BEST TURBO BRAND AND SIZE FOR RB28 STROKER ?

[Dr Evil]

Hi Guys,

I just want to pick the knowledgeable RB guys brains as to which Turbo would be best suited for my application. I am building a Street Car (Not a Race car) and will be

using mostly RON98 But will be E85 compatible. I want Response more than Top End. Still don't know which Turbo to use. The Most popular Choices are:

EFR 8474, BW 35-900 or 35-1050, PT6466 or PT8470 (although I suspect this might be a bit laggy)

Mods include:

Haltech E2500 ECU

N1 Block with Nitto 2.8L Stroker Kit

Ported/Polished Cylinder Head with 1mm Oversize Valves

ID 1300c Injectors

R35 to RB26 Coil Conversion Kit

PRP Cam/Crank Trigger Kit

Kelford 182-S Cams (274/270)

90mm DBW Intake Plenum 

T4 Twin Scroll Hypertune Exhaust Manifold

Quaife Front LSD

Cusco RS 1.5 way Rear LSD

OS Giken 5 Speed Gear Set

Custom 4" Stainless Exhaust

This car is a Toy Not a Daily Driver, Which Turbo would be best suited for this Street Car Setup giving Response before Top End ?

 

[Predator1]

EFR All Day for response. I have a 9180 on mine. The response is pretty damn amazing.

[Dr Evil]

What A/R are you using for the EFR9180 ?

[Predator1]

4 hours ago, Dr Evil said:

What A/R are you using for the EFR9180 ?

1.05

[BK]

6466 is excellent 👌 

[Dr Evil]

Do you think the PT6870 would be too laggy for 98 Pump Gas ?

[Dr Evil]

42 minutes ago, BK said:

6466 is excellent 👌 

Would the PT6870 be too laggy?

[BK]

Depends what you're doing with the car. Ultimate top end will be the 6870, so not really street usable.

6466 is still 600kw + on E85 which is more power than any sane person needs, and is really too much for the street to actually use too. I do 450kw on 22psi on 98 so you could do 500kw on 98 if pushed.

[r32-25t]

A couple of weeks ago I went for a ride in SirRBs 2.8 with a 7675 sportsman on it and it wasn’t as laggy as I expected it to be, it’s still to laggy for what I want but makes me look at 6870 and think it would actually be pretty good 

[BK]

27 minutes ago, r32-25t said:

A couple of weeks ago I went for a ride in SirRBs 2.8 with a 7675 sportsman on it and it wasn’t as laggy as I expected it to be, it’s still to laggy for what I want but makes me look at 6870 and think it would actually be pretty good 

6870 definitely won't suck, but for a 100% street only car though it's a bit over the top. If drags and roll racing is on the cards it'd be heaps better.

I bet that 7675 car is used for both right ?

[r32-25t]

15 minutes ago, BK said:

6870 definitely won't suck, but for a 100% street only car though it's a bit over the top. If drags and roll racing is on the cards it'd be heaps better.

I bet that 7675 car is used for both right ?

It’s mainly a street car that he uses for roll racing every so often, it’s also an extremely clean car

[Piggaz]

No mention of power target.

5 speed will suck. Don’t do that. Waste of money.

[Kinkstaah]

Borg Warners on a level of their own when it comes to turbos. If you know you know.

Nothing else should even be discussed. Don't even spend time using the brain cycles thinking about it.

[BK]

On 03/12/2022 at 11:02 PM, Kinkstaah said:

Borg Warners on a level of their own when it comes to turbos. If you know you know.

Nothing else should even be discussed. Don't even spend time using the brain cycles thinking about it.

Bit of a sweeping statement there. As far as spool per a given wheel sizes EFR is king  - and they should be with their exceptionally light Ti exhaust wheels. 

So if response is absolutely paramount I'd 100% agree EFR. For power production per given comparable compressor wheel sizes, the Precision line up shits on them.

