Rb25de

[godzilla-32]

hey

just bought a r32 gts25 ( obviously with an RB25DE ) i am a apprentice mechanic so i have knoledge of these engines and mechanics.

would love to know what ecu you recomend, im doing a full exhaust system (2 1/4 " ) no cat through to a 4 " tip.

new intake with 3 " polished alloy piping with silicone joiners on a simota poddy in cold air box.

what other mods do you recomend i do for quick performance changes? , i really need to know what ecu u recomend as and upgrade, which injectors should i use etc?

and useful info will be appreciated.

thanks heaps

[.:: GimpS-R34 ::.]

May I ask why your looking for ECU and injectors in an NA? Also if you're P plater you know that performance mods is still a no-no right?

[ONE-VIA]

if ur a mechanic raise ur compression

underdrive pulleys

etc etc theres shit loads of threads

[Serg]

May I ask why your looking for ECU and injectors in an NA? Also if you're P plater you know that performance mods is still a no-no right?

By vic roads its a no no, but ive never heard someone gettin done for it. Max that ive heard from p plater mates is them getting EPA'd and thats it...

Back on topic:

Check the sticky's, they have all the info there... Just read!

[godzilla-32]

May I ask why your looking for ECU and injectors in an NA? Also if you're P plater you know that performance mods is still a no-no right?

i live in new zealand, there is no modification law regarding license,

the future plan is to do a turbo setup , but for now i just want to see how much power i can squeeze out of a NA RB, injectors to pump more fuel and an ecu to boost air intake and air/fuel levels?

[Mad-Max]

if ur a mechanic raise ur compression

underdrive pulleys

etc etc theres shit loads of threads

oh so tru .... you really can do alot.

heres a start

-electric fan (and throw away that horible standard one that hangs off the water pump)

-headers,

-fuel pressure reg,

-cams are cheapish,

-up your compression

-wasted spark

-simple chip off trademe

-cold air box

then maybe

-lighten pullys/cam gears/flywheel

-underdrive pullys

-larger throttle body

-and a slightly better chip

-better valve springs

and to go all out (i doubt youll need to go this far but keep some of the ideas in mind like the vct head)

-wild mad assed cams

-lightened crank

-link ecu

-big port vct head (get rid of the vct tho! this will save you a port and polish if you dont want to spend the money)

-electric water pump

-front facing intake phlenm

-port and polish

ive probably forgotten a few things that can be done engine wise but i doubt youll need to go as far as forged internals on an n/a engine

and also for that engine dont change the injectors they will/should be fine for n/a application

at the end of the day i wouldnt do half this stuff if i was goin to put a turbo on it so i think you need to sit down and think about what you want to put into it and what you want out of it or the whole exercise will end up burning a nice neat hole in your pocket

Edited September 15, 2010 by Mad-Max

[mad082]

a cheap "performance" chip you get off the net won't do squat. probably the worst performance mod you can suggest to anyone. might as well take off the passengers side mirror and wiper blade for better aerodynamics. for basic tuning start with a safc. if you are willing to spend a bit more then go a z32 ecu and nistune.

as for going bigger injectors, unless you plan on doing major head work then you won't need bigger injectors. you have to remember that if you were to tune a relatively stock car you will actually be reducing the amount of fuel the injectors squirt in, not increasing it. you have to be increasing the amount of air going into the head by a hell of a lot to max out the stock injectors.

you also have to remember that some mods you do go get good power out of a NA can limit the power you get out of a turbo car. if you raise the compression then when you go turbo you can't run as much boost.

[rorz]

Just remember the more mods you do to the NA the less drivability it will have in terms of comfort (especially when it comes to cams). I recommend the 2.5inch exhaust and good intake then maybe weight reduction and spend the rest on good maintenance until you can afford a faster car (if that's what you want). My favourite NA car i have owned was a V8 toyota soarer, very quick, very cool.

[godzilla-32]

a cheap "performance" chip you get off the net won't do squat. probably the worst performance mod you can suggest to anyone. might as well take off the passengers side mirror and wiper blade for better aerodynamics. for basic tuning start with a safc. if you are willing to spend a bit more then go a z32 ecu and nistune.

as for going bigger injectors, unless you plan on doing major head work then you won't need bigger injectors. you have to remember that if you were to tune a relatively stock car you will actually be reducing the amount of fuel the injectors squirt in, not increasing it. you have to be increasing the amount of air going into the head by a hell of a lot to max out the stock injectors.

you also have to remember that some mods you do go get good power out of a NA can limit the power you get out of a turbo car. if you raise the compression then when you go turbo you can't run as much boost.

i can sourse and ecu out of a z32 300zx, would i have to do any internal mods for my rb25de to run this computer?

thanks heaps

[Jezza-gtR]

-electric fan (and throw away that horible standard one that hangs off the water pump)

Please explain what is so horrible about it?

