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Old 11-22-2010, 10:04 PM   #34 (permalink)
Motordyne
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Quote:
Originally Posted by Endgame View Post
I think this is a mod for some, but not for all depending on what your driving style is. If you want to fattened up your mid-range, this is the mod for you. If you plan on spending your life at the red line, maybe this is not the mod for you.

Many of the track/autoX guys may want more of that midrange power as that is where they spend their life more so on the track.
This is actually not the case. See the plot below. This is Staples dyno plot with indicators placed at the redline shifting gear RPM ranges. 6MT for all gears driven to their theoretical speed limit.

The car is faster on the street, 1/4 mile track and the road course with the M370. No matter how the car is driven or how it is shifted.

If we assume this plot is representative of performance and analyze a worst case scenario where it is shifted exactly at redline every time, the average power in each gear is higher.



What this plot shows is the usable RPM range of each gear assuming a shift at redline. When racing, it is not possible to keep the engine at redline all the time. Shifting is required to accommodate the up & down changing of speed. Speeding up and slowing down. RPM continuously sweeps through all the gears.

If you look at the area under the curve of each gear, there is clearly more area under the M370 curves. If shifting occurs at anything less than redline, the delta gain of the M370 increases even more.

On the Street:
Redline shifting doesn't happen all that often but in any case the increased torque is nice to have for daily driving. Higher power is unavoidable in this case too.

On the Drag Strip:
In the case of 1/4 mile racing its easy to see the delta results above. The last stretch of the race is with 9 more HP with the M370. Plus all the added area under the curve of gears 1 through 3.

On the Road Course:
In the case of road course racing we need to consider that the two most used gears are 3rd and 4th gear with a greater bias towards 4th. 2nd and 5th are also used but much less so.

Basically the last 2/3rd's of 3rd gear are the majority of 3rd gear use.
The first 2/3rd's of 4th gear is used most heavily in road course racing. All of the bottom. All of the midrange and much of the top of 4th. (If shifting occurs at anything less than redline the delta gain with M370 only increases.)
5th gear gets used too but it doesn't get used until the velocity is very high @ 123+MPH. And that is assuming perfect shifting at redline every time. 5th gets used but most of the course time is spent in the curves ...where 3rd and 4th dominate.

A typical time weighted average road course race velocity is about 60 MPH - 110 MPH so we can roughly bound the gears and RPM's used within that velocity range.

So it comes down to this. Acceleration rates are determined by area under the curve of each gear. (Not by peak numbers.)
No matter how the 370Z is driven or how it is shifted, it is faster with M370.



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Last edited by Motordyne; 11-22-2010 at 11:47 PM.
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