Calling any tuners out there

[PNR Welding]

I still don't understand what a tune has to do with boost?? can somebody please explain that?

to my understanding a tune will get your car to run better, efficient, and to make more power.

A car will make boost with a good tune or with a bad tune.

This is from another thread. I just need some advise of what it could be.
My problem is boost in 1st gear and 2nd gear.
I originally thought it was the converter. I told Len what was going on with it and he said it needed to be retuned. When I asked Len if I was going to need a retune when I bought this transmission he said no. So I will have to wait till Jan 17 when I have an appointment with JDM so we can see. Maybe someone can give me an idea.
This is exactly what is going on with the boost.

Sometimes when stepping on it in 2nd gear, most of the times after making a slight turn off of a highway, it will not have any boost until 4500 and then it will take off. Other times it will have instant boost. This lead me to believe that it might not be the TC.
In first gear when I take off it will give me around 8psi and then it will cut back to like 4psi, when I shift to 2nd it will spike to 10psi, and most of the time around 4500 I will get a small hesitation, boost will drop to 5psi and then it will spike up to 13psi. 3rd gear is fine.
My MPH gauge is off by 1/2. Ill be going 60 and it will read 30mph. I dont think this will affect anything but maybe.
Any feedback is appreciated. Thanks

 

[PNR Welding]

I should of gave a little more specifics to my combo. It originally was a Manual transmission and I went with Lentechs 1000 hp 4r70w AODE. It has a Full Manual Valve body and Transbrake. The stall is supposed to be 2600-2800. On the transbrake, with the pedal down to the floor I can get up to 4300.

 

[1Fast05Turbo]

Wow, that's odd. I'm no tuner but I don't think a tune will cause intermittent boost levels???

 

[cekim]

Wow, that's odd. I'm no tuner but I don't think a tune will cause intermittent boost levels???

Well, the tune can miscalculate load which in turn screws up spark advance and VVT. VVT is capable of changing boost, just sd a cam change can alter vacuum (valve timing relative to intake stroke). Not sure I'd expect such drastic effects, but then the tune might be out to lunch... That and if it changes the vacuum, then the bypass mechanism can be altered (as it operates as a function of vacuum).

I haven't done anything with the auto, so I have no idea what other feedback there might be with the trans that could be causing load miscalculations. I presume with your trans they are basically tuning it as if were a manual? Regardless the load calculations will feed through spark and VVT... Easy to diagnose with a dyno and the tune cracked open in front of you - hard to guess from afar...

 

[Hawgman]

Could you have a boost actuator valve that has a slight tear or hole or something? I fought boost issues last year and it ended up being a bad diaphram on the boost actuator valve.

 

[PNR Welding]

Well, the tune can miscalculate load which in turn screws up spark advance and VVT. VVT is capable of changing boost, just sd a cam change can alter vacuum (valve timing relative to intake stroke). Not sure I'd expect such drastic effects, but then the tune might be out to lunch... That and if it changes the vacuum, then the bypass mechanism can be altered (as it operates as a function of vacuum).

I haven't done anything with the auto, so I have no idea what other feedback there might be with the trans that could be causing load miscalculations. I presume with your trans they are basically tuning it as if were a manual? Regardless the load calculations will feed through spark and VVT... Easy to diagnose with a dyno and the tune cracked open in front of you - hard to guess from afar...

Im really hoping its the tune, rather the torque converter. I dont want to pull the tranny out again to send the Torque Converter back for this now.

Could you have a boost actuator valve that has a slight tear or hole or something? I fought boost issues last year and it ended up being a bad diaphram on the boost actuator valve.

I dont think its the actuator valve cause it started to give me problems right after we switch trannys..

 

[GI Joe]

the tune sure can do it. What it is I dont know but I had it happen. Had no boost except at WOT swap tunes and it would crack 13 psi right off throttle. put the other tune in and it would drive like an NA car unless it was at WOT...Wierd.

 

[silverpoison]

the tune sure can do it. What it is I dont know but I had it happen. Had no boost except at WOT swap tunes and it would crack 13 psi right off throttle. put the other tune in and it would drive like an NA car unless it was at WOT...Wierd.

Wierd, I still don't understad the reason why. I would think this is more a mechanical issue.

 

[GI Joe]

Wierd, I still don't understad the reason why. I would think this is more a mechanical issue.

I dont understand it either...I just know it happens. I could not believe the difference and I swapped them back and forth a few times within a half hour...It was weird.

 

[TexasKyle]

"I dont think its the actuator valve cause it started to give me problems right after we switch trannys.."

Coincidence is a bitch when troubleshooting...