Borg Warner EFR Series Turbo's V 2.0

[Nismo 3.2ish]

I do not think anything is ugly that can make a car GO faster ?

 

Edited December 17, 2016 by Nismo 3.2ish

[sucram]

On 12/17/2016 at 4:31 PM, Happy Seal said:

I tried out the 8374 and 7670 on an HKS bottom mount. Issue with the 8374 was the compressor inlet sits too close to the engine mount and also fouls the oil supply port on the block. 7670 sits much better, will have to use a sharp angle for the intake pipe right off the compressor to clear the mount. I'll dig up some pics and post them later. . .

 

old solution was to add a spacer

[joe89]

Guys short question: will EFR 8374 .92 spool faster than 8375 .92?

[Piggaz]

Yes. By a significant amount too.

[joe89]

Wow nice, how much it can be? 200?500? +-

[Lithium]

Think you'll find he means response, not necessarily rpm on a dyno plot.  I'd not count on the EFR to show a heap of improvement on a boost curve on a dyno plot - but if you get two otherwise identical cars side by side and step on the throttle from 3500rpm from vacuum you may see something more tangible.

[joe89]

I get it

I have 8375 .92 T4 divided in my forged Rb26 and HKS 264 cams on fuel pump ,and it's a bit laggy i running 21psi it's street fast car but it push hard after 4300. 

My power goal with ~2.6l capacity is 420rwkw on fuel pump 98 till 8200 rpms, 8374 with hotside .92 is the best way for fast daily car with 420rwkw? The little problem is that hotside is huge and i have little space  

One page ago i read 7670 is for max 375rwkw, with 1.05 hot side also? But also it's information the compressor is for 640hp so maybe with 1.05 it can make that close 400rwkw in 2.6l?

 

Edited December 21, 2016 by joe89

[Full-Race Geoff]

the older s300 8375 0.91 makes 1 bar boost around 3900-4000rpm

the EFR 8374 makes 1 bar boost around 3500rpm.  Considering your goal to make power to 8200rpm i think the external WG 1.05 a/r would be your best bet

 

[joe89]

Great! Thanks Geoff.

[usmair]

13 hours ago, Full-Race Geoff said:

the older s300 8375 0.91 makes 1 bar boost around 3900-4000rpm

the EFR 8374 makes 1 bar boost around 3500rpm.  Considering your goal to make power to 8200rpm i think the external WG 1.05 a/r would be your best bet

 

on a twin scroll manifold with twin gates you will get 33psi by 4400 on an rb26

in hindsight, I should have gone a twin gate setup as my single 60mm old tech gate seems to be causing lag on my 8374. I get 29 psi around 4400 whereas my mates 32 GTR with a built 26 twin gate will see 33psi on similar revs.

[Lithium]

On 22/12/2016 at 5:36 AM, joe89 said:

I have 8375 .92 T4 divided in my forged Rb26 and HKS 264 cams on fuel pump ,and it's a bit laggy i running 21psi it's street fast car but it push hard after 4300. 

My power goal with ~2.6l capacity is 420rwkw on fuel pump 98 till 8200 rpms, 8374 with hotside .92 is the best way for fast daily car with 420rwkw? The little problem is that hotside is huge and i have little space  

One page ago i read 7670 is for max 375rwkw, with 1.05 hot side also? But also it's information the compressor is for 640hp so maybe with 1.05 it can make that close 400rwkw in 2.6l?

Any theory on why that would be the case?  While they are spooling the gates should be both closed, if the system is correctly divided and sealed up to the gate then surely everything should behave the same

[sneakey pete]

I belive you quoted the wrong post and were replying to umair, but that's assuming that it is divided right to the gate?

[Piggaz]

This is a bit of an interesting one.

Over the years I've heard some pretty wild claims with using two gates vs one gate on a twin scroll single turbo setup. 200 RPM, 400 RPM, 500 RPM even 800 RPM.

Has there been anyone that's done some sort of back to back with it?

If there was no gain AT ALL why do people use twin gates in the first place? It would certainly save a lot of money in hardware and fab work that's for sure!

[Lithium]

25 minutes ago, sneakey pete said:

I belive you quoted the wrong post and were replying to umair, but that's assuming that it is divided right to the gate?

You're quite right, and I can't edit the post  And yes, that was my assumption - I stated that in the comment

3 minutes ago, Piggaz said:

Has there been anyone that's done some sort of back to back with it?

If there was no gain AT ALL why do people use twin gates in the first place? It would certainly save a lot of money in hardware and fab work that's for sure!

