Feedback on the ECU Dr. aka Specialized ECU Repair?
#31
Rennlist Member
A foreign motorcycle magazine that I subscribed to for many years used to do evaluations of aftermarket exhaust systems. They provided the baseline "stock" power and torque curves and laid all other "claims" over them. They did that every few months using different vehicles. The bottom line...save your money...the manufacturers already did 99.9% of the work for you.
#32
"The reverse is not true just because you put higher octane fuel in doesn't mean the ecu will increase the timing till it senses knock and then retard again."
Actually under certain race conditions, i.e. high ambient temp, heavy engine
loads - hard accel from turn, marginal fuel octane, etc., the engine could be
operating in a retarded mode (3 - 9 degrees) the result of knock control.
Now if race gas is used (as stated by the poster), the knock control system
would most likely reduce the retard and thereby increase the torque
(HP - performance).
As has been shown here https://rennlist.com/forums/911-foru...-the-myth.html
for every one degree change in timing an approximate 4 HP change results.
So the change from a non-race octane to a race octane could easily account
for the performance change stated by the poster. That's how sensitive
(responsive) torque is to changes in the timing and why 'tuning' is nothing
more than doing timing tweaks for a stock engine.
Actually under certain race conditions, i.e. high ambient temp, heavy engine
loads - hard accel from turn, marginal fuel octane, etc., the engine could be
operating in a retarded mode (3 - 9 degrees) the result of knock control.
Now if race gas is used (as stated by the poster), the knock control system
would most likely reduce the retard and thereby increase the torque
(HP - performance).
As has been shown here https://rennlist.com/forums/911-foru...-the-myth.html
for every one degree change in timing an approximate 4 HP change results.
So the change from a non-race octane to a race octane could easily account
for the performance change stated by the poster. That's how sensitive
(responsive) torque is to changes in the timing and why 'tuning' is nothing
more than doing timing tweaks for a stock engine.
Last edited by Lorenfb; 12-30-2012 at 01:49 PM.
#33
RL Technical Advisor
#34
Race Car
You missed the last bit of my original quote, i said...
It will never go above the pre-programmed max ignition timing, , however high octane fule will allow the engine to operate at its max timing for a given condition (load, temp etc)
You are correct, Tuning is pushing timing to gain maximum performance. Its what every tuner on the planet does, including OEM like Porsche, Ferrari, etc. Manufacturers leave a little on the table to counter the potential of poor fuel in a given country. The delta is getting less and less, however if someone was looking to get the max out of their car stock or otherwise, they could pick a specific fuel, stick to it and tune for it. Would be pretty inconvenient for a daily driver but for a track or race car would be pretty easy.
Originally Posted by trophy
The reverse is not true just because you put higher octane fuel in doesn't mean the ecu will increase the timing till it senses knock and then retard again. It will allow the ecu to operate at its max per programmed ignition timing.
"The reverse is not true just because you put higher octane fuel in doesn't mean the ecu will increase the timing till it senses knock and then retard again."
Actually under certain race conditions, i.e. high ambient temp, heavy engine
loads - hard accel from turn, marginal fuel octane, etc., the engine could be
operating in a retarded mode (3 - 9 degrees) the result of knock control.
Now if race gas is used (as stated by the poster), the knock control system
would most likely reduce the retard and thereby increase the torque
(HP - performance).
As has been shown here https://rennlist.com/forums/911-foru...-the-myth.html
for every one degree change in timing an approximate 4 HP change results.
So the change from a non-race octane to a race octane could easily account
for the performance change stated by the poster. That's how sensitive
(responsive) torque is to changes in the timing and why 'tuning' is nothing
more than doing timing tweaks for a stock engine.
Actually under certain race conditions, i.e. high ambient temp, heavy engine
loads - hard accel from turn, marginal fuel octane, etc., the engine could be
operating in a retarded mode (3 - 9 degrees) the result of knock control.
Now if race gas is used (as stated by the poster), the knock control system
would most likely reduce the retard and thereby increase the torque
(HP - performance).
As has been shown here https://rennlist.com/forums/911-foru...-the-myth.html
for every one degree change in timing an approximate 4 HP change results.
So the change from a non-race octane to a race octane could easily account
for the performance change stated by the poster. That's how sensitive
(responsive) torque is to changes in the timing and why 'tuning' is nothing
more than doing timing tweaks for a stock engine.
#37
1995 993 CCU
I had Specialized CCU exchange my broken CCU. The exchange happen very quickly, I just reinstalled the unit back into the car it works perfectly. Specialized CCU did a great job I highly recommend them. If you have any questions pm me.
Mike Walker
Mike Walker
#38
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
"ECU re-flash amounts to 8 whp and 15 ft/lbs of torque on a 97-98 computer (running 98 octane gas)."
So! And most likely above 5K RPMs.
And now the engine requires a higher octane, great right?
As indicated by the data from here;
https://rennlist.com/forums/911-foru...-the-myth.html
a simple timing 'push' appears to the naive as a significant 'tuning' effort. What a joke.
So! And most likely above 5K RPMs.
And now the engine requires a higher octane, great right?
As indicated by the data from here;
https://rennlist.com/forums/911-foru...-the-myth.html
a simple timing 'push' appears to the naive as a significant 'tuning' effort. What a joke.
__________________
Loren
Systems Consulting - Automotive Electronics
Specializing in Porsche cars
http://www.systemsc.com/
Loren
Systems Consulting - Automotive Electronics
Specializing in Porsche cars
http://www.systemsc.com/