VE Table on MAFT Pro

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supraguy31

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May 10, 2005
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Might sound like a Stupid question and Im starting to learn a little more everyday about this setup.....

How or Why would you modify the VE table. Only Problem that Im running into at this point in the setup is that under boost, I cant get my A/F ratio to Drop Quick enough....... ie, I do a Hard boost pull in 3rd gear on a roll at 40mph up to 18 PSI and my A/F will stay at 14.7 until I let off the gas then It will drop to 10.5 and back up, Im not going lean but Im not going right either until late.

Ive increased fuel at the top end 10% with no change....

Only thing that I have done different here is I went back to my HKS EVC IV boost controller as I blew the MAFT Pro one out (I guess the dual port wastegate did it) but I havent changed any of the MAFT Pro Settings yet to reflect no boost controller. Would this effect it or is the MAFT Pro trying to read its own boost still?

Did a little reading about modifying the VE Table but I have no Idea on where to start, It was a really really short paragraph. I want to get this resolved before going any farther. any Documentation would be great also for reading if anyone could link me to one.

Oh, PTT is Disabled and AFR Tracking is Disabled

Thanks all
Robert
 
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Supraguy31,

Have you been over to the FullThrottleTech forums and looked around there? There is good info there and Bob, Rick, CRE, and Jeeves all give really good info and are very helpful. You can also do search here for Doward and MAFT Pro because he has a lot of good info out, too.

When you are adjusting fuel on the top end, are you using the mainscale or user tune high load? What is your high load setting in kpa? If you have a bin, you could post that here as well. If you can, also try to get a log with TunerPro so you can see what all is going on.

I got some logs while drag racing and found I actually wasn't getting WOT TPS voltage...the logs are very useful...

HTH...
 
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supraguy31

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thats my Problem sir, Im not 100% sure what Im looking for when I look at a Log and when looking at any Specific Part of the VE table.

Now, Now Im using tune tune High but the KPa im not for sure about. Im like a Spounge here and trying to learn everything that I can. On a Side not and I did post this in another thread, 100% throttle, A/F drop Instantly at any RPM and any Speed, Right now its the anything less than 100% throttle where Im still building boost.

Basically, If Im not flooring it then my A/F doesnt want to Compensate for the Boost that is being seen.
Min TPS voltage is .47
Max TPS Voltage is 3.52

Is there somewhere I can set this in the MAFT PRO at the 70% where everyone states it suppose to be.
 
JimR

JimR

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supraguy31;1207066 said:
..............

Min TPS voltage is .47
Max TPS Voltage is 3.52

Is there somewhere I can set this in the MAFT PRO at the 70% where everyone states it suppose to be.
Click to expand...

Of course... and it's called "TPS Start". Do the math to determine what voltage corresponds to 70%, where 0.47 volts is 0% and 3.52 volts is 100%. Then set the TPS Start parameter to that voltage, and that particular setting will be correct.

Read through the "Maftpro Online Guide" for 4.x or 5.x on CRE's site here: http://supra.fadingworld.com/Electrical/
 
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supraguy31

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May 10, 2005
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JimR;1208380 said:
Of course... and it's called "TPS Start". Do the math to determine what voltage corresponds to 70%, where 0.47 volts is 0% and 3.52 volts is 100%. Then set the TPS Start parameter to that voltage, and that particular setting will be correct.

Read through the "Maftpro Online Guide" for 4.x or 5.x on CRE's site here: http://supra.fadingworld.com/Electrical/
Click to expand...


Id this setting relivant if infact you arent using the MAFT Pro boost controller. Im using a HKS EVC IV Boost controller.

Also, With Spark WOT and Spark Aux..... CREs site state that the Standard setting is 15, When I looked at mine for some reason both were at -10 across the board in each tab. What does this effect if anything.
 
JimR

JimR

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supraguy31;1208444 said:
Id this setting relivant if infact you arent using the MAFT Pro boost controller. Im using a HKS EVC IV Boost controller.

