached 7 grand (not on purpose haha) but never over..... calibration could be one thing, but i think that Rev limiting is not an exact science. I mean, the computer will try to limit the revs, but imagine the crank spinning THAT fast (7,000rpm= 116 revs per SECOND) it must be tough to control it to an exact #
Did you get off the gas yourself? or did the limiter kick in- in 4th above 7K?
I guess we'll never know if you coulda went any higher...haha
I would be too scared to try it again!

<font color=green>-Rambo</font color=green>
G35c-6MT-DG/Willow/HyperGround/BorlaExhaust/350Z-intake

 

<blockquote><font class="small">In reply to:</font><hr>

I mean, the computer will try to limit the revs, but imagine the crank spinning THAT fast (7,000rpm= 116 revs per SECOND) it must be tough to control it to an exact #

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In the old days of gear driven tach cables and mechanical tach gauges, yes. These days of digital tachs and electronic sensors, no, they're accurate. A simple crank position sensor can give a perfectly accurate RPM readout, using magnetic strips on the crankshaft. To a computer that has to interpret this binary output, 7,000 RPMs is nothing. It's accurate.


2003 G35C, 6MT, DG/G, Aero/Nav/Premium
2002 Corvette Z06, Electron Blue/Black

 

No they are not that accurate .When I did my dyno..My tach was off by 300 to 400 rmp .I saw my tach just before the dyno operator shut me down and it read 6,900 rpm and the dyno said I was at 6,490 rpm when I let off

Couldnt afford it when young...gonna play when Im old

 

That's wacky. There's no reason for an electronic tach to be inaccurate like that. I mean that's off by a lot! Hell, I think the old mechanical tachs were more accurate. [img]/w3timages/icons/shocked.gif[/img]

None of my other cars that I've ever owned were off by 300-400 rpms on the tach. I even had a '70 big block Corvette with a new Mallory Unilite distributor (electronic ignition with optical timing sensor) with an electronic Sun Pro tach hooked up to it, and that thing was totally accurate.

2003 G35C, 6MT, DG/G, Aero/Nav/Premium
2002 Corvette Z06, Electron Blue/Black

 

Z06 - I've seen several LS1/LT1 tachs off by as much as 400 rpm near readline (haven't been in enough LS6 vehicles to comment on that). On my old LT1 powered Z28, my tach was off by about 200 rpm around the 2600-2800 position on the tach - confirmed using AutoTap. I believe (at least on my car) that the tach needle was not positioned/calibrated properly on the instrument cluster.

<font color=blue>2003.5 G35 Coupe 6MT
CB/Graphite/Prem/Aero
19" BC Forged Custom BC06s
Clear Corners/Tint
Alum Pedals
Zaino!</font color=blue>

 

<blockquote><font class="small">In reply to:</font><hr>

Z06 - I've seen several LS1/LT1 tachs off by as much as 400 rpm near readline (haven't been in enough LS6 vehicles to comment on that).

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Not mine. The rev limiter on my Z06 kicks in right at the indicated redline on the tach, and the digital head-up display.

My last car, a '96 Ford Contour V-6, was the same way: accurate tach redline that matched the rev limiter.

2003 G35C, 6MT, DG/G, Aero/Nav/Premium
2002 Corvette Z06, Electron Blue/Black

 

ive gone into the 7grand and beyond before..but not by much...and it was intentional just to see how far the VQ would go

"Dont start none, won't be none"

 

<blockquote><font class="small">In reply to:</font><hr>

There's no reason for an electronic tach to be inaccurate like that. I mean that's off by a lot!

<hr></blockquote>There is every reason for any mechanical instrument to be inaccurate. A digital LED gauge - maybe not - but any mechanical device can fail to operate properly. As far as a rev limiter not acting fast enough - what a crock. If the ECU can fire off the plugs and the injectors at 7000 rpm, it will have no problem shutting off the spark or the fuel. If the RL failed to operate then either it was malfunctioning - how often does YOUR computer act up - or it didn't actually happen ( tach was off ).