Cutting a long story short, when moving from sequential to non-sequential twins I suffered heavy boost creep and have had to move back to seq. Having issues on seq (misfire when 2nd turbo kicks in etc) so wanting to try "poor mans single" again..
I\'ve been told that a "screamer pipe" might be able to assist with this..
Thus, can someone explain to me what exactly a screamer pipe is (vents built up gases to atmosphere when pushing high boost?) and does anyone know the legalities of them?
Then, I guess, the question is where to buy and cost of installation??
Mate to run a screamer pipe you need a external wastegate. As far as i know there is no way of fitting one to stock twins as they are internally wastegated!
A scremar pipe is simply a way of venting the excess gas from the manifold via your wastegate to atmosphere.
You either run the pipe back into your exhaust system to keep noise down or vent to atmosphere if you wanna wake the dead!
Neither way will have any affect on boost creep. That is controlled by the wastegate itself.
The only wa y a screamer pipe would affect boost creep is if it was too small therefor restricting the flow of gasses being released!
Hope this helps!
Ok, might pose a problem using the twins then...
Hmm..
Any other ways I can extend out-flow? I\'ve got an extended street port which I guess is causing me the issues as it\'ll be allowing higher flow in than out (? Guessing like always here..).. I\'m thinking a boost controller might be a starting point to issue resolution, but not likely to assist much overall..
Perhaps I should just bite the bullet and find the umpteen grand for a single tubby...
Enlarge the stock wastegate
Quote from: allstarukEnlarge the stock wastegate
Good point... doh!
Obvious question then - is it costly?? Just about to fork out for respray so money\'s tight (hence the poor man\'s single option...)
Dont imagine getting the wastegate opened out will be that cheap, bit of a ball ache sending them away etc too.
You could try just shoving some thing more restrictive back into the exhaust system (e.g. a cat), you\'ll lose a bit of power but a simple \'fix\'.
Quote from: 20B_boyDont imagine getting the wastegate opened out will be that cheap, bit of a ball ache sending them away etc too.
You could try just shoving some thing more restrictive back into the exhaust system (e.g. a cat), you\'ll lose a bit of power but a simple \'fix\'.
Depends on you mechancial competency, if you can reomve the turbo\'s and strip the wastegate of and get a local engineering shop to enlarge it its not gonna cost much at all.
A
Quote from: allstarukif you can reomve the turbo\'s and strip the wastegate off
And if u cant/cba = ball ache & expense :)
ive heard there are two ways to sort this problem. Both have already been suggested.
1. Port the wastegate
2. Restrict exhaust
A long shanked burr tool, a drill and a lot of time and beer - that will get your wastegates ported.
You could also replace the turbo pack for the later higher flowing ones, as IIRC the later models supported a little more exhaust flow and higher boost
Fit a Profect B2 and get it set up, it may not cure it but will defo reduce the effects.
"Fit a Profect B2 and get it set up, it may not cure it but will defo reduce the effects."
Is the Profec-E01 the same thing (but with a fancy screen etc)?
Can you not weld the internal wastegate and weld an external one to the manifold??
I don\'t know much about rx7s but that was defo a possibility on a Mr2 turbo.
Quote from: Jim_rx7Can you not weld the internal wastegate and weld an external one to the manifold??
I don\'t know much about rx7s but that was defo a possibility on a Mr2 turbo.
Yes, but the time and money it would take to do may be easyer getting a second hand single Turbo. Plus the way the Twins work and the space involved would make it very Difficult.
Yes, The E01 is basicly the same sort of thing, i use the B2 so i can Vouch for it being good but i\'ve never used a E01 so i can\'t recomend it.
Have you checked there is a Pill in the Actuator pipe?
If all this Fails you may be left with no option other than to add some sort of Restriction in the exhaust (as Rich pointed out) but from Past experiance my Profect helped alot.
Cheers guys..
Been meaning to get a boost controller for a while now, so will look to attempt to see how this goes before giving the other options a go..
Doing it this way also helps on the way towards single tubby, which is the plan at some stage!!
As you are suffering boost creep then a boost controller will not help you. Your problem is the wastegate not being big enough to expel excess boost due your free flowing exhaust, whichever you want to tackle.
An exhaust restrictor is very easy to do.
Quote from: Ricco_04As you are suffering boost creep then a boost controller will not help you. Your problem is the wastegate not being big enough to expel excess boost due your free flowing exhaust, whichever you want to tackle.
An exhaust restrictor is very easy to do.
You would think not, but I have had this problem and fitted a Profet B that reduced the problem to the point it was usable. From what i\'m told it prempts the Target boost and opens the wastegate early so effectivly the target boost is Lowered so it Spikes to the Level you want.
I can not coment on other makes or Models as i\'ve only had experiance with the B2.
Yes an Exhaust Restrictor would do the job but some of the restrictors i\'ve seen to do this job have a hole in about 1 1/2" so it would be better to refit the cat??
I would be Checking the Pill is fitted in the wastegate pipe too.
That is interesting about the controller :) (now my brain hurts :Laugh )
Yeah, I would agree that the restrictor ring is a temporary measure so if no further mods required and airpump is staying then may as well lob the cat back on or maybe even a sport\'s cat?
i just made a post about wastegate porting, should help with boost creep
http://www.mazdarotaryclub.com/forums/showthread.php?t=39764
I have not come across a setup yet on the twins that I have not been able to get control of the boost.
It sometimes starts off with boost creep,but with alot of perseverance it should be possible to control boost creep on twins in either setup,ie sequential or non sequential,on an Apexi ECU.
All this should be able to happen without any porting of wastegates and open exhaust\'s.
Regards
Carl