Fun street RB25

[WR33KD]

This is my dyno on a holset hxc35/2 it’s a nz build turbo with manifold and head to suit

That is all run on 98pump. It can be done. I don’t have a boost graph sorry to show how it picks the boost up but as you can see it picks up power 80% of the way in the revs.

If your going to build the motor build it once and build it right 

[GTSBoy]

On 5/22/2022 at 12:59 PM, Rand0b said:

I do not want a turbo to be 3psi 3k to light up 25psi at ~4k and all it does is spin the tires, that is what I am referring to as power delivery. If I can get that 6L pull feeling Hells yea I would want it all the time but I know I may need to make it linear to ensure proper traction.

so what would you say a good turbo would be?

Let's just first accept that any truly modern turbo, regardless of outright size, is going to go from not a lot of boost to quite a lot of boost over a very short rpm range. Getting the best transient response out of turbos is where almost all the development has been in the last 20 years. It is only the last 5-10 years worth of turbos that deserve the term "truly modern". That's really the EFRs and the Garret G series. The GTs, GTXs, all the "billet" output from Precision and all that, even the BW SXs and so on, are really representative of the previous generation. (And here I will point out that there's nothing particularly wrong with these turbos at all, excepting real or perceived reliability issues, etc etc, and that these previous generation turbos still represent a fine choice for many applications, potentially even yours).

What that means is that the whole 3 psi to 25 psi transition is basiccally the same for all of them. Sure, the larger ones might take a little longer, like an extra 100 or 200 rpm to complete that ramp. But the only real difference is that the smaller turbos are going to do it at a lower starting point, and they are going to do it with smaller power output at the 3 psi end of the range and also at the 25 psi end of the range. The bigger turbos just make more power at every boost level. So you'll have 500rpm more engine speed, and you'll have NA(ish) power output before the boost comes on followed by larger amounts of power all through the boost ramp. I can't see how this will equate to more traction.

Anyway, to the question of what turbo to choose. I would concur with previous suggestion towards the EFR 7163 (with some caveats, which we will get to later). I had a look into the options a few years ago and just haven't actually done anything about it. But playing with BW's matchbot software makes the 7163 seem like it is the very sweet spot in the street turbo area. There's a slightly smaller more conventional one, the 7064 or something. The 7670 is bigger. Bigger than the classic GT3076 sort of sizing, perhaps verging into the GT35 territory. Higher power potential with the corresponding tradeoffs at the lower rpm range. The 7163 seems to leverage the obscure benefits of the hybrid flow turbine really well.

One of the big issues with picking a turbo is when you find yourself right at either the top or bottom end of the possible turbo size in a given frame size. That can be quite limiting in terms of where you go next if you find that you've f**ked up and have either underdone it or overdone it. The other is simply the pain associated with physically fitting and living with a larger frame size turbo than you actually need. The 7163 and 7670 are medium sized turbos with some room to move (I think you can still go up from there in the same frame if you really needed to, best to check me on that). The bigger frames, particularly on the EFRs which are NOT compact turbos at any frame size, are simply bigger fatter lumps that you have to squeeze into the available space. Anyway, this is a sidebar discussion that you might not care about.

What you might care about is that BW seem to be having some QA problems, particularly with castings, on the EFRs. I would suggest that looking into that and finding out from people actually in the turbo game what the current state of affairs is wrt to these reports and how to mitigate and protect against being affected by them would be well worth the effort.

And, as the others have also said, if the physical lack of compactness, the potential QA problems, the perceived fragility of EFR rotating components (which shouldn't be a problem when properly selected and operated, but whatever... some people need their hobby horses), and the various other reasons to shy away from EFRs afflict you, then the G30-550/600 or thereabouts would seem to be the right sort of power for the street.

