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Boost

PostPosted: Sat Jan 28, 2012 9:35 pm
by Nate8920.
Hey

Does anyone know how much boost a standard bottom end can handle???.

Thanks

Re: Boost

PostPosted: Sat Jan 28, 2012 9:53 pm
by Kekotic
Stock VF46 is 15psi, you can push that to 16psi relatively safely provided your tuner is competent. Anything after that and you are ASKING for trouble.
And still, no matter how high you put the boost up on that turbo, you're going to blow it & other things before it makes a legit 200kw ATW from what I have heard.

Re: Boost

PostPosted: Sat Jan 28, 2012 9:57 pm
by Nate8920.
What boost would it run at when stock? 6psi?
So 12 psi would be quite safe even with other mods?

Re: Boost

PostPosted: Sat Jan 28, 2012 9:59 pm
by bass_straitener
Nate8920. wrote:What boost would it run at when stock? 6psi?
So 12 psi would be quite safe even with other mods?



1 bar or 14.67psi approximately.

Re: Boost

PostPosted: Sat Jan 28, 2012 10:00 pm
by Smithyy
I think its 8 stock...don't quote me though. I would have thought being stock that anything over 12 is just asking for trouble but im not really sure..

Re: Boost

PostPosted: Sat Jan 28, 2012 10:06 pm
by Kekotic
Smithyy wrote:I think its 8 stock...don't quote me though. I would have thought being stock that anything over 12 is just asking for trouble but im not really sure..

:roll:

Re: Boost

PostPosted: Sat Jan 28, 2012 10:11 pm
by Smithyy
Lol didn't refresh before posting.

Re: Boost

PostPosted: Sat Jan 28, 2012 11:20 pm
by Kekotic
Smithyy wrote:Lol didn't refresh before posting.

Don't worry, you can take my old position on these forums as the guy who doesn't know what he's talking about.

I have moved up in the ranks to the guy who still doesn't know what he's talking about :lol:

Boost

PostPosted: Sat Jan 28, 2012 11:22 pm
by Smithyy
Lol right

Re: Boost

PostPosted: Sun Jan 29, 2012 5:47 pm
by Jim
~15psi normally, maybe ~17psi on a crisp cool night.

I have seen it spike to 18psi before which is nothing dangerous and to be worried about, the ECU will adjust if it doesnt like it. The VF46 would handle 18psi no worries, they aren't as fragile as people think.

In saying that, i have heard reports of the twin scroll VF37's pack it in early.

I used to run upwards of 25psi on my old Legacy GTB, and those turbos are weedy. Loved it, no dramas.

Re: Boost

PostPosted: Mon Jan 30, 2012 8:59 am
by Nate8920.
Has anyone actually got a stock liberty and put the boost up near 16. If you have I would like to know how it goes.
Thanks

Re: Boost

PostPosted: Mon Jan 30, 2012 10:00 am
by senator
Nate8920. wrote:Has anyone actually got a stock liberty and put the boost up near 16. If you have I would like to know how it goes.
Thanks


I doubt an additional psi would even be noticeable.

Your best to get the car tuned where the boost will be maintained throughout the rev range and not tamper off.

I have seen are stock bottom end handle 240kw+ at 20psi with the right turbo, fuel system, exhaust, intake, intercooler and of course tune.

Re: Boost

PostPosted: Mon Jan 30, 2012 11:40 am
by dr20t
The thing people are forgetting is that a turbo's ability to produce boost depends on the pressure area the turbo is forced to work within.

Removing the restriction on the turbine hot side will allow it to make boost more comfortably. That's why a freeflowing turbo back exhaust is one of the first mods turbo owners do to free up the restriction on the turbine shaft and in doing so free up the cool side.

There is so much more to it which is beyond the scope of this thread but to answer the question if using your stock turbo without any other mods except a tune, I would not push it past 15psi simply because it will shorten the life of your turbo and the inefficiency within which the turbo is operating will produce hot air at higher boost and thus increase intake temps amd your ability to make safe power.

Re: Boost

PostPosted: Mon Jan 30, 2012 12:21 pm
by Nate8920.
Can someone tell me how I can contact phat?
Phone number would be great!
Thanks

Re: Boost

PostPosted: Mon Jan 30, 2012 12:30 pm
by <GB>