Rb25de

[.:: GimpS-R34 ::.]

haters gonna hate

[StealthX]

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.

.....

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

baaaaaaaaaaaaahahahahaha

phark! where do I start!

You really shouldn't be criticizing other people's advice mate. I could pick flaw after flaw in what you've just suggested...

1. 290* cam CAN'T be run on an injected engine. Why not? That's completely wrong dude, and why would a carb suit a cam with such duration but not a EFI set-up? A carb with a cam that size would actually run WORSE!

2.

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

Clearly you've never driven a turbo car before. This REALLY made me laugh.

3. Your best suggestion of using a series 2 VCT head is wrong. Ever heard of an RB26 or an RB25 neo?

4. At power levels below 250hp, a larger throttle body isn't gonna do anything. Your throttle is almost never going to be a restriction until you are reaching upwards of 400hp.

5. The stock computer only reads signal from the o2 sensor when cruising and light throttle loads. So a wideband sensor isn't gonna do jack for peak power, nor is it gonna help you with tuning unless you have data logging, AFR guage, a dyno and a set of knock ears...

6. Adjusting the fuel with a FPR is one of the most crude ways to adjust fuel injection I've ever heard of. Do you know what injector pulse width is? That's what determines how much fuel goes into a motor, not the pressure at the rail...

7.

lighten your drive train wether its lighter flywheel, lighter cams

lol! are camshafts part of the drivetrain now are they? And how exactly is a lighter camshaft gonna give you more power? lol

8. The size of your carb has NOTHING to do with how an engine revs. Ever heard of a rev limiter? That's what makes a car rev high or not. Adding a big carb doesn't allow your engine to rev higher lol

9.

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

hahahaha! so you think a carburettor is superior technology over an ECU and a set of injectors? Injection allows better cold start, better fuel -> cylinder distribution, better cruising efficiency, the list goes on! Carbs really are technology of the 60s bro, keep up with times.

[edit] quote cropped to shorten the post.

[Mad-Max]

firstly im not your f**kin BRO

secondly all book smarts and no practical ay.... hows your uni goin are you failing or something??

another 19yr old no it all..... you see the thing is i dont think you really no squat. you may have the book smarts and be doin a uni degree in automotive engineering but id really like to know how many n/a engines youve built?? i cant count on both hands and feet how many ive built with good success so lets break this down for you into english

1. my 290* lumpy cam was made specifically to run a carb and runs fine!! so how the f**k would you know if it makes it run worse? ....because the intake valves open so early it breaks vacuum and would f**k with the afm too much so inturn wouldnt run with a factory ecu no matter how hard you try. if i wanted it to run injected with this cam id have to go and spend alot of $$$$ on a link ecu or simmaller and many hours of tuning on a dyno ect so its not even worth it youd be better off just getting another tryed and tru good cam and be happy with that.

oh and compared to the 2x other cams ive used (stock, the bros custom injected cam) on the carb its the f**kin ducks nutts!!

2. do i really need to say it?? ive drivin plenty of turbos mate you honestly have no idea what ive driven/owned and personally cant wait to rape the shit out of my mates 402 turbo eh holden when hes finished it (comming very soon), so stick with your moms modded xtrail

3. yes ive f**kin heard of them they could also be used but how much would you end up spending on one? series 2 vct heads are cheap thats half the reason i said it so what are you a f**kin moron this guys not gonna spend mega bucks on a gtr head, im just sayin he shouldnt f**k with the stock r32 small port shitters if hes thinkin of modding the head

4. it wont make a diff till youve opened up (removed restrictions) on the engine.... why else have there been other n/a rb's that have used em or a second throttle body for that matter.

