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Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: turbotoaster on April 10, 2009, 10:35:16 PM

Title: lowering the boost?
Post by: turbotoaster on April 10, 2009, 10:35:16 PM
just wondering how you guys lower the boost pressure below the standard pressure to save buying an new ECU

my car spikes a little bit at the moment(only on the first turbo for some reason) but ill be fitting a decat pipe soon to free up a few more ponies and dont fancy it spiking so high that i kill the engine

spikes currently up to 13psi on first turbo and holds 10psi

i would imagine fitting the decat would increase this

i thought about ebc but im used to bleed valves and with them you couldnt go lower than stock, just higher(because of just bleeding air off)

i always imagines ebcs did the same thing, is this the case, or can you get it to run less than stock pressure as in my mind you would have to send the wastegates more pressure than normal and not sure how an ebc could achieve that

thanks

Lee
Title: lowering the boost?
Post by: turbotoaster on April 11, 2009, 07:38:56 PM
can anyone help at all?
Title: lowering the boost?
Post by: m1tch on April 11, 2009, 10:57:51 PM
Lower pressure would mean that if you disconnected the piping to the wastegates they would run on spring pressure, might be best to get a EBC though
Title: lowering the boost?
Post by: turbotoaster on April 12, 2009, 05:39:26 AM
you mean then change the wastegate springs or adjust the rod on the actuator then?

you want to increase the pressure going to the actuator to be higher than normal so that the wastegate will open earlier giving you a lower boost pressure going into the engine.

im just unsure on how to increase that pressure, if i were to remove the restrictor pills then im guessing that would do it then adjust it with an EBC?
Title: lowering the boost?
Post by: SiH on April 12, 2009, 08:44:37 AM
Quote from: m1tch;598294Lower pressure would mean that if you disconnected the piping to the wastegates they would run on spring pressure, might be best to get a EBC though

Do you mean disconnecting the piping to the actuators?
If so, I really suggest you don\'t do this, unless you want to run unlimited boost:flamed:spank

Your problem sounds like you are getting spikes - there can be many reasons for this, but before going any further I\'d sugegst checking all the pipes ad solenoids/valves in your rat\'s nest - if the car is otherwise pretty stock, it really shouldn\'t be spiking.

If you have an issue with this already, I really wouldn\'t advise putting a decat in without sorting it first - it\'s a recipe for engine disaster.

FWIW, you can\'t run lower boost than actuator pressure if everything is plumbed in properly.
Title: lowering the boost?
Post by: neil_jdmr on April 12, 2009, 10:45:43 AM
QuoteIf you have an issue with this already, I really wouldn\'t advise putting a decat in without sorting it first - it\'s a recipe for engine disaster.


I agree, I had a very similar problem but with the second turbo creeping and although the car still felt quick when pip put it on the dyno it was only pulling 230hp:2eek.
 
If you put a decat on it now, it is running a high chance of blowing it up, if not the stock ecu retards the stock timing when it senses higher than standard boost so if anything it will make your car run worse
 
It was a 2 minute fix for pip and the car runs like a dream with a pfc mapped with a de-cat and he got me pretty much a 100 extra ponies.
 
Best pound for pound mod i have ever known imo
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