Terrible mpg's = new interest in old ideas.

[Tygen1]

To the issue of the trunk spoiler, do a before and after with your scan gauge and let us know I don't have one. Although, on TeamZX2, David Gettle claims he gained mpg with his massive Ricer wing

To the issue of the ZX2 knock sensor. Before TeamZX2 crashed, there was a dyno and datalog showing how the knock sensor was always pulling timing, anywhere from 3-6* all the way from bottom to top rpm. The before dyno has all sorts of dips in the curve, the after was smooth and 6 hp more from 3K up to redline. Before I pulled mine, I always had this surging over 30mph. I just thought it was normal. Drove more than 100,000 miles that way. After I pulled it the surge went away and it ran sooooooo much better. I haven't had any ignition timing related pinging, have had some vacuum leaks that I thought were knock sensor pulling related. The knock sensor on the ZX2 is useless. The ZX2 is timing starved, thus the addition of a 5.6K ohm sensor on the IAT makes such a big difference in mpg's for most folks. I saw around 2mpg better from that.
Oh yea, I tried high test and it still pulled timing.
Yes, excessive hot air could cause troubles.

[Christ]

Originally Posted by Tygen1

Oh yea, I tried high test and it still pulled timing.
Yes, excessive hot air could cause troubles.

That's exactly what I meant, about hi-test gas... If it still pulls the timing while you're running hi-test, it's not doing what it was intended to do. It's not, simply because of the inherent vibration of the engine block itself.

The best use I've seen for a knock sensor is to monitor it, rather than allow it to interfere directly with engine operation parameters. Monitoring it can yield better results in that you'll notice over time what readings are garbage and what readings are authentic knock, and if you have the skill to understand that, you'll have the skill to fix whatever is causing your issues.

[mhmitszach]

This weather is making it way to hard to get solid evidence of a positive or negative gain.

It was only 5f today and I was in heavy traffic so I only averaged about 30 mpg today. But last ~30 mile trip averaged around 35 mpg which is what I've been getting.

Throttle position was reading higher today at 55 until last 30 mile trip. I think I need to re do under tray so its flat instead of sloping downward toward ground. Its so hard to say though.

Also, Sideview mirror broke and is hanging by wires. -___-

I'm just tempted to do all the "mods" at once and see what happens.

16 inch pizza pans from wal mart, only 3 dollars, are the perfect size btw.

[Christ]

Originally Posted by mhmitszach

I think I need to re do under tray so its flat instead of sloping downward toward ground. Its so hard to say though.

I'm going to chance a guess and say the added frontal area caused by the angle is defeating any aero gain you'd have.

I'm also going to say definitively that having it flat with as few aero-obstructions under the car as possible will show a better result, since the flow won't have to "get out of the way" of the things that deflect airflow.

[Tygen1]

Originally Posted by Christ

The best use I've seen for a knock sensor is to monitor it, rather than allow it to interfere directly with engine operation parameters. Monitoring it can yield better results in that you'll notice over time what readings are garbage and what readings are authentic knock, and if you have the skill to understand that, you'll have the skill to fix whatever is causing your issues.

So why aren't you in some sort of engineering career?

I wouldn't take a guess at the neutral results. You really have to do a before and after in the same conditions to draw any real conclusions.
My mpg's have taken quite a hit this tank. The temps were in the 40's last week, it's in the teens this week and I'm off 40miles by a half tank. So right back to where I started and just the temps have dropped. No other changes.
I must visit Walmart when I get from vacation....

[Christ]

Originally Posted by Tygen1

So why aren't you in some sort of engineering career?

I wouldn't take a guess at the neutral results. You really have to do a before and after in the same conditions to draw any real conclusions.
My mpg's have taken quite a hit this tank. The temps were in the 40's last week, it's in the teens this week and I'm off 40miles by a half tank. So right back to where I started and just the temps have dropped. No other changes.
I must visit Walmart when I get from vacation....

Several bad choices, coupled with severe impatience on my part.

Check your PM's.

[Tygen1]

Ok, got the manual shifting box all done, just need to hook it up. Problem is tomarrow is my last day at home before flying out for vacation. So I'm hoping to leave work early enough to get it all hooked up and tested. I also fill up tomarrow night, so we'll see just how good or bad this tank was.

[mhmitszach]

I'm going to try re doing this undertray soon. I've got a bit of coroplast but not enough for one continuous piece from bumper to radiator. It'd only cover the middle section.

I should note that the last tank was recorded as dad took the car a bit and filled it up for me. Probably about 32 at best. This one is going to be another 30.

Bad news. Transmission is still shifting terribly even with correct amount of fluid. Hopefully I can get a new filter and fluid soon.

Can't wait to hear how it works out!

[Tygen1]

Ok, I left work way early to install this It does work, but there are some catches. First the pros: I can shift into 4th gear at 20mph vs. 30mph normally. Now the cons: The PCM seems to not know what gear it's in, so if you switch it off it goes into second/third and stays there. Once you turn car off it resets and it's fine. So once you start shifting with the box, you gotta keep shifting. Because the PCM doesn't know what gear it's in, it won't engage the torque converter lock up. Also it doesn't cut spark and fuel between gears so the shifts are quite abrupt.
It does work quite well though, I can easily shift at 1500 rpm vs. it automaticallly shifting above 2000 rpm. Once I get the pulse width modulator I'll be able to complete this so it can lock up the torque converter.
On a side note, by being able rev it up higher, it is 0.1 seconds quicker 0-60mph

[Tygen1]

Oh yea, got 34.91 mpg on the last tank, not as bad as I thought
Also crossed 239,000 miles...