350 Magnum EFI (TBI) Performance Improvements
 

"lifespeed" wrote in message
m...
I've been 82 mph in a blown Malibu, and it was quite stable...in fact,
it
felt very secure.

A nose-down attitude has more implications than just drag. Dynamic
balance and re-entering the water after hitting some chop come to
mind.


along with bow steer which is not good at idle speed, and is VERY bad at
high speed. I'd like to see video of a Malibu doing 82 mph. That speed
and that hull/design/evrything do not compute.

350 Magnum EFI (TBI) Performance Improvements
 

"no one" wrote in message
...
Geoff, show me the evidence O2 sensors are primarily for cat performance.
If you've ever seen a fi system go into a bad full rich open loop state,
you'll see the cat is REAL efficient. Like white hot efficient.

Not a conventional three-way catalyst. Once it goes rich and all the stored
oxygen is gone it loads up with carbon really fast and it cools off. In
fact, excess fuel is used to for catalyst protection when it gets too hot.
I didn't read the posted link but hopefully it included little story on the
oxygen-bucket theory. Sometime in the near future (post-Super Bowl) I'll
find the catalyst efficiency vs. lambda charts online and post a link - TWC
efficiency diverges quickly from stoichiometry.

350 Magnum EFI (TBI) Performance Improvements
 

"Tom Ruta" wrote in message
...
On Fri, 30 Jan 2004 08:02:41 -0500, "NetSock"
wrote:

...
I don't think what you call "semi-displacement" hulls are any more
dangerous
than other hulls at a given speed.


Compared to what? A supercharged jon boat? Put me in a V at 60+
please.

Compared to other vees.

I've been 82 mph in a blown Malibu, and it was quite stable...in fact, it
felt very secure.


I'd love to see GPS proof of that.

It was in fact on a GPSR.

Most passes were about 74-78 mph (2 average men aboard), but as fuel
lightened the load, we had one good pass with the wind on glass, of 82.

This is exactly what high-performance boaters try to minimize...wetted
surface. Maybe that's why my buddies Malibu seemed so "solid"...it had a
good plant in the water, however, that engine would easily break 100 in a
"trimable" hull.


He should have added a set of Bennett tabs.

I cant see how tabs can help a fixed-prop inboard. And I'm 90% sure the
Malibu Corvette had a "ride plate"...not adjustable tabs.


--

It's just about going fast...that's all...

http://home.insight.rr.com/cgreen/

350 Magnum EFI (TBI) Performance Improvements
 

On Mon, 2 Feb 2004 08:13:16 -0500, "NetSock"
wrote:
....
It was in fact on a GPSR.

OK.

Most passes were about 74-78 mph (2 average men aboard), but as fuel
lightened the load, we had one good pass with the wind on glass, of 82.


Ah... downhill with the current... got it. 74 is a darn sight away
from 82. And it is interesting that less gas would give a higher
speed since the loss of weight in the rear would drive the nose down.

....
I cant see how tabs can help a fixed-prop inboard. And I'm 90% sure the
Malibu Corvette had a "ride plate"...not adjustable tabs.


Trim tab, "ride plate", Hydrogate, (you work for Tige or Correct Craft
or something? That is marketing speak!), whatever - a moveable plate
at the stern that alters the wetted surface.

350 Magnum EFI (TBI) Performance Improvements
 

"Tom Ruta" wrote in message
...

Ah... downhill with the current... got it. 74 is a darn sight away
from 82.

It was a very large reservoir...no current. And there are many more
variables such as, weight, temperature, chop, wind, humidity, barometer,
etc.

It is not uncommon to have a "spread" of 10% on top end with a blown V8,
throughout the day because of these variables.

And it is interesting that less gas would give a higher
speed since the loss of weight in the rear would drive the nose down.

Apparently not. :)

Trim tab, "ride plate", Hydrogate, (you work for Tige or Correct Craft
or something? That is marketing speak!), whatever - a moveable plate
at the stern that alters the wetted surface.

Tom, the Malibu Corvette does not have a "moveable plate at the stern that
alters the wetted surface".

The ride "plate", is fixed, and does not extend pass the rear of the
transom. The purpose is most likely for strength.

Again, I see no reason (performance gain) for adding adjustable trim tabs to
a fixed prop inboard, other than to compensate for uneven (right to left)
loading.

--

It's just about going fast...that's all...

http://home.insight.rr.com/cgreen/

350 Magnum EFI (TBI) Performance Improvements
 

"Geoff" wrote in message
gy.com...

"no one" wrote in message
...
Not a conventional three-way catalyst. Once it goes rich and all the
stored
oxygen is gone it loads up with carbon really fast and it cools off. In
fact, excess fuel is used to for catalyst protection when it gets too hot.
I didn't read the posted link but hopefully it included little story on
the
oxygen-bucket theory. Sometime in the near future (post-Super Bowl) I'll
find the catalyst efficiency vs. lambda charts online and post a link -
TWC
efficiency diverges quickly from stoichiometry.


I found what I was looking for if anyone is still interested -
http://www.autoshop101.com/forms/h64.pdf, the top of page 4 shows the plots
of HC, CO, and NOx efficiencies versus air-fuel ratio.

350 Magnum EFI (TBI) Performance Improvements
 

"Geoff" wrote in message igy.com...
snip

I found what I was looking for if anyone is still interested -
http://www.autoshop101.com/forms/h64.pdf, the top of page 4 shows the plots
of HC, CO, and NOx efficiencies versus air-fuel ratio.

That is the same document I posted above. Thanks for the more direct
link. Here then is the direct link to the Toyota document for oxygen
sensors.

http://www.autoshop101.com/forms/h37.pdf

The first line is:

"The ECM uses an oxygen sensor to ensure the air/ratio is correct for
the catalytic converter."

I hope the "evidence" is good enough.

350 Magnum EFI (TBI) Performance Improvements
 

"Doug Meredith" wrote in message ...

along with bow steer which is not good at idle speed, and is VERY bad at
high speed. I'd like to see video of a Malibu doing 82 mph. That speed
and that hull/design/evrything do not compute.

Absolutely. I had some mild bow steer at high speeds on my old
Schiada when I let off the throttle too quick (long story, since
fixed) at 85 - 90 mph. It was *not* a good feeling.

Lifespeed

350 Magnum EFI (TBI) Performance Improvements
 

"NetSock" wrote in message ...
Tom, the Malibu Corvette does not have a "moveable plate at the stern that
alters the wetted surface".

The ride "plate", is fixed, and does not extend pass the rear of the
transom. The purpose is most likely for strength.

The purpose is to avoid issues of blasting the gelcoat off the bottom
with propwash. Any powerful V-drive has the keel after the prop
plated with stainless for this reason.

Lifespeed