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older&wiser
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Discussion Starter #1
Just wondering about my 6 speed manual 2.5. In 6th gear I am at 2000 rpm's at 55mph. So I would assume I would be going 110mph at 4000 rpm's. and 138 at 5000 rpm's. Question is where will the tach top out at in 6th gear. Would it ever get to 5000 rpm's?
 

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I think the wind resistance would slow you down and you would never reach red line. I had a 6 speed in my 2002 Camaro and 6th gear was a .5 overdrive so at 90mph I was only tacing 2000 rpm and redline was 6000. So working that out my top speed should have been 270mph, lol, but I could never get above 160mph because of wind resistance.
 

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Despite the car going through multiple road tests in the major mags I couldn't seem to find a consistent source that verified top speed. A few sources indicated it's governed to 130 mph (C&D is one of them in their recent long-term 2015 sGT manual update). That would make sense since 210 km/h is a common governor point in non-US cars and 210 km/h converts to 130.48 mph.

If that's the case then the car can't see 5000 rpm in 6th no matter what. You'd be looking at 4500-4750 or so.

Let's pretend it doesn't have a speed governor though. Building on @Rdrokit's point above though wind resistance coupled with a very tall 6th gear on a car with less than 200 bhp would really start to work against it. 5000 rpm might even be about where it would top out which -- based on the gear ratios and tire size -- would give it something like a 140-ish top speed in 6th.

Going a tad further, most cars that aren't governed achieve top speed one gear down from the highest. 5th gear at the fuel cutoff of 6200 rpm would yield 146 mph based on gear ratio and tire specs (I know redline is 6500 rpm but the car cuts the fuel officially at 6200 so redline is useless -- I know because I've nailed the fuel cut-off in 2nd and 3rd gear a few times before redline :surprise: so I went and looked it up). So if the 3 didn't have a guv'nah it could have a shot at the low to mid-140s if it had the power to get to redline.

I once owned a 1995 Maxima that had 190 bhp and worse aerodynamics and according to reports -- if I recall correctly -- the car topped out at 143 mph. So 184 bhp with better areodynamics and not much weight difference (surprisingly) makes the low 140s feel about right for top end potential (if the governor was defeated) for the 3.
 

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Quote: "In 6th gear I am at 2000 rpm's at 55mph."

That's surprising. My 2.0L automatic is running about 70 mph at about 2000 rpms. I wonder why the big difference?
Easy. Different gear and final drive ratios for the automatic. It's common on most manufactuers' models where a stick and auto are both available to offer the auto version with taller (numerically lower) gear and final drive ratios. It's the main reason the automatic turns in much higher fuel economy numbers on the highway in the EPA test.
 

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Official Ricer
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I wonder if Mat at OVT could tell you - or even change/remove it?
That is classified information.
Only those of us who's tuned with him know. ;)
 
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