Huh???... It was a pro MD post... what part (if not all) did you not read or understand?

 

BTW - don't take replying to my post with a sig "the Mafia" lightly... one of us might get hurt.

PS one of us might be kidding.

 

I just did a powerband calculation (4000-6400rpms) for "average HP" using Cartest. This calculation allows you determine the acceleration potential during a race because average HP (assuming same car/driver/traction) is what wins/looses the race. Here are the results:

Stock: ~220.4hp
Modded: ~221.3hp

Yes, the gains appear to be healthy at certain portions of the powerband, however the real gains (+5hp) are spread over only two 500rpm portions of the powerband and there's a significant dip in power above 6100rpms. In the end, it appears the car will be no quicker in the 1/4 mile and fractionally slower above 110mph.

*as required*
But then again, I'm just an ex-Maxima owner with no VQ35 experience so WTF do I know.

 

hey daveB wassup? hehe thinking about modding my G35 is frustrating. especially since i get this feeling i won't run NA 13's even with everything in the parts bin. so who cares? not as cut and dry as basic maxima tuning and def not as effective as tuning an SR20DET. extra weight is def a negative when it comes to performance and efficiency. sports luxury or whatever that means...bs

 

Ooooh.. which version of Cartest do you have? I remember playing with that program back in '97--when it was still free. Did you just eyeball the points (rpm,hp) on the graph and enter them into Cartest? What rpm resolution did you use?

 

Not sure how that program works, but I can tell you I did not just gain 1 hp. This car is much faster than that.

 

Hey All,

Here is my review of Motordyne's new MREV mod . . . Enjoy!

https://g35driver.com/forums/reviews/73093-motordyne-mrev-mod.html

 

Ok, so answer this....

This mod is only for the Rev Up engine or is it just best if used with the Rev Up? In other words, is there any point for a non- Rev Up driver to install this mod? Would there be any reason for me (a 1/2" spacer with IsoThermal gasket owner) to switch to this new mod? Will it even fit a non-Rev Up car?

 

Sorry, MREV benefits the '05 6MT equipped G35 for the time being.

 

Man, I feel like I'm in the "uncool crowd" with my sorry non-RevUp engine!!!!

 

What goes around comes around...and I'm sure Tony has a few more things in store for those of us who are not MREV worthy.

'04 Full-O-Torque

 

Cartest uses a crapload of data to generate ET/MPH. It uses things such as roll out, 60', tire height, gear ratio, shift quickness, grade, curbweight, drivetrain layout, DA, the particular powerband, blah, blah, blah. It can get quite detailed if you want it to. I kept all the variables the same except for the different dyno plots. I used a per 100rpm snap shot of both of your plots. I've found Cartest to be pretty dang accurate for my cars and many others have too. Hell, Cartest calculated I was going to run a 14.45@97.1mph the day I took my G to the track. I ended up doing 14.49@97.6mph.

You're right, your car did gain a hell of a lot more power than just 1hp. At some points it appears the car gained as much as 12-13whp, but average HP is what wins the race, not peak or brief gains along the powerband. The thing is, when you take the gains per 100rpms across the powerband and average out the numbers from 4000-6600rpms, the gains get normalized and you get about 1hp in favor of this new mod. If the entire powerband was lifted by 12whp across the board, the average power would heavily favor the new mod.

I'm sure a lot of people are thinking to themselves, the car is clearly making more power, how can it not be faster? Look at where and how the gains/losses hit and for how long. The "useable" gains (5hp+) hit for 500rpms each, one from about 4,200-4,800rpms and another from 5,400-5,800rpms. Then there's the fairly significant loss from 6,200-6,600rpms, which if the dyno would have gone to the 7,000rpm limiter, would have most likely made things even worse. It could be possible this mod *may* make the Rev-Up slower, but I don't have the 6,600-7,000 data. It's my opinion that this new mod uses the non-Rev-Up intake lower manifold and if it's true, it would be easy to assume that the ending power at 6,600rpms (235whp) would carry till 7,000rpms or possibly go lower because the non-Rev-Up manifold really wasn't designed to breath better above 6,200rpms. That's all speculation though. We won't know until someone dynos in 4th so they don't hit the MPH limiter when dynoing in 5th.

