Stock rb25det neo questions

[Wazmond]

Hey lads,

Sorry to add another thread, to this frequently asked question (couldnt find much on a mostly stock motor...)
Ive got a S2 Stagea with the Rb25det NEO, mostly stock.
Only thing done is 3" JJR bellmouth downpipe, 3" catco hiflow cat(its rattling so due for replacement soon), kakimoto catback
Walbro 255lph and i think thats about it...
Fuel economy is ass, doing around 18L/100 (150km half tank in Syd), and just looking to do a nistune to hopefully get it a bit better.
End goal is probably a hiflow turbo, to get to <300kw. 

Just wondering if I need to do anything before the nistune like upgrading to R35AFM, or injectors etc?

TIA

[Duncan]

Not really....get that tune done ASAP because the stagea ECUs really don't like extra airflow, they go very rich quickly leading to horrible fuel economy instead of more zoom.

For 300 I think you might need injectors but others can comment, and the AFM will max out somewhere there as well so putting in a Z32 AFM is worthwhile

[Wazmond]

Cheers for the response, for the intake side, im looking into a cooling pro FMIC kit, still debating on return flow or cross over. From what ive read, return flow seems to be good enough for 300kw too so not too sure which to go with aha.

Other wise, im running the stock airbox, though the car didnt come with the top cover of the airbox + snorkel so its just held on by a metal cover/clamp. W/o the snorkel, its currently sucking in engine bay air so could be reducing economy through there too? Car also came with k&n pod filter too. Just debating on spending the $200~ on the SRI Alloy pod filter air box (to make it legal in NSW) or $100-$150 ish on the airbox + snorkel....

[Duncan]

Ahh good point, it's been so long since I modified the Stagea I forgot the intercooler....I ran a return flow one on mine for years up to about 280kw although these days I have a cross flow one as I also changed to a forward facing plenum (not really necessary in hindsight)

[Wazmond]

okay, ill go with a cross flow one too.
What do you reckon in regards to the intake? 
Stay with the stock airbox and source the top cover + snorkel? 
or a airbox for the k&n pod filter?

[GTSBoy]

You cannot exceed about 220rwkW on the stock AFM. So if you're planning to go higher, then yes, R35 AFM required (for Nistune). Same with injectors. They top out at the same sort of power. So you will want 725s. NOT 1000s. Nistune is not great with big injectors. The ECU tech is too old for really short pulse widths.

Intake doesn't matter at the power levels you're talking about. Do what you like.

Returnflow coolers start to present extra resistance at the <300rwkW level you're talking about. They still work, but at a cost. If you want to unload the turbo a bit, make tuning easier (ie from less exhaust back pressure) then a cross flow is sensible.

[Wazmond]

Okay ill go for cross flow. Is a fmic even worth it at this point? Or would the stock smic suffice 

 

You mentioned the afm has a limit of around 220kw, same as injectors. A completely stock motor with stock turbo, just turbo back wont hit 220kw will it? So considering that, i wont need to upgrade AFM/Injectors until a turbo upgrade right?

thanks again

[GTSBoy]

13 minutes ago, Wazmond said:

would the stock smic suffice

No. Not even good for turning the boost up on a stock turbo.

13 minutes ago, Wazmond said:

A completely stock motor with stock turbo, just turbo back wont hit 220kw will it?

No. Stock turbo, running to ~12 psi, which is about the max that is reasonable on a 25Neo, will max out at <200rwkW. Depending on the bullshit factor of the dyno, of course. Mine, on a very reasonable dyno, made 191rwkW.

15 minutes ago, Wazmond said:

So considering that, i wont need to upgrade AFM/Injectors until a turbo upgrade right?

Yes, true. Although, having them in place and tuned before you upgrade the turbo is a wise move. That way, you know that they work and you have a feel for what headroom you have before you do the turbo. If you do it all at once, when the inevitable problems rear their ugly heads, trying to get it started or trying to tune it on the dyno, you have multiple changes all at one time that could be responsible for the problem.

[Wazmond]

Ah gotchya.

Quote

Mine, on a very reasonable dyno, made 191rwkW.

What was the mods of yours? 

With the R35 MAF, its an option you select on the software right? Which im assuming will change the maf 'parameters'? With it accordingly?. So would it be something you just install and select and just converts over, or would it require another tune? Understanding that the piping size on the MAF affects it too.

[GTSBoy]

1 hour ago, Wazmond said:

What was the mods of yours? 

Stock engine & turbo. No changes to anything except:

• Divided dump, 3" catback wit good cat.
• FMIC return flow (good core and hand fabricated tanks & pipes to make the most of the space behind the bumper reo.
• Steel turbo inlet.
• Boost controller.
• Oh. & Splitfires, which is worth nothing, really.

[Dose Pipe Sutututu]

10 minutes ago, GTSBoy said:

Divided dump, 3" catback wit good cat

Bellmouth is better, IWG flapper on highflows, non-OEM CHRA will hit the divider and you'll have other problems to deal with.

