I have catback exhaust, kinetix plenum and jwt intake. I had the car dynoed today and my AFR was 16.5. The guy said the normal rate is 13-13.5 and even lower at high end. at about 1500 rpm all the way to 5500 rpm the car is running 16.5.

My question is: Is there place that can tune the car with stock ECU so i won't have the problem? I asked Church Automotive, they said they dont have the software for the stock ECU to tune.

 

What were they using to monitor the a/f? Was there a tailpipe sniffer or were they monitoring an wideband o2? If it was running at 16.5 consistenly and you pushed the car then I would be pretty confident in saying you would already have damage on your hands.

 

tailpipe sniffer, I have the printed paper with the exact graph. I will post as soon as a get a chance.

 

You're going to need to get some sort of ECU piggyback. In the meantime, yank that JWT intake off. The car will run richer and I guarentee you the car will be faster.

 

^I think i am going to do that. Dave do u think my idle rpm is caused by the car running lean, because my car idles at 500-600rpm instead of 800-900rpm after i put the kinetix plenum on.

 

Check if your catalytic converter internals are intact. I had a similar experience to your's when I had random technology cats and I pulled a very high AFR reading on the dyno with loss of power. Turned out one of my cats had imploded...

 

Before you get too worked up, where did you have it dyno'd? Early last year I had my car dyno'd and saw crazy a/f's, some upwards of 16:1. I started wigging out, thinking about piggybacks and such. I even removed my crawford cats. I dyno'd again a few months later at a different location, and everything was fine. And I highly doubt the stock ecu is gonna let you run 16.5 all the way till 5500rpms.

I have attached a chart with three a/f's. The Blue line is from the first dyno location that just got goofy readings. Mods at the time were k&n filter, ztube, mrev+, crawford cats, and stillen exhaust. That particular day they had problems getting good reads from the sniffer. Temp: 72, Humidity: 25%.

The red line was two months later, at a different location. Much more competent. Probably the best local dynojet. Mods at the time were k&n filter, ztube, mrev+, and stillen exhaust. The only difference was I had removed the crawford cats. Notice the curve of the red line more closely resembles a typical g35 a/f curve. Temp: 72, Humidity: 33%

The green line was a dyno almost six months later, at the same location as the red line. I had added kinetix resonated test pipes and a stillen airbox. The curve is very similar to the red line, just shifted upward a bit(leaner). Below 5500 rpms, the airbox and test pipes made me run on average less than 5 tenths leaner. After 5500, I ran a bit richer. Temp: 77, Humidity: 23%

In summary, I think it's too early to flip out. Find another location and get another reading. Then you can make a decision.

 

IF his car is actually running that lean, and IF it's because of the intake, then I'd agree. But I have my doubts.

 

Where the hell you been?

Anyways, I think it's a factor of all his mods causing the lean condition. Changing out the intake is the easiest way to gain back some fuel, especially since MAF and intake are in such close proximity of one another. IMO, it worth a shot since swapping the setup takes less than 30 minutes.

I also agree that the A/F ratios are most likely not as bad as he thinks. The tail pipe sniffers have a tendency to show leaner conditions than what is truely occuring just south of cats. The readings of the sniffers can sometimes get skewed because exhaust can sometimes get slightly mixed ambient air if the sniffer isn't stuffed into the pipe. Also, these cars run lean to begin with. At part throttle, they run really lean....as do most cars.

Klubb- I don't know about the idle on 6MTs, but my 5ATs idle has always been an indicated 500-600rpms (650rpms actual according to the logger). I'd think a 600rpm indicated idle would be right and 800-900rpms seems too high if the motor is full warmed. If the car doesn't shake at idle, I wouldn't worry about it. I also don't see how the mods could influence idle unless there was a vacuum leak and if you did have a leak, you'd know it by how crappy the car would run.

 

I took a break from the whole car thing for a while. But I'm back now.

Agreed.

 

Or look at what the O2 readings are doing via an OBDII data logger?

 

It's good to have you back and I'm kind of in the same boat. I'm still heavily involved in the car thing, but my spending has been curtailed dramatically over the past two years. I guess I got sick of trying to have the quickest *insert whatever car here*. After a while it gets old, expensive, and often times the mods don't work as advertized. I've learned to enjoy what I have and buy a mod maybe once a year or so. Also, having a young child (currently 2) has greatly curbed my spending. I don't know if this is why you bowed out for a while or not though. I see your wife got a new G35. I'm jealous.

/off soap box

 

Please check your voltage to the fuel pump, and make sure your fuel filter is clean. Fuel pressure to the injectors is very important. The gas today has so much trash in it. It could be that simple.
In most cases Iv seen intakes make VQ engines go on the rich side.

 

Sorry Klubb for cluttering your thread.

I got a bit down because only partly because of the cost. The real reason I got down was because I couldn't make sense of my 1/4 times. First time ever at the strip I ran a best of 14.7@95, in huge heat. 6 months later, in temps in the mid 30's, I was running low 14's@101/101. Then I pulled some high 13's@101/102; I'm sure you remember that. And that was with a k&n and cats.

So in a period of 6 months, I dropped almost a full second in my ET's and picked up 6 to 7mph in traps; partly conditions, partly experience, partly mods. When the next summer came around, I was trapping in the 1/8th right at the same speeds I had the previous winter, so I was expecting a big jump when winter rolled around.

My one visit to the 1/4 in the summer saw traps of 101mph(~80 degrees). Then when I went later in October, in the mid 40's, I still only saw 101mph traps. I just couldn't make any sense of it. At no point had I lost power. And I had started to drive more and more poorly. That's the point that I started questioning the whole car thing.

Then, just after Christmas, I helped my buddy install a mopar stage2 kit on his srt4. That got me going again, a bit. Then I noticed oil consumption. The dealer has since given me a new long block, and I had headers put in for free. And I'm going in for a utec+tune in a couple of weeks at Sharif's.

After that, I'll be getting some 16" wheels+DR's, and I should be seeing some low 13's in cooler weather. And my performance mods will be done.