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Still trying to decide if i want -5 or -9 turbo's.

How is the car revving before you reach full boost?

Also, How do you go about fitting bigger injectors in the stock fuel rail? or am i better off getting a bigger fuel rail? (where do i buy the adapters?)

This may help

stockturbosvs5turbosdyn.jpg

that was on BAKES r34 GTR - the engine just had bolt on's similar to yours, but a restrictive exhaust which hurts the -5 result a fair bit.

http://www.skylinesa...gtr/page__st__0

If you wanted a -5 set-up to be as/near responsive as stock, you would have to look at VCT or a stroker.

However, if you look at 2.6's that are built for a -5 setup (ported head, 260 cams, 4"inch exchaust etc), the power curve virtually follows a -7/-9 curve...just with a significantly higher peak. Not sure how the revability is affected...will know in a couple weeks once my -5 build is finished & tuned :banana: .

Edited by wedge_r34gtr
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Can't believe this hasn't been said,

I'd be getting rid of the apexi fc and the afms..

For the cost of all that you could easily buy and install a far superior ecu such as a link G4 or a vipec..

Get rid of the afms :)

Nismo pump will make 350 as long as it's got full voltage.

Id1000s are a good option as long as you don't plan on making ALOT more power down the track or switching to E85.

If your ONLY chasing 350 and you want it responsive I'd go GT SS though your set up must be spot on.

-5s will make 350 alot easier and have the potential for 400rwkw but once again if your set up isn't correct, I've seen cars not make 350 on-5s... Usually due to exhaust restrictions

Also loom at getting some cam gears

You ll also save money by keeping your stock air box if you still have it.. Is good or 400rwkw+

Edited by GTR_JOEY

Hi Joe, few questions.

1. How come people still use Apexi's if there are better ECU's out? I didn't even know there were others out!?

2. Got links to the other ecu's joe?

3. Why would you want to go to E85 (other then emissions)? Isn't it less economical and makes less power? :\

Hi Joe, few questions.

1. How come people still use Apexi's if there are better ECU's out? I didn't even know there were others out!?

2. Got links to the other ecu's joe?

3. Why would you want to go to E85 (other then emissions)? Isn't it less economical and makes less power? :\

1. Because they are easy to get, install and set up.

2. Other ECUs? Link, Vipec, Haltech, Motec, Autronic, Wolf, Adaptronic, Megasquirt, Microtech, etc. All able to run an RB26, some better than others.

3. E85 is much worse for economy, in terms of litres per 100km. But in terms of $ per 100km, it's about the same as unleaded, depending on where you are. So unless you need the range provided by a tank of unleaded, or if you have a problem with accessing E85, then E85 is not worse to use from an economy point of view. E85 needs a bigger fuel system, but provided you do have the system size required to get enough of it into the engine, then it will make a lot more power than unleaded on the same engine. You can wind a lot more timing and/or boost into it before it will detonate, so you make more power.

Cheers GTS

Saved me alot of iPhone typing

One thing I will say though is that the links/vipecs haltechs are quite common now and you may find they are just as simple to install as a PFC, if not alot simpler then a d jetro

Edited by GTR_JOEY

I agree with ditching the afms and pfc and going for something like a link g4. Cost wise they are about on par i would think once you factor in the cost of the fpc and 2 afms.

You can also get a mac valve to control boost using the ecu as well so you dont have to worry about a seperate ebc.

Hmmm,

Random thought.

Can i just wack on a set of -9's and not change anything else without causing any harm?

Then at least i know my stockies won't randomly go boom and it will give me more time to sort my shit out, ask more stupid/noobie questions and decide on the other parts i want.

Still running stock solonoid (though restrictor is out), and don't plan on changing it till i figure out what ecu path i want to go down. As some of these other ones listed control boost for you.

So stock ecu and just replacing turbo's won't do anything bad?

Edited by Booki

Not really no. You can run -9s on a stock ECU as long as you keep the boost down.

Set them to 1bar and you'll make around 260-280rwkw and it'll be fine (I've run that setup on my GTS-R for the past 3 years). Of course have it checked on a dyno and all that to confirm it is indeed set correctly timing wise.

I believe the -5's are capable of more power (if the need arises) and have similar response to stock turbo's if not better?

Not even close. -5s won't come on until 4,000rpm+ around town in 1st/2nd/3rd.

I suggest you do some more reading - specifically around the -7/-9 threads. There are plenty of them across the forum

However, if you look at 2.6's that are built for a -5 setup (ported head, 260 cams, 4"inch exchaust etc), the power curve virtually follows a -7/-9 curve...just with a significantly higher peak. Not sure how the revability is affected...will know in a couple weeks once my -5 build is finished & tuned :banana: .