[ONE-VIA]

rb30 bottom end

[Mad-Max]

Please explain what is so horrible about it?

there radiator munchers

oh and nothin wrong wiff chips if you get em from the right person just gotta make sure its from a trusted tuner ..... as for cams a mild cam is nice to use, i run a 290* lump cam on a rb30e and it doesnt f**k wiff drivabilty that much

Edited September 16, 2010 by Mad-Max

[WYTSKY]

godzilla32, if you are eventually planning to turbo the car, do it now...

Eg. If you raise the compression now and do all this work to the motor, you will have to reverse it when you want to turbo it.

there is no point spending all this money on a little 2.5 n/a and barely getting any results.

If you do want to wait on turboing it then I would do brake upgrade + suspension upgrade, wheels,etc. instead of worrying about the motor.

Also, I think you'll find you wont need to upgrade injectors because you probably wont be able to suck in enough air to max them unless you do some major amount of intake mods.

gl with it.

[StealthX]

there radiator munchers

oh and nothin wrong wiff chips if you get em from the right person just gotta make sure its from a trusted tuner ..... as for cams a mild cam is nice to use, i run a 290* lump cam on a rb30e and it doesnt f**k wiff drivabilty that much

Sorry bro, but for someone who proudly says they 'know about engines and mechanics', you don't really know diddly squat.

A 'chip' won't do f**k all, listen to our advice, regardless of who you get this 'chip' you speak of from...

If by a 'chip' you mean a device that allows a tuner to add timing/fuel then it's almost wasted money in terms of the gains you get for an NA RB25. You can't just add more fuel and expect more power, and the factory ignition maps will give you enough power, the only thing you could do in terms of tuning is advance the timing by a few degrees to run 98RON, but it's gonna give you less than 10wkw difference... Bigger fuel system won't do anything unless you have the air to compensate, and you won't get enough air from an NA setup to warrant extra headroom from the fuel system. The factory system will do fine until you start spending upwards of 15k on headwork (BIG cams, massive porting), stroker motors, lightened internals, big comp ratios etc...

And as for the thermo fan, I wouldn't go as far as to say they are 'radiator munchers', many big power RBs still use the stock fans with no dramas, dunno where you've pulled that from...

And yes, the more you do to an NA, the worse your drive-ability will become. Things like lightened flywheels (harsher engagement), underdrive pulleys (need a raised idle, more tendency to over heat in bad traffic), big exhausts and phat cams (loss of low down power) will all decrease your drive-ability.

The best you can do for a street driven NA RB, is a free flowing exhaust, cold air intake (not just a shitty pipe and a pod, but a proper airbox - sounds like you've got this sorted ) and a lightened fly and some nice midrange cams (240-260* and 9-10mm lift).

P.S. I hope you realise how much of a job it is to 'raise your compression'. lol So many people make the mistake of thinking its an easy job...

[Super Drager]

Sorry bro, but for someone who proudly says they 'know about engines and mechanics', you don't really know diddly squat.

A 'chip' won't do f**k all, listen to our advice, regardless of who you get this 'chip' you speak of from...

If by a 'chip' you mean a device that allows a tuner to add timing/fuel then it's almost wasted money in terms of the gains you get for an NA RB25. You can't just add more fuel and expect more power, and the factory ignition maps will give you enough power, the only thing you could do in terms of tuning is advance the timing by a few degrees to run 98RON, but it's gonna give you less than 10wkw difference... Bigger fuel system won't do anything unless you have the air to compensate, and you won't get enough air from an NA setup to warrant extra headroom from the fuel system. The factory system will do fine until you start spending upwards of 15k on headwork (BIG cams, massive porting), stroker motors, lightened internals, big comp ratios etc...

And as for the thermo fan, I wouldn't go as far as to say they are 'radiator munchers', many big power RBs still use the stock fans with no dramas, dunno where you've pulled that from...