Never heard of a back to back, and there has been some pretty strong argument for it - the argument FOR makes sense in terms of "on gate" behaviour but when most of the claims relate to spool and on-boost behaviour, in which situations there should be no difference at all I don't know what the story is.  Fwiw everyone I know that have done single gate setups have done the manifolds more or less how you'd expect from twin gates, as in sets of 3 cylinders have individual feeds which merge at the gate but pretty much the only way that the two pairs of 3 can interact are from the point the gate opens.    In terms of the tubing while the gate is closed I'd expect that the gases shouldn't know much, if any difference from if it were twin gate - and the performance that guys I know who are running single gate setups as I describe is decent, to be fair if they got 500rpm better spool from what they have currently then they'd be rewriting the rules on spool with a given turbo size!

[GTSBoy]

I think the logic might be pretty simple on this one.

The whole idea of twin scroll turbos is of course to acoustically isolate the two halves of the exhaust stream.  There are nozzles at the turbine inlet that serve as the "end" of the exhaust path, as far as the manifold is concerned.  Therefore if you have no wastegates at all, whilst the exhaust might merge at the turbine, the two halves are isolated from each other at the point.  The acoustic wave reflections bounce back from the nozzles and the exhaust is properly split.

But if you put a single wastegate onto a split pulse manifold then it forms a bridge between the two halves of the manifold.  It doesn't matter that there's no flow down those pipes when the gate is closed and you're trying to spool the turbo.  What matters is that the pressure pulses can travel down the (currently) active half's leg to the wastegate, then go back over to the (currently) inactive half of the exhaust.  Thus wasting the exhaust pulse energy that you paid extra for (in the turbine housing and the manifold).

Twin gates keep it all separate.  So on spool up the split pulse thing does what it is supposed to.

[Lithium]

2 hours ago, Lithium said:

everyone I know that have done single gate setups have done the manifolds more or less how you'd expect from twin gates, as in sets of 3 cylinders have individual feeds which merge at the gate but pretty much the only way that the two pairs of 3 can interact are from the point the gate opens.    

 

14 minutes ago, GTSBoy said:

But if you put a single wastegate onto a split pulse manifold then it forms a bridge between the two halves of the manifold.  It doesn't matter that there's no flow down those pipes when the gate is closed and you're trying to spool the turbo.  What matters is that the pressure pulses can travel down the (currently) active half's leg to the wastegate, then go back over to the (currently) inactive half of the exhaust.  Thus wasting the exhaust pulse energy that you paid extra for (in the turbine housing and the manifold).

Let me get this straight, There are 3 pipes meeting a dead end at a closed valve, and a separate 3 pipes meeting at a dead end at a closed valve, somehow the pulses from cyl 1-3 pipes will interact with the pulses from the other 3 cylinders despite (beyond maybe ever so slight leaks if there is not a perfect seal with the fabrication) there being no clear path to get there?  Sort of like quantum entanglement?  

What you describe would make sense if you were a useless flamin mongrel and just joined 1-3 and 4-6 into a single pipe and had THAT meet the gate, but I'm talking about is what I described above - so there is literally a divider in the middle of the manifold's WG flange which keeps 1-3 and 4-6 separate at the join to the wastegate.

 

[GTSBoy]

4 minutes ago, Lithium said:

 

Let me get this straight, There are 3 pipes meeting a dead end at a closed valve, and a separate 3 pipes meeting at a dead end at a closed valve, somehow the pulses from cyl 1-3 pipes will interact with the pulses from the other 3 cylinders despite (beyond maybe ever so slight leaks if there is not a perfect seal with the fabrication) there being no clear path to get there?  Sort of like quantum entanglement?  

What you describe would make sense if you were a useless flamin mongrel and just joined 1-3 and 4-6 into a single pipe and had THAT meet the gate, but I'm talking about is what I described above - so there is literally a divider in the middle of the manifold's WG flange which keeps 1-3 and 4-6 separate at the join to the wastegate.

 

But is it not universally the case that the wastegate does not isolate the two pipes leading to it?  How could it?  it's not as if there is any divider inside it.  It's just a poppet valve with one inlet.  The pipes have to join, either 10 feet away or 1 inch away, it doesn't matter.

[jet_r31]

6boost has done the twin gate versus single test i believe, i think he said it wasnt worth it?

goleby parts was doing same test or have to by now maybe?

cheers

darren

[Lithium]

15 minutes ago, GTSBoy said:

But is it not universally the case that the wastegate does not isolate the two pipes leading to it?  How could it?  it's not as if there is any divider inside it.  It's just a poppet valve with one inlet.  The pipes have to join, either 10 feet away or 1 inch away, it doesn't matter.

So this divider extends to the face of the poppet, and there is a full seal between manifold and gate.  Any imperfection there is enough to completely screw any advantages of having a divided housing?

Edited December 23, 2016 by Lithium

[sneakey pete]

I'd say you'd want to have a tight seal agains tthe face of the gate for the inter pipe divider if you did go single...

I think there's another layer of confusion here as any potential difference might show up on the street but not on a dyno?