Boost issue

[EgoXR6Turbo]

Hi Guys,

 

So I have a FG turbo it’s got all the usual bolt ons standard turbo and tune. It has 4 tubes through PCM Tech. Low boost, high boost, boost per gear and valet.

 

It’s basically got full exhaust including dump, intake fuel pump, injectors, intercooler, gfb diverted valve usual type stuff. 

 

I have this issue so if I’m on the highway and try to accelerate in 5th gear it will boost up to 10 psi and then surge up and down between 10 to 15 and really struggle. The boost is all over the place. Even if you are WOT to redline in 4th then hit 5th it basically does the same thing will hit 10 psi then won’t make any more boost before finally shooting to 15. 

 

In 3rd gear also it will hit 10 pound and sometimes it will sort of struggle to make more boost then shoots to 15. Other times it’s fine. this is in boost per gear tune and high boost. 
 

1st, 2nd and 4th gear are fine. Pulls up to max boost beautifully. 
 

I suspect it’s a boost control issue. Cleaned solenoid seem to make it a bit better in 3rd gear but not 5th. 
 

im looking down the path of actuator which is standard. My tuner advised me it doesn’t need the flapper mod and so did a few other places. He did mention it could be the reverse light switch being a manual. Basically he said when it’s under max load in these gears it’s triggering the ECU to think the car is in reverse and is dropping power. Apparently it’s not super common but has seen it happen a few times. Mine is manual. 
 

I would be surprised if it’s a bad tune. Where I got it done all they do is mustangs and Falcon s for the past decade and he would have seen hundreds of set ups like mine.
 

Anyone heard of this or have any other suggestions? 

thanks

[k31th]

it does sound like your boost-by-gear tune isn't that good in those specific gears... I can't think of what else would explain something like that... not sure on the "thinking it's in reverse" hypothesis

[EgoXR6Turbo]

Yer I was a bit surprised by the reverse light switch but hey they are supposed to be the experts.

The only thing with that is it does the same thing on the high boost tune so it’s gear specific rather than the tune

[k31th]

well, if it's gear-specific across multiple tunes then it's related to the boost-by-gear for those specific gears in the tunes, I'd still think and they copy+pasted the source of the problem from your low-boost to your high-boost tune etc... or the tune(s) is(are) good and the parameters are actually not sending good information to the tune and it's stuffing up along that pathway... either way, the tuner should be able to sort it by defaulting some values and seeing if the problem goes away.

[EgoXR6Turbo]

Yer true it’s really given me the sh*ts. They are 1 hour and half away and can’t get in until 2 weeks. 
 

He is quite arrogant as well so I’m half inclined to take it somewhere else however if I do take it back there it’s prob not going to cost me anything. If I take it somewhere else I’ll have to pay for it again. 
 

I’m wondering as well when it was on the dyno id say the load is prob different compared to the road and don’t they normally run it up as in come on full boost in 4th gear. 

 

so they are not even testing out other gears is there just an assumption that the same parameters will work from 4th gear to the others?

 

1st and 2nd and 4th gear on boost drives amazing. Normal driving drives great. 
 

So doesn’t sound like a waste gate actuator? 

[k31th]

nah, doesn't sound hardware if it's perfect in 3 gears and not so in the other 2 (I figure you don't bother boosting in 6th haha)

[EgoXR6Turbo]

Haha nah only a little half squirt to overtake. 
 

Good help is hard to find. Hopefully they can sort it. Thanks mate 

[biddie_fiddler]

Often issues like this are best brought up with the tuner.

 

I had a misfire issue that I was too scared to bring up with my tuner because of his high rep and it sounding like a stupid problem.

Eventually had enough of the issue and went to see him. He dropped what he was doing and really tried to help. Got the laptop plugged in and we went for a drive. Now its fixed!

 

TL;DR. Talk to your tuner. They could have missed something in the tuning process. The fact they do a lot cars can also make them forget simple things.

You paid to have a solid tune and to have the right to bug them about issues with the tune  

[k31th]

Yeah, surely they can sort it out, and arrogance isn't the worst trait if they get the job done haha. Good luck.

[EgoXR6Turbo]

The conversations I have had with them are basically he can’t believe this is happening he has done hundreds of these etc. Those comments and his persona was where the arrogance comment come from. He wasn’t aggressive or anything just arrogant. 
 

So It makes you reluctant to keep going back as it’s not very accommodating. They are going to check it out and put back on the dyno in a couple of weeks and hopefully sort it out. But 100% you pay for it and it should be right. They said if it’s tune related there will be no cost. 
 

No problem with the arrogance as long as it gets sorted. 
 

hopefully will be all sweet in a couple of weeks. Thanks guys