And yes, the more you do to an NA, the worse your drive-ability will become. Things like lightened flywheels (harsher engagement), underdrive pulleys (need a raised idle, more tendency to over heat in bad traffic), big exhausts and phat cams (loss of low down power) will all decrease your drive-ability.

The best you can do for a street driven NA RB, is a free flowing exhaust, cold air intake (not just a shitty pipe and a pod, but a proper airbox - sounds like you've got this sorted ) and a lightened fly and some nice midrange cams (240-260* and 9-10mm lift).

P.S. I hope you realise how much of a job it is to 'raise your compression'. lol So many people make the mistake of thinking its an easy job...

This pretty much. Ready to go on my 300ZX are Ported heads which have been shaved for CR11:1, NIstune & Reground cams(262*/8.9mm lift). All of which will still keep the standard fuel system(270cc injectors, stock pump). So your fuel system will be more then adequate.

[Gerg_R31]

ill also add, lighten a RB crank by knife edging only other wise it effects the throw of the crank, and make sure its nitrided afterwards

[Mad-Max]

Sorry bro, but for someone who proudly says they 'know about engines and mechanics', you don't really know diddly squat.

A 'chip' won't do f**k all, listen to our advice, regardless of who you get this 'chip' you speak of from...

If by a 'chip' you mean a device that allows a tuner to add timing/fuel then it's almost wasted money in terms of the gains you get for an NA RB25. You can't just add more fuel and expect more power, and the factory ignition maps will give you enough power, the only thing you could do in terms of tuning is advance the timing by a few degrees to run 98RON, but it's gonna give you less than 10wkw difference... Bigger fuel system won't do anything unless you have the air to compensate, and you won't get enough air from an NA setup to warrant extra headroom from the fuel system. The factory system will do fine until you start spending upwards of 15k on headwork (BIG cams, massive porting), stroker motors, lightened internals, big comp ratios etc...

And as for the thermo fan, I wouldn't go as far as to say they are 'radiator munchers', many big power RBs still use the stock fans with no dramas, dunno where you've pulled that from...

And yes, the more you do to an NA, the worse your drive-ability will become. Things like lightened flywheels (harsher engagement), underdrive pulleys (need a raised idle, more tendency to over heat in bad traffic), big exhausts and phat cams (loss of low down power) will all decrease your drive-ability.

The best you can do for a street driven NA RB, is a free flowing exhaust, cold air intake (not just a shitty pipe and a pod, but a proper airbox - sounds like you've got this sorted ) and a lightened fly and some nice midrange cams (240-260* and 9-10mm lift).

P.S. I hope you realise how much of a job it is to 'raise your compression'. lol So many people make the mistake of thinking its an easy job...

not trying to be rude mate but i laughed pretty hard when i read that i honestly had to lay down my sides hurt so much.

i maybe new to this site but i think you should stop trying to disect/critisize everything people say. (even tho it was f**kin funny)

"turbo x-trail" your on the right track and your pretty damn correct with what you say would make a nice street n/a rb25de, and in reality i wouldnt do much more than that if i was gonna go to a turbo in the future.

this guy is a mechanic in training and asking for some advice so befor you type your next comment critisizing what im about to say (which im pretty sure this post will be pulled apart and disected for flaws by most of SAU to critisize) just remember im offering some advice and letting this guy and the rest of you in on information i found out the hard way (which i doubt many of you have really tryed).

im on my 3rd tuned up n/a rb engine and looking at doin a 4th/5th one so i can only tell you what worked well for me with out touching the bottom end or doin too much to the head so below is what i have done in the past. its kinda long but i added some tips/tricks for a decent n/a build, what i personally have done for tuning plus a few little facts about air intake cfm rates and there affects (i had to use this for deciding what carb to use)

first things first to clear a few things up i wasnt goin to post any of this info about what ive done ect ect and i only said that about the chip since its a mod that alot of people do but personally ive never used one and im not gonna get into an argument over whos right and wrong (and i dont really give a shit about them)

second of all i will agree that clutch engagement with a 12lb flywheel is a bit ruff but if your a good driver its easy to deal with.

you are spot on about underdrive pulleys, and big exhausts infact you seem to be quite onto it.

cams will decrease your drivabilty but not really that much since there not that much bigger than standard and no where near as lumpy/wild as what im currently running

also i absolutely hate those damn fans that hang off the water pumps .... ive lost 2x r31 radiators due to them and one in my ceffy (which cooked it), lets just say i dont trust them and its a personal preference of mine (to keep this short)

oh and one thing i wouldnt worry about is changing the ecu untill a tuner tells you to or you turbo it!!

