TDStuart Tuning Adventure

[tdstuart]

This is related to the VCT phaser and their range of motion. After market cams you could change EVC, IVO, and IVC, but it doesn't change the phaser range of motion so all your MP angles don't need to be changed.
I don't think the opening and closing events remaining stock or changing them will do much.

There seems to be a big difference between the cams and ivc * assuming I have the right cam specs.

I am just trying to think on the issues I have been having. Only thing that makes sense is the cams are throwing off the cars calculations. If the valve opening and closing angles could be corrected I would think that would help a lot.

For others I am working through this thread where @markmurfie and others were discussing these parameters as well as how the engine was using the vct settings.
https://forum.hptuners.com/showthread.php?53421-2015-GT-Valve-Overlap-Tuning

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[tdstuart]

I don't see where any of this really helps, though, because all the calibration data isn't that accurate anyway. Scooting the cam angles around a bit might help a little but not the right way to fix it and it's a crapshoot that might improve some things and hurt others. I do think your SD model needs work more than anything else.

The main difference between the cams is the duration and the opening and closing positions of the valves. If I could correct one of those things I would assume I would get a lot closer. Would probably also get my mp settings closer to being correct.

Let me know if I am thinking about this wrong. If I can get the car to "know" that the cams are different then I would assume everything would be a lot closer and maybe I wouldn't be having some of the weird baro and drivability issues I am having.

 

[WildHorse]

I'm learning quite a bit from all this. Kudo's to all !
@Jarstang do you think we can get this thread stickied ?
There's like a ton of very good info.

 

[engineermike]

@tdstuart sorry, that's not how it works. The calibration data that is fully populated into the torque, spark, and SD models is based on extensive computer modelling and testing of an engine. Just changing these valve event parameters isn't going to automatically correct all the calibration data. For instance, the intake valve event data is used to determined when it needs to turn on the injector to achieve Open Valve Injection, and may have nothing to do with the applicability of the SD model. I'm sorry to say that there will be no good shortcut to correcting this data.

If it were me, I'd start by minimizing the mapped points in use. Set up like 0/0, 20/0, 30/30, 15/15, and -20/15 as your only 5 active mapped points. Create snap lines between them in the order of flow. Then only command cam timing that lands on these points or on the snap lines. Next, isolate one mapped point and start tuning it. It will save time to just concentrate on the loads and speeds where you want to use that mapped point. So 30/30 would be used most often; lock the cams at 30/30 and start tunning it. Torque probably isn't that critical at this stage, but SD is. Start tuning the SD model until observed MAP = calculated MAP. My guess is you'll need to achieve higher MAPs for any given MAF. To simplify things you might just concentrate on the slope values to get "close". Then you can move on to MBT and Borderline timings. MBT will need to be estimated based on similar engines, perhaps by comparing Voodoo, Gen3, and Gen2. Borderline can be determined by logging of knock activity vs timing. Then move on to another mapped point once all this is done. After all 5 are reasonably calibrated, then unlock the cams and let them follow a normal distance table.

 

[tdstuart]

I'm learning quite a bit from all this. Kudo's to all !
@Jarstang do you think we can get this thread stickied ?
There's like a ton of very good info.

I think it would be better to make a DIY Tuning section. If anything should be stickied it should be write-ups of tunes and direct information (info on mapped points, info on calibrating xyz, info on tuning spark, etc.).

 

[tdstuart]

@tdstuart sorry, that's not how it works. The calibration data that is fully populated into the torque, spark, and SD models is based on extensive computer modelling and testing of an engine. Just changing these valve event parameters isn't going to automatically correct all the calibration data. For instance, the intake valve event data is used to determined when it needs to turn on the injector to achieve Open Valve Injection, and may have nothing to do with the applicability of the SD model. I'm sorry to say that there will be no good shortcut to correcting this data.

So here is my logic.

The car has all this data torque, spark, sd, etc. for the car at certain loads, rpm, etc. + vct. They split the vct part into mapped points. The mapped points are based on what the car is advancing/retarding based on the base ivo, ivc, and evc data.

