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Hey,

I am very interested in finding out what an n/a rb25de could make in power when tune. I know that n/a tuning is very pricery compare to a turbo (in the dollar for power value).

Im interested in what would needed to be done to produce something like 250rwhp on an n.a rb25. Also would you beable to increase the rev limiter to something very high like 10,000rpm if you foucs on tuning the n/a side of the engine? (i found that n.a type engine have the characteristic to be able to rev higher for example i know the 4ag is able to produce nice power between the range of 7 to 11,000 rpm after tuning)

The reason for the question is i fine that with turbo comes lot of problems and money issues (pinging etc). I dont plan on swaping anytime soon but interested if what it would cost to produce 250rwhp with a nice rev range in an n.a rb engine.

cheers mike

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Turbo comes a lot of problems and pinging issues?

Its just a money matter with converting a car over to turbo.

There are no 'problems' or pinging issues unless the car is not running correctly due to a dodgy fuel pump or bad tune.

I wouldn't go to the extent of port/polishing, pistons or balancing for NA. It really would be a huge waste of money as a decent rebuild inc. balancing pistons & port polishing will cost $5000 just for the motor + labour to remove and install which could easily tack on another thousand or two. Then there's the ecu and tuning.. That could easily blow out to another 1500-2000.

Then add on another $1k for cams.

So all up the motor will be worth damn close to $9000 for what??

A motor that makes the same power as a Turbo version WHEN STOCK & running STOCK boost.

I would put up with the n/a until one day you can afford to buy a turbo or simply sell it and buy a V8 Commodore if you want more power. :D

right but if you wish to proceed the best option int to go for an rb 25/30 whihc is rb 25 head on an rb 30 bottom end with goo size cams high compression, head work and aftermarket ecu you could achive your goal.

you could also build an rb 26 as an n/a motor is has been doen the you get a an 8500 9k red line and pretty good power.

but these motor in this state of tune would only last around 20 000 klm if your lucky may be less

meggala

theres no way you will be able to run a 10K rpm limiter on stock internals regardless of the tune or whether its turbo or non turbo

the rods will no doubt snap and mangle themselves, and probably shoot through the block

tensile loads increase exponentially with rpm, so keep that in mind when going over stock limiter

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