What turbo for RB20?

[Turbine]

Hey guys,

The idea we had with this turbine housing was to put the wategate air path directly in line with the air comming out of the exhaust manifold. This way the air doesnt have to do a right angle turn to escape. We thought if we are going to boost this engine.... how are we going to get the air out of it. We could have gone the usual way with the standard 40 - 50 mm external gates that look pretty good but are crap for big airflow, or just crap for airflow full stop.

Now the trick with this is that it's a .63 A/R turbine housing with a custom size wheel put in it (larger). Without a wastegate, this engine would have a big restriction at the turbine and wouldnt allow the exhaust to escape, building pressure in the exhaust manifold, clogging the engines breathing. With it setup like this, not only does it have the wastegate, but it's path is dead straight to atmosphere, very little restriction. The valve itself is 3" in diameter, once used as a shutoff valve from an F/A-18 Hornet engine bleed.

I'll only have to modulate the valve enough to get the boost I need.

Hopefully with this setup, the intake manifold pressure will be greater than the exhaust manifold pressure.

O.K I'll talk to you some more about this later.

Turbine

[Roy]

Just bouncing soem thinking off you:)

  Turbine said:

Hey guys,

... We thought if we are going to boost this engine.... how are we going to get the air out of it.  We could have gone the usual way with the standard 40 - 50 mm external gates that look pretty good but are crap for big airflow, or just crap for airflow full stop.

What do you mean by crap for big airflow. What lbs/min does that turbo supply, isnt it somewhere around 40-43 lbs/min. I wouldnt really consider that big airflow.

  Turbine said:

.

Now the trick with this is that it's a .63 A/R turbine housing with a custom size wheel put in it (larger). Without a wastegate, this engine would have a big restriction at the turbine and wouldnt allow the exhaust to escape, building pressure in the exhaust manifold, clogging the engines breathing.  

First question. I dont understand what you mean without a wastegate. You mean if the wastegate was mounted on the exhaust manifold as per the norm?

Also what sort of power are you aiming for. You probably already know this but i often see people being mislead by what the A/R number is/means.

Its a ratio standing for Area/Radius. As its only a ratio then not all 0.63 housing are alike, so when people say that is too small and will be restrictive, that assumption sometimes does not allow for the fact that a housing may accomodate a larger turbine wheel so has to have a larger R.

So if the R is big then dont forget that the area A has to be bigger as well to maintaint he A/R ratio. So i can have a T88 with a 0.61 A/R housing, i wouldnt think its going to have a problem with exhaust flow on an RB20. (LOL surge maybe but not an exhaust restriction)

Since it looks like you have a larger turbine then most...well i wouldnt automatically consider the 0.63 is going to cause a lot of back pressure on an RB20. It may, i dont have your turbo setup and i havent crunched numbers but gut feeling says that it wont cause a restriction, I think thats about the housing size that im using on a turbo that flows about 42lbs/min

  Turbine said:

With it setup like this, not only does it have the wastegate, but it's path is dead straight to atmosphere, very little restriction. The valve itself is 3" in diameter, once used as a shutoff valve from an F/A-18 Hornet engine bleed.

I'll only have to modulate the valve enough to get the boost I need.

Hopefully with this setup, the intake manifold pressure will be greater than the exhaust manifold pressure.

So comes back to what power are you looking for. The turbo you are looking to use doesnt make HUGE power, good power yes but not huge. I thought it was possible to have a wastegate that is too big and is too hard to control as it bleeds off too much airflow when it opens meaining it has too quickly close to maintain the turnbine at the correct rpm only to find that when it has to open again the cycle repeats.

LOL..this is interesting, the way your going about things seems to differ from the norm which is cool and good to see someone thinking outside the circle , but sometimes you end up running around the circle:(

[B-Man]

I had to look 3 times at that turbo before I understood what you were doing with it - Crazy (but good) stuff.

Back on topic a bit - What is wrong with the HKS 2510 on an RB20 ?? Some say it runs out of puff at 6200 RPM ?? What does run out of puff mean ?

Some say it makes 210 rwkw on an RB20

If it spools up fast and makes good average power - then I think this is a good thing.

I've done the big laggy turbo thing with great max power - my aim this time round is super responsive , good average power (over whole rev range).

HKS 2510s second hand off the japanese yahoo auctions are like $600 or something - So seems good value to me.

I'm also looking for cheap.. well not cheap but very very good value for $$$

And I like HKS turbos ......

What other options are there apart from Hi flow standard and hi flow RB25 ??

[Roy]

LOL... if your willing to buy from Yahoo Japan you can get TD06-20G , 8cm^2 kits pretty cheap, and guess who normally has a manifold/gate handy:)

HKS SUCK...TRUST RULE:)

With the GTS4 it should make for hell funny launches and low 12s:)

[B-Man]

If only Trust made ball bearing turbs - hey Roy :) ha ha

thanks for the PM - Might be an option

[Turbine]

  Roy said:

Just bouncing soem thinking off you:)

What do you mean by crap for big airflow. What lbs/min does that turbo supply, isnt it somewhere around 40-43 lbs/min. I wouldnt really consider that big airflow.  

First  question. I dont understand what you mean without a wastegate. You mean if the wastegate was mounted on the exhaust manifold as per the norm?

Also what sort of power are  you aiming for. You probably already know this but i often see people being mislead by what the A/R number is/means.  

Its a ratio standing for Area/Radius. As its only a ratio then not all 0.63 housing are alike,  so when people say that is too small and will be restrictive, that assumption sometimes does not allow for the fact that a housing may accomodate a larger turbine wheel so has to have a larger R.  

So if the R is big then dont forget that the area A has to be bigger as well to maintaint he A/R ratio. So i can have a T88 with a 0.61 A/R housing, i wouldnt think its going to have a problem with exhaust flow on an RB20. (LOL surge maybe but not an exhaust restriction)  

Since it looks like you have a larger turbine then most...well i wouldnt automatically consider the 0.63 is going to cause a lot of back pressure on an RB20. It may, i dont have your turbo setup and i havent crunched numbers but gut feeling says that it wont cause a restriction, I think thats about the housing size that im using on a turbo that flows about 42lbs/min

So comes back to what power are you looking for. The turbo you are looking to use doesnt make HUGE power, good power yes but not huge. I thought it was possible to have a wastegate that is too big and is too hard to control as it bleeds off too much airflow when it opens meaining it has too quickly close to maintain the turnbine at the correct rpm only to find that when it has to open again the cycle repeats.

LOL..this is interesting, the way your going about things seems to differ from the norm which is cool and good to see someone thinking outside the circle , but sometimes you end up running around the circle:(

Roy,

Great comments mate, I've decided to create a new thread for our project "RB Racing_Turbine & TurboX" jump over if interested.

The compressor flow rate is 54Lb/min for ours at the moment in that photo.

Turbine