Technical Details about Stock ECU Tuning

[Westrock]

Most standalone's allow for MAP right out of the box since MAP is much more friendly to "modified" cars. For the time being this solution will still rely on the MAF setup that the stock ECU uses. MAF has more limitations. MAP's only limitation is you have to get it setup for the particular engine, since it makes some assumptions about the volume & efficiency of the engine.

[DanKeen]

Originally Posted by hackish

It starts and idles happily in all temperatures

Hahahahaahahahaahah! Considering mine, when idling by my garage this morning, dropped down to 350, shot up to 1800, and then oscillated around normal idle speed... The stock supercharged ones are known to not idle that nicely.

(Nicely compared to, say, a BMW. Compared to a high-duration cam'd SBC's... sure, it's butter.)

[evansp60]

Smooth as butter......compared to most of the standalones (certanly all of the ones I've experenced!)

Originally Posted by DanKeen

Hahahahaahahahaahah! Considering mine, when idling by my garage this morning, dropped down to 350, shot up to 1800, and then oscillated around normal idle speed... The stock supercharged ones are known to not idle that nicely.

(Nicely compared to, say, a BMW. Compared to a high-duration cam'd SBC's... sure, it's butter.)

[hackish]

Originally Posted by DanKeen

Hahahahaahahahaahah! Considering mine, when idling by my garage this morning, dropped down to 350, shot up to 1800, and then oscillated around normal idle speed... The stock supercharged ones are known to not idle that nicely.

(Nicely compared to, say, a BMW. Compared to a high-duration cam'd SBC's... sure, it's butter.)

The cars I've seen that were completely stock and did this had vacuum leaks fixed or MAF sensors cleaned and they idled properly afterwards. I recently had one with an aftermarket blower attached and we put an air straightener on the MAF sensor and it settled down considerably.

I know Lotus tuning is a little rough in some spots but one should expect it to start and idle properly. If not, there is likely a mechanical/electrical issue somewhere.

-Michael

[me73]

Originally Posted by Westrock

Most standalone's allow for MAP right out of the box since MAP is much more friendly to "modified" cars. For the time being this solution will still rely on the MAF setup that the stock ECU uses. MAF has more limitations. MAP's only limitation is you have to get it setup for the particular engine, since it makes some assumptions about the volume & efficiency of the engine.

With a MAP system, you have to have a 3d map of the pressure (load) vs fuel delivery which is specific to every engine. This map represents the efficiency (VE) of the engine. It is in essence a correlation between manifold pressure and engine intake air flow. Every time the engine volumetric efficiency changes, you have to remap the ECU. In addition to internal modifications, the ECU needs to be remapped with significant changes in breathing from the intake and exhaust.

A MAF system directly measures the airflow ingested by the engine, no need for correlation to the VE at all. This type of system is much more tolerant of engine modifications since it's directly relating fuel delivery to the measured flow rate. The MAF needs to be recalibrated if the intake tube in which it is housed changes in geometry.

Both systems still need the TPS for corrections under idle and full throttle.

[dstevens]

The issue with MAF is any modification to the intake system inevitably introduces turbulence, and the AFM doesn't correctly meter the air after that. We've seen fuel trims of +-35% from just an intake change. VE tables don't have this problem but they take longer to tune and don't compensate for small changes.

[hackish]

I find in the long run MAF based systems are easier to deal with but if you have a poorly laid out or improperly engineered intake you may be stuck with a vehicle that cannot be tuned correctly no matter what.

The reality is that speed density (MAP sensor) requires a lot more care and feeding. Any time you do a modification you need a retune. Many V8 MAF based cars will get a full exhaust, headers, cam(s), heads etc and require little to no fuel adjustment even thought the owner bolted on 100hp of extras.

Change the cam on your 2ZZ speed density without retuning and you'll run so lean every exhaust valve in the engine will burn.

Each camp has it's advantages and disadvantages.

-Michael

[me73]

Originally Posted by dstevens

The issue with MAF is any modification to the intake system inevitably introduces turbulence, and the AFM doesn't correctly meter the air after that. We've seen fuel trims of +-35% from just an intake change. VE tables don't have this problem but they take longer to tune and don't compensate for small changes.

The MAF directly reads speed. The ECU needs to know the geometry info to convert it to volume flow. If the intake changes anything regarding that geometry, the maf signal needs to be retuned.

Without knowing specifics, if the system can't get a clean, consistent maf signal, there's a problem with the intake design and potential performance is being wasted.

[me73]

Originally Posted by hackish

I find in the long run MAF based systems are easier to deal with but if you have a poorly laid out or improperly engineered intake you may be stuck with a vehicle that cannot be tuned correctly no matter what.

The reality is that speed density (MAP sensor) requires a lot more care and feeding. Any time you do a modification you need a retune. Many V8 MAF based cars will get a full exhaust, headers, cam(s), heads etc and require little to no fuel adjustment even thought the owner bolted on 100hp of extras.

Change the cam on your 2ZZ speed density without retuning and you'll run so lean every exhaust valve in the engine will burn.

