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Discussion Starter #1
small question but does anyone know how much rpm the stock valve gear on a rb25de from a 97 r33 can handle ?

as im going to be doin a mild n/a buld on my 33 id like to raise me rpm limit up a bit, am takeing alot of weight from the car to help performance aswell,

everyone keeps telling me go turbo but im sticking to my guns on staying n/a :) going to prove skylines can be fast without a turbo

also what options have i got for ecu tuning, remeber this is on a budget aswell :(
 

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Bigblock R33
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small question but does anyone know how much rpm the stock valve gear on a rb25de from a 97 r33 can handle ?

as im going to be doin a mild n/a buld on my 33 id like to raise me rpm limit up a bit, am takeing alot of weight from the car to help performance aswell,

everyone keeps telling me go turbo but im sticking to my guns on staying n/a :) going to prove skylines can be fast without a turbo

also what options have i got for ecu tuning, remeber this is on a budget aswell :(
NA RB's sound great on throttle bodies..... i'd say keep the rpm under 7300 and you'll be fine on stock bits.... also the cams will be way past peak by then so your not really gaining anything other than heat... Webber make a good NA ecu, theres always megasqirt too.... TBH you could probably get abbey to remap your stock ecu, it would be cheaper and they are pretty fecking good!
 

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Unfortunately with a limited budget, tuning N/As is a very unrewarding practice, any gains are hard won and usually expensive, with some decent cams, stronger springs, you may be able to get another 500 usable RPM,
add a gas flow and valve job, decent manifold and exhaust, and remap/piggyback and you may see another 15-20BHP.
 

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Discussion Starter #6
i know it can be expencive to tune na engines, this is why im going to drop weight rather than going ott on tuning, im happy with the way the 25 performs but just could do with i bit more rpm and a bit more get up and go from low revs,

im looking at custom building a more free flowing intake manifold as one of my main projects,

as far as ecu goes im lost here, with hodas i just converted them to run obd1 ecus which were chipable, this was done with a plug an play harness, easy work for anyone,
is there a chipable ecu that can be put into the 33 or can they be flash mapped ?

ill port flow the head and raise compression soon but just getting al the bolt on goodies done first
 

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Cams will help with a bit more RPM and top end, however the only cure for low end grunt is displacement really, as for ECU, I'm not sure if the nistune route is open to N/As, but otherwise a piggyback such as Emanage would be the cheapest option.
 

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Discussion Starter #8
so a rb30 block with 25 head, cams and port polish, more free flowing intake and exhaust manifolds all tuned on e-manage and i should have a decent n/a powerd car with a bit of extra bottom end grunt ?

very familiar with e-manage so sounds like a good idear to me, this was may second choice if i cant chip a nissan ecu
 

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Discussion Starter #9
could i see close to the 250bhp mark with this setup ?

and has anyone on here done this ?
 

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Well the 3lt block would certainly help with a bit more low end, as for the end figure i cant help with, but as it would be very similar to the 2JZ lump, i would say that extracting any more than 20-25 BHP max is pretty unlikely, i have seen countless posts from N/A owners saying they are going to try for 300BHP from the 2JZ (220 BHP std) but the only one i have ever heard of is a money no object in the US with some heavy duty engineering involved.

As for ECU, yes the EMB or preferably the EMU should be fine, however not knowing just how much the std ECU hangs onto closed loop, i suspect the only way to get around it would be to fit something like the innovate LM-1 or 2 and use the NB output to skew the lambda to the std ECU.
 

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Discussion Starter #12
sounds awsome :) think this may be the way, had an n/a built honda on itb's, was fun and sounded like atomotive porn,
thinking rb25head, cams, itb's and decent exhaust, going to look into this now, you could see this build comeing soon :) be prepaird for mental eargasams :p

dont supose you could clue a nissan newby up on EMB and EMU ecu's ?
 

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TBH if your going to run RB30 block and ITBs then i think you would be far better off with a decent stand alone ECU like syvecs, it would make having to fool the std ECU out of closed loop, which as i said can be a real pain using piggyback and WB, by the time you add the price of an EMU and a decent wide-band set up together, you will have two thirds of a stand alone price anyway:)
 
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