Re: [DML] Performance Chips

[William T Wilson <fluffy@xxxx>]

[moderator: This is not really DeLorean related so you don't have to post 
if you don't want to :) ]

On Sun, 4 Jan 2004, grandprix9598 wrote:

> I know this isn't directly related to a DeLorean, but I keep seeing
> performance chips on sale for cars. Do they really work, or add any
> performance that is noticeable? Thanks

The answer is definitely YES. The ECU (Engine Control Unit) upgrade chip
on a modern fuel injected car essentially takes the place of carburetor
and distributor modifications on older cars, so you can pick up a lot of
performance.

Of course, there is a downside: altering the ignition and fuel delivery 
parameters may increase emissions, decrease the life of the emissions 
equipment and/or engine, increase the quality of the required fuel, or 
decrease fuel mileage. (Especially the last two). This also explains why 
this slack is present in the stock mechanical components in the first 
place.

As an example, take the new RX-8. The car, as sold, produces somewhat
less power than originally promised. It turns out that Mazda could not
meet EPA-mandated lifetime requirements for the catalytic converter with
the engine in its originally designed state of tune. Mazda had to reduce
the power output to satisfy this requirement - even though the car doesn't
actually exceed pollution limits when tuned as designed. It's sort of
like how the DeLorean front end was raised at the last minute to satisfy
"safety" regulations. ECU modifications can put it back the way it was 
supposed to be in the first place.

Not all performance chips are created equal. There are basically two 
kinds - those which are "piggyback" chips and those which completely 
replace the stock ECU. A piggyback chip works by modifying the outputs 
and/or inputs on the stock chip to adjust its behavior. For instance you 
might modify the fuel injector outputs to increase (or decrease) fuel 
delivery, or you might modify the crankshaft position sensor input to 
trick it into advancing timing. Although a piggyback chip can be 
powerful, they don't have the ultimate flexibility of a standalone ECU 
replacement. Most performance chips fall into this category. One nice 
advantage to the piggyback chips are the ease of removing the chip if you, 
for instance, want to sell the car to someone who might not appreciate it. 
Some of these modifications can be installed or removed in less than an 
hour.

A standalone ECU completely replaces the stock ECU which allows for total 
control over all fuel, turbo, and ignition settings. As you can imagine 
this is very powerful and also difficult to install. While these are used 
by the "famous" tuners and semi-pro drag racers, etc. on all their most 
powerful cars, they come with a lot of tradeoffs - not only expense, but 
sometimes these standalone systems break things like digital dashboards, 
airbags, ABS systems, GPS systems, etc. Haltech and Electromotive are the 
most popular manufacturers of general purpose ECUs. A system like this is 
a good way to go if you are planning on an engine swap, especially to a 
turbo motor, and happen to be good with electronics.

A third modification is to simply modify the stock ECU. The memory which 
holds the ignition and fuel settings is simply modified with newer, 
higher-performance data. The advantage here is that there is minimal 
expense and modification involved, but the flexibility is the least.

The biggest gain with performance chips is realized on turbo cars. The
chip can increase the turbo boost and fuel delivery which directly
translates into more power. It's not uncommon to pick up 10-20% power
with even a fairly basic performance chip. Another advantage to such
modifications is that, if you've increased performance in other ways (such
as with a bigger turbo, camshafts, exhaust, intake, whatever) the ECU
modification, if it's sufficiently powerful, can increase the performance
gain from the other modifications, and reduce the risk of damaging your
engine in the process.

Even on a naturally aspirated car you can gain some benefit from a 
performance chip. The primary advantage here is adjusting timing and fuel 
mixture. If you have an engine/transmission that can take it, you can 
also eliminate the rev limiter with some types of performance chips. This 
can improve performance especially if you have opened up the intake or 
exhaust.

> Overseas in Operation Iraqi Freedom

Keep up the good work and come home safe :)