When should the 85 ECM really be re-programed
Thread Starter
Instructor
Joined: Aug 2006
Posts: 220
Likes: 12
From: Hagerstown MD
When should the 85 ECM really be re-programed
Vader looking for your input on this!!!!!
85 vette L98 4+3
mods=LT headers, HF cat, B&B mufflers, Moded Air Intake, moded MAF, Accel injectors, Accel disti.
with those basic mods does the stock ECM have enuff of a learning curve to pick this up?
or is there enuff to justify a eeprom reprogram?
if the stock program will do at what point is it a given that the ECM will need reprogramed
85 vette L98 4+3
mods=LT headers, HF cat, B&B mufflers, Moded Air Intake, moded MAF, Accel injectors, Accel disti.
with those basic mods does the stock ECM have enuff of a learning curve to pick this up?
or is there enuff to justify a eeprom reprogram?
if the stock program will do at what point is it a given that the ECM will need reprogramed
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Your Okay
With the mods that you currently have, you don't need a new chip. You will need a chip if you change out the cam. You can add roller rockers and more bolt ons without problems.
A custom chip will fine tune the car to get a little more out of the engine. A chip alone for the 85 will not produce a large increase in HP.
A custom chip will fine tune the car to get a little more out of the engine. A chip alone for the 85 will not produce a large increase in HP.
Safety Car
Joined: Sep 2003
Posts: 3,599
Likes: 24
From: Orange County NY
St. Jude Donor '10-'11-'12-'13
Are the injectors the same size as stock? If so, the stock chip will be ok with those mods. BLMs might increase a bit due to the additional airflow from the modified MAF and (eventually) the ported base and runners as the ECM makes corrections, but the ECM must go into closed loop for this. Have you verified that the ECM is going into closed loop after the LT header installation? If not, you will likely need a heated O2 sensor.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
I agree with both of these fellows. You should be fine with the stock tune with what you have listed. If the injectors are larger than stock, then you will likely need an adjustable fuel pressure regulator. As byebyeL98 stated, you need to confirm closed loop. The headers get rid of heat faster than stock and will cause the ECM back into open loop. A heated O2 sensor will help.
Team Owner
Joined: Sep 2001
Posts: 62,126
Likes: 1,727
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Should be fine as is, I might go for an AFPR to make a few adjustments (on a dyno or at the track preferably).
