Open loop problem GT500

[spitune]

I have an older Ford with a built GT500 engine swap and a 3.4 Whipple. The car starts and idles decent but struggles to rev past 3500rpm. What I`m noticing is that the engine will accelerate smoothly and then will drop into open loop and then it`s like it hits a wall. You can see in the datalog, as I bring up the RPM it immediately falls flat when open loop hits. I have tried a number of different things in the tune to prevent this from happening with no luck. The engine feels like it is getting loaded up and if I push it it,will actually build boost in neutral - something I have never seen. It acts like a car with plugged cats. It does not have cats. I spoke with a tech at Whipple and he was baffled. Apparently the base tune was written using SCT, not sure if this is why I can`t seem to get the tune to react how I want it to, if SCT maybe has a different strategy for open/closed loop that I can`t see. Would appreciate any input on this. I have attached the base tune and a datalog. The datalog is a little long but you can really see the issue around the middle. Thanks!

[15PSI]

There is a GT500 modded calibration by Lund in the repository. I don't know what blower or TB is on the Lund car, but you might do a compare and see what they have done to that tune.

[spitune]

Thanks 15PSI, I took a look at some of the tunes. Not much there and nothing really different from what I have.

[mstang_man]

Whats your setup, MAF, INJETORS, CAI, YR , 5.4 or 5.8 GT 500 i assume 5.4

[spitune]

From what the owner knows this is what I got. Built engine stock displacement 5.4, ID725 injectors, Whipple 3.4, stock MAF, Ford racing twin 63.5mm TB, Ford Racing standalone harness and ECM, long tube headers, return style fuel system.

[wayno]

you can kick up your open loop tps threshold.....I would start by cleaning up your maf curve.

it needs to be a smooth curve and yours is really jacked up, once you do that the car will come around for you and run right.

[spitune]

I tried the openloop threshold and it did not work. I agree about the MAF curve, that is how it was brought to me, I have cleaned it up and it doesn`t correct the issue I am having.

[murfie]

My guess is your throttle body model is what is causing your issue. I attached an image and hopefully you can see it and fix it.

TBM.PNG

[spitune]

Thanks murfie, I hadn`t noticed that. I`ll clean it up and give it a try.

[spitune]

I cleaned up those tables, and although they definitely needed to be repaired it made no change at all to how the car is running.

[murfie]

Do you have a wideband log of the issue? I see the o2 sensor voltage go over 1 when the car goes to OL and the fuel trims cut off. This means the car is running rich and thats what the fuel trims indicate just before they cut off as well. I just want to see how rich its really getting. Looking over your injector data compared to what ID has in their spreadsheet for those injectors your high and low flow rate values are different from what they say they should be.

[spitune]

The tune I posted was the original tune. I did correct the injector data, again the car ran the same. I did notice the O2 and fuel trim as you mentioned. I think there must be a mechanical issue with car. No matter what is done to the tune it it just always runs terrible. And the fact that I can build boost in neutral is leading me that way as well. I'm going to check the cam timing, it is a fresh motor and I'm thinking it was assembled incorrectly.