Each camp has it's advantages and disadvantages.

-Michael

The other issue with MAP systems is that they can't compensate for changes as the engine ages. Ring seals, carbon build up, air filter efficiency, etc. all change VE and aren't corrected for by a MAP system. Likewise, tuning on an engine that isn't yet broken in can have the same issue. This is minor in most cases, but an engine tuned right to the edge is pretty sensitive.

On the other side, MAF sensors get dirty pretty easily and need more periodic attention. If you don't have any margin for error in your tune, when the maf gets dirty, the engine could be in trouble.

[hackish]

Unless the car is a race car in which case it will probably see the dyno and tuner between every race or two, it should be tuned nowhere near the bleeding edge.

As an example, hondas have used speed density for many years. They have variable lift and timing - similar to vvti/vvtl. I don't feel their engines are quite as well built as the 2ZZ but all the same they generally stay together for many years.

I hope it's realistic to expect that every Lotus owner will be keeping their cars in reasonably good mechanical shape. Clean air filters, good sparkplugs, clean MAF, good O2 sensors, all very basic items necessary for a good running car.

This tuning system is designed to enable owners to have their car professionally tuned by whomever they choose. The plan is to allow speed density as well as direct measurement as the tuner wishes.

-Michael

[Giantmcm]

[jacks1071]

Where are you up to with the 2005 exige software?

[hackish]

Still working on the '06-'07 stuff. Been quite sick since Christmas. If you're offered the Flu plus pneumonia you're best to pass.

[me73]

Originally Posted by hackish

Still working on the '06-'07 stuff. Been quite sick since Christmas. If you're offered the Flu plus pneumonia you're best to pass.

That sucks, sorry to hear that.

[jacks1071]

Originally Posted by hackish

Still working on the '06-'07 stuff. Been quite sick since Christmas. If you're offered the Flu plus pneumonia you're best to pass.

Any time frame and cost estimate on the 2005 ?

[komiko]

So cool. I'd blow up my car though as I don't have a clue. And my Koldfire REV400 tune (stock cat to pass emissions) at 336.4hp is holding up nicely. Phil at BOE took 12 hours on the dyno to get it right.

[hackish]

Some people do want it to make the adjustments themselves. I've been tuning professionally for over a decade and can honestly say I've only ever see one (out of over 1000 cars tuned) that's ONE completely customer tuned car that was very well done.

If you jumped out of an airplane with a parachute would you survive? At best if you had figured out how to put it on properly 75% chance of survival... With proper instruction and an easy to fly parachute it's highly likely 99.999% perhaps. Don't expect your first landing to be beautiful and without soiling your knees or butt on the ground... or other things

The same principle applies to tuning. With proper instruction and a mostly sorted out easy to tune engine survival (of the engine) is highly likely. Like the parachute example the end result may not be that pretty. It really does take a lot of background knowledge and experience.

Now, if you needed or wanted to make an adjustment like change your idle speed, that's quite safe. Idle mixture, again, safe. There are lots of basic easy things the home user can do.

The main point of this product is that it puts that power of choice in your hands. Sure you could fly me in to adjust your idle speed but I'd feel like a doctor putting on a band-aid.

I'm sure if you put the system in the hands of any of the well known tuners here they'd be able to do great things with it. Anyone with experience will be right at home. I'll probably even do some demo videos to show the features.

-Michael

[Elige]

Will this software let you edit the VIN that's within the ECU? I only ask because Lotus just sent out a recall to address certain model years not having the correct VIN stored in the ECU. They are suggesting that the car may not pass SMOG if it does not have the correct VIN stored in the ECU. If you take the car to Lotus to have the correct VIN embedded, then it will revert the ECU back to stock settings. This could be a big mess for a lot of people (my self included) here very soon.

[Elige]

Originally Posted by dstevens

The issue with MAF is any modification to the intake system inevitably introduces turbulence, and the AFM doesn't correctly meter the air after that. We've seen fuel trims of +-35% from just an intake change. VE tables don't have this problem but they take longer to tune and don't compensate for small changes.

Another issues with MAF is if you are making high HP, you can max out the stock MAF, then you have to either upsize the tubing or switch out to a MAF with a higher voltage and then rescale. Either way is a PITA. In my previous custom turbo endeavor I know that switching from MAF to MAP was the best thing I ever did for the setup. I think a lot of it had to do with a turbulant MAF housing setup that lacked vanes.

[hackish]

Originally Posted by Elige

Will this software let you edit the VIN that's within the ECU? I only ask because Lotus just sent out a recall to address certain model years not having the correct VIN stored in the ECU. They are suggesting that the car may not pass SMOG if it does not have the correct VIN stored in the ECU. If you take the car to Lotus to have the correct VIN embedded, then it will revert the ECU back to stock settings. This could be a big mess for a lot of people (my self included) here very soon.

I am aware of the VIN issues. It's merely a software issue. I can make the VIN, Calid and CVN return whatever numbers I want since I re-wrote a lot of the communications routines. Lotus did such a crap job of the code in there even in assembly language it looks like an elementary student wrote it!

-Michael