[Lithium]

45 minutes ago, BK said:

Bit of a sweeping statement there. As far as spool per a given wheel sizes EFR is king  - and they should be with their exceptionally light Ti exhaust wheels. 

So if response is absolutely paramount I'd 100% agree EFR. For power production per given comparable compressor wheel sizes, the Precision line up shits on them.

This is all accurate, but kinda leaves out a critical part - unless you are racing in a class that has a wheel size limitation then the "given comparable compressor wheel sizes" thing is a completely pointless comparison, other than fitting class rules there's not tangible benefit to it.

Power vs response EFRs shit all over Precision turbos, and that's what actually counts in real life.

[BK]

27 minutes ago, Lithium said:

This is all accurate, but kinda leaves out a critical part - unless you are racing in a class that has a wheel size limitation then the "given comparable compressor wheel sizes" thing is a completely pointless comparison, other than fitting class rules there's not tangible benefit to it.

Power vs response EFRs shit all over Precision turbos, and that's what actually counts in real life.

Agree, but what it does point out is that the aerodynamic design of the EFRs is not as superior as what it's made out to be purely from a power / flow point of view. They NEED bigger compressor wheels to match the design of the Precisions, which prove they are doing something right with their aerodynamic designs.

Comparing a 6266 to a 8374 with very close comp/exhaust sizes, if say the 6266 had a Ti exhaust wheel I'd wager it would be at least comparable spool to the 8374 and still make more power. This is all completely theoretical of course, but the point is the EFR Ti exhaust wheel really makes them what they are.

[Lithium]

4 minutes ago, BK said:

Agree, but what it does point out is that the aerodynamic design of the EFRs is not as superior as what it's made out to be purely from a power point of view. They NEED bigger compressor wheels to match the design of the Precisions, which prove they are doing something right with their aerodynamic designs.

Comparing a 6266 to a 8374 with very close comp/exhaust sizes, if say the 6266 had a Ti exhaust wheel I'd wager it would be at least comparable spool to the 8374 and still make more power. This is all completely theoretical of course, but the point is the EFR Ti exhaust wheel really makes them what they are.

It's not really that simple, and again it's making a comparison of things that don't exist.  Often with aero there is a compromise, where you get more flow from a given size you sometimes need more speed before it starts working well - a smaller wheel that flows more can end up being less responsive.   Defining aero as only being good if it makes more power for a size is a very drag racing view of the world, aero which starts pumping effectively quickly for a given size is also a thing.  The Precisions are fairly lazy for their wheel sizes as well, before you even bring Ti-AL into it.  The Ti clearly helps transient a huge amount and is part of the package, but it's not the only thing that is making the combination work.

Either way, the reality is that a 8474 smashes a 6266 in response and beats it in flow as well - so no need to speculate on what a thing that doesn't exist goes like because there is something that already exists that offers it all.

[Dose Pipe Sutututu]

Then we throw into the mix a good percentage of GT-R owners use their car for drag racing/roll racing more than any other kind of motorsports, the whole response debate is then some what invalid. 

I've done plenty of track days, not as much as @Duncan however 95% of the cars I see are not R32/33/34 GT-Rs (this is when they were cheap, now would be probably 0% GT-Rs on the track).

 

 

[Lithium]

21 minutes ago, Dose Pipe Sutututu said:

a good percentage of GT-R owners use their car for drag racing/roll racing more than any other kind of motorsports, the whole response debate is then some what invalid. 

 

 

Just to remind you the key requirement of the thread:

 I am building a Street Car (Not a Race car) and will be using mostly RON98 But will be E85 compatible. I want Response more than Top End. 

Edited December 7, 2022 by Lithium

[Kinkstaah]

If it doesn't have a Ti-al wheel then everything else can be ignored.

Yes, more manufacturers should use better materials. It makes so much of a difference in the real world that I just cry when people spend money on turbos without doing proper research. The only other variable is packaging, but if you physically can't fit a huge turbo somewhere, you are well outside of the "Street car" category.