First off hello! Long time reader first time poster.
I have burned many chips for my GTA and I have used many tips from this board. It is a great referance. Well today I purchased a vortech supercharger. It comes with a piggy back fuel control unit. Making it possible to install without modifying the ECM.

My question is would it be feasible to do the following.
purchase a two bar map sensor from a GN
Then modify the VE tables by turning down the resolution on the KPA side and creating an axis that has negative and postive pressures. Am I simplifying this to much? Does the ECM not have the ability to read a positive pressure output. Will the checksum calculate right if the KPA axis values are changed? Is it possible to modify an axis and still have the ECM be able to interpet.

I realize my question probably needs to be more pointed, but I will appreciate any advice anyone is willing to give. It is not a big deal I just thought it would be neat to not have to clutter up my bay with extra controls

 

You could just get a SyTy ECM and not have have any extra controls to mess with. There have been guys rumored to have installed a two bar map in a 730 but I haven't seen it listed anywhere or any specific instructions on what to do. I'm sure if you were real good at writing code you could just add the extra table for boost and not lose any resolution but if you could do that something tells me you wouldn't be asking if it could be done.

 

I have already written the low resolution code I spoke of. My qustion is not "can it be written" It is does the ECM have the ability to interpet the modified y axis. I am aware of the cyclone ecm, but I rather use the fuel control module that came with the vortech before I change ecms. I am leary about installing a chip with this many changes. I feel I have gone overly rich, so I guess I don't have to worry about leaning out and burning something up. I have already hooked up the inline vortech pump so supply shouldn't be an issue either.

 

I think the 730 uses the MAP sensor to calc baro before startup.

We have a reference of 5V. I'm thinking if you insert a 2 bar MAP the baro calcs will be off because the 100KPA reading is no longer the same. 2 bar sensor @ atmospheric pressure will read 2.5V (aprox) while the 1 bar sensor reads 5V (aprox).

My thought is there is more to it than just changing the VE and spark tables.

 

MAP is Manifold Absolute Pressure. There is no positive, and negative. 0 K/Pa would be an absolute vacuum.
You don't want to clutter up your bay, but po po'd the 749 idea, it's your best answer, or run the syty code in your 730. Most the stuff lines up but you'd lose the TCC.
Checksum just a value, it doesn't care what you change just so long as the numbers tally up.

 

The 749 code will work in the 730! So the 730 is capable of reading pressure from the manifold absolute pressure (MAP) sensor. I did not mean to make it sound like I "po po'd" the idea of the cyclone/typhoon ECM. I agree it would be the best solution. After purchasing the supercharger I just want to keep the spending to a min for awhile. The old lady gets grumpy when money starts flying out the door for the second love of my life. Given 50-100 more seems like chump change compared to the 3000 I just dropped. THen I must also figure the 3000 I dropped did have a solution also. It just wasn't pretty.

I know these questions are redundant and annoying, but it is hard to find a complete ecu file and unmolested binary file. So here it is: where can I find a good complete typhoon/cyclone binary and ECU file

[This message has been edited by DAVECS1 (edited December 11, 2001).]

 

If it reads MAP before startup to get a baro reference it might still work. It will be a different voltage, but it will still be the correct value for atmospheric pressure.

It might throw some error-code too, if it wants a near 5 volt value before startup.

Somebody will have to test it ...

I have also been thinking ablut using a 2-bar MAP sensor with a non boost ECM.

------------------
Jonas Bylund

 

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