Here's some important considerations wrt E85 and lesser E concentrations. You get almost ALL of the benefits of E85 at only half that (so, E40 - E45) territory. Those benefits being resistance to detonation, and outright power output. But, there's typically no such thing as E30 or E42.5 anywhere. So you end up having to blend that shit yourself. So there's no point in planning for power output at those E concentration levels. Just plan for E85 and 98ron, with flex tune to cover whatever happens to be in the tank at the time, and live with what you get. E85 is free power but dismal tank range.

[Lithium]

On 22/05/2022 at 7:30 PM, GTSBoy said:

It is only the last 5-10 years worth of turbos that deserve the term "truly modern". That's really the EFRs and the Garret G series. The GTs, GTXs, all the "billet" output from Precision and all that, even the BW SXs and so on, are really representative of the previous generation. (And here I will point out that there's nothing particularly wrong with these turbos at all, excepting real or perceived reliability issues, etc etc, and that these previous generation turbos still represent a fine choice for many applications, potentially even yours).

What you might care about is that BW seem to be having some QA problems, particularly with castings, on the EFRs. I would suggest that looking into that and finding out from people actually in the turbo game what the current state of affairs is wrt to these reports and how to mitigate and protect against being affected by them would be well worth the effort.

 

Yeah pretty level stuff.  Thought I'd throw in that the Xona Rotor range of turbos that use the UHF turbines are also an interesting "modern" generation turbo which due to design pretty low inertia vs turbine flow as well.   

Funny you mention the EFR casting issue, I half blew the whistle on that here as much as I'd potentially be viewed as biased towards them.  I just want people to be aware of the goods and bads of things so they can make their own choices and people spouting misinformation to suit their bias is going to be called out - as you also do  

There is a chance we're at that "things are looking better" now, but either way it's a shame there was some reason for concern relating to QC as you do have to be wary of that kind of thing - and it's a shame when the likes of the EFR8474 are pretty much the best thing you could put on an RB that you're pretty keen on partying with in terms of the whole cake-and-eat-it-too of usability and power making potential and if QC is going to be a problem it may not be worth the risk.  At the very least at that price point you SHOULD expect decent build quality.  I know quite a few people who have run 8474s and 9280s over the last couple of years and haven't heard anything recently so maybe some hope there?

In closer relation to this thread topic while following on from the EFR 2.5ish yarns - ignoring recent history of QC (I'll ask people who have been using them and report back for better or for worse) a mate has an EFR8474 on his stock stroke "man cam" RB26 and despite the huge cams it makes full boost in the low 4,000rpm range, "lights up" boost wise with minimal provocation under foot - its super super lively for an RB26 with *any* upgraded turbo combo, and makes ~530kw @ hubs on BP98.   Power is still hanging >500kw at 8500rpm, so it's kinda like having an 90s'ish spec RB26 build in terms that from 6000-8500rpm the dyno curve and sound are reminiscent of a T88 equipped RH9 car *but* if you're side by side with a -5s or Garrett GT35 based turbo GTR at 4000rpm and put your foot into it.... the Garrett fellow is going to be watching tail lights before you even get to the party revs, at which point you'd need an even laggier Garrett option to try and make the numbers to keep up with.   

Edited May 22, 2022 by Lithium

[Rand0b]

On 5/22/2022 at 2:56 AM, Murray_Calavera said:

I'm not trying to derail this thread, but I'm curious why you are talking about driving the car on e30 or e50? Surely if you have access to e85, you'd just run that all the time and only drive on 98 when you don't have access to e85? 

dyno run would be on VP race fuel or e85 / e98, E85 is not easily accessible by me. Closest pump is 30 min in a direction I do not travel. So while I will go out to get it. It will also get pump gas 93 octane is highest avilable in US so overall power will be down if mix fuels  e50, e30, e10 ect 

Edited May 22, 2022 by Rand0b

[BK]

On 22/05/2022 at 9:03 PM, Rand0b said:

dyno run would be on VP race fuel or e85 / e98, E85 is not easily accessible by me. Closest pump is 30 min in a direction I do not travel. So while I will go out to get it. It will also get pump gas 93 octane is highest avilable in US so overall power will be down if mix fuels  e50, e30, e10 ect 

VP race fuel like VP 109 ron unleaded is a waste of money compared to E85. Just go flex fuel setup so you can run on pump unleaded or E85 all without draining tanks or switching tunes.

