Hey guys just purchased the 5/16 copper iso spacer from motordyne and i have done a search and cant seem to find the answer. i was just wondering if after install if i have to do the idle air relearn for the ecu or not

 

Won't hurt, but I don't think it really matters. The car will learn it soon or a later.

 

U can either reset the ECU yourself or it will make the appropriate adjustments on it's own.
It's not necessary.

 

+1 and +1 to the above.

Its not really necessary but sometimes it can make a notable improvement, so it can only help.

 

Since the ECU isn't programmed for the spacer from the factory I don't see how doing a reset will make a difference. It will have to "learn" either way.

 

Its not so much about the ECU learning the spacer, its about the ECU learning to go into what I call "lazy mode" where it retards spark timing.

There are three basic levels to the ECU performance:

1) Performance mode
2) Lazy or Granny mode
and
3) Safe mode

Sometimes just normal everyday driving will cause it to go into lazy mode.
Assuming there is nothing causing it to go into safe mode and it is already in Lazy mode, a ECU reset can put it back into performance mode.

Hence the optional nature of a reset.

 

so are you recommending a reset after the install then

 

If you want to, yes, but its not required.

 

I think it's a myth. My car has about 27,000 miles on it so I suppose it's safe to say it's in lazy mode. If I take it to the track, do a 1/4 mile run, reset the ECU and then do another 1/4 mile run, how much quicker do you think it will be? I know there are other variable and the difference, if any, would be so small that it really would be very difficult to measure. If it can't be measured, then I'm calling myth. I think the only exceptions would be if there is something wrong with the car or a higher octane fuel is used, resetting the ECU after it's repaired is probably a good idea. Either way, it's not a make or break decision and I don't claim to be an expert on the subject.

http://saft7.com/?p=77

Myth
There is quite a bit of mythology revolving around resetting the ECU. Many people mistakenly believe that they need to reset the ECU after installing major engine modifications. Others believe resetting will resolve engine problems. Neither are correct.

Reality
The ECU is always tracking the engine’s sensors and actuators. Resetting the ECU does not cause the ECU to learn engine changes any faster. The ECU is always tracking the gradual changes in the engine sensors and actuators. The ECU never gets satisfied with a setting, and is always updating the trim values. It will discover whatever change you made to your engine and make the appropriate changes. In fact, unplugging the ECU will most likely increase the learning curve of the new part.
On a DSM, there are only two reasons why you would want to reset your ECU. One is to clear a CHECK ENGINE light or error code after fixing the problem that caused the error. The other is to reset the spark advance trim value. The advance trim controls how much the timing is retarded from what the factory engineers considered optimum. This particular trim value is the only one the ECU “resets” to a non-neutral MAX value. If you are driving on low grade gas, the pinging picked up by the knock sensor causes this trim value to be lowered, and your timing to be retarded. If you go to the track and put good gas in the tank, you might not want to wait for the ECU to learn about the new gas and advance the timing. So resetting the ECU in this case makes sense. However, in the process, you will lose your idle and fuel trims (probably not too important for drag racing, though).