Screamers?

Started by Aceman, June 11, 2007, 03:08:53 PM

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Aceman

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??

Lum

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!

Aceman

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...

allstaruk

Enlarge the stock wastegate

Aceman

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...)

20B_boy

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\'.
R.

allstaruk

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

20B_boy

Quote from: allstarukif you can reomve the turbo\'s and strip the wastegate off
And if u cant/cba = ball ache & expense :)
R.

chrisJDM

ive heard there are two ways to sort this problem.  Both have already been suggested.

1. Port the wastegate
2. Restrict exhaust

Prof

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
"Plus this engine is probably one of the most volumetric engines going! It passes more air than a herd of cows eating vindaloo\'s" - courtesy of AtomicRex


Grizzly

Fit a Profect B2 and get it set up, it may not cure it but will defo reduce the effects.

Aceman

"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)?

Jim_rx7

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.

Grizzly

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.

Aceman

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!!