[Dose Pipe Sutututu]

2 hours ago, Wazmond said:

With the R35 MAF, its an option you select on the software right? Which im assuming will change the maf 'parameters'? With it accordingly?

Yep, there's a drop down and also pipe size to select.

However...

It never works perfectly as everyone installs the card differently, different pre length of pipe, different pod filters etc. all have a massive affect on it.

Is your car manual or auto? If it's a manual, maybe look at a better ECU. If it's an auto, well you don't have many choices that don't involve big money.

I used to do heaps of Nistune tuning back in the day, and always really hated the Nistune for NEO ECUs. Just a pain in the anus to get right, never drove right, etc. always bogged on rapid throttle transitions, where as the RB20DET modified for the RB25DET drove like a factory car.

[GTSBoy]

28 minutes ago, Dose Pipe Sutututu said:

Bellmouth is better, IWG flapper on highflows, non-OEM CHRA will hit the divider and you'll have other problems to deal with.

Yeah. Except. It doesn't. Big Tao highflow WG flapper swings freely in there. Is no problem.

[Wazmond]

1 hour ago, Dose Pipe Sutututu said:

Is your car manual or auto? If it's a manual, maybe look at a better ECU. If it's an auto, well you don't have many choices that don't involve big money.

Auto unfortunately, though despite manuals being more fun, and more 'manly,' its a daily driver, and autos... convenient...

Anyhows, cant afford to dosh out 2k+ for an aftermarket ecu anyways either. Wanted to tune soon due to fuel costs and it feels a bit lacking in power too. Maybe associated with poor afr?

Upon further thought though, I might just go for a return flow intercooler. Im not wanting to cut a piece of the REO or the chassis to fit the crossover piping and risk it being defected etc. End goal is just an OEM+ build.

 

Appreciate the advice lads. To buy list, FMIC return flow, Boost controller, 3" hi flow cat,  and a nistune!
And then later down the road, hiflow turbo, afm, injectors and possibly coilpacks etc.

[GTSBoy]

16 minutes ago, Wazmond said:

feels a bit lacking in power too. Maybe associated with poor afr?

Yup.

[Dose Pipe Sutututu]

2 hours ago, Wazmond said:

manuals being more fun, and more 'manly,'

The fastest weekender/track/semi-daily cars at Sydney Motorsport Park are all auto 😀

Meanwhile all the manual guys are too busy doing complex mathematical calculations and deciding on which gear to grab to do fast laps lol

 

[Wazmond]

Hey sorry to revive this thread but just wanted to ask some more questions.
1, FMIC. Im still debating between the brands... Whether the blitz is worth the extra $300 ish over the cooling pro etc. (from the countless searches, i havent really been able to see a definite answer on this... Some claim cooling pro can do 300kw+, and some says its restrictive compared to the blitz). If anyones got either of em, did it require cutting on the front REO?

Or possibly finding a smaller intercooler and get some custom piping as a return flow.

2, boost controller, a user wrote that nistune will be able to control boost. Just wanted to double check that before pulling the trigger on a greddy profec...

Thanks.

[Kinkstaah]

The blitz does require cutting on the front reo to actually fit the thing. Sadly I had to.

Any intercooler can "Support" 300kw. The issue is how much it dissipates the heat. I'm yet to really see any back to back where someone will do say, 30 continuous pulls and then compare the heatsoak between the different intercooler setups, which is what an intercooler is really for.

It heavily depends on your use case to determine which one is going to work. Typically speaking though you can't really go too big, or have too much cooling, so everyone generally fills the gap with the biggest thing possible (in terms of the actual intercooler core).

[GTSBoy]

1 minute ago, Kinkstaah said:

Any intercooler can "Support" 300kw. The issue is how much it dissipates the heat. I'm yet to really see any back to back where someone will do say, 30 continuous pulls and then compare the heatsoak between the different intercooler setups, which is what an intercooler is really for.
 

Perhaps it is more correct to say that "support" needs to be put into context. If the core is just too small (cross sectional area internally for the charge flow) and puts up a lot of pressure drop, then the turbo has to make way more boost than is eventually seen at the engine which makes the turbo work harder, increases exhaust backpressure, etc etc. Not good.

So, to "support" 300kW, the cooler has to be big enough to not do that, and also big enough to shed the heat that you need it to for the use case. heat dissipation requirements for single street pulls is different than for drag is different than for circuit, etc.

[Stick180]

7 hours ago, Wazmond said:

 If anyones got either of em, did it require cutting on the front REO?

Blitz will fit, but requires cutting of either the reo, or knocking back the chassis rails like on the 260RS.

 

7 hours ago, Wazmond said:

2, boost controller, a user wrote that nistune will be able to control boost. Just wanted to double check that before pulling the trigger on a greddy profec...

Nistune does do boost control, but only upto 18psi (max res on OEM map sensor) and Nistune must be upgraded to FP2 software. I had limited success with this back in the day, but ultimately i went to a Link G4X.