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Old 06-01-2011, 10:00 PM   #1
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Default RPM Limit

What are you track ***** running for RPM limits on built motors? What do you find is enough? Do you wish you had more? What transmission/final drive?

I'm running an 8000RPM limit right now but am considering dropping it down a bit so I can gear my Rotrex higher in the lower RPMS.

For those of you who don't frequent the supercharger sub-forum....


https://www.miataturbo.net/showthrea...575#post733575
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Old 06-01-2011, 11:38 PM   #2
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6sp, 3.909, 7400rpm. Wish I had another 400rpm or so, but I need to change the intake cam first (VVT cam harmonic).
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Old 06-02-2011, 12:03 AM   #3
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On 15's right? A 3.9 and 6spd should be comparable to a 4.1 and 5spd I think?

I recall at Knox I was shifting around 7K because it was all uphill and there was no torque after 7k. At AutoX, I tend to use all the RPMS because it's flat and my local track is flat so I think a 7600-7800 limit would be ideal. That would put me at about a 95mm pulley. Worst case I don't like it and I can always throw the old pulley back on and bump it back up. But I think 200RPM shouldn't bee too noticeable.
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Old 06-02-2011, 12:28 AM   #4
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6sp, 3.909, 7400rpm. Wish I had another 400rpm or so, but I need to change the intake cam first (VVT cam harmonic).
What are the options for this. I will need the revs for auto x.
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Old 06-02-2011, 12:44 AM   #5
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7000rpm for Mr. Reliabilitaur. I make torque and HP everywhere. Next time I'm going to set my cut at 6800rpm to lower my peak power numbers for classing.
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Old 06-02-2011, 09:32 AM   #6
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What are the options for this. I will need the revs for auto x.
5spd and a 4.1 will give you a long enough 2nd gear. Short shift to third if need be.
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Old 06-02-2011, 11:41 AM   #7
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5spd and a 4.1 will give you a long enough 2nd gear. Short shift to third if need be.

It doesn't. I have to do 2-3-2 shifts alot.
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Old 06-02-2011, 11:45 AM   #8
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On 15's right? A 3.9 and 6spd should be comparable to a 4.1 and 5spd I think?

I recall at Knox I was shifting around 7K because it was all uphill and there was no torque after 7k. At AutoX, I tend to use all the RPMS because it's flat and my local track is flat so I think a 7600-7800 limit would be ideal. That would put me at about a 95mm pulley. Worst case I don't like it and I can always throw the old pulley back on and bump it back up. But I think 200RPM shouldn't bee too noticeable.
WTF, no torque after 7k? Don't you have a C30-94 on that car?

e: Just saw your S/C section thread, 14psi and you're only making 225whp from a C30-94?

6sp+3.9s is nothing like a 5sp and 4.1s. 6sp and 3.9s is probably closest to a 5sp and 4.44s, but still nothing like it since the 5-speed's 2nd and 3rd would be way shorter. 6sp+3.909+7400 is 80 in 3rd, 100 in 4th, 130 in 5th, and 155 in 6th. I would like another 5-7mph in 5th, and an additional ~8mph in 6th.
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Old 06-02-2011, 11:46 AM   #9
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how would a C30-94 not have any torque past 7K....isn't that the whole point of a centrifugal supercharger?
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Old 06-02-2011, 12:38 PM   #10
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WTF, no torque after 7k? Don't you have a C30-94 on that car?

e: Just saw your S/C section thread, 14psi and you're only making 225whp from a C30-94?

6sp+3.9s is nothing like a 5sp and 4.1s. 6sp and 3.9s is probably closest to a 5sp and 4.44s, but still nothing like it since the 5-speed's 2nd and 3rd would be way shorter. 6sp+3.909+7400 is 80 in 3rd, 100 in 4th, 130 in 5th, and 155 in 6th. I would like another 5-7mph in 5th, and an additional ~8mph in 6th.
He has a 1.6L

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Old 06-02-2011, 01:15 PM   #11
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Quote:
Originally Posted by Savington View Post
WTF, no torque after 7k? Don't you have a C30-94 on that car?

e: Just saw your S/C section thread, 14psi and you're only making 225whp from a C30-94?

6sp+3.9s is nothing like a 5sp and 4.1s. 6sp and 3.9s is probably closest to a 5sp and 4.44s, but still nothing like it since the 5-speed's 2nd and 3rd would be way shorter. 6sp+3.909+7400 is 80 in 3rd, 100 in 4th, 130 in 5th, and 155 in 6th. I would like another 5-7mph in 5th, and an additional ~8mph in 6th.
The intake manifold is causing a restriction. It's a 1.6L not a 1.8L. If you look at what power it's making at what RPM/boost it's not terrible but it could be more... 11PSI at 7k and 215whp, 9PSI at 6.5.K at 200whp, 8PSI at 6k at 180whp. When I am done with the new manifold/pulley I am going to do a pull on another dyno just to see if the dynapack is reading low. It feels pretty on part with a friends 260whp turbo miata he had.
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Old 06-02-2011, 10:05 PM   #12
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Quote:
Originally Posted by Savington View Post
WTF, no torque after 7k? Don't you have a C30-94 on that car?

e: Just saw your S/C section thread, 14psi and you're only making 225whp from a C30-94?

6sp+3.9s is nothing like a 5sp and 4.1s. 6sp and 3.9s is probably closest to a 5sp and 4.44s, but still nothing like it since the 5-speed's 2nd and 3rd would be way shorter. 6sp+3.909+7400 is 80 in 3rd, 100 in 4th, 130 in 5th, and 155 in 6th. I would like another 5-7mph in 5th, and an additional ~8mph in 6th.

6spd 3.636 = 5 speed 4.3 plus another gear.
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