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Discussion Starter · #1 ·
Hey guys, Sorry if this post has been answered already, I've looked all over the site and may have overlooked it, but I have a question...

Firstly, I've just turbocharged my '94 2,5 V6 mx6 and i've been trying so hard to get an external wastegate with a weak spring... my boost is about 0.5 bar +/- 7psi with stock internals. (the lowest i can get) I will be changing my pistons and rods later in the year and was wondering what is the safe maximum boost that i can run my car at for the next 6months with stock internals? Its going in for new engine management and mapping on Monday (19th Jan) and really don't wanna break anything...

is 7psi acceptable?

If this question has already been answered, my humble apologies, but any help or pointers would greatly be appreciated.

Thanks
...Peter
 

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the engine will handle it, depending on several things...

fueling?

size of turbo?

injectors?

specify those, and we can give you a more complete answer.
 

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Discussion Starter · #3 ·
the engine will handle it, depending on several things...

fueling?

size of turbo?

injectors?

specify those, and we can give you a more complete answer.
I'm replying from my mobile, so excuse the lack of paragraphs. I've added an additional fuel pump from a BMW 540i, stock injectors, 'XS Power' t3/t4 turbo, starts boosting around 3500rpm, gonna b running a 'dictator' stand alone management &a 57mm exhaust. I hope thats enough info?
 

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sort of.

What kind of fuel flow does that 540i pump produce?

What kind of fuel pressure do you have currently, and in what ways will the dictator stand alone allow you to modify this? (not all standalones are created equal, and i'm not familiar with your brand)

7lbs from a t3/t4 and stock injectors isn't a good idea. Moreso than the fuel pump - i think you need to upgrade injectors, at least to the millennia S red-top injectors, which are direct drop ins for the stock rails, and harnesses.
 

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My first suggestion would be to attain a wideband O2 sensor so you know if your running lean. I know the stock 2.5 V6 injectors cannot handle 7 PSI (@230cc)

I my millenia S injectors (@270cc) were maxed at 8 PSI on a standanlone system.



So to sum it up, Wideband, Standalone, and Injectors. Until then I wouldnt go past 5 psi unless you want to blow the motor before you do the new build :)
 

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Discussion Starter · #6 ·
Thanks you for all the info... When the mapping will be done, i will know if its running lean or not... as for the fuel pump, not sure of its output, but its for a V8. Basically, I will change everything that will still be necessary for adequate fueling, etc... just want to know if the stock rods and pistons will handle 7psi boost. today I modified my wastegate a bit and managed to get it down to 6 psi...

I shall post a photo next week.

Hope you guys have a great weekend :)
 

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Yeah, stock rods will handle 7 PSI not much more than that though.

If you have a 7psi spring in your wastegate you wont be able to boost less than 7psi. I wouldnt modify the wastegate to attempt to go lower. Either buy a new spring or modify your pedal foot action :)
 

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hey were about in south africa are you based peter ?

The dictator management system is good, its similar to megasquirt but has one or two less features .
 

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Discussion Starter · #9 ·
Yeah, stock rods will handle 7 PSI not much more than that though.

If you have a 7psi spring in your wastegate you wont be able to boost less than 7psi. I wouldnt modify the wastegate to attempt to go lower. Either buy a new spring or modify your pedal foot action :)
Ok, its official, I've managed to have a test run... I'm boosting 6psi, so I'm hoping it will hold out for 6months or so till i get some more time off work to change the pistons... :) lol

Hope everyone has a great week!
 

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Discussion Starter · #10 ·
hey were about in south africa are you based peter ?

The dictator management system is good, its similar to megasquirt but has one or two less features .
Everyone's recomended dictator, so I've gone with that one :)

I'm based in Durban too... have you ever seen a "dakar yellow(like the M3 yellow)" mx 6 with black bonnet and a full body kit driving around? as far as i know there are only two yellow mx6's driving around, one is completely stock, and then there's mine... not so stock lol...
 

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"And a standalone fuel management system, nice way to spend $10,000"

well, our engines (de) have good compression for turbo, i'm pretty sure 7 psi would be no problem. It depends on how healthy your engine is really.
 

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Discussion Starter · #12 ·
"And a standalone fuel management system, nice way to spend $10,000"

well, our engines (de) have good compression for turbo, i'm pretty sure 7 psi would be no problem. It depends on how healthy your engine is really.
lol... I hope so...

Well, today's the day... it'll probably only be finished tomorrow, so lets hold thumbs...
 
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