LotusTalk - The Lotus Cars Community - View Single Post

DSLeach · 01-02-2009, 08:49 AM

Sorry if these questions have been asked/answered before but I've spent the last couple days reading posts on this forum and I haven't found really clear answers.

I'm fairly experienced with ECU operation and tuning but not for Lotus or Toyota systems. I built (SC, CAI, exhaust, fuel system, ported intake, etc.) a 2001 Cobra. Used a piggy back system to dyno tune up to 423 ft-lbs RW torque. Frankly some of the stuff I read on this forum doesn't make sense based on what I think I know about Ford ECU operation and tuning. Ford is not Toyota I know but engine management software is engine management software.

So, to the questions all applying to an 07 Exige S:

1. Will a slightly smaller SC pulley require tuning to be effective? Won't the MAF signal reflect the increased airflow and the ECU adapt by increasing fuel delivery? Is the MAF capacity or the injectors near max capacity for the stock configuration?

2. Has anyone tried porting the blower? Maybe the newest versions of the M62 already include the porting that Magnuson was offering a few years back but when I had my blower ported it was worth about 10 degress lower IAT (improved blower efficiency) at full boost/load.

3. Does the ECU really compensate for the mods like improved intake air flow or exhaust flow? I've read several threads indicating that the ECU eventually learns to cancel out such mods for open loop operation. This is counter intuitive to me as all the ECU strategies I'm familiar with are intended to allow the engine to benefit from better breathing. Some engine management systems are limited in their ability to take advantage of improved air/exhaust flow due to the capacity of the MAF, injectors, head flow characteristics, A/F ECU maps, etc. But, I've never come across an ECU with a strategy intended to counter improved airflow.

4. Is the ECU tuning out a mod more of a problem for closed loop operation vs open loop operation?

4. In one thread, I read that the Exige S ECU uses a constant for fuel pressure rather than picking up a value off the injector rail. Is this true?

5. Are there tuning tools available to "tweak" the stock ECU to allow changes to A/F in open loop operation, ignition timing, etc. short of complete replacement of the control system (e.g. EFI)?

I don't have a Exige S, yet. I will have either an Exige S or a Cayman S soon. I like to tinker with my cars and I'm trying to understand how hard or easy it is to "tinker" with the Exige S.

01-02-2009, 08:49 AM	#1 (permalink)
DSLeach Registered User Join Date: Jul 2008 Location: Aiken, South Carolina Posts: 2	Newbie ECU/Tuning Questions Sorry if these questions have been asked/answered before but I've spent the last couple days reading posts on this forum and I haven't found really clear answers. I'm fairly experienced with ECU operation and tuning but not for Lotus or Toyota systems. I built (SC, CAI, exhaust, fuel system, ported intake, etc.) a 2001 Cobra. Used a piggy back system to dyno tune up to 423 ft-lbs RW torque. Frankly some of the stuff I read on this forum doesn't make sense based on what I think I know about Ford ECU operation and tuning. Ford is not Toyota I know but engine management software is engine management software. So, to the questions all applying to an 07 Exige S: 1. Will a slightly smaller SC pulley require tuning to be effective? Won't the MAF signal reflect the increased airflow and the ECU adapt by increasing fuel delivery? Is the MAF capacity or the injectors near max capacity for the stock configuration? 2. Has anyone tried porting the blower? Maybe the newest versions of the M62 already include the porting that Magnuson was offering a few years back but when I had my blower ported it was worth about 10 degress lower IAT (improved blower efficiency) at full boost/load. 3. Does the ECU really compensate for the mods like improved intake air flow or exhaust flow? I've read several threads indicating that the ECU eventually learns to cancel out such mods for open loop operation. This is counter intuitive to me as all the ECU strategies I'm familiar with are intended to allow the engine to benefit from better breathing. Some engine management systems are limited in their ability to take advantage of improved air/exhaust flow due to the capacity of the MAF, injectors, head flow characteristics, A/F ECU maps, etc. But, I've never come across an ECU with a strategy intended to counter improved airflow. 4. Is the ECU tuning out a mod more of a problem for closed loop operation vs open loop operation? 4. In one thread, I read that the Exige S ECU uses a constant for fuel pressure rather than picking up a value off the injector rail. Is this true? 5. Are there tuning tools available to "tweak" the stock ECU to allow changes to A/F in open loop operation, ignition timing, etc. short of complete replacement of the control system (e.g. EFI)? I don't have a Exige S, yet. I will have either an Exige S or a Cayman S soon. I like to tinker with my cars and I'm trying to understand how hard or easy it is to "tinker" with the Exige S.