You're right about hitting the speed limiter in 5th.

Now that I'm dong the analysis, I noticed what looks like a slight RPM calibration issue on the dyno. The car is run to redline but the plots show only 7300~7400 RPM.

...fairly typical dynajet RPM calibration behavior. Maybe the tire size wasn't entered in exactly correct?
The pre/post results are measured the same way so its all good.

No, you're right IT IS 1:1 in 5th gear. What I should have said was, I made more power in 4th gear then 5th. For some reason, every dyno I have been to I made 15-20 more whp in 4th gear then 5th. :confused:

OK, I have the gearing and shift points worked into the plots.
1/4 mile racing deltas have been worked in.

Has anyone datalogged their RPM's during road course racing?

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.

http://i352.photobucket.com/albums/r...d/RPMlarge.gif

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.



.

Nice data --- need your ART pipes before I think about using the redline regularly on this vehicle.... stock cats and this Z does not like >6500 rpm realistically.
Interested to have this and the ART pipes on, I like to have a punch right where you want it.

This mod is good in increasing gas mileage too. :tup:

Great data, Tony!

I have now put a 1000 km on the new Motordyne intake and my 370 z. I gave the ECU time to ajust. I also ajusted the fuel curve as it runs rich at top end. I also made a few small ajustments to the fuel curve using Cobb. My car has every bolt on + 4.08 gears and it is a 7 AT.
It is way quicker now. I shift at 7800 rpm. 1st and 2nd gear are so quick that its easy to hit the 8100 rpm limiter. ( there also is a 200 rpm error on my tack. It is read to low at high rpm.)
The aceleration is increadable. Tony has my dnyo of the car and im sure it makes more power now. It also a very deep sounding growl to it now.
Some young guy with an Audi A3 had a go with me and lets just say in the first 400 ft i blew him away by a mile. It was a 80 km speed zone and we took of from the lights I lifted at 100km. Ive been to the drag strip many times and the car really is a lot faster now. I have no traction issues as i have 305 35 18 tires on the rear of the car.
It to bad that the track are closed up here now as i will have to wait till next year to get the 1/4 mile times for the car.
I expect to get my GTM stage 2 SC some time in 2011 and i will ge trying the manifold on it .

Z

Would be a million times better if you could put stock engine cover back on.

Mine arrived yesterday and as usual from MD, well packaged and uber quick FEDEX, (delivered on Sat, nice) starting install today. ;-)

You can.The stock manifold has two stud bolts holding down the rear end of the back cover, just use two 10mm blackened bolts and your are in business.As Tony said in another thread you can order the manifold without the Motordyne plate.

New best 1/4 mile time at the track
12.421 @ 114.37.
Full bolt on's with 4.08 gears and the MOTORDYNE INTAKE M370.
1/8 times 8..020
It pulls hard ,really hard and its a 370 sports 7 AT
quickist 370Z AT all motor
more to come next time at the track.

Z

With uprev tuned?

No i tuned it with the cobb.

What are your 60ft times and are you running street tires, drag radials, or slicks? Thanks :tiphat:

370Z testing Motordyne's new intake manifold - YouTube

After the manifold install it lost 10 Peak WHP and gained some torque. But the torque was increased nicely over the whole RPM range.