NoDelta

I recently replaced O2 sensors (both) and felt like my acceleration improved afterwords.

B serious

That is a placebo effect. The O2 sensors are ignored more and more as you tip into the throttle. They don't affect acceleration.

The O2 sensors affect fuel mixture and efficiency when the car is warmed up and is at very light throttle or idle, closed loop conditions.

Save the Manual Wagons!

Yes, you will have a redline 3-4 shift during the test. Doing the entire run in 4th will give an incorrect time. Also, this is for the AP2.

If you have an AP1 and more room to run, 60-120 MPH should take 18.2 seconds. https://www.caranddriver.com/reviews...parison-tests/

Chuck S

At the risk of pushing this thread even more off topic...

Starting at 60 mph is right about 6000rpm on the AP2 gearbox so the engine should be on the high power (VTEC) cam from that point providing maximum power. 6000rpm (VTEC threshold at WOT) in 4th gear is right about 75mph so the AP2 engine should remain on the high power cam with a shift at 80mph if the speed is maintained.

Looks like two trips to the rev limiter-shift which is gonna be hard for me to work a stop watch at the same time. I'm thinking hitting the rev limiter is gonna cost some time when it cuts off the engine. I'll bet the original test was rehearsed several times to get the feel of the car.

I'm interested in also trying this in 4th gear with my 3600rpm VTEC and no shift so it's well within the high power output at 60mph even in 4th.

-- Chuck

Save the Manual Wagons!

I don't think it's off topic. It's fundamental to the question the OP is asking. Is his car actually slower than it's supposed to be, and if so, how much?

Yes, definitely avoid hitting the rev limiter. Acceleration testing is indeed a skill, but the hardest part is the launch which is why I suggested the 60-100 test. A botched launch with a peaky engine like the F could add two seconds to a ~5.5 second 0-60 time, making the test essentially useless. Plus, I'm assuming most people don't want to subject their cars to redline clutch dump launches...

dtsol

I checked, no potato. And our two feral cats keep the rodents away.

Air filter is a possibility, though. Wouldn’t it be nice if it were something simple like that! I’ll report back when I get a chance to check it out.

Chuck S

To eliminate intake blockage it won't hurt to run without the air cleaner for a bit or without the whole air cleaner assembly.

The DBW cars have a throttle cable from the pedal just like the earlier cars although it's much shorter. Any chance that got disconnected and not reconnected properly preventing full throttle?

Bad or stale fuel remains a suspect. Those of us who store our lawn equipment over the winter sometimes have trouble starting it in the spring due to fuel issues. Since the car is driveable just less "punchy" drive until the yellow "20 minute fuel warning" light illuminates and fill with the best gas you know of. Large gas station frequented by performance cars should have cleaner, fresher gas than one in some tiny town where they mostly sell regular.

I would think the DBW cars can display throttle position or percentage with the proper reader as this data has to be on the buss for the car to use it. Enough (real) experts here will confirm this.

-- Chuck

Save the Manual Wagons!

I have to recommend against this. Idling in the garage, sure. Driving at full throttle is too risky IMO. Car and Driver had an article a long time ago (I can't find it online) where tuners were in a contest. A few of them removed air filters in the search of a couple more HP. At least one sucked a pebble into the engine, game over.

The intake is very simple to check for blockage. There is no reason to drive without it, and a filter, attached.

Chuck S

Sucked in a pebble? Half the high school guys run their Mom's car without the air cleaner for that Fast-n-Furious sound and they're not sucking in rocks. Besides this only takes a few minutes, not the East African Safari on unimproved roads.

-- Chuck

dtsol

Replacing the air filter seems to have helped a bit. I'm also going to check the throttle cable. Appreciate everyone's input!