You go VP race fuel you will have to change tune when using it, then change back to a pump unleaded tune. VP109 for example will support about the same boost and timing increaes as E85, but it requires the afr's to be a lot leaner than E85 but richer than pump unleaded.

[Rand0b]

On 5/22/2022 at 8:36 AM, BK said:

VP race fuel like VP 109 ron unleaded is a waste of money compared to E85. Just go flex fuel setup so you can run on pump unleaded or E85 all without draining tanks or switching tunes.

Flex fuel setup is what i am building the fuel system to handle, Just mentioning i am open to use race Fuel if needed.

On 5/22/2022 at 3:30 AM, GTSBoy said:

Here's some important considerations wrt E85 and lesser E concentrations. You get almost ALL of the benefits of E85 at only half that (so, E40 - E45) territory. Those benefits being resistance to detonation, and outright power output. But, there's typically no such thing as E30 or E42.5 anywhere. So you end up having to blend that shit yourself. So there's no point in planning for power output at those E concentration levels. Just plan for E85 and 98ron, with flex tune to cover whatever happens to be in the tank at the time, and live with what you get. E85 is free power but dismal tank range.

Correct, I noted the Closest e85 pump is 30 min in a direction I do not travel. So while I will go out to get it. I will also get pump gas 93 (93octane is highest available in US) so overall power will be down if mix and could be e50, e30, e10 ect   i am just making aware I could have a 1/3 tank of e85, and go fill up with  1/3 tank 93 octane,

[Rand0b]

On 5/22/2022 at 3:30 AM, GTSBoy said:

the 7163 seem like it is the very sweet spot in the street turbo area. There's a slightly smaller more conventional one, the 7064 or something. The 7670 is bigger. Bigger than the classic GT3076 sort of sizing, perhaps verging into the GT35 territory. Higher power potential with the corresponding tradeoffs at the lower rpm range.

the GT3076 being tried and true this is where i started my comparison. But going to something BW with HP in the range between 3076 - 3582 since the BW having the Gamma-ti wheel and everyone saying transient power felt amazing , so i was looking at 7670 and possibly 8370 (which would get me closer to my goals) the precision 6062 but kept coming back around to the  BW.  Within the past week found the hypergear turbos atr43 : SS2 and SS3 / SS3Pro.

[tridentt150v]

Your  93 RON is our 98 RON, so don't get too hung up on that as an issue.

Taken off the interwebz.....

United States Vs. European & Asian Octane Ratings

"In Europe 98-octane gasoline is common and in Japan even 100-octane is readily available at the pumps, but this octane nomenclature is misleading to Americans as foreign octane ratings are derived entirely differently from their own. So, like every other measurement system it seems that everyone else uses a different scale than the United States does, but unlike most other instances where we have had the good sense to create different units of measure(e.g., inch vs centimeter), in this case we all use the same name: Octane.

Japan and Europe use a system called RON or Research Octane Number to determine the octane rating of their gasoline, while stateside we use a system called AKI or Anti-Knock Index to determine gasoline's octane rating. To further complicate things, the AKI system is actually derived from the average of the RON system and another more complicated system referred to as MON or Motor Octane Number.

To recap, The USA's methodologies for measuring gasoline's octane rating are different, but share some common elements. With the commonality of RON in mind a good rule of thumb is:
 

Multiply the foreign RON Octane rating by 0.95 and you will have the US AKI equivalent

( RON Octane Rating x 0.95 = AKI Octane Rating )
98 RON Octane x 0.95 = 93.1 AKI Octane (US measure)
100 RON Octane x 0.95 = 95 AKI Octane (US measure)

So, as you can see the 93 or 94 octane fuel we are all paying an arm and a leg for is actually quite comparable to the higher octane fuels found in Europe and Japan. The people whom have to worry about low octane rating are our friends out west in places like California that top out at 91 octane.