If the camshaft ivo, ivc, and evc data changes then the mapped point data will all be off unless the base ivo, ivc, and evc is corrected. Im not saying it will make it perfect as the camshafts have different duration and separation but it should help get the data closer.

Even if it doesn't help the mapped points data be more accurate, it should make the mapped points more accurate because now the modified base + vct should = stock base + vct.

 

[Pistol_91]

Correct me if I'm wrong here guys but, PCMtec doesn't have an SD calculator like HPT does? Or do they now?

 

[tdstuart]

My question is which way should I adjust the base cam timing? And do I use comp cams data for the base adv of the stock and aftermarket cams to compare?

 

[engineermike]

@tdstuart the mapped point locations are based on IVO and EVC. According to the cam data you posted, Comp didn't change IVO and EVC much at all. The biggest changes are on the other sides of each lobe, and the changes are significant. So, even if you were right about the mapped point calibration data, you would only be moving each one a couple of degrees at the most which would make no discernable difference. Even if this wasn't the case, it still wouldn't work at all because no Ford-calibrated mapped point data is going to be correct when you add 20+ deg duration to the camshaft. Youd be better off randomly moving mapped points and hoping the data fits better at some other location.

 

[engineermike]

@Pistol_91 HPT does have an SD calculator and PCMT does not. Not sure if you've played with it, but it basically just does the quadratic regression for you if you modify some load-to-map points in the matrix. You still have to isolate mapped points and run each speed through a number of loads to get MAF:Load corrections, populate the SD calculator, transplant the data, rinse and repeat.

 

[tdstuart]

@tdstuart the mapped point locations are based on IVO and EVC. According to the cam data you posted, Comp didn't change IVO and EVC much at all. The biggest changes are on the other sides of each lobe, and the changes are significant. So, even if you were right about the mapped point calibration data, you would only be moving each one a couple of degrees at the most which would make no discernable difference. Even if this wasn't the case, it still wouldn't work at all because no Ford-calibrated mapped point data is going to be correct when you add 20+ deg duration to the camshaft. Youd be better off randomly moving mapped points and hoping the data fits better at some other location.

Yes but the ecu still has a parameter for ivc I can change so maybe it uses that in some calculations.

I don't think it would hurt, just may not make any significant improvement.

I just need to know the correct way (direction) to adjust it and if I should base my adjustments off of 0.05" or 0" of lobe lift. I also need to know if I should compare them with the cam advance comp says (7 for stock, 9 for aftermarket).

 

[WildHorse]

Just get as much overlap as you can.

 

[engineermike]

Yes but the ecu still has a parameter for ivc I can change so maybe it uses that in some calculations.

The IVC parameter is NOT used to determine, adjust, or offset SD, torque, and spark data. That data is simply tied to a certain [stock] cam location. Just lying to the logic about the cam location will not suddenly correct all the calibration data. This short cut isn't how you calibrate an engine. As far as I can tell, the IVC and IVO parameters are only there for injection timing reasons.

 

[tdstuart]

This short cut isn't how you calibrate an engine.

Yes, but why have the incorrect data when I can have the right data? That is what I am saying. Why purposely have the wrong cam data when I can adjust it to be more correct.

 

[Pistol_91]

@Pistol_91 HPT does have an SD calculator and PCMT does not. Not sure if you've played with it, but it basically just does the quadratic regression for you if you modify some load-to-map points in the matrix. You still have to isolate mapped points and run each speed through a number of loads to get MAF:Load corrections, populate the SD calculator, transplant the data, rinse and repeat.

Ok that's what I figured. I have messed with it many times. It's very finicky. It doesn't like big changes when entering data as it will revert it back to something it was already near when you calculate it.
He can make a histogram and put a filter on it for each mapped point that way he doesn't need to lock down mapped points and it will only show data in the histogram for when that mapped point weight was being used. Time consuming though. Either way calculating SD is going to be a pita for him.

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