5. blah blah blah ... thats why you go see a tuner to finish it off

6. bullshit.... yea it maybe crude but it works and doesnt need to be permanent! ... yea i know what injector pulse width is

7. lighter cams if you wanna be technical it should have been cam gears and that helps with response you should know this

8. The size of your carb has NOTHING to do with how an engine revs. Ever heard of a rev limiter? That's what makes a car rev high or not. Adding a big carb doesn't allow your engine to rev higher lol

8. oh yes it does and you should know this if your doin a degree.... a 350cfm holley on a v8 is ok for cruising and economy but good luck being able to rev that sucker with out leaning it out up top! put a 750cfm holley or simmaller on the same engine and hey presto now you can rev the beast right out!!

heres some simple maths for you which youve probably covered at uni plus this is just a guide to work out how much cfm an engine needs for selecting a carb... http://www.ehow.com/how_5488366_choose-carburetor.html

and wtf are you stupid or some fin?? rev limiter speeks for its self! omg i dont even know where to start with this one. ohhh im gonna remove my rev limit now i can rev 10k rpm, WRONG sure you can in theory rev over what was once the "rev limit" but valve springs with help stop valve bouncing and improve harmonics in the top end on the head only. obviously you will still need to do more work to stop wear and tear to improve the engines life span. restrict your airflow and i doubt youll even get be able to get decent revs. maybe the bigger throttle body will help to achieve higher rpm dont you think? but in reality 7.5k rpm max is fine for the rb this guy wants

9. i was only using cfm rates and carbs as an example...... oh and like i said dont knock it till youve tryed it.

i know its old technology im not stupid and i did it for a laugh but personally i like the benifits i got out of it so untill youve done it how would you even know the difference on an rb engine? and why on earth would people rip the injection of 4ages and replace it with twin sidedrafts if it was that bad??

when it was injected sure it was a bit better but it really comes down to how you drive it. injected is much better for f**kwits that have just got there liscence (like you id say) but the skill involved with driving it now means being in the right revv range, clutch kicking more often an shit ect ect blah blah blah (do i really need to go on?)

and its quite funny that the stock carb'd r31's from south africa produce more power standard than a stock rb30e (if you bother to look up the stats).

so unless youve got some thing decent to say to help this guy/others out i dont really care what you have to say, stick with driving your mum's xtrail and next time read between the lines and dont try point out useless bullshit.... heck maybe go and get some practical skills and try somefin different.

cookie cutters are old news and every one with a bit of knowledge should know how to do them, go an try something different!!

i was gonna save this for my 350 chev sunbird but i could go ahead an use one side of my suck through setup, 650cfm demon carb and adapter for the sc14 charger thats in the shed and slap that puppy on my rb30 just to see how it goes for shits an giggles, which id say would perform nicely and none of you f**kers have ever done that or even atempted to do anything of the sort....so next time befor you decide to pick out bullshit and state half assed logic just think to your self "maybe this guys tryed a few things i havnt, how did he do it, and what was it like??"... you never no you might even learn something from it

[Rallye]

Pics of your car man? Im interested in buying a GTS25 in 8 months or so. They are quite rare. How much did you buy it for if I may ask?

Anyways, just leave it stock man. Your driving a Skyline of P's so your already attracting attention. Police will molest you and any way they can, so leave it stock. RB25DEs arent that bad, the extra torque/revs over a 20 is well worth it.

[Jay11]

Anyways, just leave it stock man. Your driving a Skyline of P's so your already attracting attention. Police will molest you and any way they can, so leave it stock. RB25DEs arent that bad, the extra torque/revs over a 20 is well worth it.

+1

Can't say how happy I am now that I only did exhaust and pod on my old silvia when I had my P's, I was looking at spending a bit on it too.

But as soon as I got off my P's I got a R34 GTT

As for Mad Max...... BRO, you've only been on here for 4 days and already made enemies. It's okay, you're lack of social skills is made up by your wealth of knowledge

[UWAM]

6. bullshit.... yea it maybe crude but it works and doesnt need to be permanent! ... yea i know what injector pulse width is

If you're using the fuel pressure to adjust the amount of fuel going in, how are going to put relatively more fuel in at 3k rpm than 4k, to account for different resonance effects perhaps?