Unfortunately, you haven't 1/4 mile tested your car, so we'll never know the before and after outcome. The calculations say the car won't be any quicker.

 

Hi Dave,
I am curious. How were you able to integrate the difference in area under the curves between the two plots. Without the electronic source data it would be extremely difficult to do with any reasonable degree of accuracy. Your +0.9 average HP gain, time and speed estimates seem understated.
Did you use a ruler at every 1RPM interval to integrate area from G35TXs JPG scan? I doubt that would be all too accurate. I asked for the electronic data for these dynos, but aparently it is not exportable.

I did the same type of analysis for Klumzyees car but calculated it directly from Excel with the actual electronic dyno data.
Using 1RPM resolution dyno data bits, when area under the curve is integrated with Excel for Klumzyees car, it is clear that his car is quite a bit faster in just about every catagory. And especially the 1/4 mile.

The plot below covers the RPM range you mention 4K RPM to Redline. There is no comparison... Even at a casual glance it is clear the MREV adds a vast amount of area under the curve. It shifts the peak HP to the left and boradens it out. Average area under the peak is also higher within the 4th gear range.

If you consider that a good Z or G 1/4 mile driver will cross the finish line half way through 4th gear (~6100 RPM) , the MREV has a tremendous advantage over the stock configuration. Not only with a higher peak TQ and HP, it has a much higher average TQ and HP. And all the added power comes on sooner.

You can see from the plot below that just as the driver crosses the finish line the MREV has already delivered its power band and the stock car hasn't even started its power band.

And where top speed is concerned, MREV has a large advanteage in realistic terms. As Klumzyee recently demonstrated, he was able to hit the speed limiter at 156MPH in his car with the MREV. I believe he said he did it in 6th gear @ ~6100 RPM. That also puts his car at its peak power at the speed limiter cut point. And because it takes so long to get to 156 MPH the added TQ got him there much sooner than it otherwise would have taken.

If we are to assume terminal velocity occurs strictly at MAX HP, there is only a ~2.5HP difference between the stock peak HP and the MREV peak HP. The stock configuration will have a 2.5 HP peak advantage at terminal velocity, but that won't make much of a difference at 156+ MPH. All the added power the MREV makes below 156MPH will help you get there much faster.

So unless you have a very, very long strait to hold the gas WOT for a long period of time, the MREV will be faster. In fact, if it was a 1 mile drag race the MREV car will have put so much distance on the stock car, the stock car may not be able to recover for potentially 2 or 3 more miles. possibly more mabey much more.

A lot of time will be spent in the lower RPM range of 5th and 6th where MREV has as much as a 13 TQ advantage. And a simple short shift at 6500 RPM will keep the MREV in its optimum power band.

When it comes to top speed, the MREV is going to have a significant advantage for a long time. Only after 6100RPM in 6th gear (156 MPH) will the stock configuration start recovering ground and it will only do it at a very slow crawl. I don't know how long it would take to catch up and overtake the MREV modified car, but my guess is its going to take a very long time.
And unless the speed limiter is removed, the stock configuration will never have an advantage. It will be left behind and stay behind indefinitly.

There aren't going to be very many opportunities to drive at speeds like this anywhere. Even on the track. So may as well optimize the power and put it where it can be used.

 

The car gained almost 20 hp and 20 tq. Read the graph again. Each line is 10 hp.

Okay so you use some PROGRAM to figure it out, but then you won't believe a gtech, or dyno runs because there are too many variables. Give me a break!!!

Sure, I am going to believe some program over a dyno. And a video of the car racing another G35 and beating it by 4+ car lengths with this mod. Yea its not faster.

 

LOL . . . Those two are too technical for me and as they should be. However, following Tony's explanation/description of the data . . . Explains the performance changes, which have happily found themselves in my G.