I have an 05 6mt coupe w/29k miles and it just doesn't have the acceleration that it should. It did have the oil consumption issue and the engine was replaced. When it was at the dealer they gave me an 09 G37 sedan auto for a loaner. Now that car was fast. It had no problem breaking the wheels loose. And since I was getting a new engine, I thought this was what I had to look forward too. Granted the 37 has a bit more power but it still should be somewhat comparable. But after breaking in the engine I tried getting on it a bit and it is still SLOW! Knowing that it wasn't the engine causing it to be slow, what else could it be? I do have carbon build-up on the exhaust tips from the previous engine burning oil. Could this oil consumption have ruined the o2 sensors? When I initially took the car in for OC they must have done something because it had GREAT acceleration when they gave it back to me. But this only lasted for a couple miles then it was blaw again. I have done the ecu reset, but it didn't help. And I always use 93 octane. Anyone have any idea what is causing this?

 

If the O2 sensor was toast, you would get a code. Try disconnecting the battery overnight to start from a clean slate.

 

I will try it. It almost feels as if it is starving of fuel. The low end is decent, but the higher revs seem to lag power. I had a car do this once and it was the fuel filter. The rpm's would get up there, it just felt like I was towing a boat.

 

Oh, I had also pulled the spark plugs and they looked lean.

 

maybe your injectors are clogged? it could be your computer hasn't adjusted yet....

 

The G37 and the G35 engines are not comparable. Why would you think that? It is pretty much a brand new bigger engine.

Our cars stock are not fast, you're probably just used to the power already. If you're really worried, go get it dynoed. If you make less than ~220whp then you should be worried. If you don't, then your car is normal.

 

Comparing dyno's for the G35 and G37, the G37 really doesn't have that much more torque except above 6k rpm. This is why it has more horsepower. So yes they should be somewhat comparable. I find it very hard to believe that a G37 rated with a little over 30 more horsepower and roughly the same amount of torque is supposed to be night and day compared to the G35. Like I stated before, I know the potential is there, but there is something that is hindering the performance.

 

Yea dude, our cars are heavy boats. Not the quickest but decent.

 

our cars are pretty heavy... Fat bitches with huge ***

 

Most all dynos I've seen of a VQ37 are about 280whp from what I remember. The VQ35 dynos in the 220-240 range. Big difference.

 

After owning both, I wouldn't say "night and day" difference. But maybe "Afternoon and Evening" differences.

The Sedan "feels" much faster however- especially with the 7AT and the lower gears...

Check your intakes. You might be sucking in some hot air.

 

The 7at probably has something to do with it. I am also coming from owning two turbo porsche's with powerbands much different. The thing that really gets me is the time I picked it up from the dealership and it having some serious *****. Now they seemed to have shrunk a bit.

 

You might be feeling a slower response from the throttle if you have an exhaust leak, like I think I do.

 

Have you done any mods to your car? Have you tuned at all? That will help get a little more "in your pants" happiness.

 

Ok I have think I have found the problem. Dirty fuel injectors. I was at the auto parts store and saw the seafoam on the shelf and decided to give it a try. After about a 1/4 tank the engine is significantly stronger, more responsive and runs smoother. This begs the question: Why didn't they use fuel filters on these cars? I don't know of any other car that does not use fuel filters. To think that it could have clogged injectors after only 25k miles. Sure contaminated gas could do it, but that is what filters are for.