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Rb26 Twin Or Single? Best Power And Response


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bigger dumps wont help spool up time, it will increase flow and reduce back pressure meaning more lag but more power/kick

once ive converted my gtr to single then ill be able to comment from experience but for now i cant :(

Bigger dumps can and often will help spool time... My trust dumps spooled up my T517Z's quicker.

Keep it simple, bolt on -7's, -5's, -9's- T517Z 8cm's would be my pick.

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That's not an rb26

Appears the driver loves the flutter more than gate :)

Soon as he pegs boost, gate opens - gear change.

Only once does he almost wind a full gear out... :(

RB26's with external/single sound no different to RB25's really as the sound is predominately a product of the manifold itself.

Different manifolds, tyres, lengths change the sound. Same as the length/cut of the screamer pipe, size of the gate itself etc etc.

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Mine makes full 15 psi by 3800rpm

I am probably seeing positive pressure by 2500 i would say by the feel of it. would have to plug the laptop in to get exact rpm but mine is still running very rich so a little sluggish atm and is still quite quick onto boost :D never under estimate a decent manifold lol

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Just remember there is a gigantic difference in police attitude on modified cars between Townsville and NSW/VIC. A high mount turbo will be defected instantly by 90+% of Victorian cops. Not sure where the thread owner is located.

And no bigger dump pipes will not cause more lag. They will either reduce lag or stay the same depending on how restrictive the old ones are. The theory from Garrett and others is the bigger the exhaust after the turbo the better.

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As above the police up here are relatively fair but won't hesitate to slap you with a hefty fine if its due.

The "hoon" squad from Brisbane have been up here many times. In saying that you do have a valid point with police attitudes

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Located in nsw, I have been pulled over in my old show car but never been pulled up in the skyline amazing what attitude 4 doors get :)

Weapon are u using a single entry 35r and what ecu boost controller? What pwr are u making on 15psi?

When are the garrett -5 seeing boost?

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And another example lol

My favorite workshop in japan, shop downstairs and on the upstairs level is a cool shot bar which over looks the lower level... and a no f**king sign on the toilet door :)

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Hay guys, pretty sure you cleared this up already but just putting my 2 cents in.

got a t04z and went from a 3" dump to a 3.5" and i gained 300 rpm in response. also will be putting cams and from what ive seen ill gain about 400 rpm there..... so a bigger dump definatly helps with response on big turbs.....

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having a poke in the dark! what if you wer to say run a 2860 -5 and a 2871r? the 2860 to get you going but the 2871r to help it from running out of puff at the 400 mark

Instant recipie for a dead motor!

Doesnt work on these motors,

Why....Small turbo comes on boost, with pressureises the intake system, air will find the easiest way out, and so will force its way out of the turbo that isnt spinning very hard and bam worlds biggest boost leak, untill the exhaust gas can finally turn the larger turbo and then there is a pressure differential blah blah blah.

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having a poke in the dark! what if you wer to say run a 2860 -5 and a 2871r? the 2860 to get you going but the 2871r to help it from running out of puff at the 400 mark

same principal as cars like FD RX7 and Supra and TT soarers. they are a sequential or 'staged' turbo system. it's not as simple as two differentl sized turbos. you need a complex arrangment of valves and piping on both the intake and exhaust side to make it work. GTR is 100% parrallel system. both turbos feed a common inlet. so no you cannot run 2 different sized turbos. well you could but it won't run very nicely. they are a good idea but in practice too difficult to make reliable and for outright performance two equal sized turbos in parallel is the way to go.

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Located in nsw, I have been pulled over in my old show car but never been pulled up in the skyline amazing what attitude 4 doors get :)

Weapon are u using a single entry 35r and what ecu boost controller? What pwr are u making on 15psi?

When are the garrett -5 seeing boost?

I am not running any form of boost controller other than the wastegate itself. It is a sigle entry so no split pulse for me lol. Well its a little disapointing as i am having a boost control issue basically which limits my power run to 5000rpm before it spikes (due to where gate is plumbed in) However with no timing and running to around 5000rpm or so its ramping up to 278rwkw before it takes off with boost.

Keep in mind due to this the tune is no where near as good as what it could be so given its performance with no timing etc i was assured around 300-330rwk on 1bar boost. I am running a ViPec plug in ecu and the engine is completely standard ie no cams etc. Custom made 3in dump and front and rest of exhaust is 3.5in with no mufflers in sight

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same principal as cars like FD RX7 and Supra and TT soarers. they are a sequential or 'staged' turbo system. it's not as simple as two differentl sized turbos. you need a complex arrangment of valves and piping on both the intake and exhaust side to make it work. GTR is 100% parrallel system. both turbos feed a common inlet. so no you cannot run 2 different sized turbos. well you could but it won't run very nicely. they are a good idea but in practice too difficult to make reliable and for outright performance two equal sized turbos in parallel is the way to go.

Everything above is 100% correct. :):D:):P:P:cool::cool::cool:

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So with a decent ebc and tune should.be even faster onto boost then what u have now weapon? What's the drive ability like and touque like ?

I think its alot better than the standard twins in terms of off boost torque, even now it still has good low end urge and top end torque is still damn impressive. the last time it was on the dyno it was making peak torque by about 5-5300rpm

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