I finally got around to recording the exhaust note of the car at
idle. You can hear it by looking in my Audi gallery. I hope to make a recording of the engine under load
soon. I have parts on order to turn up the boost, but still have a
few items I want to clear up before I do that. I had tried to cut
a corner when building the engine and did not put in new lifters.
Now I think I need to as they make a serious racket with the hood up.
Something quite unexpected happened a few days ago. While driving
to work in 40°F weather I needed to cross a road briskly. I
launched the car hard for the first time. Even on rainy days this
car has never spun tires before. It sure did this time. I am
sure that it was due to the cold weather giving more engine power and
making the tires slicker, but it was gratifying. Strangly I don't
think the front tires spun, but it felt like both rear tires spun from
the way the car behaved.
I have been driving the car for a few weeks now. Aside from a
small hot start problem it has been running extremely well. My
odometer has even decided to start working again so I can calculate some fuel economy values.
I used to get between 21 and 24 MPG with my normal driving with as good
as 27 MPG on the highway. So far with three tanks of gas I have
averaged 19.8 MPG. I would imagine that some of this is due to my
slightly heavier foot now, but mostly that this motor uses more fuel.
My commute is rather short and
through habitated areas so I don't get full boost very
often. The motor makes 6 psi of boost when it is warm outside,
but for some reason makes 7.5 psi when it is below 60°F
outside. I still have not changed anything from the factory as far
as boost settings. I want to let the motor break in a little bit
first. I have noticed that the oil temperature comes up quicker
on this motor, but stays at about 105C with normal driving.
The clutch is very different feeling. For some reason the pedal
effort is lower (which I don't like). It has taken some getting used
to. It is a little tricky to drive smooth in a parking lot as it
tries to grab. I guess that is due to the higher coefficient of
friction and the segmented design.
The part throttle torque is no comparison. The car will happily climb
almost anything in 5th gear at 2000 rpm (about 45 mph) with the throttle
barely cracked open. My old motor was VERY strong for a JT and I
do miss the off the line launch it had, but it got weasy by 4000
rpm. Once on boost the new motor is far stronger everywhere.
I hope to have some firm numbers to post soon for 0-60, etc. I
have noticed that the motor is very strong at part throttle, but does
not feel much stronger at full throttle. This may be the full
throttle enrichment switch or it may be as simple as throttle cable
adjustment. I have not really started trouble-shooting it yet. I
think most of it has to do with having a single throttle plate when I am
used to a progressive two plate unit.
I plan to up the boost using pneumatic controls only. Once I get
to that, maybe later this month, I will post that on this site along
with my results. At some point along the way I will likely go to
electronic fuel injection, but that is likely farther off as I have
other projects (non-car related) I have to work on first. I am also
considering making an exhaust manifold at some point.