Is remapping needed after BPU setup changes

[Pedroby]

Probably this question is asked many times but I can't find the answer via the search function.

 

I have a J-spec (A/T) GTE stock twins setup with stock SMIC, both decats, Blitz Nur spec R catback and go for upgraded Walbro 255 pump and HKS FCD.

Will also replace the spark plugs for a colder type. Apexi BOV will also be installed but I suppose that will have no influence for the setup.

 

I know after removing both cats and mount a free flow catback the turbo pressure will go sky high and blow the engine.

But is it that easy just to add a proper boost controller, such as the Greddy, Blitz or HKS?

 

A member just told me even with a boost controller I still need the restrictor ring between the decat pipes. But that sounds kinda weird...you upgrade to bigger for free flow and than add another restrictor. Can we conclude the aftermarket exhaust systems are all oversized then?

What do I have to do to lower the boost without a restrictor ring?

 

Or do I need to remap the ECU? Add a piggyback or something different?

 

If so, what remapping is required or recommended?

Edited March 18, 2013 by Pedroby (see edit history)

[listy]

No remap is needed. Even a Boost Controller is preference over need. All that is needed is a 1 bar restrictor ring in the exhaust.

[mellonman]

the stock ecu can not be mapped, but its all good for bpu but when hybrids or single a piggy or stand alone is best fitted

[Dim Sum]

Just adding to what members have already mentioned

 

You don't need a re-map but the stock ECU can't be map anyway.

Here's a link about BPU

 

http://www.mkivsupra.net/vbb/showthread.php?94705-BPU-(Basic-Performance-Upgrade)

 

I guess it depends on your budget, I'm BPU at the moment but i want to buy the Syvecs to make it more efficient.

[Pedroby]

Thanks for the replies and link, which I already knew, but couldnt find any info about remapping or adding piggybacks to the ECU to make it more efficient.

Complete ECU remap is maybe interesting for any future projects with single turbo.

[Guigsy]

Also to add. You need the restrictor to stop too much boost blowing your turbos. So you fit a 1 bar restrictor. This will keep the boost arround 1 bar. But could be more or less depending on environment etc.

To increase the boost you need a boost controller. Boost controllers only increase not reduce boost. So without a restrictor ring in there it's useless

[Guest Budz86]

The reason you would fit a RR is to ensure the turbos don't overspin and break. The boost controller allows you to safely increase the pressure to a level you want, and it makes sure it won't rise past that level, keeping them safe.

[Pedroby]

Thanks guys, I understand that part and just fabricated myself a restrictor ring with 50 mm hole.

But in theory you could also experiment with bigger size restrictor rings.

But then still in my opinion this is stupid tuning as you first put a big pipe on the engine and then restrict it again

 

Would say there must be a better way. But this is definitely the most cost efficient way to be effective.

[CanisLupus]

There is. Get the Turbos to a Turbo Specialist and let them machine the wastegate more open. There is some space to do it. Don't know how it works on Stock Turbos but with that mod i can drive Hybrids at OEM Pressure if i want with a 3" Turboback exhaust