my first nissan n/a was a series2 rb25de (with vct) in a ceffy, it was a 20det eater and blew the socks of most small turbo cars.

it ran a 12lb flywheel, headers, 2.5 mandrel exhaust, cold airbox (with good piping), electric fan, wasted spark mod, and an after market fuel pressure reg.

it wasnt cammed and went bloody well.

the next one i did was a rb30e in an r31, again all i ran was 12lb flywheel, headers, 2.5 mandrel exhaust, cold airbox, electric fan, an after market fuel pressure reg, xf falcon throttle body, a mild cam and redtop rb20det injectors. it went wicked but to be honest it wouldnt keep up with what ive done to it now how ever it was very very peppy and i did get used to it.

now i run the same rb30e i just mentioned (with all the mods above) and i run probably one of the most maxed cam shafts you can get for an rb30e.

its a custom 290* lumpy cam (i think its the most wild regrind in nz but im probably wrong) and cannot be run on an injected engine so yes i did throw out all the injection side of things plus the ecu and wiring and replaced it with a bloody carb. all it needs is re-jetting and a good tune up (since i put the cam in it 3 months ago) but it still goes like a raped goat with the tune it has and is much faster/responsive than it was befor only over 3500rpm tho... with the carb its got it has a lazy bottom end below 3500rpm so it is still good for cruising and good on gas (which is a bonus over how it ran injected) but when it gets to 3500rpm and the foot goes down the mechanical secondaries kick in and it sets you back in your seat, kinda like a turbo once it spools up

my next project im lookin at is a rb25/30 hybrid and probably end up using a 4 barrel holley. ill use my rb30 bottom end. ill most probably jam on most of the gear i have laying around from previose builds and have it injected befor i goto the holley (and befor any one says anything, i dont wanna hear any critisism from any one about carbs on rb's till i hear from some one thats done it!!)

ok so i know this is turning into a long story now but if your seriosly lookin at doin a rb25de n/a my biggest suggestion is get a series2 vct head, mod it like you would if you were putting it on an rb30 bottom end (basically removing vct), have it skimmed (not hard out just enuff) and run a good set of non vct cams with the mods already explained above. also id go with a slightly larger throttle body for better air flow (either xf falcon or ka24 i dont think you would wanna go much bigger)

the only reason i say use a series2 vct head is the fact that the porting is huge compared to whats in the r32 rb25de heads and will run any dohc rb cams (good to know if you want to get some cams reground or use some after market series 1 cams).

if you wanna be a pro and do the tuning your self the ecu is a great piece of technology and there are tricks around tuning it untill you can have it dyno'd and chipped (which i recommend doin last)....use the original injectors you wont need to go any bigger with a decent fuel pressure reg.

throw away the exhaust sensor it will cause nothing but problems for tuning with a fuel pressure reg, and replace it with a good lambda gauge (get a bloody decent one tho no cheap Ripco deals!!). this will help you to trick the ecu since theres no sensors after the tps and will allow you to adjust the fuel with the fuel pressure reg to get it right.

you can also install a vacuum gauge which can be a really huge help if you know how to use it.

since the only 2 things you can really do is control the fuel and timing, adjust your fuel till its right and and advance the timing for 98 (probably 18-22* advanced). if your not confident about this ask your boss for help or see a good tuner and ask him for his advice about this but thats how i did mine with out having it chipped and is really one of the best ways to do it in your shed befor seeing a tuner

just try and remember these tips when you do anything on an n/a if you want to get as much power as you can.

the faster you can get rid of the fumes the faster you can cram more in the cylinders.

lighten your drive train wether its lighter flywheel, lighter cams, some alloys or light weight race rims (chromies are too heavy and will rape your power) and lastly remove un-necessary lag on your belts/crank (air con and that gay radiator munching thermo fan which is probably fine for big power engines but on an n/a engine you want as much power as you can get dont you?? even if its 1kw it all adds up in the end)

and lastly i know with carbs the bigger cfm you go the shittyer the bottom end power will be but the better and higher revving the top end becomes. for instance i use a 300cfm webber carb (which is good for a rb25/30) if i went to the next size up (350cfm) id probably gain 500 more rpm but i would suffer down low. if i went to a 500cfm holley or simmaller id most probably need better valve springs and gain another 1000rpm. this principle will probably apply to injected aswell so you will most probably have a crap bottom end if you use a bigger throttle body and a nice peppy powerfull top end.

