up grade computer what do they really do????

[Supercharged Vipermad]

I have heard all about the Mopar up Grade computer, no one has said what it really does. 1. does it retard spark, or advance it and will it change whole curve how . 2. HOW MUCH. 3. does it richen the fuel across whole band with or just top end. 4. does it change temp. ranges on the fans. what else does it do???? 5. I have already purcased from BTR 1/2 shafts $699. special, Nos system look like the best way to fly. Headers and complete system from Mike Adams Ziano, Canada (his $2,900 special) 6. Where can I buy it the CHEAPEST I have seen prices from $500. down to $325. Don't have car yet but will be ready for it when it arrives.

 

[Marv S]

A direct, specific answer to this Topic "up grade computer what do they really do????" has to be the most elusive of all Viper questions.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by JonB-Pace Car Pilot:
It does not really do squat by itself.
it just makes the fuel map and the EGT for those upgrades more efficient. Those upgrades give the HP gains anyway!
<HR></BLOCKQUOTE>

But Just what is it doing with the fuel map and the EGT? And if it provides no power gain why does MOPAR suggest/recommend/offer it for use with the other parts.

Mike A, I believe, posted that it deleted using the rear 02 sensors. Fact or fiction?

A car I was in seemed to idle just a little bit higher, reducing the NGR it had with the stock ECU

Also, Sean Roe's VEC-1 is used to:
WOT: leans out the mix and advances the timing
Partial throttle: Backs off the timing and runs it richer.

The theory on the VEC-1 is that the stock ECU runs way rich and not much timing advance at WOT and that it runs the car way lean and way too advanced at partial throttle. This seems supported by the AF gauge that comes with the unit when the dials are placed in stock setting.

Sean has posted that his VEC-1 does not produce much in noticeable gains when used with the Mopar performance ECU. What's the conclusion there? That the Mopar unit works like a "fixed" position version of the VEC-1?

Lots of pieces to opine about, (idle speed, rear 02 sensors, fuel mix, spark timing, etc) but no straight answers from Mopar Performance, etc. Steven has valid questions. Can't we just get the tech on exactly what it does and the theory behind the program change?

Thx.

 

[luc]

I paid $360 from my local Jeep dealer.

 

[Supercharged Vipermad]

What I am looking for is if I modify my car, headers,3"cat back tubes,heads ported, cam, throttle body's. Will the modified ECU take care of my fuel, timing, etc. WHAT does it control, WHAT are the parameters???? I am quite knowledgeable on Accel DFI. I have a blown 1471 injected(16) 588 cube, and a 426 small block naturally aspirated both on DFI. You need to change a lot of parameters going from stock to high horse power. What are the changes that the ECU accomplishes. Beside Sean has an one been able to modify the ECU program like SUPER CHIP??? Sean's black box wont help if I run NOS, and I will. You must retard at top end THAT is why I would like to know what the modified ECU does. Has anyone been able to use an MSD retarder, or MSD shift light where they are not set up for v-10.

 

[HouseofSpeed]

Hmmm...sounds like we have reached an area out of your expertise Jon B. I would be willing to bet that neither Cragin or Roe will have fuel mapping info for either PCM.

Does the Mopar PCM do anything to improve performance???? I have only see minimal gains via dyno testing. It will improve idle quality on a modified vehicle...and can even assist in diminishing idle-hang that seems common with aftermarket and stock PCMs after modification.

14-1 is a wonderful AF ratio if we are studying auto mechanics at a technical school...and the question would be " What is the stoichiometric ratio for an Otto cycle engine?"...but it doesn't mean squat when discussing how to make power...or how to improve emissions.

FYI...from an emissions standpoint the ideal AF ratio is 16-1...a modern ICE will make the most power somewhere around 12.5-1..and since the Viper is SD (and not mass air) it doesn't measure air flow as such (in grams per second), it measures load primarily from the ignition profile and manifold vacuum..then indexes that with a VE table to determine fuel and ignition mapping. In this soup lies the "SECRET" to the VEC1...how can we modify an input signal and make the fuel and timing maps change...what signal would we modify? How much? When?

Now...what happens when the O2s tell the PCM a different story...that the cats aren't efficient (or missing), that would be the job of your downstream O2s. Their input is vital to the proper signal delivery from the upstream O2s...and subsequently to proper short term and long term strategy (BLM and INT for those GM gurus out there). That is something that the VEC1 can't correct for....if you want to know about that, drop me a line and I will be glad to supply you with the cure. Later.