[Mad-Max]

+1

Can't say how happy I am now that I only did exhaust and pod on my old silvia when I had my P's, I was looking at spending a bit on it too.

But as soon as I got off my P's I got a R34 GTT

As for Mad Max...... BRO, you've only been on here for 4 days and already made enemies. It's okay, you're lack of social skills is made up by your wealth of knowledge

thanx but if mad082 and turboX-trail wernt so abrasive with there posts i wouldnt have had to say what i said... i thought they'ed be more interested in helping people out rather than trying to tear apart others posts and critisize. obviously they dont comprehend the concept of how to do that or how to give good advice.

from a new members point of view there actions makes this whole site seem like a joke since i didnt register to this site to make friends just to help out if i can and to see what others are doin to there cars.

oh and btw over here in nz we dont have p-plates so we dont have to worry too much about what can and cant be done to ours cars so godzilla-32 pretty much has free reign on what he can do

If you're using the fuel pressure to adjust the amount of fuel going in, how are going to put relatively more fuel in at 3k rpm than 4k, to account for different resonance effects perhaps?

i dont quite get what you mean there .... basically your only tricking the ecu into thinking its still using a normal amount of gas when its not, so lets say you have a pipe with a tap and that tap opens for 5 secs and closes for 5 secs. if that tap has more pressure behind it its goin to release more liquid everytime that tap opens.

its pretty crude but i hope that helps explain it

Edited September 19, 2010 by Mad-Max

[mad082]

the problem is that by using the fuel pressure to adjust the fuel you doing it in possibly the worst possibly way. lets say that at 3000rpm the fuel is right, but you need 10% more at 4000rpm and 15% more at 5000rpm and then need to take out 5% at 6000 rpm. how would you plan on doing that with a FPR? you can't. if you add in 10% more fuel then you are going to make it less powerful at 3000rpm and 6000rpm.

[Rolls]

the problem is that by using the fuel pressure to adjust the fuel you doing it in possibly the worst possibly way. lets say that at 3000rpm the fuel is right, but you need 10% more at 4000rpm and 15% more at 5000rpm and then need to take out 5% at 6000 rpm. how would you plan on doing that with a FPR? you can't. if you add in 10% more fuel then you are going to make it less powerful at 3000rpm and 6000rpm.

exactly it is a dodgy ass way and Im surprised it runs at all.

converting to a carb is a retarded backwards idea, surely all the money for custom intake manifold, carb, tuning the carb etc could buy you a $300 nistune module and go towards a $3-400 tune which is all you'd need for a simple NA cam.

I think people should just wait the year or two and get an rb25det, better power, better powerband, better economy, sounds better wins in every single possible way.

I get that you are trying to give advice mad max but it isn't good advice financially or engine wise, it is a bunch of backwards hacks that aren't legal (try passing emissions with a carb and a massive cam lol), better off advising to just save your cash for when they got off their Ps and get a turbo. I bet that carb + cam solution uses 25L+ / 100km

Edited September 22, 2010 by Rolls

[Mad-Max]

exactly it is a dodgy ass way and Im surprised it runs at all.

converting to a carb is a retarded backwards idea, surely all the money for custom intake manifold, carb, tuning the carb etc could buy you a $300 nistune module and go towards a $3-400 tune which is all you'd need for a simple NA cam.

I think people should just wait the year or two and get an rb25det, better power, better powerband, better economy, sounds better wins in every single possible way.

