I Searched But Did Not Know What To Look Under. If There Is Already A Thread On This Please Let Me Know.

I Was Wondering What Speed The Car Should Be At Depending On Which Gear Your In. If I'm In Second Gear And At 7,000 Rpms, Then What Speed Should The Car Be At? I'm Trying To Figure Out If The Issues I'm Having Are From The Engine Or A Faulty Clutch.

Thank You

 

uhm...shifting out of first into second at about 3500 RPMs and then punching/redlining second im at about 67. maybe 55ish?

That probably doesnt help but it was worth a shot.

 

First post in the thread below has a chart.

https://www.rx8club.com/series-i-tech-garage-22/rpm-versus-mph-25420/

 

Don't think this is an accurate way to diagnose clutch problem.

 

Here's some approximate values (I believe they were calculated, and do not reflect speedo error, drag, etc).

 

Yeah I know it's not the most accurate way to tell. The problem is that the dealer is telling me my issue is with the clutch not the engine, which of course we all know is b/s. He said that if my car is in 2nd gear and only at 55-60 mph, then he can conclude that it is the clutch, not the engine. He said that the mph in 2nd gear should be 80... yah right!

Thanks for the help guys!

 

I redlined first today and then on the way back up in second at 7000RPMs it was like 57.

 

Dang! Wish I'd seen that before. I looked all over the net to find an rpm/gearing calculator! The numbers I get are very close to those on the chart, maybe 2-3% lower. Let's see if a 'paste' will work:

Gear
RPM 1 2 3 4 5 6
500 2 4 5 7 8 10
1000 5 7 10 14 17 20
1500 7 11 15 21 25 30
2000 9 15 20 28 34 40
2500 11 19 25 35 42 50
3000 13 22 31 42 50 60
3500 16 26 36 49 59 70
4000 18 30 41 56 67 80
4500 20 33 46 64 76 90
5000 22 37 51 71 84 100
5500 25 41 56 78 92 110
6000 27 44 61 85 101 120
6500 29 48 66 92 109 130
7000 31 52 71 99 118 140
7500 34 56 76 106 126 150
8000 36 59 81 113 134 160
8500 38 63 87 120 143 170
9000 40 67 92 127 151 180

According to this, 2nd gear at 7000 rpm should be around 52 mph, give or take.

 

ps - Here's the address for that Speed/RPM Calculator

 

My manual says the recommended shifting points are (speed wise):

2nd: 14
3rd: 22
4th: 29
5th: 36
6th: 46

 

I gotta think they tell us that in an effort to achieve their claimed MPG numbers.

However, I think that shifting at those speeds is:

1. Not really too good for the engine

2. Not really too much fun

I mostly shift at 5,000 to 6,000 RPM, higher if I'm feeling frisky. Both the engine and the driver seem a lot happier that way.

 

Yeah, those numbers imply shifting at ~3,000 RPM. Blech. My normal is around 5,000.