 

[Maverick The Electrician]

One thing I have found is you dont want to use the mopar computer with nitrous, the timing is screwed. It didnt give me any HP gains but gave me 25 foot pounds of torque.

 

[Sean Roe]

I have recorded the air / fuel ratio (read by oxygen sensor voltage) and ignition spark advance in stock PCM's under most all driving conditions, full and part throttle while testing and developing the Viper Engine Calibrator. At the time, I used an OTC brand enhanced monitor. But now, this is even easier to do with the EASE OBD2 software.

Though our VEC1 and the Mopar Performance PCM are comparably priced, we have many advantages to offer over the Mopar part.

1. Adjustability, for your specific engine, from stock to highly modified, low or high altitude, etc. Our VEC1 allows you to go farther than the preset limits in the Mopar PCM. We provide a user guide and tuning manual that educates you on how to understand what your engine management system is doing and how to adjust it correctly using the supplied air / fuel ratio gauge.
2. Proven performance. All VEC1 owners have been able to achieve improvements in throttle response, horsepower, torque, improved fuel economy, driveability in heavily modified engines, etc.
3. Technical support. With the supplied user manual, there is no guesswork involved or risk of damaging the engine and I'm always available to help out.
4. 30 DAY MONEY BACK SATISFACTION GUARANTEE.
5. 6 month warranty. No returns allowed on Mopar electrical components.

The Mopar PCM does eliminate the possibility of setting a service engine code when removing the cats on 1998 and newer cars. However, we have some parts out there being tested by other VCA members that we developed to emulate the correct oxygen sensor signal, as though the cats were still in place.

Keep an eye on our web catalog as we have a lot of exciting new parts and products in development. www.roeracingonline.com/portfolio.html

 

[Supercharged Vipermad]

gUYS NOW WERE COOKING SEAN CAN TAKE CARE OF AIR FUEL, WITH HIS UNIT. SEAN CAN YOUR SOFT WEAR READ THE AMOUNT OF AdVANCE AND WHAT CAN WE USE TO RETARD SPARK. DOES ANY OF THE AFTERMARKET MANUFACTURES HAVE A UNIT THAT WILL WORK ON V-10????? I THOUGHT I SAW SOMETHING ON A SHIFT LIGHT OR A WINDOW SWITCH THAT ONE ONE THEM HAS MODIFIED. YOU PEOPLE IN THE BUSINESS SHOULD TALK TO THESE VARIOUS MANUFACTURES AND SHOW THEM HOW ACTIVE WE ARE. THEY MIGHT THINK THERE IS A LIMITED MARKET, WE KNOW THE PRICE IS SECONDARY.

 

[Sean Roe]

Steven,

The EASE software does allow you to monitor, record and graph many signals and parameters, including spark advance.

We do alter both fuel and spark with the calibrator. The VEC1 adjusts fuel and spark advance together, not independently. Positive settings on the low and high load dials add fuel and reduce spark advance. Negative setting on the low and high load dials reduce fuel and add spark advance.

The stock PCM settings call for high spark advance (over 45
degrees) and little fuel under light loads, which adversely affects throttle response. To improve throttle response, we recommend going to a positive setting on the low load adjustment (for stock cam engines), adding fuel and reducing the excessive spark advance. It feels like you've added an accelerator pump when it's adjusted right.

Under full throttle, heavy loads, the stock PCM calls for a tremendous amount of fuel (richer than 11.5:1) and little spark
advance (as low as 18 degrees over 5,000 RPM). To improve full throttle power, we go to a negative setting on the high load dial (on stock cam engines), reducing the excessive fuel (preferably down to about 13.2:1 to 12.7:1 air / fuel ratio) and increasing spark advance up to about 29.5 to 30 degrees total advance.

Highly modified engines and forced induction engines have different requirements and we cover their settings in the user manual.

I hope that helps answer some of your questions. Thanks for the
opportunity.

 

[HouseofSpeed]

OK....here we go:

Sean, you are incorrect about the Mopar PCM not throwing an MIL in the face of exhaust system changes and the removal of cats. I have personally observed the above scenario in the shop on at least three different cars. Fortunately, I have adapted some GM "technology" to the Viper and can cure the downstream O2 failure...whether it be a Mopar PCM, or a stocker. Currently it seems to be an issue with just the 2K PCMs...and I believe it relates to the PCM self-test threshold for the downstream O2s.