so my last piece of advice is think about how you want it to run and filter out what you think you wont need but id say you dont care too much about drivability and just want it to go like a rocket. the one good thing about injected is you wont notice the bottom end power flaws as much compared to if you were runnin a carb

Edited September 16, 2010 by Mad-Max

[mad082]

you see now after reading what you have said about what you are classing as hig powered rb's i sort of have to laugh a bit. especially the bit about your extremely mildly modded rb25 being a rb20 eater. sure it probably beats relatively stock rb20's. hell i had a stock v6 magna (with just a catback exhaust) that would beat relatively stock rb20 turbos. all of the motors you have listed wouldn't have enough power to get the car to low 14's or high 13's, which a lot of turbo rb20's will do. how do i know this? i have a mate who had a rb30 powered 31 that did run high 13's (was still only a single cam head). the list of mods was much much longer than yours and included a butt load of headwork, twin throttle bodies, custom plenum, lightened flywheel, crank work, raised compression, rb26 oil pump, bloody big cam, big injectors and it reved to 8000rpm. this thing was an absolute pig to drive on the street (locked diff and button clutch didn't help either). i'm also pretty sure that at the drags he didn't run it on pump fuel either.

now back to 'chips'. you first stated about getting a chip off tradme. well the problem is that generic 'chips' are just that. generic. they will maybe give you 1% more power if you are lucky, and certainly aren't worth the money. there is also a chance that it will rob you of power or damage the engine. getting the ecu remapped or an aftermarket ecu will give you more power, but if that mod alone you will still only get maybe 10kw out of it if done well.

and you don't need to play around with fuel pressures until you get close to maxing out the stock injectors. if you raise the fuel pressure without a programable ecu you will actually lose power rather than gaining it. stock ecu's run richer than they need to as it is safer to be richer than leaner. if you lean things out then you will make more power, up to a point.

[.:: GimpS-R34 ::.]

He starts off saying he's laughing at Cam's response.. Then agree's with him about it all :S.. And rest was TL;DR

[Mad-Max]

ahhh hahahahaha just another critic

none of mine id consider to be high powered rb's. they were worked as much as i wanted to do to them but lets face it if i was chasing better numbers i would have gone to a turbo along time ago and probably triple side drafts on my latest build or put these engines in a bloody s13/14.... all my builds i did as some thing different and you do make a good point but every one has a mate thats done.?.?.?..

stock rb25's/rb30's beat a stock rb20det's but lets face it a simple boost tap can make all the difference. ive seen gti-r pulsars with a $12 tap burn off v8 holdens/fords but that was at about 17lb boost (same with starlet glanzers). your mate must have spent alot of money to get it to do that and i cant see my self wasting 1000's on an n/a build. all the mods i mentioned help to open up the rb30/25's with stock internals/heads but youve gotta remember i only spent $1000 on my 25, $1000 on my 30e, and the new one ows me $600. they have all been street legal ricers but you must remember theres only so much you can get from a n/a application.

on the carb'd beast i could have gone with triple side drafts but what a waste that would have been im quite happy with what i got out of a $50 falcon webber, $50 vacuum advance dizzy and $100 stock carb manifold besides what would you rather do, spend thousands on doin a complete intake/comp rebuild (the list goes on) or just $10-15 per jet??

toyota k series engines max out at about 145 hp with quite a bit of work done to them and cost thousands to get them above 150hp but who wants to do that. i mean christ my old boss's worked up mini did 18's!! and that had very exstensive head work done

like a said the chips thing has been an gone im not here to argue about it just offering some decent advice for a cheap build or i can see this guy spending thousands and gettin bugger all gains from it

i agree with alot of what you guys are sayin but at the end of the day im only posting what ive done to help out this poor lost soul. 10kw increase is a sweet amount for an n/a build and youd probably get just that from doin headers/exhaust and intake mods

the fuel pressure reg isnt neccesarily there to up the fuel its only there to adjust fuel whether its dropping the psi or raising it, plus i always did this with the help of a lambda gauge, vacuum gauge and timing light

ive heard of that r31 (i think) and i can understand why it revs like it does but i think he'd be pretty hard pressed to get 8k rpm from a single throttle body and his low down power must have really been shit, so definatly a pig to drive.... wasnt it 150rwkw beast?? (probably more correct me if im wrong)