I reset the ECU, and took the car out for a little flogging. The ECU reset was an interesting experience. My homelink now needs to be reprogrammed. I lost all of my presets. My two twip meters were lost, as was the REV setting. Fortunately, XM did not have to be re-registered. However, the most interesting thing is the fact that the car now starts idling at 800rpms. Ever since I got the car new, whenever it was cranked, it would start idling at around 2000rpms, then gradually drop until it settled around 600.

I took out the car, and noticed a few things. First, the exhaust note has completely changed. It is much, much lower in tone. Also, it's not nearly as loud. As for performance, it's actually quite a bit worse. I couldn't bark the tires unless I shifted near redline. Cheryl drove the car a little bit later, and she noticed the same thing.

Now I've just got to have some patience...

 

These two things along with a much quieter exhaust is what I notice after reseting the ECU on my VQ35 and on my old VQ30. You might also notice a slight decrease in MPGs.

I'm very sorry to hear about your dyno runs and I totally understand the heartbreak and frustration. Your honesty is commendable because most guys aren't willing to admit that a particular mod they installed might not be working as advertized. I think the problem lies in the TD exhaust teamed with the MREV. The fact that you didn't feel any gains with the MREV makes think this. From all the MREV dynos that have been posted, I'm certain you'd feel a significant kick in the pants from 2500-5500rpms after the install of the MREV. Gaining a solid 20wtq is something that really can be felt.

Now the question is do you buy a $1000 piggyback and spend $300 to tune and hope to restore power or do you start removing mods to find the culprit? I have to say this is one of the reasons why I'm not going to go mod crazy on my G35 and will be getting a 3rd car (5.0 Stang most likely) strictly for drag/auto-x fun.

 

Trey, ECU reset, if there is no difference pull the cats. There are dynos with the MREV and Stillen Exhaust I believe that DaveO has access to that show that combo gained a good amount as well. No loss was shown and its not because of the TD combo. Trust the ones that have helped you on here that you know of. Not the ones who has never tested any combo of this type.

 

Today it was 34 degrees and on my way home from work I checked to see if I could spin the tires from a 3K-4K 1st gear roll. It did it with ease. I could punch it and the back would step out wide, get off the gas, do it again. What kind of video do you want, one from in the car or from the outside? I don't have a way of posting it so I hope your email can handle larger files.

You're missing the point. Yes, it takes power (and torque multiplication) to spin the tires, but just because a car light the tires up from a roll or through multiple gears doesn't mean it's a powerhouse. You can take a stock manual turbo diesel Ram and roast the tires through 3 gears if you wish, but the truck is still only going to run in the 16s. Crappy tires and massive low rpm torque make for tire roasting ease. I've driven a 400whp twin turbo Supra auto that would barely spin a tire yet it ran 12.7s on z-rated 18s. My old CRX Si on aftermarket 15X7 rims (fairly wide rims for a small car) and Z-rated summer rubber could easily spin the tires on a 3000rpms launch and spin them so badly into 2nd that the steering wheel would consistently yank hard and left for the nearest ditch. The CRX only ran 15.8s. With a simple 2200rpm stall, the new 3.8 liter V6 Grand Prix GT I had for a rental this week would lay two perfect strips of rubber for about 20-30 feet and chirp into 2nd. I believe that car only has 205hp.

 

Okay, I am breaking the rules.

DaveB you are missing the point again as usual.

It's not the point of it spinning the tires. It's the point of 2-3 days before it didn't till you added the mod and now it does all the time and the only thing that changed was the mod.

So that proves the car has gained some additional power. Who knows how much, but it shows.


Also now I think of it, some of the early 03s would spin one rear tire easier than the later models. Now this part I do not know for sure and some of the veterans can answer this. Do some auto 5AT come with LSD? Because it takes more to break a LSD loose than it does without it.

 

All 03-04 5AT sedans have open differentials. The VLSD was never an option. I can tell you that my car is not peg-legging (one wheel spinning). When the back end of a car steps out sideways, that means both tires are loosing traction. In most straightline situations, a VLSD isn't going to help you much at all. The VLSD is more for controlling wheelspin when coming out of turns at WOT. My friends Lotus Elise has no problems cutting 1.75 60 foots with an open differential and street tires.

Don't be confused into the thinking the LSD in the G35 is some sort of "locker" type differential. The VLSD unit used in the G/Z uses a set of wet clutches and the system only operates when the induced spin from one wheel is greater than the other. When the offset occurs, the clutch fluid warms up and expands which locks the clutchs. This means it takes a little time for the system to operate and the resulting lock is only about 20%. This is why it's called a limited slip differential. It's not a 50/50 split.

 

Why not both?? And yes my email can handle whatever file size you send as far as I am aware.


Why don't you go back and read what I wrote. In this case it is YOU who have missed the point.

 

Now here is an interesting note: Post ECU reset NOT post MREV the exhaust note has changed quite a bit. I am actually not irritated to ride in the car at this point. I find this interesting to say the least.

I think this is going to take a fair amount of time to resolve. We talked about this earlier and have some differences of opinion as to the possible causes. We agree on the course of action to take however to a large degree. I am sure that we will find out some very interesting things about how the MREV reacts to a few mods before it is all said and done.

 

This is what you posted:

I read this as meaning a high HP car means it should easily roast the tires. I gave you examples of slow or heavy vehicles with rather weak overall power to weight ratios can also spin their tires in multiple gears. Tires, gearing, powerband, drivetrain layout, etc all play a huge role here. Not just "power".

 

Trey
Just a quick question for you. When you installed the M-REV, did you UN plug the throttle body connector with the battery still hooked up? If that was the case, when you will need to perform the throttle body learning procedure. What ever the problem is, IM sure its simple.
Your mod's should work and make HP.

 

I'm not sure what you mean Pasta. I never disconnected the battery while installing the MREV, so whatever I did, the battery was still "live". But what do you mean by the throttle body connector? I never removed the throttle body from the upper plenum; I didn't get the copper option. The only things I disconnected from the throttle body were a coolant hose that connects to the bottom of the throttle body, 2 hoses that connect to the back(not sure what these hoses are for), and the MAF sensor.

 

Got the run files. Just to refresh everyone's memory, this shop does 3 pulls. To make sure I could compare against my November baseline(at the time ztube, k&n, kinetix cats, and 350z midpipe), I had the first two pulls performed in 4th, and the last in 5th.

The first graph compares the first pull yesterday to the first pull in november.
The second graph compares the second pull yesterday to the second pull in november.
The third graph.. bla bla bla.

 

Here are more graphs. The first graph is just yesterday's pulls. The second graph is the three pulls from november. The last graph is all 6 pulls on the same chart, so it's a bit difficult to read.

 

Here are two more graphs. The first graph compares a 4th gear pull against a pull in december(ztube, k&n, crawford cats, 350z midpipe). The second graph compares the same 4th gear pull against another pull in december where I ran without my muffler.

 

So, there are 8 graphs to comparison and analysis. At this point, I'm not entirely sure the A/F is *the* problem. I'm honestly quite concerned with the signature of my torque curve. This is just an assumption, an uneducated one at that, but I would guess that even with my a/f problems, the torque signature should show a greater resemblance to what we've all seen for the MREV instead of shadowing my previous curve.

So, next step is to take off the crawford cats and dyno again. Fun fun fun.

Also, for anyone that has winpep and wants to do a more depth analysis, I have attached a zip containing my 3 pulls from November, and my 3 pulls from yesterday for your edification: