Stock rb25det neo questions

[niZmO_Man]

Might as well throw in a Peter Brock "polariser box" in while you're at it.

[Dose Pipe Sutututu]

On 03/04/2024 at 10:02 PM, Wazmond said:

Hey I've got a Hyper Hot InaZma? some voltage stabiliser, thats hooked up when i bought the car. Any idea what the pros/cons of this is and whether its worth keeping?

Rip it out and sell it, someone will buy/install it so their JDM is period correct lol.

[WMDC35]

3 hours ago, Dose Pipe Sutututu said:

Rip it out and sell it, someone will buy/install it so their JDM is period correct lol.

I've got a type LR, for low to mid rpm, saves doing a stroker etc, imagine using the LR and HR together, hella power. 

[Dose Pipe Sutututu]

Won't need a billet block at this rate 🤣

[Wazmond]

Hey lads, reviving an old thread. 

As an update, since the last time replied to this thread, ive done mostly suspension. Havent touched the motor except for maintenance. Though upon changing spark plugs, found out i had splitfires pre-installed!

Updates:
- Got me some stock airbox top cover and snorkel to fit onto the original intake. Should be free of defects
- Bought a set of R34 GT-T brakes (not installed yet, going to rebuild + respray in champion blue + white 'Nissan' text)
- Bought the last set of bilsteins from @Sydneykid and had them installed. Has been making some sounds on the rear but hopefully should be sorted out after this New Year break.
- Regreased front caster rod bushings (poly bushes..)
- Rear upper camber arms
- Whiteline sway bars (BNF27Z 22mm + BNR11XXZ 24mm). 
The rear sway bars are a bit short (ive read 50mm else where) but was still able to get them in. 
Anyhows, I reckon suspension is sorted now. Maybe replace bushes (do have a set of front upper control arms from SK not installed yet) but should be okay for now.

From now, I'm wanting to start working on the motor, drivetrain etc etc.
Still debating on the order to go on and what to buy etc but:
- ECU ( Haltech or Link ( Link states that it dont support A/T or AWD functions... Can anyone attest to this? )
- Highflow turbo ( ATR43ss2 )
- Intercooler ( Not decided yet, but cant find many good afoordable ones. Toshi says to opt for crossflow Japanese. Bit difficult this one, unless I get a returnflow Blitz from JJ? )
- Injectors ( Any recommendations ? I do have a nismo FPR ( Thanks SK ) )
- Seats
- Tune by either Toshi or DVS

To be fair, I did consider just keeping the stock turbo and nistuning it. Sat in a mates stock N, that had something like 200kw, and I reckon that felt more than enough. Maybe I should just go this route ahhaha. Too many choices....

Planning a trip down south, so wanting to just clean things up and make sure it gets to and from in one piece. Anything else specifically I should do before ?
Cheers lads
 

[GTSBoy]

If you've only done the upper control arms on the rear, AND you have changed their length (by more than about 1mm) to set the camber you want, then you will definitely need/want to install traction arms also. Adjusting the camber arms on their own WILL introduce bump steer and make the car unpleasant to drive. Most owners have no idea that their car could behave infinitely better than what they put up with.

I'm not entirely sure what the Stageas need, but I am thinking that unless you have massive front spring rates and pretty soft rear springs, you have waaaay too much rear bar. Oversteer city, in my estimation. Combined with possible excessive bump steer from maladjusted arms, that could be a recipe for nastiness.

ATR43SS2 is not a highflow. It is an outright replacement turbo. It's a little bit bigger than the largest highflow profile that Tao does. Probably a solid 300rwkW turbo where the bigger highflows will be about 30-40rwkW less. Nevertheless, we're only talking about ~300 rwkW, which is well within the abilities of the stock ECu to run with a Nistune on board. I would do so without hesitation - and I will be doing so when I get my finger out and actually get the injectors and AFM installed.

But, if you would prefer to drop a whole lot more money on the ECU side, then I suspect you're looking at Haltech. The Haltech fanbois here will all spout on about all the available engine protection you can have, that you can't have with the Nistune option. And they're right. But it doesn't really come for free either. You will spend more money on extra sensors and the like, plus the work to install them. If the engine was built and therefore represented a big investment to protect, then I'd say definitely do it. If you view the current (and forever into the future) shortage of replacement engines as something to prompt similar protection, then also, do it. If you see a destroyed RB25 as an opportunity to put in a Mercedes or other V12 (like I kinda do)... then your perception of the risk/reward might differ.

These are good injectors. You can also get a "better" set of the same with more flow matching, for more $$. 1000cc is where you will want to be.

You will need an R35 AFM and adapter tube if you want to stay with Nistuned stock ECU. Otherwise, if going Haltech, you can ignore.

As for intercooler. Just about anything will do. You're only talking about ~300rwkW. Just put a big core in there. Be aware that return flows do add significant pressure drop and will cost power and will make the turbo work harder to achieve the same goals. If you can manage a proper crossflow, do it. I'm keeping my very good return flow because I'm only expecting to be in the ~250rwkW range, and will live with whatever outcome I get.