Also, With Spark WOT and Spark Aux..... CREs site state that the Standard setting is 15, When I looked at mine for some reason both were at -10 across the board in each tab. What does this effect if anything.
Click to expand...

The answer in both cases is nothing. TPS Start only does what the manual states it does, nothing more. If you're using another boost controller (I missed that part, oops), then it is irrelevant.

As for Spark advance values, they are also irrelevant unless you are wired for maftpro timing control. I'm going to assume you aren't.
 
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supraguy31

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Im only wired as the Installation requires.

Thanks for that Information. So now its to the More complicated stuff, Tuning Part throttle and WOT.....
 
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supraguy31

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Ok all, First I want to thank you all for your help and Im going to throw this last Question out there at you all and I think Im good to go from here. From what I have been told from Sources that our cars go back into Open loop at 68% throttle. Since this is the only Issue I have right now is that it isnt going into open loop at this precentage then what can I do to accomplish this.

Other words, 100% Throttle to the floor, A/F instantly drops to the 11 area.

If Im on the Highway and I have to increase speed to get around a car and I start going into boost levels ie... 6-10psi and my foot isnt all the way to the floor then my A/F will stay at 14.7-15.7 A/F. It will continue to stay at that AF until I either floor it which at that time the A/F will drop or I get off the gas.

No Issues with Idle what so ever... 14.6-15-7 VF Consistant 3.00v (+ or - 10)
No issues with Cruising A/F what so ever....14.6-15.7 VF Consistant 3.00v (+ or - 10)
No Issues with WOT A/F what so ever..... (Average 11.3 to 11.7)

Its the building of Boost without have 100% throttle is the area that is my Issue.

15psi without 100% throttle and I still have the 14.5/15.5 AF levels. Do I add a ton of Fuel to the Mid/high Tune area in those RPM Bands and force it to go rich?
 
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JimR

JimR

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What you appear to be dealing with is actually a limitation of using a piggyback to control open loop AFR's, where the stock ECU still controls closed loop AFR. Don't worry, there are ways around it!

There are actually two main conditions that need to be met in order for the ECU to switch from closed to open loop (when the engine is warm). The first you already know... about 70% throttle. The second is RPM. When the engine is spinning at 3500rpm or less, and the throttle is less than 70%, you will remain in closed loop. If you go over 70% throttle, or 3500rpm, you'll switch to open loop. Those two conditions are independent of each other.

On a stock vehicle, this isn't an issue because your turbo will never build enough boost on part throttle before 3500rpm to go lean. But as you increase the engines ability to breath, you can get 10psi or more in closed-loop, which is an issue. Keep in mind that the ECU is going to hammer away at its trim points to try and maintain 14.7:1 in closed loop, regardless of boost pressure.

There are a few ways to tackle this:

1. Adjust your VE table (through doing runs and logging) so that your points around 2500-3500rpm and > 100 kpa are heavy heavy, say 105% or so. That's the first solution I tried, and it worked fairly well. The ECU's trim adjustment only goes to 20% richer or leaner from the stock map, so you are basically overriding this value by adjusting the VE so it simply can't "correct" that much.

2. Go permanent open-loop, and use the maftpro ptt and wot afr tracking features to control the AFR's across the entire spectrum. This involves removing your stock 02 sensor, and getting a resistor in place to stop the 02 heater signal code from tripping. Then you get the FUN of remapping large sections of your VE table... it just takes time! This is my current setup.

3. Dig into the *Enhanced TPS* function that may have been implemented for 5.xx ... but I'm not sure on this one, because I'm still on 4.8 and I haven't done the research. Anyway, the idea here is that if the Maftpro sees >100kpa (or whatever you set the threshold to), and the TPS is still under 70%, it will go full hard on your AFR's (the signal it gives to the ECU) to richen things up. Don't quote me on the specifics... it's been about a year so read up on this one.


Hopefully that info will point you in the right direction. Each of those options is documented, although you might have to search a bit to find them.

Cheers,
Jim
 
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