Yeah but in/out of gears - you still notice the difference in lag and transient response. What is shown loaded on a dyno for response is often not the true picture.

I've gone from -9s to -5s on my very own GTR with a built motor etc. I can tell you for a fact that driving around the street/hills it's totally different. The -5s are noticeably laggier regardless of what the dyno sheet tells you.

I've said it 100 times, -9s for a 2.6ltr GTR that is street driven is the best choice for twins.

-9s all the way mate and they will make 350kw

You just need to push them and have all supporting mods, if the engine is stock stick to the 300-320 region unless you want to rebuild the engine

Not really no. You can run -9s on a stock ECU as long as you keep the boost down.

Not really? So i can damage something? I'm confused now. What happens if you up the boost? I take it other parts (fuel pump, injectors ect) will not be able to keep up and it will run like ass?

Set them to 1bar and you'll make around 260-280rwkw and it'll be fine (I've run that setup on my GTS-R for the past 3 years). Of course have it checked on a dyno and all that to confirm it is indeed set correctly timing wise.

Not sure if i am running 1 bar, but i do remember reading. removing the restrictor in the stock solonoid hose will give me 1 bar of boost. If so, then i should be right. Currently running the stockers with the restrictor out. I don't have any boost gauges or after market controllers.

I suggest you do some more reading - specifically around the -7/-9 threads. There are plenty of them across the forum

Will do as much reading as i can, heaps more to learn especially seeing as others are recommending ecu's other then the PFC units.

I've said it 100 times, -9s for a 2.6ltr GTR that is street driven is the best choice for twins.

Think you have sold me on the 9's...It may not give me the most peak power, but will give me the best drive ability as it is my daily car.

I think the issue will be that whilst you are running the stockers on higher boost than stock the cars ecu can cope better to a degree because the factory ecu is tuned with those turbos. Bigger twins untuned on the same boost level will mean they are flowing much more air and the stock ecu may not be able to handle that.

So by turning down the boost on the bigger twins you can hopefully avoid problems caused by the extra flow capacity. 12psi on the stock turbos will flow less air than -9's at 12psi.

Edited by Mitcho_7

Not really? So i can damage something? I'm confused now. What happens if you up the boost? I take it other parts (fuel pump, injectors ect) will not be able to keep up and it will run like ass?

Not really as in - No it wont do any damage.

You just wouldn't push it past 1 bar, with the -9s on there. I've done it, on 2 cars - without a problem as long as you CHECK it on the dyno etc. The RB26 ECU isn't as hell bent on destroying the fun like the RB25 ECU is with it's Rich/Retard mode when you increase boost and so on.

Injectors/AFMs/ECU need to be upgraded for anymore than 280rwkw IMO.

Think you have sold me on the 9's...It may not give me the most peak power, but will give me the best drive ability as it is my daily car.

Yes if you drive your car daily, in around town and so on - having the -5s you never have any fun with them as below 140km/h, you simply don't get to use them effectively.

-5s have a great top end, they were awesome fun when punting my car around above 100km/h doing track stuff but below that as a street driven GTR. The -9s come on so much sooner and you never have to "drop back" an extra get to move in/around traffic which is the big difference IMO.

Like the rest above have said for 350kw GTS-S or -7's are more than enough. Unless you want to go for 400+ kw with or without E85 (id1000 jectors etc) on -5's. Most guys seem to be obsessed with PFC.. its good bang for buck but its REALLY outdated.. if your going to spend money on your car you might aswell spend abit more coin and get yourself a HALTECH.

For a street car, what do the extra logging features actually offer though from the more expensive ECU's?

That's the question you have to ask yourself really because they don't offer much for the general joe-blogs who just wants to drive his car to/from work but also have a bit more power and keep it all nice and simple. The PFC tells you enough about whats going on in terms of knock, temps and so on for the "set and forget" type person.

Sure ignition cut would be nice, oil temp pressure cut off and other things - but realistically they are a want, not a need. You also need extra input/sensors and so on which costs more money.

If you intend on going E85 down the track and run dual fuel/E-sensors etc then obviously that argument is entirely different and you need to look at other ECUs as the PFC won't support that easily for a street car.

For a street car, what do the extra logging features actually offer though from the more expensive ECU's?

That's the question you have to ask yourself really because they don't offer much for the general joe-blogs who just wants to drive his car to/from work but also have a bit more power and keep it all nice and simple. The PFC tells you enough about whats going on in terms of knock, temps and so on for the "set and forget" type person.

Sure ignition cut would be nice, oil temp pressure cut off and other things - but realistically they are a want, not a need. You also need extra input/sensors and so on which costs more money.

If you intend on going E85 down the track and run dual fuel/E-sensors etc then obviously that argument is entirely different and you need to look at other ECUs as the PFC won't support that easily for a street car.

Well put. Basically answered everything.

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