I don't see the VEC as a cure for the "problems" outlined in any discussion of the Mopar PCM. Idle hang? O2 heater circuit failure? I would think that for most people, the absence of a check engine light far outweighs the advantages of a couple of HP or TQ numbers.

Jon B, I think you are assuming too much when you speak of the other gurus as having performed ECM mods....I don't believe Sean would categorize his unit as an ECM mod...perhaps a unit that masks or disguises the true nature of things to serve as band aid on a slightly modified vehicle...but far from restructuring a fuel map or a VE table to accomodate serious modifications.
As for Mr. Cragin....I haven't seen any of his PCM mods.... fan bypasses, battery drain kits, and load sensor manipulators do not qualify as PCM mods in my book.

No, the Mopar PCM is not the answer to the problem that plagues the Viper....a lack of proper fuel and timing control because of an archaic fuel management system. Reflashing and establishing the proper load tables for the conditions and components would be the proper way to address the problem.

Here's the real issue...we, as Viper tuners/collectors/drivers, have a limited production piece that is very unique. For those that have no performance experience outside of Vipers, they are truly exciting. But to a person that builds and tunes "serious" combinations...to make 500-600 HP out of a 488 inch motor is truly laughable. The answer to that is control....as in a programmable system (much like the GTSR uses)...

All just food for thought...and don't ever underestimate the guy in the white T-shirt that just posts occasionally...he is probably smarter than you think.

 

[HouseofSpeed]

Obviously the cat is out of the bag on the "simulators" that Sean mentioned...my beta testing is finished and they are currently available for purchase through Hennessey Motorsports. They are plug and play....very easy install...quality part and factory connectors. You can reach me at HMS during the day...281-579-2223.

 

[Sean Roe]

Kyle,

If the Mopar Performance PCM does not ignore the downstream O2 reading and is still capable of setting a cat failure code, this is information that needs to get out there to many people. Several people have asked me over the last couple months about buying the Mopar PCM to eliminate the check engine light (1998 and newer cars with cats removed). My advice to them was, that is an expensive way to go to keep a light off and there has certainly got to be a better solution.

If you've seen the code set with cats removed and the Mopar PCM installed in cars at the HMS shop, that pretty much settles that issue. There is a lot of misinformation out there, including the information given to me.

Regarding the downstream O2 signal emulators, I didn't know you were putting together something also. Have John put it on the new products section of the message board. There are several people ready for them right now. My signal emulators are still in the testing and verification phase. I built one set, tested them on my car and then sent them to a '99 cat removed car owner (who's check engine light was coming on) to test on his. Do you guys have a price on yours yet?

Also, you are corrct that the VEC1 does not change other parameters beyond fuel and spark advance and I've never promoted it as being able to do anything beyond that. I term the product an engine calibrator. Something it does pretty effectively, as you have seen.

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[Supercharged Vipermad]

Kyle I must have missed something or it flew over my head. What simulator are you talking about and what will it do???? I will call you this week.

 

[Jason-Middle Tennessee]

One question for all you. If your purchase a Mopar Performance Computer for the Snake will they give a core exchange for the old one? I know when I got one for my Ram they gave me 100 bucks back for the old one.

 

[94 RT/10 Black MAMBA]

FYI...from an emissions standpoint the ideal AF ratio is 16-1...a modern ICE will make the most power somewhere around 12.5-1..

HouseofSpeed - I'm no physicist but I believe you're statement above (which I copied from you're post) is incorrect. I don't believe fuel will ignite/burn outside of a range of 13.9-1 to 15.0-1. This is why if you drop a lit match into gasoline it may go out. Only the gasoline vapors can be ignited if they are in the range above.

 

[HouseofSpeed]

Black Mamba....you are comparing apples to oranges. The AF ratio has nothing to do with whether gas is more volatile in its gaseous or liquid state. When we measure AF with an O2 sensor or gas analyzer, what are we doing???? WE are allowing that galvanic battery (the sensor itself) to generate a voltage by exposing it to the exhaust stream, which is obviously POST COMBUSTION, and then the voltage generated gives us a correlational ballpark as to AF ratio in an OE application.

Bottom line, we are measuring the concentration of oxygen (not fuel vapor) in the exhaust stream, and using that as the catalyst for the sensor.

IT is indeed possible for AF ratios of 20+ to exist...have seen it many times with a gas analyzer. If you need a more involved explanation of combustion byproducts...we can go there off board so as not to bore those that just come here for the milk and cookies.