My MPGs went in the toilet when I had my Borla TD installed for almost 4 days. I wasn't driving hard at all either. I was saw ~11mpg in city vs the 17 I usually see with the winter gas. I imagine that the mpgs would improve once the ECU fully adjusted because I'm sure it was running really rich when I first installed the system. Regardless, I think there is a negative mpg impact with the TD exhausts. The 350Z crowd reports the same thing.

As for the spinning tires things, it's a rather pointless test gauging gains. Some days I can roast my rear tires to oblivion from a standing start or slow 1st gear roll and bark loudly into 2nd and then some days it will only spin them about 5 feet and won't make a peep going into 2nd. This was all prior to installing my MD spacer (my only power mod). My G feels stronger with the spacer and it does seem easier to roast the tires, however, it's winter and colder (sub 50 degree temps) which makes it very easy to spin the tires.

About your Stillen TD, have you noticed any additional cabin vibrations due to the resonnance of the exhaust. I know my Borla did introduce quite a bit more resonance vibration into the cabin/steering wheel/seat. I think this is due to the fact that Borla (and Stillen) neglect using flex sections in the y-pipe. IMO, it's a stupid not to have the flex sections because their primary purpose is to reduce NVH.

 

With regards to the butt dyno by measuring the amount of tire spins induced, I agree that it is a bit hand-waving..

For the resonance part, I only experienced low rpm droning but not any kind of vibrations that you have described from steering wheel/cabin panels?

Cheers

 

We are not talking about spinning tires from a standing start or shifting to 2nd fast and spin again. We can do that on a stock G35. But if you are at 3-4k rpms cruising in 1st gear and stab the gas to the floor, I loose traction. Hit 2nd gear, cruising at 3-4k as well, and your flooring it and once you hit those rpms the tail starts to go sideways and your slip light comes on.

With 275s in the rear with the MREV I could not make this happen. Now after the intake was installed it has come back. It did this with the stock tires with the MREV kit but not before the MREV.

It is a good judge. Especially if the car didn't do it before.

 

I'm surprised a stock 6MT can't light up the tires at a 3K-4K roll. Even my super weak 2003 auto can do that.

Are you sure you're not bending the truth here a little? It seems rather hard to believe unless you're on a loose or wet surface. A 240rwtq 3,500lb rwd car in 2nd gear at 3K lighting up the tires. Even my friend's 04 Cobra with 400whp can't "light them up" from a 3K-4K roll. His 285s (not DRs) simply plant and go. Same goes for my friend's 385whp 02 vortech'd GT with 4.10 gears.

 

Wish I was....I can give you a friends phone # if you wish to call to verify. He was with me on one moment that it did happen. It's more like 4k.

Sorry if your not a believer.

Edit: Oh yea so now your saying all tires are equal? Man we need to just start buying any tires because they all have the same grip!

 

Trey
What, you are talking about is drivability. Its the form of how the engine comes on to loads.
Drivability, is a very important part of your engine setup, or car. You give me a car with drivability with hp/tq as the next guy and he has poor drivability, I will smoke him at all levels. Understand that when most hi-PO products come out, whey may make better HP numbers but, will kill drivability. Drivability needs to be talked about more on this forum.
Low end torque and drivability wins races. The M-REV has many advantages that the dyno cannot tell you. Just a quick note for you guys with true duel exhaust's. My 2005 Mt BANGED OUT 26.59 MPG on my way home from California with the cruise set at 79 mph, plus the fact I hit over 135 mph a few times enjoying the nice mountain roads of Saint George Utah. I was happy with that

 

Dennis,

What sort exhaust set-up are you running? I am installing my HKS in the next day or so.

 

Glad to hear that. Can't wait for my exhaust to get here.

 

When I installed my mrev plus, I did not notice a difference at all. You can see it on a dyno chart around 4500rpm where the stock torque curve has a dip. At 2500, you can see the better torque curve of the mrev. As for the borla dual exhaust, I dynoed three times with the stock cats and manifolds. I ended up with exactly ONE hp and more noise. The drone is the worst around 2.5k-3k at part throttle in the higher gears. The dyno was so pathetic, I could not embarass myself by printing and posting it.

 

Andy
Your choice is first class, and might, I add one nice setup.
I went with the Invidia setup and em very pleased with it. The intake and exhaust timing on owes cars is very different from most cars. When I have the time and get down to Motordynes garage for some testing, Lets put it this way Tony, will get the camshafts figured out and your exhaust setup will come to life when the cam timing gets the exhaust breathing better.
Did you guys see a picture of Tony's ZEE? damn sexy ride. Trust me, I will not let a ZEE take out a G35 on the dyno.

 

OK

Try this Take two aspirin, drink plenty of fluids, get a good amount of rest,
And PM DR. DaveO He will take very good care of you, And. Your friends here will get you dialed in, You will live thru this, and be happy. Pasta

 

Well we'll see when you get out this way but be aware that at least one person is calling complete and utter bullsh!t on this one. This one you are going to have to *prove* to me at least. I've heard some good ones but this one is just too much.

 

This is DaveO's exhaust. The drone is not so bad but the power gain is less than minimal for the noise.

 

My gas tanked when I installed the exhaust as well. Under my normal mix of city and interstate driving, I usually see around 260 miles at the 1/4 tank level, which comes out to around 19 to 20(usually right at 19.5)mpg. When I installed the exhaust, I had 3/4 of a tank, and when I filled up at a 1/4 tank, I had only put on something like 220 miles or so. I didn't even bother to calculate the mileage for that tank, but I figure it would have been in the 16mpg range.

However, I filled up the day before I installed the MREV. After the install, I basically did WOT runs every time I could, to bitchslap the ecu into submission. That tank, I was back 19.5mpg.

I've never been able to light up my tires, in any gear, except when shifting and launching.

I've already mentioned that there's a buzz coming from the b pillar where the driver's side seat belt mounts. Other than that, there aren't any new rattles/buzzes/pops/what have you. However, at idle, I can feel a slight wobble through the brake and accelerator. Very slight actually. It's not so much to be bothersome, fortunately.

JBX had reported the same thing with his 2nd gen stillen, and noted the lack of flex piping in the x pipe.

 

That is a very impressive dyno chart. Were these two runs the "best of" before and after runs? And it looks like they were about 2 and a half hours apart. Was the MREV installed at the garage after the first set of pulls? And did you get a chance to do an ECU reset before you started your second set of pulls? Also, did you dyno in 4th or 5th?

This comment isn't directed at you, but I'm disappointed that most dynos of the mrev we've seen haven't been taken out to 7k rpms.

Regardless, impressive numbers.