newr

should have quit while you were on top... j/k

Rasengan

that's probably because you get used to PWR...i tried that once, i switched back to normal during the work week and on the weekend i put it back to PWR and holy crap the difference! then i started getting used to PWR again...i wish there was a PWR PWR button somewhere

IStreefidy

Maybe try octane booster?

Koz

Weather conditions (atmospheric pressure, humidity, temp.) have a major affect on times. It is amazing how big of a difference one day to another makes. Sometimes without that much of difference in conditions. There are days where you are not going to get good times for no apparent reason. If after a couple visits, you come up with the same lower results you need to look back at what may have changed. I do not think the mileage had anything to do with the times.

Koz

al503

I'm with gern on this one also. It probably took at least 4-5K miles on the odo before my rears started breaking loose while in first gear. It never did that before.

With that said, after the initial break-in when the engine does get a little stronger, you will start to lose power as the engine wears. This shouldn't really happen until you get up there in miles (20-40K depending on the engine and maintenance.) The only engine that doesn't follow this is the Wankel powered Mazdas, which continue to get stronger as you rack up the miles.

Gernby

iTrader: (1)

Have you checked your air box for debris that might be sucking up to the air filter? I found a bunch of leaves in my air box a couple months ago...

HKS350

iTrader: (4)

I`d try reseting your computer/not just at the battery.Reset at the harness on the computer.This way you won`t loose your radio settings etc...Sounds like the comp.has learned around you mods.

HKS350

iTrader: (4)

BTW-changing you octane above 93 will do nothing for ya.Don`t waste the money.

ALLCHILL

you may also need to re-tune the air/fuel ratio because of your intake and exhaust. im guessing you're running lean...

lobuxracer

iTrader: (2)

Not a chance. It's running exactly where Toyota expects it to run. No way is it running lean. That's what the WB O2 sensor in the header does - set the A/F ratio to the expected values.

Resetting the ECM will only change the A/F to the initial factory settings for a very short while.

The learning mode for the transmission will not affect WOT runs, only part throttle shift points based on your driving habits. Besides, the transmission shift points will only affect ET, not trap speed. Trap speed is your best indicator for horsepower. You can change gearing all you want and change your ET, but your trap speed will be pretty constant regardless of your gearing. Low traps mean low power. High traps mean high power. It's the easiest way to compare two "identical" stock cars. The one with the higher trap speed has the better engine. Period, end of story, no real driver skill required.

mort

I think Rasengan’s comments could be worth considering, because after driving in a less aggressive manner during the last few months, due to snow tires and winter road conditions, my IS350 was feeling a bit sluggish. Just during the last week, with my summer rubber on and resuming my regular driving habits, she is performing back to normal.

wushuboy

Hey Gernby, can you give me specifics on how you broke in your car?

caymandive

iTrader: (2)

Maybe it's the weather over the whole country right now. Huge Low pressure systems. I'm going back to the track tonight with the new Tanabe exhaust and I'll let you know if it's still running consistent or not. Barometric pressure right now sucks at 29.80 and dropping. Have you guys seen this Altitude Density calculator? http://users.erols.com/srweiss/calcda.htm You may want to start using it and plugging in weather conditions and compare which nights are better for the car. Combfilter, most likely you just had some weather variable against you.

lobuxracer

iTrader: (2)

That's even more depressing. The density altitude the night I went to the track was -712 ft. Getting less than 82 mph in the 1/8 at this density altitude means my engine is weak. Really weak. I may have to remedy that soon.

If you want to find a very local weather station with historical statistics, click here. They have everything you need to calculate altitude density for literally thousands of locations across the country, not just the airports, but even the neighborhood stations.

Gernby

iTrader: (1)

I just drove it. I wasn't particularly easy OR hard on it during the first 500 miles, but I've definitely been hard on it since. I'm at 15K now.