[Watermouse]

2 hours ago, GTSBoy said:

 

These are good injectors. You can also get a "better" set of the same with more flow matching, for more $$. 1000cc is where you will want to be.

GTSBoy

on your suggestion on another thread I had a look at those injectors and ended up getting them because of the quality.  Got the expensive ones.

 

[Murray_Calavera]

14 hours ago, GTSBoy said:

The Haltech fanbois here

Haltech fanboi reporting in. Buy the Haltech! 

[Wazmond]

On 18/03/2024 at 12:55 PM, GTSBoy said:

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.

14 hours ago, GTSBoy said:

These are good injectors. You can also get a "better" set of the same with more flow matching, for more $$. 1000cc is where you will want to be.

Sorry just wanting to clarify, at this power goal, which should I be going?

Also,
More info regarding suspension, the rear upper camber arms were used to get the camber back to i believe around -0.5 ~ -1 degree (@ Road and Race in Rydalmere), I forgot the exact figure, but ALOT less camber than what it came originally which was like -2.5degrees. Are the traction arms still recommended?

The bilsteins from SydneyKid, they've got 400lb/in fronts & 275/in in the rear, revalved to his specs.

Intercooler, I'm just having a look at some on Rakuten.jp and some other japanese sites. Might get something from back there, GReddy, Blitz or HPI, all crossflow. Looking at roughly $450-$500 AUD + shipping... Theres not many choices except that chinese branded Justjap unless you go for blitz return flow.

Yeah, only downside with Haltech is the price ahhaha, so expensive, and with all the sensors if I go that route... $$$$$ yeesh.

Are headstuds/gaskets needed for <300akw?

[Murray_Calavera]

1 hour ago, Wazmond said:

Are the traction arms still recommended?

Yes. 

The only scenario I can imagine when the answer isn't yes, is if you drive like there is highway patrol behind you at all times. 

1 hour ago, Wazmond said:

Yeah, only downside with Haltech is the price ahhaha, so expensive, and with all the sensors if I go that route... $$$$$ yeesh.

If your car currently runs, enjoy it and keep saving. Better costs more, keep saving until you can budget the better ECU. It's worth it. 

1 hour ago, Wazmond said:

Are headstuds/gaskets needed for <300akw?

Nope. Plenty of us making >300kw on unopened motors. Mine is unopened and makes about 350kw if I turn everything up, its fine (lots of caveats here, how the car will be used/abused, how long you expect the engine to last between rebuilds, how has the engine been maintained prior to coming into your ownership, etc etc). 

 

[GTSBoy]

4 hours ago, Wazmond said:

Sorry just wanting to clarify, at this power goal, which should I be going?

Hmm. Yes. I should have been clearer. 1000s for Haltech, for extra headroom. 725s for Nistune. You might even be OK with 640s, but if the possible power ends up much more than 300 rwkW you will run out of headroom on the 640s. That would probably be OK and a signal to not push it to that sort of power with Nistune anyway. At that level you probably do want to be thinking about engine protection functions.

Oh, and all of that presumes 98 only, not E85. Well....the 1000s would allow you to run E85 at ~300rwkW territory, again, maybe sort of running out of headroom. Hard to tell with E85 - depends on the tuner as to how rich they like to set it up.

[Duncan]

5 hours ago, Wazmond said:

....More info regarding suspension, the rear upper camber arms were used to get the camber back to i believe around -0.5 ~ -1 degree (@ Road and Race in Rydalmere), I forgot the exact figure, but ALOT less camber than what it came originally which was like -2.5degrees. Are the traction arms still recommended?

Pete knows these cars well, he does my car too, if he was concerned about the traction arm length for your use he would have said so. Do you have adjustable bushes in that arm, maybe he got enough adjustment there (or maybe the bump steer was not material for your use of the car)

[Wazmond]

5 hours ago, Murray_Calavera said:

Mine is unopened and makes about 350kw if I turn everything up

What do you have in that bad boy ?

2 hours ago, GTSBoy said:

1000s for Haltech, for extra headroom. 725s for Nistune. You might even be OK with 640s, 

Oh, and all of that presumes 98 only, not E85. 

Ill go with the 725cc since I'll be going with Nistune ( would definitely like more engine protection but Haltech is too far out of reach at the moment... plus, Ill probably have a pretty safe tune as its a daily, not gonna be chasing peak power 24/7 ahahah ). Are Xspurt a safe choice? 

1 hour ago, Duncan said:

Pete knows these cars well, he does my car too, if he was concerned about the traction arm length for your use he would have said so. Do you have adjustable bushes in that arm, maybe he got enough adjustment there (or maybe the bump steer was not material for your use of the car)

Pete's great. He didnt mention anything about traction arm length so I reckon it may be good. When I get some new wheels/tire later down the road I'll ask him about it and get his opinion on em. I heard from Gary that you've got the bilsteins too, are you running the sway bars too? and what other suspension goodies do you have installed or would recommend?

