Gt35r Vs Garrett T04z - Discussion (just Post In This Thread To Create A Database)

[SimonR32]

Correction - you will need to run two external wastegates - one for each bank of collectors which feed into each scroll of the turbo. Like this sr20 manifold:

you only need to run one...

just merge the two wastegate collectors together

thats how my 6 boost t04z spli manifold was done

[SimonR32]

Thanks for your input. I currently have a 3582 .82 on a 6boost manifold, response, power are all very good (refer to earlier posts in this thread) but boost control is a real problem - believe it or not the current build was a result of similar boost control issues with an internally gated xr6 turbo so I'm essentially back to square 1 after more than a year of building the thing. Seeing as the manifold needs to come off regardless I'm looking at options - which is where the FR stuff has come in.

I dont want to go with another 6boost manifold, but over 4k for a fr manifold isnt appealing if they arent perfect either.

nick, didnt brad (scradly) have a chat to you about how to sort out 6-boost problem?!?

[juggernaut1]

you only need to run one...

just merge the two wastegate collectors together

thats how my 6 boost t04z spli manifold was done

That is one way to do it....but not the best way. Geoff at full-race found there is stronger pulse energy by utilising two separate gates as he found there was a small discernable "leakage" from one gate tube to the other under the single gate method.

[2BNVS]

my custom etm manifold has the 2 merge collectors for the gate, i cant see it being that different if its been designed properly

[discopotato03]

The problem is that you need to have a small gap between the divider and the external gates outer valve face (to allow for thermal expansion) because if the valve touches it may not seat and seal properly .

For the nth degree you need two seperate wastegates - be they integral or external .

A .

[skylinekid]

my gate runs directly off the exhaust housing. all custom from etm manifolds. wat u guys reckon btw its a t04z .81 rear and everything is ceramic coated. will be goin onto a tomei 2.8lt stroker motor

[discopotato03]

Thats one way of doing it though it limits you to that turbine housing .

ATP is starting to sell turbine housings with bosses cast in for external gates but possibly not T04 sized .

A .

Bottom line is that we have to convince the manufacturers that we need twin scroll twin integral gate turbine housings because it's the simplest neatest solution , makes the manifolds straightforward and the bypassing and dump layout soooo easy .

Garretts TS Evo 10 GT3076R IW turbo should not be under wraps too much longer , all cake .

[STR8E180]

well just to add to the topic of GT35 series turbos, manifolds and twinscroll setup's

im running a GT35 with anti surge compressor housing with .78 divided exhaust housing ATPturbo.com did all the work on the turbo B4 sending it over to me

the exhaust manifold is a custom steam pipe item, it only runs 1 external gate each part of the collector has a pipe coming of it feeding into a external gate

after putting the setup on the dyno and getting it tuned i realli should of modified the manifold to suit twin external gates because i have no boost control wat so ever

even with the boost controller set of 0psi it still peaks to 20psi (the only crap thing now is i already got the manifold coated so modifying the manifold now means i need to get it coated again )

the car made 400kw on BD4's dyno a few weeks ago but had problems with fuel pressure

ill be getting the problem looked at some time this week

will post up new results when every thing is finished

Edited December 12, 2008 by STR8E180

[saliya]

the exhaust manifold is a custom steam pipe item, it only runs 1 external gate each part of the collector has a pipe coming of it feeding into a external gate

after putting the setup on the dyno and getting it tuned i realli should of modified the manifold to suit twin external gates because i have no boost control wat so ever

even with the boost controller set of 0psi it still peaks to 20psi (the only crap thing now is i already got the manifold coated so modifying the manifold now means i need to get it coated again )

Hey,

a) The only things I can think of that would cause this is if the outlets to the gate; the gate itself; or the pipework aft of the gate is too small (not because you have 1 rather than 2).

If you make the gate a screamer, is boost still uncontrollable?

If you put a bigger gate on, is boost still uncontrollable?

If you take the wastegate off completely (put some pipework in to redirect the gases out of your engine bay ), still uncontrollable?

b) You should just be able to cut away the merged part and weld flanges on each side for twin gates; you shouldn't need to get the manifold recoated unless you really want to...

Regards,

Saliya

[STR8E180]

Hey,

a) The only things I can think of that would cause this is if the outlets to the gate; the gate itself; or the pipework aft of the gate is too small (not because you have 1 rather than 2).

If you make the gate a screamer, is boost still uncontrollable?

If you put a bigger gate on, is boost still uncontrollable?

If you take the wastegate off completely (put some pipework in to redirect the gases out of your engine bay ), still uncontrollable?

b) You should just be able to cut away the merged part and weld flanges on each side for twin gates; you shouldn't need to get the manifold recoated unless you really want to...

Regards,

Saliya

a) the gate is alread a screamer a

havent tried putting on a bigger gate and i dont think putting on a gate will help enuff, im sure it will help but i dont think it will waste enuff exhaust gas to be able to control boost

havent tried running the car with out a gate its to much work making a pipe just to redirect gas, ive only got 1 v band flange and im not using it for a test pipe

b) u cant weld onto the coating so any modification's done to the collector will need the coating removed b4 any welding can be done which means ill need the manifold coated again other wise it will look pretty crap if the whole manifold is coated but the collector

[r33_racer]

I dont think twin gates will fix the problem...the problem is very little back pressure and flow resistence to and through the turbo. The gasses are bypassing the wastegate pipe almost completely....if you chuck a gt30 on or something with a smaller turbine housing creating more back pressure it will control boost/ or atleast better then atm. Other wise you need to make the wastegate pipe protrude more into the collector to create a little turbulence so it tries to catch some gas and force it towards the wastegate, or mount your wastegate straight off the turbine housing where it is in the gases flow path.