91 AKI Octane (US measure) = 95.5 RON Octane

100 Octane need from a non-US perspective is still quite high, though, as we are generally unable to easily obtain 95 Octane at the pump. As that number increases, it is more difficult to find it in unleaded variants as well. If your JDM car/engine calls for 100 octane, you'll probably be just fine running it on pump 93, especially if it retains sensors like knock and so forth which will pull timing if it's sensing detonation or incomplete combustion. If you're going to modify the engine, you should always dyno tune your car for best results and proper fueling."

[BK]

On 23/05/2022 at 10:07 AM, tridentt150v said:

Your  93 RON is our 98 RON, so don't get too hung up on that as an issue.

Taken off the interwebz.....

United States Vs. European & Asian Octane Ratings

"In Europe 98-octane gasoline is common and in Japan even 100-octane is readily available at the pumps, but this octane nomenclature is misleading to Americans as foreign octane ratings are derived entirely differently from their own. So, like every other measurement system it seems that everyone else uses a different scale than the United States does, but unlike most other instances where we have had the good sense to create different units of measure(e.g., inch vs centimeter), in this case we all use the same name: Octane.

Japan and Europe use a system called RON or Research Octane Number to determine the octane rating of their gasoline, while stateside we use a system called AKI or Anti-Knock Index to determine gasoline's octane rating. To further complicate things, the AKI system is actually derived from the average of the RON system and another more complicated system referred to as MON or Motor Octane Number.

To recap, The USA's methodologies for measuring gasoline's octane rating are different, but share some common elements. With the commonality of RON in mind a good rule of thumb is:
 

Multiply the foreign RON Octane rating by 0.95 and you will have the US AKI equivalent

( RON Octane Rating x 0.95 = AKI Octane Rating )
98 RON Octane x 0.95 = 93.1 AKI Octane (US measure)
100 RON Octane x 0.95 = 95 AKI Octane (US measure)

So, as you can see the 93 or 94 octane fuel we are all paying an arm and a leg for is actually quite comparable to the higher octane fuels found in Europe and Japan. The people whom have to worry about low octane rating are our friends out west in places like California that top out at 91 octane.

91 AKI Octane (US measure) = 95.5 RON Octane

100 Octane need from a non-US perspective is still quite high, though, as we are generally unable to easily obtain 95 Octane at the pump. As that number increases, it is more difficult to find it in unleaded variants as well. If your JDM car/engine calls for 100 octane, you'll probably be just fine running it on pump 93, especially if it retains sensors like knock and so forth which will pull timing if it's sensing detonation or incomplete combustion. If you're going to modify the engine, you should always dyno tune your car for best results and proper fueling."

Correct. BP ultimate for example is 98 ron, 86 Mon = 92aki.

[Dose Pipe Sutututu]

If E85 is hard to come by, and you're worried about knock ceilings - why not look into WMI?

If you have a modern ECU, let that control the spray, timing advance, etc. 

[Chopstick Tuner]

Mind me asking what you've owned/driven before this build since you say it's your first Rb25? 

 

Just curious, as you've asked for inputs on whether your power goals are too much for a street Rb25, then kinda tried to tell them why you should build it for 700whp anyway then potentially dial it back to 500. That's a big drop and the components used to make 700hp safely are going to have drawbacks in a 2.5L, which won't be remedied by dialing back to 500hp nor will you see the benefits of them. 

Your injector argument is not the same, going from an 850cc injector to 1000cc is not going to change your power delivery like putting a much bigger turbo on than is necessary. 

But just for my two cents and to humbly answer one of the questions in your post, I would consider that power level too much for fun street use. You see guys run that kind of power and they're changing gear as soon as the wastegate cracks open, because otherwise they're frying tyres, seems a waste if you can't get on full boost. 

