I have an idea about flash tuning

[backpacker3]

The way I see it is if I have a tune for my stock car with no mechanical upgrades it would work on all other cars of the same model with no performance upgrades if there was a way to build this myself perhaps by arduino or something similar I could then share the tune with someone else for a portion of the cost of the tune. Alternatively I wouldn't mind learning how to tune ECUs so I could do it myself then write a custom tune.

[sarguy01]

Originally Posted by backpacker3

The way I see it is if I have a tune for my stock car with no mechanical upgrades it would work on all other cars of the same model with no performance upgrades if there was a way to build this myself perhaps by arduino or something similar I could then share the tune with someone else for a portion of the cost of the tune. Alternatively I wouldn't mind learning how to tune ECUs so I could do it myself then write a custom tune.

Tunes don't work like that. You could have a basic tune, but it would not reap the full potential of each vehicle.

Even though the same model vehicle with the same engine was built to the same specs, each one is different enough that your car's specific tune could damage another car.

This is why the companies selling flash units will include a canned tune, but recommend a custom tune for your specific car to maximize the full potential.

[backpacker3]

How do stock tunes not damage cars then? If what you're saying is true then a stock tune could damage a vehicle. My car is stock there are no upgrades and no aftermarket parts all maintenance parts are OEM spec therefore if I tune my car conservatively not maxing out everything to its limit (I wouldn't max anything out anyway) I don't see why another Sunfire of the same year, model, engine, and transmission couldn't use it. You wouldn't reach the absolute full potential of the vehicle but that's not the point of a flash tune.

[sarguy01]

Originally Posted by backpacker3

How do stock tunes not damage cars then? If what you're saying is true then a stock tune could damage a vehicle. My car is stock there are no upgrades and no aftermarket parts all maintenance parts are OEM spec therefore if I tune my car conservatively not maxing out everything to its limit (I wouldn't max anything out anyway) I don't see why another Sunfire of the same year, model, engine, and transmission couldn't use it. You wouldn't reach the absolute full potential of the vehicle but that's not the point of a flash tune.

Stock tune, as in the OEM?? The stock computer is a pretty complex device. It uses base maps, then learns as it goes. The stock ECM/PCM is designed to keep the engine running right through changing conditions. Like bad gas at 5,000 feet one day to good gas at sea level the next day. The OEM's do a pretty good job of programming, even taking into account each individual car's differences.

Flash tuning is just a way to reprogram the vehicle's computer. You can flash the stock ECM/PCM with a canned tune or you can have your tuner write a custom tune then flash your ECM/PCM with it.

Aftermarket tuners tweak what the factory programmed. They can only tweak so much for a canned tune, since too much tweaking doesn't allow room for changing variables, like a bad tank of gas. If you really wanted to see an MPG difference, you'd need a custom dyno tune specific to your car. That custom dyno tune that works on your Sunfire might cause trouble for another Sunfire. The differences in cars are very subtle. An example would be leaning your car out to the max safe limit, but that might put that other Sunfire's engine past the safe lean limit.

Plus, I haven't really seen any testing to show that a canned tune really increased fuel economy. SCT makes claims, but without some proof it is hard to believe their claims.

Again, if you have the money and aren't worried about a return on investment, go for it. Just don't expect huge gains.

[Vekke]

On my Lupo 1.2 TDI we did over 25 different tunes/tests.
Fuel consumption went from 2.2 liters -> 2.0 liters mainly because of the ecu tuning.
So difference was about 10%.

Tuning and tweaking will continue next summer when same engine will be put to the Audi A8. We will try some different setups to learn more.

[sarguy01]

Originally Posted by Vekke

On my Lupo 1.2 TDI we did over 25 different tunes/tests.
Fuel consumption went from 2.2 liters -> 2.0 liters mainly because of the ecu tuning.
So difference was about 10%.

Tuning and tweaking will continue next summer when same engine will be put to the Audi A8. We will try some different setups to learn more.

25 tunes? Sounds like you have a lot of experience. 10% is quite an improvement. What kind of testing did you do? How much are you into the tuner/software and dyno time??

Also, is there more potential tuning a turbo diesel versus tuning a naturally aspirated gasoline motor?

Sorry for the barrage of questions...I am curious.

[niky]

The reason stock tunes don't damage the car is the same reason you can get such gains on a fully-custom tune... they leave a ton of leeway in order to prevent engine damage.

Even on high economy cars like, say, the Mirage, we're seeing parts of the engine map on the dyno that default to a very, very rich running state during certain drive situations... such as low rpm under load, or at cruising rpm.

A canned tune can fine tune these maps and remove some of the waste, but tuning specifically for maximum economy on a canned tune is like tuning specifically for maximum power. It can cause problems when you get a batch of bad gas. Or if one of your customers lives in a very hot environment, or at high altitude, or etcetera.

Custom is where it's at.

I'm not surprised Vekke can get 10%... though that is a delightfully high number on a car that's so efficient from the factory. On one propane conversion, we saw a change of around 30% when the ECU was retuned.

...because that particular motor defaulted to an AFR of 10:1 at idle.

[Cobb]

Well,afr is one thing, I d like to change the vtec and shift points too. I had asked hondata if the crz will work on the insight or the civic on the insight and they said flat out no.

[sarguy01]

Originally Posted by Cobb

Well,afr is one thing, I d like to change the vtec and shift points too. I had asked hondata if the crz will work on the insight or the civic on the insight and they said flat out no.

that stinks. I don't think Hondata has much of a market with Insights. do they sell anything that will work?

[American Viking]

Originally Posted by backpacker3

How do stock tunes not damage cars then? If what you're saying is true then a stock tune could damage a vehicle. My car is stock there are no upgrades and no aftermarket parts all maintenance parts are OEM spec therefore if I tune my car conservatively not maxing out everything to its limit (I wouldn't max anything out anyway) I don't see why another Sunfire of the same year, model, engine, and transmission couldn't use it. You wouldn't reach the absolute full potential of the vehicle but that's not the point of a flash tune.

First of all Stock tunes can damage an engine, simply by trying to adjust to mixed up variables.
Now stock ECU tunes are designed to be safe over the entire range of temperatures and most consumable fuels. That means that there is efficiency to be found in just tightening up the base maps.
But not with a general tune.
No two engines are the same, even 100% original oem engines are not close enough for a serious tune on engine "B" to be afe for engine "A".
Levels of wear, dirt, lubrication, even construction tolerances and the local atmospheric conditions will effect the what makes a Safe tune.
Since each OEM has their own proprietary programming, the only way to effectively tune an engine. Whether its for performance, emissions or efficiency - the most important thing to do is to tune that engine and only that engine.