Playing wiht the computer

[Sypherz28]

Okay I have an interesting concept and I 'know' someone has already perfected this idea. So for those that already have done so enlighten me please.
Okay lets get to the point. There are many many sencors all over an engine, many of which have a connector that can be unplugged and disconnected for removal of whatever componant it may be plugged into.
Well lets say you hook up a variable resistor to one of these connectors wiht it off of the componant, for example one to your air intake, and adjust the resistance to give a false reading to the computer.
In theory wouldn't the computer adjust the air fuel ratio and if done right increase horsepower?

Basicly what I am trying to achieve is a low budget way to mess wiht my computer in my car wihtout putting a laptop in there.

Any input is greatly thanked
Chris

[KC Ron Carter]

The issue for the OBD I, built before 1996 and after 1971 it is possible.

The EPA rules will not allow any shop to modify any certified car or truck.

Individuals can make modifications for off road usage.

Even some manufactures used resistors to make mixture changes at temperature points, BMW added a resistor to 1977 to 1983 M30 cars to fix idle issues.

After 1996 the OBD II computers are required and the systems now are smarter. If the ECU gets a signal it is not expecting it can decide to not use that signal and even replace the sensor imput with another different sensor. Most OBD II check engine lights are not apparent since the car will be running fine.

I hope this helps.

Now on older cars there are companies that make controllers and PC controlled add on processors to allow changes to be made.

On my e24 I have added a Split Second controller that allows me 4 points to set the AFR on my car.

The controller is in the glove box, and is indexed to allow me to play with settings and get back to smooth running.



Here is the Ford 65mm MAF and it is made in JAPAN.



If this engine was shiny enough to reflect,
you would see me smiling while taking the pictures.
Cause I really like the output of the MAF.

Six hours, DIY, including the indicator and can switch back to AFM in 2 minutes, Two screw clamps on MAF, two quick electrical connectors and the OE connector is tie wrapped back out of the way.

OE is
3430cc M30
Motronic
DME II
92x86, 8.0:1
185bhp/5400rpm
214lb.ft/4000rpm


I own a dyno so here is the output at the wheels.


HP loss in transmission and differential 25%
So 222 HP at shaft is the result.


I am using the J C. chip also, a 3.71 ratio, with 265 Getrag.

The sweet spot of the m30 is now at 2200rpm where it was at 2800rpm.

That is the point where the rumble of the exhaust resonates in frequency with the intake. On the unmodified it is only seen on the cold mornings when the fuel system adds a little more fuel and the cold air is giving it's all.

I really like it.




My Cartech RRFR installed and test in advance of the M102 12 psi turbo.



I hope to sneak up on a few Stangs and Meros on the Dyno.

My source:
http://www.bmpd.com/bmw/parts/catalog/engine_32.shtml

Later,

[SaabJohan]

Originally Posted by Sypherz28

Okay I have an interesting concept and I 'know' someone has already perfected this idea. So for those that already have done so enlighten me please.
Okay lets get to the point. There are many many sencors all over an engine, many of which have a connector that can be unplugged and disconnected for removal of whatever componant it may be plugged into.
Well lets say you hook up a variable resistor to one of these connectors wiht it off of the componant, for example one to your air intake, and adjust the resistance to give a false reading to the computer.
In theory wouldn't the computer adjust the air fuel ratio and if done right increase horsepower?

Basicly what I am trying to achieve is a low budget way to mess wiht my computer in my car wihtout putting a laptop in there.

Any input is greatly thanked
Chris

The risk is very large that you destroys your engine with this.

[pod]

mabie if you are tring to get 80 hp out of an aspire but thats about it just keep the settings on the sane side

[Sypherz28]

I greatly thank you for the information to those that went through the trouble.. Someone gave me the idea an I wanted to see what everyone else thought about it.. I have a 1988 Chevrolet beretta that is my guinea pig for all my weird tests and it only has 90HP stock.. I do all my tests on that so I don't blow up my real ride.. !986 Toyota Celica GT-S, fully loaded, and any working way to increase horsepower I'll do to the celica

Chris