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Slowxr6t

Overboost

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Iv put a boost guage in my xr6t and it boosts to 10psi then boosts up to 14-15 psi on the overboost on the stock ecu. Can the overboost in the ecu be disabled so it just boosts straight up and doesn't surge? Or is this a 3rd world problem we just have to put up with? I'm getting 2psi boost at 1500rpm with my gt3582r with .7 comp housing. How does that boost response compare with others?

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yes, the overboost control by the ECU can be disabled and your tuner should have done so in the tuning process.

that's pretty normal to have a bit of boost quite early in the rev range, its where in your rev range you have full boost that matters most (it's around 2,800-3,200rpm in a stock turbo car.

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@JETURBO HI, my tuner used hp tuners software to tune my car, he couldn't find the overboost disable function. Do you know where in the program it is, what heading its under? He has asked me to ask you aussie experts on here. Thanks

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He's a good tuner, dynopro.co.nz has a good rep over here, doesn't charge the earth either. Can you help us out? Which section of the program do we find the overboost disable?

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“IF” your tuner can’t work out the very simple boost strategy of a turbo falcon platform he hasn’t even done step 1 R&D 

 

“IF” I tell him how to overcome it you then have a vehicle that’s got a boost error target and how do I know he knows how to fix it ....? 
 

Your tuner might be gods gift but he doesn’t know what is very elementary strategy configuration modifications and knowing what the ECU is doing and commanding is pretty dangerous especially if you say you’re up over 400rwkw already

 

”IF” in fact your tuner does know what he’s doing but going about it in a very backwards way again this isn’t correct and needs to be addressed..

 

There is a reason I tune the turbo falcon for some very reputable tune shops around Australia as the factory falcon ECU is going about engine control in a different way to nearly every other make and model car out there, the WRX platform is closest ;) 

 

I’m not being a *beep* but in-fact looking after your engine for you 

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Ok fair enough, good points there JET. My tuner hasn't done many Falcons, but he's got my car going really nicely and very smooth and safe, he tunes hundreds of cars and hasn't lunched one yet. He's not Gods gift and I'm guessing you weren't either when you tuned your first few Falcons. I respect and appreciate your experience and opinions, thanks

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18 hours ago, Admin (as if) said:

NZ doesnt have any good tuners

Not true. David at Tune Technic only does dyno tuning (nothing else) and has tuned pretty much everything you've ever seen.

Sam at CTB is also very good. Both are in Auckland, not sure about the other end of the country.

 

If you go see either of those guys I can give them phone support to walk them through the boost control issue. It's not that hard once you are made aware of all the tables that influence it.

 

One that catches most tuners out is there is a VCT adder for over/underboost. Not all software packages have these tables mapped, so if you disabled closed loop boost control (lots of tuners do as time is limited and they do not have the budget to tune it) and have a boost error the PCM will play with the VCT to try and help reach the boost target, this will result in very weird torque curves.

 

22 hours ago, Slowxr6t said:

Which section of the program do we find the overboost disable?

https://forum.pcmtec.com/topic/15-howto-boost-control-babf/

 

The FG has more tables again on top of this and the Sprint/5.0 supercharged also have temporary overboost and boost by gear on top of it as well. So depending on which vehicle you have there is a slightly different approach. It isn't as simple as just disabling the overboost, you need to configure the whole boost control strategy correctly, if you do this you retain all the factory safety features (overboost and sensor failure) and also retain the underboost (100% duty) to help get the car on boost faster at part throttle.

Edited by rollex

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So today I went out for a thrash and to see how my car was boosting again, and long story short, I realised that in 3rd gear tip tronic when I boosted it and the boost guage needle was all over the show it was actually the traction control pulling power out and it would go to 5psi then 10psi then surge a bit then go to 14psi. I thought it was the overboost but it is not!! I tried 4th gear and it boosted straight to 15psi, then I turned traction control off and tried 3rd gear and it boosts straight to 14psi, ya. So @JETURBO just to let you know nz does have good tuners. I was glad to find this out.

 

My tuner was glad to hear that he did have it right after all. I didnt realise it was slightly losing traction in 3rd.

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