I get that you are trying to give advice mad max but it isn't good advice financially or engine wise, it is a bunch of backwards hacks that aren't legal (try passing emissions with a carb and a massive cam lol), better off advising to just save your cash for when they got off their Ps and get a turbo. I bet that carb + cam solution uses 25L+ / 100km

yea it probably is but it worked for me

its just as good on gas as it was injected untill the foot goes down

and my carb manifold is a stock rb30S manifold ($100) with a $50 webber (which im upgrading as we speek to a 40mm down draft from a 3l v6 capri/granada another $50) if i wanted to make another manifold it would only cost me materials since i have all the gear i need to do pretty much what i want. dont you wish you had a shed like mine??

hmmm i think all up to do it it ows me $300 and i get the tuning done properly for free from a good qualified friend of mine

seems to me that you guys in reality only know skylines and havnt really tryed anything that isnt a cookie cutter maybe your to scared to try anything different i dont know

oh and we dont have emissions problems or p plates im from nz we can have shit sticking out of our bonnets ect (dumb aussie laws thats where you guys fail tryna do shit to the book)

like i said i didnt change it to carb'd to get any performance out of it i did it for shits and giggles so unless youve owned a carbed rb just stfu ay!

like i said earlier theres alot that can be done its just a matter of filtering out what you wanna do from everyones advice given maybe my advice isnt good, if you dont think it is then dont reply but im only speeking from experience of what ive done and has worked for me

[Rolls]

havnt really tryed anything that isnt a cookie cutter maybe your to scared to try anything different i dont know

There is a reason everyone does it the same way, including 99% of ALL car manufacturers. That reason is because it is the cheapest, gives the best emissions, the best performance, the best drivability and is the simplest.

Being different for the sake of it is retarded, being different because you can do it better or have a smarter solution on the other hand... that is true engineering.

[SKiT_R31]

While some of MAD-MAX's methods may be un-orthodox and quite old school backyarder, it doesn’t mean he is wrong. And I do believe he has a lot more hands on experience than most of the people posting in this thread. Doesn’t mean his info is suitable for the OP, but it is interesting to hear and once you sift through there might be 1 or 2 things you can take from it. I’ve learnt a lot from old school backyarders, stuff that people just learn is best from 50 years tinkering, not from reading dribble on the internet. That said, you need to be able to filter information into relevance and accuracy, just because it was the best option then doesn’t mean it’s the best option now. But other things, things that had to be done to make shitty old engines make big numbers, a lot of the time are still applicable today, and can be put into modern builds, just most people don’t bother as it’s just easier to fit a bigger turbo or boost it. I’ve seen people make a lot more power with L28’s and 202’s than what we seem to be able to make with RB30DE’s which are a far superior starting point.

The Shits and giggles reasoning is the best, it’s why I do most of my stuff I do, that’s what it’s all about imo.

Just want to clear some stuff up at risk of flamage, Carb's (while they are definitely old tech) are cheap/easy to come by and are easy to tune if you know what you’re doing. And I agree that they would be an excellent budget way to fuel a car with a massive cam over injection. The reason is, all the air being breathed by the engine is pre mixed with fuel, so regardless of how much of it end up going out the exhaust (ignoring emissions, let’s say for track) you are always going to have the correct air fuel ratio. Whereas injection, especially shithouse multipoint like our RB's have, fill the intake runners (when the valves are closed) with fuel, then when it opens it all blows straight out the exhaust on an overlap stroke, leaving only the fuel still being injected once the exhaust valve closes remaining in the cyl (i.e. excessively lean). Ways around this are with sequential injection (or of course if your engine is direct injection) management with massive injectors, then adjusting the injector timing so that it only sprays when the intake valve is open and the exhaust valve is closed. While of course possible, the management and injectors cost a fair bit of cash, plus it needs a lot of dyno time to tune (can't just be done on the street with a wideband). For those who don’t know, an injector at 100% duty cycle isn’t an injector open for the entire intake stroke; it is an injector that is simply open the entire time.

Of course the solution is to just not run a massive cam, but the point is if you want to run a massive cam "for shits and giggle" on the cheap, this is probably a good option.

Sifting through, another thing is fuel pressure for fuel adjustment. Of course you can’t adjust it at specific revs, it’s a blanket change over the whole range - but that’s not a bad thing. I've got -30% taken off the entire rev range on my SAFC, increasing to about 35% up top. If I was to blanket drop just 30%, I’m still a lot better off than where I was before.

