Hi all, i wrote now a really big post and that took to long.. so it was automatically deleted..

ok again.

as I can currently not afford a 3 inch Downpipe, I made my own one to reduce the exhaust temps and the decrease the restriction of the oe downpipe. I bought a tial waste gate and welded it to the DP...that looks like this:

Clicky

and again

Clicky


The WG opens at approx 0.8 bar...sounds like this:

https://www.gscf.biz/OpenGroupware/wa/vi...JiQgIan8NzWnZpj

sorry for the short post but I really dont want to write again all the stuff I wrote

if you have questions, please asked...wanted to share my ideas with you....super forum

more info will come, as soon as the GT28R is installed and the exhaust temp sensor...this will be end of august..i think...if I got all parts needed by then....

greez mirco

doesn't the external wastegate need to be mounted prior to
the turbo ?

that's what I thought myself

mirco: can we have a close up photo of the begining of the DP please?
I'm thinking of builting a custom DP as well on a GT28R 5stud flange... Dunno how easy it is to built especially the top bit

V.

That can't be right the wastgate should be connected to the exhaust mainfold before the turbo. I'm sure what you have done is causing the back pressure to exit via the valve.

I guess maybe he is running internal wastegate and this "mod" is only for releasing some of the pressure in the dp out through the valve?

EDIT: yogisdk, exactly

Hi pistole,

Yes thats true..a ext. wastegate originally is to bypass the turbo..like our internal wastegates...

but my project here has actually nothing to do with a wastegat for the turbo..mhh...its difficult to explain for me..

as all of you probably know..the oe downpipe is a peace of crap...the exhausts can not flow well...in my Idea, all the exhausts go out of the external wastegate an bypass the whole exhaust system..is like you do not have an exhaust

the idea came from atp...its called VES here:

http://www.atpturbo.com/root/releases/release091004.htm

and here you can see the whole OE DP with the mirco made wastegate bypass

http://666kb.com/i/afpofyudt8tr88huh.jpg

greez mirco

mirco,

isn't this VEs thing you built too high up in the exhaust gases path?
(too hot, too messy for the engine bay) or are you going to stick a side pipe to it?

I have no sidepipe until now..it seems to be ok..but you have to cut out the undertray..but to be sure, i would recomend to fit a sidepipe or just a pipe alowing the exhausts go straight down..

Im driving like this since april or so...everithing is ok...no increase of temps..

An additional pro is, that it only opens after loading 0.8 bar...so I can cruise and its closed...after pulling it opens and the sound is great the people arround are shocked like hell ..spool up is also much better...

greez mirco

I thought I'd read on here that it was actually a little better for the turbo (oil seals) to have a little back pressure from the downpipe - catalytic converter?

By adding the bypass valve, would this not reduce back pressure, and in turn would that not run the same problems as those who have removed their catalytic converter and found their turbo oil seals start to leak?

circolo:
That problem is only for the std turbo as far as i know...

what are the other specs of your car mirco?
What turbo are you running?

V.

currently only:

digitech
the DP
Valeo competition clutch

but the GT28R will be installed in the mid or end of august..

I think what Mirco has here is effectively this :-

http://www.atpturbo.com/root/releases/release091004.htm


ie , something of a 'bypass' system.

Think there is someone else who has done this to a coupe using the ATP kit. From Thailand maybe?

sounds like a good idea.

maybe paired with a big ext. wastegate , it'll work great
and will probably be cheaper than that ATP setup.

mirco , where did you hook up the pipe for the ext.
wastegate ? and the pipe goes to ?

I think that DavidL has it from ATP...

which pipe do you mean?the pipe for the input of the WG? this goes to a boost nipple which I put right before the throttle....I can make pics if you want...

greez mirco

Ok, now I understand. Well the theory makes sense but does it actually work in practice or is it like one of those ebay electric superchargers but on the exhaust (another gimmick). When that valve opens it must make loads of noise as there are no back boxes in the way. I would like to try this but I don't intend to cut my custom 3" DP I would put it just after the DP as shown in the ATP pics. What valve did you use and how much?

I guess it should work, it quite free flowing and no restrictions...it should make a lot of noise, and can imagine some flames coming out also Well depending on the power

it works for sure... as i said, im driving with my custom DP since some month....the turbo spools up quicker...regarding the exhaust temps, if they decrease, I have to check when I got the manifold temp sensor.

The Wastegate you can almost get everywere...it is a Tial WG

yogisdk: no flames until now noticed wait until the other part are installed and then lets see...thinking about a little camera unter the coop to see how flamy it will be



BTW: A friend of mine is also driving a DP like mine with the same Turbo that you have...sound is

Mirco,

what's the diametre of the ext.wastegate you fitted there?

I'm thinking that this way you could have everyhing:
- quiet run (up to a point that is )
- keep whatever cat and exhaust you have (assuming a 21/4 or 2.5" system)
- keep some backpressure for low boost situations
- have a 2"pipe out of this extwastegate running just behind the ofside (most likely) front wheel flaming the surrounding and sounding ace

This way, I'm sure 2" 1/4 + 2" > than 3" expensive decat ss system, right?
Only cost is a custom dp all the way to the stock (or what have you cat box) and the ext wastegate.

Please don't tell me I've got something wrong, as this should save me enough euros for my WI

On another note, how difficult would be to use a CFD program to calculate / design an half decent reasonably flowing DP for the 5stud wastegated ending 28R/RS turbos?
[me recons it's rather easy, anyone tried it?]

cheers

you right m8

you only need a wastegate actually. and weld that to the OE downpipe.the same way I did. Its super easy to do...

I took a 38mm ...so its a little one..but this should be sufficient...

BTW. did the videos work for you?

I see,

need to check the costs of these ext.wastegates. Is there some sort of regulator to set the opening point of the gate (say I want to tune it to open at 0.6 bar to improve fueling, or keep it up to 1.0bar since mixture is lean high up...)?
I'd also be tempted to customise the area around where this wastegate fits, so that the flow is smoother along its path.
God, every aspect of modification takes a bit of studying, by the time car's finished (if ever!), I could have setup a tuning business...

Videos are okay, but sound is not clear enough and I couldn't figure out when the gate opened... will try again later.

cheers

I couldn't get the vids to work mirco. Would like to hear them if you can host them some other way?

Edited to say: Ahh, works ok in Internet Explorer, just not in Firefox

If you could get a clear recording of the sound so that we can disguise when it opens and shuts that would be great.

you can buy different springs for the WG..so you can actually saywhen it should open...additionally you can install a boost controller..and adjuste the boost with it...easy...

m8s...il try to get some better vids, prob. is i got no cam...lets..see...try my best to organize a cam...

greez mirco

thanks Mirco.