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Couple Of Rb25 De Conversion Questions


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Anyways, so im just wondering if im on my P-Plates and i put a rb25de in my skyline, will i still be able to drive it? Like i can do whatever i want to my rb20 (cept those 2 damn intake mods) but can i lob a rb25de in it? As an rb25de it wont have as much power as my rb20, and seeing as mods after stock dont count towards weight/tonne ratio's i cant tell if theres any problem with my putting my rb20 set up onto the 25de. Any suggestions?

A rb25det conversion would be over power/weight and cost to much. The bloke who offered me the 25de conversion, said itll cost about 1k for motor and 1100 for installation (including swapping rb20 crap into rb25)

He's got 2 skylines at his workshop (one which he owns) with the same mods in them and it all sounds pretty micky to me. Do many people opt for the non turbo conversion then swap the junk over or not?

With my current set-up (check my siggy) will i be looking at a much faster car, or should i just buy a 2530 set up or something

Also, on another topic, ive heard that the rb20's 270cc injectors limit power alot after 150rwkw, which i think is bs ( i thought was more like 190/200kw) any suggestions on this?

thx in advance

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as mods after stock dont count towards weight/tonne ratio's
Yes they DO. If you modify a vehicle so it then exceeds the ratios, then it's illegal (yes I realise it's harder to detect / determine).
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ohh what, even in victoria? If i get canaried, they won't run it on a dyno ay? I haven't ever heard of any one getting defected for having engine modifications, so i wasnt to worried about that front. At least my turbo looks stock and such

Anyone else wana answer a question or two?

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Also, on another topic, ive heard that the rb20's 270cc injectors limit power alot after 150rwkw, which i think is bs ( i thought was more like 190/200kw) any suggestions on this?

Depends on the dyno I guess.

I have 2 examples..

Mine on the stock rb20det turbo that made 176rwkw at 9psi (wouldn't hold any more boost = turbo out of airflow).

It was hitting 92% duty at peak power, stock afm was seeing 4.98v, rev past peak power and it would require 100% duty to hold 12:1 afr's.

Another R32 running a GT35r .82 on 8psi made 183rwkw

That hits 100% duty and max's out the stock afm (5.115v).

Both of us are running aftermarket fuel pumps. Myself, I run a bosch item; the other dude, no idea but its not stock.

Regarding the RB25de... As you are probably aware they look the same as the rb20det.

The only issue with the RB25de bottom end is the high comp the pistons give you. 2 options on the cheap... Drop a set of s/h rb25det pistons in it or a really thick headgasket. I don't think a thick headgasket will get you low enough though.

A good tuner will be able to work with a high comp rb25de. Keep the boost sensible and there's no reason it won't make good power. Remember peak power is nothing, average power is everything.

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ahh ok thanks for that, wasnt sure if they will be ok, but i didnt think to check my AFR's either (assuming that if my injectors werent sufficient, my afr's would stray higher, than 12, which the bloke reckons is fine)

Hmm that thick head gasket sounds like a pretty good idea, itd have to be hella chunky, but i wouldnt have thought of that. Its the same bloke who did my remap (pretty damn well) works at dr drift, who'll be doing this so i guess he's what i'd call a "good tuner" and he didnt say anything about low comp pistons so yeh, assuming he'll work with it

I just wanted the car to see low 13's maybe high 12's eventually and im hoping with this new engine ill be able to achieve that, although i guess ill have to get rid of my newly installed 34 neo turbo and go for something bigger?

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