[Rand0b]

On 5/23/2022 at 6:58 AM, Chopstick Tuner said:

Mind me asking what you've owned/driven before this build since you say it's your first Rb25?

Just curious, as you've asked for inputs on whether your power goals are too much for a street Rb25, then kinda tried to tell them why you should build it for 700whp anyway then potentially dial it back to 500. That's a big drop and the components used to make 700hp safely are going to have drawbacks in a 2.5L, which won't be remedied by dialing back to 500hp nor will you see the benefits of them. 

 

On 5/23/2022 at 6:58 AM, Chopstick Tuner said:

Your injector argument is not the same, going from an 850cc injector to 1000cc is not going to change your power delivery like putting a much bigger turbo on than is necessary. 

Built 2003 Ford Focus ~330whp

LS swap Nova ~400.

I asked for inputs because i know how both my prior cars drove and they were great on the street. the focus had a bolt on turbo kit and was super fun. both these cars drove different being v8 and a turbo 4cyl. I dont know how a RB drives or whats acceptable in this case.

I have a RB motor with a spun bearing i picked up. I only want to open this motor once so i upgraded internals because i was in there. Want to make more power then my prior cars. Of course.

the point i was trying to make here is i know down the line i am going to want more power. So i Get a turbo 6-700whp capable now. Dyno and  hit 6-700 awesome great,  Drive around at ~5xxwhp. why because i can and i want to learn the car and motor. i get bored 6 months later boost goes up and now in 6xx range. Now I am not worrying about selling a turbo and having to buy something new and spend another 2-3k, Hope i am able to keep the the manifold and downpipe ect. 5xxwhp from a 700 capable turbo uses ~75% of its capability and then when  6xxwhp ~ 90%. 

If i came in asking about 9174 then i am out of my mind i wouldn't even use half of the turbos capability

 

[Ben C34]

what size turbo did you use on the Focus?

[Rand0b]

On 5/24/2022 at 8:26 AM, Ben C34 said:

what size turbo did you use on the Focus?

2871r

[hypergear]

SS3Pro is a modern hybrid combination of a turbo. It came out of a mixed & matched wheel set during our R34 GTR turbo development. This one is very driveable with good power to boost ratio. It pulled 444awkws on 23PSI. Its then put on to an R33 drift car with a stock spec forged engine that pulled 456rwkws @ 24psi. All in by 4K

This sort of power band would be a good street car or a track car.

 

[Rand0b]

On 5/24/2022 at 12:28 PM, hypergear said:

SS3Pro is a modern hybrid combination of a turbo. It came out of a mixed & matched wheel set during our R34 GTR turbo development. This one is very driveable with good power to boost ratio. It pulled 444awkws on 23PSI. Its then put on to an R33 drift car with a stock spec forged engine that pulled 456rwkws @ 24psi. All in by 4K

This sort of power band would be a good street car or a track car.

 

i was looking at this recently when i mentioned that turbo a few posts back.what size Turbine housing was used on the drift car?

if a T3 flange i was thinking of the SS3PRO

If a T4 TwinScroll i was thinking the 45SS1, what size A/R .86 or 1.06?

 

[hypergear]

T3 housing was used on that drift car and recommended to run on Rb25det motors.

[Rand0b]

On 5/24/2022 at 7:20 PM, hypergear said:

T3 housing was used on that drift car and recommended to run on Rb25det motors.

t3 with .82a/r?

 

 

[hypergear]

On 25/05/2022 at 11:00 AM, Rand0b said:

t3 with .82a/r?

 

 

No, that was in T3 .63 rear housing

[Rand0b]

On 5/24/2022 at 10:34 PM, hypergear said:

No, that was in T3 .63 rear housing

What if i ended up with a T4 Twin scroll Manifold, I was thinking the 45SS1, what size A/R .86 or 1.06?

or would you have any reasoning against it. Looking at the Dyno graph it does not appear to be to much different then the 43SS PRO. Obviously may be a bit laggier