Lowering the fuel pressure does complicate things, it effects spray pattern among other things, but raising it a couple on a lean motor (maybe when running high oxygen fuel), or dropping it <5psi on a rich motor (monitoring fuel mixtures at light-mid and full throttle on a data logger) is a cheap and easy way to blanket change your mixtures over the whole rev range. I've done it multiple times before with no problems, I've run higher pressure and tuned an ecu leaner to get more flow out of injectors, and I’ve wound the pressure back to get a turbo car (RB30ET) into more reasonable fuel mixtures (since there is no cheap add on like SAFC available).

While they're not the most ideal solutions, if it works and it’s your best option (cost/availability etc) then why the f**k not imo.

[Rolls]

Ways around this are with sequential injection (or of course if your engine is direct injection) management with massive injectors, then adjusting the injector timing so that it only sprays when the intake valve is open and the exhaust valve is closed. While of course possible, the management and injectors cost a fair bit of cash, plus it needs a lot of dyno time to tune (can't just be done on the street with a wideband). For those who don't know, an injector at 100% duty cycle isn't an injector open for the entire intake stroke; it is an injector that is simply open the entire time.

Lol rbs already have sequential injection, it is just after about 3500rpm that they switch into batch injection, or at least the CA and SR motors do, I'm fairly sure the RBs are the same due to the fact that the time delay between being sequential and batch is so small at high rpm and WOT it makes basically zero difference. A good comparison is a wolf 3D ecu which does batch mode the entire time resulting in unstable idle and poor fuel economy.

[SKiT_R31]

4. At power levels below 250hp, a larger throttle body isn't gonna do anything. Your throttle is almost never going to be a restriction until you are reaching upwards of 400hp.

The easier the engine can breathe the better. You want the ideal air speed at your peak power (too big will lose power and will bog the car down somewhat at lower rpm, just like an oversize exhaust), but just because it’s not hitting mach 5, doesn’t mean the engine isn’t working harder than it has to fill the cylinders.

5. The stock computer only reads signal from the o2 sensor when cruising and light throttle loads. So a wideband sensor isn't gonna do jack for peak power, nor is it gonna help you with tuning unless you have data logging, AFR guage, a dyno and a set of knock ears...

I would assume he meant a wide band for monitoring, not for the engine. I.e. either a datalogger or just a simple gauge. While 'knock ears' are a good idea, they are not required, you can simply monitor EGT's (And tune against them) as reliably (whilst listening for audible pinging).

7. lol! are camshafts part of the drivetrain now are they? And how exactly is a lighter camshaft gonna give you more power? lol

Makes the engine rev quicker (less VALVEtrain loss) the BMW M5 for example, has hollow cam shafts

8. The size of your carb has NOTHING to do with how an engine revs. Ever heard of a rev limiter? That's what makes a car rev high or not. Adding a big carb doesn't allow your engine to rev higher lol

Engines don’t rev by magic, they have to breathe. Have you ever driven a carby car? Hold it flat to the floor and it will top out (wont just rev until it pops) and that’s without a limiter. Fitting a larger carby will push the revs further until the choking point is the cam. EFI cars don’t have this problem as they generally have much larger TB's (than the same in a carby would have, among other things) therefore cut revs with a limiter.

[StealthX]

Okay I stand corrected on a few things i.e. carb things, but for the record Mad Max, I don't just have the book smarts and no practical experience, I work for a racing team lol. I've built and tuned a QR25 turbo in my x-trail a ITB big cam NA 4A-GE and Formula SAE car/engine, had a honda CBR motor and a MoTeC M800, and I'm saying that Mad Max's methods are VERY primitive and backyard. Don't wanna fly my own flag here, but I reckon I sort know what I'm talking about... They (the methods) might work, but not half as well as they could.

But I do apologise for sounding a little forward in my argument!

Soz dude.