[GTSBoy]

6 hours ago, Wazmond said:

the rear upper camber arms were used to get the camber back to i believe around -0.5 ~ -1 degree (@ Road and Race in Rydalmere), I forgot the exact figure, but ALOT less camber than what it came originally which was like -2.5degrees

1 hour ago, Duncan said:

maybe the bump steer was not material for your use of the car

Hmm...

From my experience you get about 0.25° camber change per mm of RUCA length change. So, to correct from -2.5 up to less than -1° (or, more than -1° if you look at the world as a mathematician does) then you'd be making 6-8mm of length change on the RUCA. From a stock length of 308mm, that's 2-2.5% difference in RUCA length.

My RUCAs are currently very close to stock length - certainly only 2-3mm different from stock. I had to adjust my tension arms by 6mm to minimise the bump steer. That's 6mm out of 210, which is 2.8%. That's a 2.8% change on those, compared to a <1% change on the RUCAs. So the stock geometry already has worse bump steer than is possible - you can improve it even if you don't change the RUCA length.

If you lengthen the RUCAs at all, then you will definitely be adding bump steer.

Again, with my car, I recently had an unpleasant amount of bump steer, stemming from a number of things that happened one after another without me having an opportunity to correct for them. I only had to change the tension arm lengths by 1mm to minimise the resulting bump steer. (Granted, I also had to dial out a lot of extra toe-in in the rear, and excessive rear toe-in will make bump steer behaviour worse). Relatively tiny little adjustments having been made - the car is now completely different. Was horrifying how much it wanted to steer from the rear on any significant single wheel bump/dip. And it was even bad on expansion joints on long sweepers on freeway entry/exits, which are notionally hitting both rear wheels at the same time.

My point is, the crappy Nissan multilink is quite sensitive to these things (unlike the very nice Toyota suspension!). And I think 99.75% of Skyline owners are blissfully ignorant of what they are driving around on.

Sadly, it is a non-trivial exercise to set up to measure and correct bump steer. I am happy to show my rig, which involves nasty chunks of wood bolted to the hub, mirrors, lasers, graph paper targets and other horrors. Just in case anyone wants to see how it is done. I'll just have to set it up to take the photos.

[GTSBoy]

3 minutes ago, Wazmond said:

Are Xspurt a safe choice?

They are what I will be installing. 640s for me.

[Murray_Calavera]

2 hours ago, Wazmond said:

What do you have in that bad boy ?

Pretty much what you'd expect at that power level. Hypergear turbo, long list of supporting mods, full Haltech catalogue, etc. 

2 hours ago, GTSBoy said:

And I think 99.75% of Skyline owners are blissfully ignorant of what they are driving around on.

I'd say this goes for most drivers, suspension is still a dark art for most people. And it's really hard to convince someone how much better their setup could be...

 

[Watermouse]

1 hour ago, Murray_Calavera said:

I'd say this goes for most drivers, suspension is still a dark art for most people. And it's really hard to convince someone how much better their setup could be...

 

I mean this in no disrespect to u mate; Are there clear tagged examples/explanations in our SAU forum for example, in my interest, this is how to do R34 Gtt suspension the right way?

U guys did so much taking risks with experimentation that deserves recognition and those results helps us morons take the RIGHT path to buy quality / buy once. 🍻

[Murray_Calavera]

3 minutes ago, Watermouse said:

how to do R34 Gtt suspension the right way?

That's a hell of a question right there and so broad that you could get 100 different answers and have them all be correct. 

To avoid me typing up a 2000 word thesis that doesn't answer your question, do you have specific things you are unsure of? Does the car currently handle in a way that you don't like?

Or is it closer to, you think the car drives fine currently. But you'd like it to be better, but you don't know what that 'better' is or what that 'better' feels like?

[Watermouse]

I’ll go last point,

For me it’s, can I do better relying on the expertise of u experts in the field

but my point was, is there a way and a will to sticky important tried/true/tested facts that come out of a question relating to each area of improvement. I mean like not losing valuable info when u end up relying on google without success. Some times. I just see so much knowledge being passed but unless u are a guru or lucky, the diamonds end up hidden in our forum

sorry guys I’ll leave it at that

respect 

[Duncan]

22 hours ago, Wazmond said:

Pete's great. He didnt mention anything about traction arm length so I reckon it may be good. When I get some new wheels/tire later down the road I'll ask him about it and get his opinion on em. I heard from Gary that you've got the bilsteins too, are you running the sway bars too? and what other suspension goodies do you have installed or would recommend?

In the 32 race car, I basically run what Gary told me and it is lovely across a range of conditions which is what I needed. I've got revalved bilsteins, adjustable solid sway bars, adjustable bushes all round. Just looking at Neil's R33 GTST and it has pretty much the same on board, Gary Bilsteins, Selby/whiteline sway bars.  Gary knows suspension generally and these cars specifically very well across street, street/track and track only use and gives a very well balanced set up.

Just be aware his preference is for light springs and heavy sway bars, there is another school of though (eg MCA) that prefer lighter swaybars and heavier springs/shocks. The evo I raced had that setup and it was also very nice so there are multiple ways to skin cats.