Magnaflow Fpr Vs Stock, Rb25 With Gtr Injectors, ~250kw

[Rolls]

I've got a rebuilt rb25det with a gcg highflow etc, currently it just has stock injectors/reg new pump and is running 10psi. Tuner said it is ok on the stock injectors and making about 200kw, anymore though and I risk leaning it out due to 100% duty cycle esp in cold weather or if I get a boost spike.

I had a fuel rail with gtr injectors, magnaflow regulator etc in it initially but it had to pass a full roadworthy so I removed them and got it retuned. Anyway its all on the road and I'm itching for more power, will be getting a Z32 afm and putting the rail and injectors back in, but I am unsure what to do about the regulator. I've read everywhere that the stock one is good for up to 300kw and theres no reason to change it, but being as I already have the reg are there any advantages to using it, or is it just going to make it harder for the tuner to tune? Will be putting the turbo up to 14-16psi depending on how it responds.

The other thing is its shiny and pink so it really screams defect me, so if I put it back in I'm going to paint it black along with the ultra shiny fuel rail to keep it looking stock.

Cheers.

Edited June 20, 2010 by Rolls

[JonnoHR31]

keep the stock reg if it works fine. if you somehow max the gtr injectors way short of your power goals (unlikely) then, and only then, should you consider an adjustable reg

[Rolls]

So theres actually disadvantages to the aftermarket reg? What are the differences, just the fact that it is adjustable and you can easily bump the pressure up? Or does the fuel pressure rise differently to a stock one, eg exponentially instead of proportionally?

Sounds like theres no good reason to use it so I will most likely adapt the stock one back on and sell it then.

[JonnoHR31]

rising rate regs rise exponentially, normal adjustable ones just let you adjust the base pressure. not sure about the magnaflow but most aftermarket regs simply arent as good as the standard one and also a waste of money/illegal if you dont need it.

[Rolls]

rising rate regs rise exponentially, normal adjustable ones just let you adjust the base pressure. not sure about the magnaflow but most aftermarket regs simply arent as good as the standard one and also a waste of money/illegal if you dont need it.

Thanks that is all I needed to hear, I will adapt the standard one onto my aftermarket rail. Wasn't sure if the stock ones were a proportional rise or exponential, if they are prop then there would be a definite tuning disadvantage with the aftermarket exponential one.

[R31Nismoid]

Factory ones will go over 350rwkw no problems.

GTR injectors will do 280-300rwkw

So easily within the stock reg.

[Rolls]

So easily within the stock reg.

Yep so all I will be doing is making the tuner's job harder if I put the magnaflow back on?

[R31Nismoid]

Depends... some regs don't work all that well.

There are a few nasty experiences with Malpassi (as an example) across my mates so ye... where possible i'd personally stick with stock.

[GTScotT]

+1 to confirm rising rate is important, stock is rising rate.

Can you confirm what motor you are running? You said RB25DET and GTR injectors... Unless its an R34 NEO can you please explain your use of GTR injectors?

Cheers.

[Rolls]

Series 2 rb25det rebuilt with forged pistons etc. Has series 1 running gear and some rb20 stuff as it is in an R32 gts-t. Turbo is rb20 but highflowed by gcg so it is basically identical to a 25 highflow hence the need for GTR injectors.

[GTScotT]

Although what inlet manifold are you running?

Did you do a conversion to run the GTR injectors or is it an RB20 inlet you are using?

[Rolls]

rb25 intake with custom fuel rail and I think there is a slight modification to the inlet manifold to accept the bigger injectors as well.