Slight miss at Idle.

[Daryl333]

2017 Mustang GT
25,000 Miles. 6R80
Whipple Gen 3
ID 1050 Inj. been professionally inspected
New NGK 6510 Plugs .028".
No codes.
Can feel miss in my seat and see in the puffs in exhaust stream.
Can see minor fluctuations on tach and vacuum gauge.
Install has been inspected with smoke,Propane and visual twice. Tuner says logs are fine.
Have a short video.
Is this my OCD or is something amiss here?
Thx.

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[Proshop]

Any fuel mods other than the 1050’s? Looks pretty normal to me but my car behaves like a race car most of the time so..

 

[HKusp]

I don't see anything out of the ordinary from my experience. Engines have a little bit of fluctuation from time to time during idle. I don't doubt that you are sensing something different than you are used to if this is a new install, things are going to be different from when it was stock because the tuning is different.

 

[Daryl333]

Any fuel mods other than the 1050’s? Looks pretty normal to me but my car behaves like a race car most of the time so..

VMP Fuel Boosta Pump.
I've been told the Whipple 132 TB causes this slight fluctuation. But being able to feel it in my seat bothers me...
Lol

 

[Daryl333]

I don't see anything out of the ordinary from my experience. Engines have a little bit of fluctuation from time to time during idle. I don't doubt that you are sensing something different than you are used to if this is a new install, things are going to be different from when it was stock because the tuning is different.

My 3V cars had a 2.3 Roush and a 2.3 Whipple and never felt this miss. But people are saying live with it but...

VMP Fuel Boosta Pump.
I've been told the Whipple 132 TB causes this slight fluctuation. But being able to feel it in my seat bothers me...
Lol

Is the vacuum gauge supposed to fluctuate like this?
Thx

 

[BlackandBlue]

Larger injectors lose resolution since they are moving more fuel and the pulse width is lower than smaller injectors. At high Rpm/load it is the same but not at idle.

They will be less precise so a random miss at idle comes with the territory.

 

[HKusp]

Again, I am not saying you are crazy. We know our cars and you obviously have significant experience with forced induction cars. One thing I would do is plumb in a mechanical boost/vacuum gauge and see if it is mirroring the electronic gauge you are seeing on the dash. That one the car is using , obviously is electrical and uses data from sensors and the PCM infers boost/vacuum from input it receives and uses an algorithm. Some of that input is now changed based off of tuning so that may account for some if not all, of the fluctuation you are seeing.

 

[Daryl333]

Again, I am not saying you are crazy. We know our cars and you obviously have significant experience with forced induction cars. One thing I would do is plumb in a mechanical boost/vacuum gauge and see if it is mirroring the electronic gauge you are seeing on the dash. That one the car is using , obviously is electrical and uses data from sensors and the PCM infers boost/vacuum from input it receives and uses an algorithm. Some of that input is now changed based off of tuning so that may account for some if not all, of the fluctuation you are seeing.

Well I didn't use a mechanical but installed an AEM Digital Boost/Vacuum gauge coming off a port in the Whipple Manifold.
Dash gauge reads 18.5 AEM Gauge reads 20.
Have a dyno appt on the 10th to get a WOT log so haven't gone into boost yet.
What concerns me is my tuner thinks that the Whipple 132 Throttle Body Angle is causing the slight stumble at idle. And that he can't do anything about it.
Wouldn't all cars with Whipple TBs be fluctuating at idle? Lol Or is it time to be looking for a new guy.

 

[Daryl333]

Larger injectors lose resolution since they are moving more fuel and the pulse width is lower than smaller injectors. At high Rpm/load it is the same but not at idle.

They will be less precise so a random miss at idle comes with the territory.

Okay sort of what my tuner said. But he said it was due to Throttle body angle of the Whipple 132 TB and there's nothing he can do about it.
So after hearing you it's starting to make sense.

 

[HKusp]

I know a lot of Tuners had difficulty with the early Whipple 132's. I don't know if Whipple changed them, or if people eventually got a better handle on them, but it's not as big of a problem now as it has been in the past.

 

[Daryl333]

I know a lot of Tuners had difficulty with the early Whipple 132's. I don't know if Whipple changed them, or if people eventually got a better handle on them, but it's not as big of a problem now as it has been in the past.

I contacted a four letter tuning company and they said they have no troubles tuning tuning the Whipple TB. But $800 is a lot to spend for an idle fluctuation.
We'll see I guess, thx for the feedback.

 

[Daryl333]

Any fuel mods other than the 1050’s? Looks pretty normal to me but my car behaves like a race car most of the time so..

Li Tuning Return style system

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