Geoffrey

Loren, lets get facts straight here:

1) MoTeC DOES have compensation tables which allow the ECU to compensate for a variety of variables, including fuel pressure, fuel temperature, oil temp, cylinder head temp, water temp, air temp, exhaust pressure, manifold pressure, barometric pressure, EGT, etc. (those are just the ones I can think of in 10 seconds)

2) MoTeC DOES have knock control available, I've received factory training on it, have the special tools to program it, have used it, and it works. It is expensive.

3) In the 20 years I've been doing MoTeC, I have had exactly 1 engine damaged from detonation and it was a supercharged 911 engine where the programmer (me) made a mistake in the timing values. The MAXIMUM timing the engine would tolerate under 4psi of boost was 6 degrees advance. I started with what I thought was conservative at 10 degrees. Any engine that can tolerate only 6 degrees of timing is a design failure in my opinion. The failure was on a dyno during a test experiment.

4) I think you need to go back and understand how timing actually works before suggesting that knock sensors are the only way to allow for maximum torque under all loads. I always program the ignition timing so there is maximum torque under all load conditions irregardless of whether or not here is knock control. A knock sensor is a protective device, not a performance device. The Judd v10 engines running the LEMANS series in europe do not use knock control because they feel it detracts from the performance. I feel I'm in good company with my approach to tuning.

Full disclosure on Mark's car. I did not tune or program his car, I sold him a parts kit. I provided a base map I created for another project for Mark to start and initially run the car. Both of the cars ran 91 octane fuel, not 93 fuel.

Lorenfb

"In your opinion what is the best route to go then if you were looking to top 300 bhp?"

Mods to the engine itself are required. The Motronic ECM is not the limiting factor.
The Motronic ECM can maximize performance basically of all engine mods, e.g bigger
bore, different cams, etc., obviously with exception of a turbo/supercharger which
require mods to the electronics.

"I think you need to go back and understand how timing actually works before suggesting that knock sensors are the only way to allow for maximum torque under all loads. I always program the ignition timing so there is maximum torque under all load conditions irregardless of whether or not here is knock control. A knock sensor is a protective device, not a performance device."

Really? Maybe others need to understand knock control:

1. Maximum torque basically occurs at maximum ignition advance prior to
detonation.
2. All conditions for detonation don't always occur simultaneously, e.g.
maximum loads for detonation may occur at two different temperatures.
3. Various conditions for detonation require varying ignition retarding
from the absolute maximum advance, e.g. very light load, cold temp,
and best fuel octane.

Thus, if one attempts to program an ECM for all the worst case conditions
at once, as described above, one can never achieve maximum ignition
advance as when maximizing the advance curve until detonation occurs
and retarding as required, which is what knock control achieves. Based
on this, knock control is both a protective system element and a performance
maximizing element.

Now with knock control an engine management systems operates in closed-loop
from an ignition control standpoint just as the earlier AFR optimization was achieved
with closed-loop operation via the O2 sensor. Both key variables, ignition & fuel,
are optimized for the ideal combustion chamber conditions to achieve maximum torque.

Oracle

I don't think that is applicable to road cars where you get from decent to crap fuel throughout the year in all weather. For racing like anything else, if not needed don't put it.

J richard

...uhhh....

hey Geoffery, hows the flying comming? Don't mean to jack this thread but its pretty much left the building at this point....

Geoffrey

Agreed!!! Great, I'm working on my instrument rating now and have been using the plane quite a bit. I've flown 150hrs since Sept last year and am really enjoying it. Earlier in the year I was doing my instrument work at night which was great, and have been flying in IMC when possible. When they say a VFR pilot lasts 3 minutes after flying in IMC, they aren't kidding. When you drive a race car, you want to "feel" everything in order to drive it on the edge. In the plane, it is amazing how your body lies to you. I have a tendency to turn right and decend if I don't pay attention. Straight and level my body is telling me we are climbing and turning left. Too bad there isn't an "off" switch.

dfinnegan

Geoffrey, do you suppose that's from so many hours turning right and braking?

J richard

Yup, that's one of the weirdest feelings you can have. You just really want to fight everything the instruments are telling you cause it doesn't feel right. That decending right turn is also known as "the death spiral" taken from the old WWI fighter pilots auggering in, I always wondered if it goes to the left south of the equator...it's what did JFKjr in. I learned on steam guage panels, talk about learning to trust your instruments, or your ability read them, thank god for GPS moving maps TCAS and map of the earth...

Sounds like your having fun, jump into a pitts or decathelon and get some unusual attitude or acro, it really helped me on the inner ear thing. It's an addiction!

Jim

Geoffrey

Yep, my plane has steam gauges, but will probably move up to a G36 Bonanza at some point. A master CFI at my field has a Decathelon and does acrobatics and unusual attitude training. Its on my list for the summer.

I wonder if the right decending tendency has to do with one of more of the four left turning tendancies of the aircraft.

J richard

The 36 is a great platform, perfect for ifr work and nice to fly. You would think Pfactor has something to do with the tendancy but it gets us counterrotating twin drivers too...

careful with the acro it's actually more fun than racing...shhh, don't let the secret out!...

Premier Motorsp

Nahh, it is because the ignition timing is under advanced. Put a Motronic on it, all the problems will disappear!

Steve Weiner-Rennsport Systems

Thats really funny stuff,...

(FWIW,..Porsche did use Motronic on the long-gone PFM-3200's)

Geoffrey

Yea, they really screwed those Mooney guys...

sonny1

FWIW, The injection system on the 3200 is CIS, not Motronic.,cheers.

Steve Weiner-Rennsport Systems

Yep,..I stand corrected.

I just looked at my PFM pics and catalog sheets and it sure is CIS. One can spot the FD and CIS injectors in the heads.

Good catch!!