What turbo for RB20?

[warriorbrawl]

Trust they are the best- the 2530 is old technology now they are a little limited on the power side but the trust keeps going with very similar response.

[Roy]

As much as i love my Trust setuo, i think the ball bearing Garret based HKS turbos are newer technology...but thats not to say the Trust turbos dont deliver the goods. Im still yet to see a std RB20 with a 2530 with the response/power of the TD06-20G.

...But, there is always the but, the 2530 makes almost the same power, with similar response all whilst using the std manifold etc etc. I doubt that the bolt on TD06-20G turbos would match a 2530, could be wrong and wait with interest to see the results of someone running one, but the fact that my TD06 uses the manifold and external wastegate i think it helps the overall performance.

[R31Nismoid]

From memory, R31nismoids GT30 equipped RB25 sees about 16psi at about 4,000rpm with a tuned length exhaust manifold and all support systems.

The RB25 is 25% larger in capacity than the RB20 so in theory it would see 16psi 25% later in the rev range at approximately 5,000rpm.

So I guess, if funds allowed and you wanted to take that route a GT30 might be a decent match for a no holds barred 9,000rpm RB20.

mine is with the 82 rear housing, with a .63 you'd be limiting power output of the turbo to around 500hp instead of 550/600... but IMO too laggy for the RB20.

you'd need to wring the guts out of it all day to get anywhere.

Oh, and my 24psi isnt on much later than around 4300-4400 where it goes to 8000rpm

[Psymon]

Just quickly with the 2530... when i bolt it on do the water lines and oil lines etc. bolt on?

[DLuded]

just curious as to what the difference is bewteen a garret and HKS gt2530 are

ive seen heaps of hks version but only for gtr/silvia engines, and ive seen heaps of garret version only for rb series engine. can u show my a pic of a HKS gt2530 and NOT a garrett 2530. i just dont want to buy the wrong one

THX

[killemaul]

what about a disco??? anyone heard of anyone using one on an rb20? i'm looking for an upgrade but i would like decent low end but an alright output.. i know you can't have the best of both worlds with out some gassy help but i was just curious if anyones tried this combo?!?!?!?!?!?!?!!?!? oh and if you don't know what a disco is its a garrett GT28RS.

Chris

[Turbine]

That's what I decided to run on my RB20

http://www.skylinesaustralia.com/photopost...&cat=500&page=1

Turbine

[Roy]

Is there a reason why the wastegate flange was welded at that angle? First up gut feeling ways that may not be the ideal angle?

[MattSR]

Its perfect - The gasses going out the wastegate have a clear, unimpeded shot stright through the turbine housing.

This pic shows it better:-

http://www.skylinesaustralia.com/photopost...&cat=500&page=1

[netrati]

That's the strangest thing I've ever seen.

[MattSR]

Strange, but extremely well thought out.. The collector is the most important part of a turbo manifold, and positioning the wastegate like this enables a pefectly smooth collector design (ie no funny holes at strange angles that interfere with the gas flow path even when the wastegate is closed)

Ive seen several big HP drag cars with this mod - it works well.

[Roy]

Its perfect - The gasses going out the wastegate have a clear, unimpeded shot stright through the turbine housing.

 

Thats the problem. You dont want the air going straight out the turbine housing. You want the air to go thru the scroll of the housing, spin the turbine then out the exhaust. When there is a a certain amount of pressure in the housing you want the wastegate to open and bleed of airflow/pressure so that the turbine does not continue to accelerate.

Wastegates work on basically back pressure (pressure being theoretically equal against all surfaces) whilst the turbine relies on airflow which is directional...

Thats why my gut feeling is that is not the ideal orientation of the wastegate, but could be wrong...just curious to know why it was done this way?

[MattSR]

"Thats the problem. You dont want the air goign straight out the turbine housing."

Well, you actually want part going through the housing and a small part going out the wastegate

"You want the air to go thru the scroll of the houisng, spin the turbine then out the exhaust. When there is a a certain amount of pressure in the housing you want the wastegate to open and bleed of airflow so that the turbine does not continue to accelerate."

Thats right - and to get any semblance of decent boost control, the gasses going through the wastegate need to do it easily. If the wastegate gasses have to turn 90 or 180 degrees to go through the wastegate, then they're going to take the easier path and go through the exhaust housing instead, which will cause overboost.

My above post explains why its been done this way. Im sure when Turbine replies he will back me up.

[Roy]

Sorry not convinced. Pressure isnt directional, and wastegates work to regulate pressure. Air is lazy and will piss out wherever/however it can, just look at what happens when you pop a gasket between the turbo flange and manifold.

I have seen this type of setup before, a few old school rotors/VLs etc, and dont have a problem with a wastegate being welded to the housing (very nice welding by the way), but i would have thought the angle at which it has been welded is not ideal.

Anyway, well will see:)

[MattSR]

I guess we can respectfully disagree.

In a properly matached manifold, the gasses are traveling at at local speed of sound. They really dont want to change direction. Pressure may not be directional, but flow certainly is, and thats what we're trying to achieve. Flow..

Its a nice job thats for sure...

One thing - Wastegates work to regulate turbine speed, and boost pressure - not exhaust manifold pressure. The wastegate doesnt care what pressure is in the exhuast manifold - it only knows that it has to bleed off exhaust gasses when a certain amount of boost is present.

PS - I Love your Skyline

[Roy]

I guess we can respectfully disagree.  

LOL..yeh no problem:) This is a discussion forum:thumbsup:

In a properly matached manifold, the gasses are traveling at at local speed of sound. They really dont want to change direction. Pressure may not be directional, but flow certainly is, and thats what we're trying to achieve. Flow..

I know about Mach numbers, flow etc:) But i thought you would want flow thru the turbine first and foremost not the wastegate.

One thing - Wastegates work to regulate turbine speed, and boost pressure - not exhaust manifold pressure. The wastegate doesnt care what pressure is in the exhuast manifold - it only knows that it has to bleed off exhaust gasses when a certain amount of boost is present.

If there was not pressure in the exhaust manifold then there wouldnt be a pressure differential for the air to bleed off and control the turbine speed. The rest of it i agree with though.

Will wait and see i suppose...and thanks:)

[MattSR]

"I know about Mach numbers, flow etc But i thought you would want flow thru the turbine first and foremost not the wastegate."

Cant disagree with that one

"If there was not pressure in the exhaust manifold then there wouldnt be a pressure differential for the air to bleed off and control the turbine speed."

I should clarify this - theres definitely pressure in the exhaust manifold, I just wanted to say that wastegates regulate intake manifold pressure, not exhaust manifold pressure..

Anyways, i think ive said enough

Cheers,

Matt

PS- nice to know people can still discuss things without resorting to a pissing contest

[Roy]

LOL..too right. I aint no mechanic, discussing and listening to others plus some reading is what its all about:)

[Turbine]

Sorry not convinced. Pressure isnt directional, and wastegates work to regulate pressure. Air is lazy and will piss out wherever/however it can, just look at what happens when you pop a gasket between the turbo flange and manifold.

I have seen this type of setup before, a few old school rotors/VLs etc, and dont have a problem with a wastegate being welded to the housing (very nice welding by the way), but i would have thought the angle at which it has been welded is not ideal.

Anyway, well will see:)

Roy, I know you like this mod, but air is not lazy, It's a powerfull mother of a thing wich if controlled properly can be used to develope big horsepower. The air at speed becomes like a solid and will not turn corners in a hurry at high speed.

[Roy]

Fair enough then...