With the merge collector style manifolds, they are great for flow and aiding turbo response, but as a result of the design they suffer from boost control issues when you have descent sized turbos on there with little backpressure in the exhaust side of the system.

If you check your wastegate manufacturers booklet they normally show how it should be mounted....and im fairly certain it should be mounted at a minimum of 90 degrees off the flow path or less. I think at a 45 is ideal and the way to go.

[STR8E180]

..if you chuck a gt30 on or something with a smaller turbine housing creating more back pressure

im using a .78 divided exhaust housing on a 2.6L engine i dont wanna go any smaller then i already have

i also dont have enuff room in my engine bay to be picky about my external gate mounting if i had enuff room to mount my external gate at a 45 degree angle to help wastegate flow i would have

Edited December 13, 2008 by STR8E180

[r33_racer]

My bad, i meant the gt30 as an example, not as something you should do.

Well if you cant mount it at a better angle to increase flow to the wastegate, then maybe mount it right off the turbine housing if space allows...otherwise i dont think you will be able to control boost with that setup.

Try welding some extensions off each half of your waste gate pipe in each half of the collector protruding into the exhaust flow a little, it might help direct some of the gas into the wastegate.

[saliya]

a) the gate is alread a screamer a

havent tried putting on a bigger gate and i dont think putting on a gate will help enuff, im sure it will help but i dont think it will waste enuff exhaust gas to be able to control boost

havent tried running the car with out a gate its to much work making a pipe just to redirect gas, ive only got 1 v band flange and im not using it for a test pipe

Hey,

You're going to fab up for twin gates because that's easier than trying a larger single gate or buying a flange and dummying up some pipes for testing?

If you say so

You also didn't mention whether:

* the gate was tested off the car (maybe faulty gate or incorrect spring?)

* any signal-altering devices like boost controllers were bypassed and/or tested separately (maybe faulty signal?)

* the size of the gate you were using

I think that testing the kinds of things I've mentioned is way easier than re-manufacturing part of the exhaust.

Further, the test results should tell you whether what you want to do will be able to fix the problem.

Still, to each his own...

FWIW a single HKS 50mm gate seems to be able to control boost just fine (the lowest I've gone is 15psi) on my 26 T04Z 0.84 twin-scroll.

b) u cant weld onto the coating so any modification's done to the collector will need the coating removed b4 any welding can be done

You only need to remove the bare minimum of coat to weld the gate flanges on (say a 2mm strip next to each flange, not the entire manifold).

Performance-wise there's no way that forces a recoat... if aesthetics makes you do it then fair enough, to each his own.

Regards,

Saliya

Edited December 13, 2008 by saliya

[l0WRB]

I know someone who has a gt42r he had huge problems controlling boost with his turbosmart 48 gate he made bigger wastegate pipe re done the manifold still no fix, he put on bigger 50mm gate and woolah fixed it that extra 2mm who would have thought lol

[Ryan1200]

What spring does your wastegate have inside Stre180 20psi possiblly? Keep your spring as close to your target boost as possible so your controller doesn't have to work as hard...

[Adriano]

Is there an issue with running 20 psi, that boost curve looks pretty good.

[STR8E180]

Try welding some extensions off each half of your waste gate pipe in each half of the collector protruding into the exhaust flow a little, it might help direct some of the gas into the wastegate.

i dont like the idea of causing a restriction in the manifold just to try and control boost

What spring does your wastegate have inside Stre180 20psi possiblly? Keep your spring as close to your target boost as possible so your controller doesn't have to work as hard...

the spring is a 14psi spring

Is there an issue with running 20 psi, that boost curve looks pretty good.

i have no issue at all running 20psi which is why i been to anal about fixing the problem yet

[juggernaut1]

Further to the above - if you are considering a FR manifold you may want to confirm whether it is a straight bolt on fit for you car.

I'm fitting a FR TS manifold to my s15 and I've had to have a bracket made up to lower the aircon compressor 30mm and have had to relocate the power steering resevoir further around the strut tower and make up new ps lines. The 2 gates are also an extremely tight fit.

I also had to open up the flange plate on the manifold to match to the exhaust ports and tidy up the manifold collector a little with a die grinder. If I was to do it again (or the manifold cracks) I would give Kyle a call at 6Boost to make me up a manifold as it would also suit the right hand drive layout whereas the FR manifolds are primarily designed around left hand drive cars. Having owned both types of manifolds (but not tested both) I prefer the 6Boost manfold as the flange plate is the correct size and the tube welded onto the flange plate on the 6Boost manifold is flared to suit the port flange size.

My 2 cents

Here's an example of what I was talking about above regarding opening up the flange face on the FR manifolds. This particular FR manifold is for an evo and you can see that they have opened up the flange face to match to the port (admittedly evo motors have reasonably larger exhaust ports). Unfortunately, I didn't receive my manifold with this mod and had to take to it with a die grinder myself.

[STR8E180]

heres a picture of our evo manifold and we had to do the same as well other wise the manifold ports would be to small for the cylinder head ports