My buddy and I put on the stillen hi flow intake kit last night on my 07 g35s at. i dynoed it and i lost power! someone tell me why? i talked to scott my salses rep at stillen he told me that there was a 1000 mile learning time for the ecu on our cars? i have the stillen exhaust on too. i had my car dynoed with just the exhaust a couple weeks ago and i was running high 250's at the wheel. when i took it in today with the intake on i was running low 250's almost 240's. should i sell it? or wait it out?

 

You could reset your ECU and then it would re-learn evrything from it's new, static state basically the moment you start the car.

Were the conditions at the Dyno the EXACT same as they were 2 weeks ago? Temperature, humidity, pressure, etc? That makes a difference.

 

yeah they were all pretty close i just dont see how there could be a loss. should i take it to the dealer to have the ecu reset?

 

could you post a video/sounds clip

 

Temperature difference of the days?

 

When you installed the intake did you remove the negative side of the battery
like they suggest? I wish every time I installed a mod to my G I had the ability
to throw it on the dyno, I only have the one I'm sitting on!

 

Definitely reset the ECU and test it again.

 

Won't resetting the ecu right before the dyno artifically inflate the dyno readings?

 

some aftermarket parts actually cause power loss. with the e46 m3, if you add on an exhaust system then it actually causes power loss through a certain rpm range. it's crazy because exhaust systems for an m3 costs up to 3000 dollars and causes power loss. this actually isn't unusual and it may not be the conditions.

but to play devil's advocate you have to remember the engineers at nissan designed the exhaust system of the car with hours of thermodynamics research to give the most efficient flow for the exhaust.

 

Actually they have many more varibles to consider than peak peformance but the G exhaust is a fairly well designed system. There's a few ponies to be had but not much.

 

thanks ill take it in to the dealership and have the ecu reset. i didnt do the battery thing before installation but i did do it rite befor the dyno

 

or just drive for 1000 miles and it'll adjust(learn) itself

 

I installed the fujita intakes a while back. I currently have just under 12k miles. I dynoed my car about 3 weeks ago and managed 254, whith a high of 257. There was also another '07 G35S, with only 1500 miles. He managed in the low 240s I believe. They guy running the shop told him to wait to roughly 2500+ miles, then try it. The same thing happened to a new 350z with dual fujita intakes and less than 2500 miles. When dynoed, it seemed to lose a little power. He's going to test it when he's over 2500 miles. Seems to make a difference with allowing to ECU to 'learn' the new pattern or something like that. I'd just keep it.

 

I used to think it was necessary to reset the ECU, but a wise mechanic on another board told me it's completely unnecessary because with minimal mods such as exhaust and intake, you're adding marginal amts of air to the engine. In fact, the difference in air density btw a car w/ an aftermarket intake vs. stock would probably be less than the difference between driving your car during the warm daytime vs. driving it in the cold night air. We know that none of us ever reset our ECUs when we're driving in different temperature conditions and the car runs fine all the time.

But if you still really want to reset the ECU, just disconnect the negative terminal as mentioned by garyc.

 

It doesn't surprise me for a few reasons.

1. The stock intake looks like it flows pretty well.

2. Quite a few newer cars lose power when you mess with anything in the intake.

3. There is a learning curve for an ECU to adjust fuel trims and fuel cells. BUT, if these computers calculate fueling tables the same way my last car did.... at WOT, it shouldn't matter much. Fueling at WOT was doen by using a PE multiplier against stoich at different rpms. The fuel trims were all for part throttle and zero out when you go into power enrichment (PE) mode.

05 Mustang GT is an example. The way the car measures airflow and calculates a/f ratios..... if you change anything on the intake without tuning the car, you lose power.