Few Questions About My Rb20

[Roy]

RB25s, pfft

[Bl4cK32]

I didn't say it was similar....just that it was better value. Why many spend hundreds or a couple thousand on rebuilding (or building) an RB20, when that money gets you a good portion of the way to a 25?

How is spending $800 on getting new rings and bearings in a bottom end similar to spending $6000 on sticking a second hand rb25 into the r32?

Its never only a little bit extra to do a motor swap in a skyline. The entire drive line will end up being swapped out once you start hunting for that "extra"

[D.I.Y. Mik]

Not to mention engineering certs cos a 25 is over 15% bigger than a 20,

the 20 is cool id stick with it too

If you really care so much about power and speed get a sportbike, you will never go faster.

I like my 32 cos i can eat and drive and stay out of the rain, not cos its super fast.

Nothing wrong with a 20.

[Bsa]

20s are fun but 25 is a better motor but unless you want to start making big power the 20 will just keep going

[Missileman]

20s are fun but 25 is a better motor but unless you want to start making big power the 20 will just keep going

When my 20 eventually pops, I was going to go with a 30, what's so great about 25's?

Edited February 19, 2012 by Missileman

[Roy]

Yeh, RB20s are terrible! Here is a comparo from a few years ago ... The RB20 gives away 500cc, half a point of compression and variable timing on the inlet cam ... AND is an older engine. So on paper where you dont have to pay for things or get them registered it seems a no brainer. But in the real world where your folding stuff is what you are handing over, and you want to get the car registered with correct engine numbers etc

BassJunky R34: GCG Hi Flow, Poncams same tuner and dyno as me

Abo Bob R34: GCG Hi Flow, built engine, think he had Poncams as well. Different dyno, different tune

My setup: Std RB20, std plenum, a TD06-20G setup

Main reason for the difference is the R32s higher final drive ratio adn 17" wheel vs 18s of the R34...but all are 4th gear pulls. Even if you only compare BassJunky's result and mine as they are both from teh same dyno and tuner....you can readily see that when you open up the taps why the RB20 easily keeps pace with the RB25NEO with a Hi-Flow GCG turbo.

So not saying the RB25 isnt superior...but I sure as hell have made the decision to keep my money in my bank account and spend the money on tyres, fuel, oil and driving it at the only place you can legally and safely enjoy the performance.

So getting back to the OP, fix the bolt on gremlins and ascertain the health of the engine. In which case a $600-800 wrecker motor with warranty is your quickest, cheapest and safest fix. If you have the budget to rip it all out and start again with a later model engine then go for it...just talk to industry people as it is not as cheap as many people make out

PS...i will add both R34 engines popped at that power. One going forged internals after melting a ring land and Bass Junky's car having another engine put in...neither saw as much let along more track work then my car...though they both probably see more road kms than my car. Not to say their cars were inferior, both tops cars and modded carefully/well. A large part of the reason my engine is still running is luck, but a part of it is testament to the strength of the RB20

[GTSBoy]

But how annoying was it before it came on boost?

[the_wolf]

haters gonna hate.......long live 8.5k with the '20.

[Roy]

But how annoying was it before it came on boost?

I have had this setup since early 2003. You would think I dont find it too annoying when you consider I have ran this setup for 9 years! I appreciate its not for everybody...but sticking with the 20 is definitely the cheapest, very reliable and easiest option.

[GTSBoy]

I don't hate the RB20. I've had mine since 1999. But that whole time the total lack of any torque before it comes on boost (and that's with the standard turbo!) followed by the chance of it breaking traction (will it, or won't it? wiil it or won't it? Will or won't it?) has bothered me. A bigger engine that actually makes some torque and does some acceleration before it comes on boost is a much nicer thing.

The reason I say an RB25 is a good thing (and not an RB30) is simply because it's all that much harder to do the RB30 thing. Both from the point of view of putting it together, and from the legal side.

But sucks to all you guys who have to get an RB25 engineered in the eastern states. Here in SA you just roll up to Regency with with 25 in (and everything else legal enough to pass) and put over the pits. Sure, maybe you have to go back if they bust you on something. But all the same....

[iruvyouskyrine]

Ahhhh, the 'ol 20 vs 25 thread again hey? SHould have seen this coming

Have been away for the past few weeks so just got back and stuck into it. Compression test results were;

1 - 140

2 - 140

3 - 137

4 - 140

5 - 142

6 - 140

I understand that to be a farily healthy RB20? Hardly any variance between the cylinders would indicate that its just an older engine wearing evenly? The cluster has 180xxx on it so i think its about right. Should i get a leakdown test done as well if there doesnt seem to be anything wrong with the compression test?

When pulling off the throttle body intake pipe to do the compression test i noticed lots of oil in there, sorry for all the noob questions but what does having oil in your intake pipes mean? Surely it cant be a good thing haha, f**ked turbo seals? There was also one other thing i found when poking around in the engine bay, all the turbo->manifold nuts had come undone, even with locking tabs! So i decided i will pull the turbo off to have a look at it to decide how healthy it is. It will be good to know in what sort of condition everything is before i go stupid with the mods and find my engine or turbo is in shit confition! Will post pics of said turbo when its off

have you put new plugs in it lately?

as for the smoke id say its fried rings-with it having blowby.

It got 6 new BCPR6ES about 5 months ago and had not been having any issues. I did finally get the coilpack issue sorted out and it was a dead #4 coilpack. As i dont have lots of money to throw around at the moment i just bought a single coilpack off my mate and next time one goes will get some yellowjackets.

All six plugs looked like this, i have no idea if its running lean or not, anyone here know?

As for the smoke. Are you using oil? Do you run a catch can setup and is the factory PCV valve still plumbed into the rocker cover and turbo inlet? Is it smokey at idle or with a quick punch of the accelerator to 2k or so? Or is it only after load/boost and lift off? Also, do you run a boost gauge and do you know the boost its running? Have you pulled the kick panel off to see if the ECU has any stickers and things on it or other signs it has been tampered with...if so by who?

Yes, i am using oil haha. It got brand new fully synthetic Penrite 15-w40 the same time as spark plugs, so about 5 months ago. No i dont run a catch can or anything like that, and im not sure what the PCV is, is the the breather hose looking things on the top of the cam covers? What do they do/where are they supposed to run to? And it was only smokey after coming off boost. It goes up to 14psi and then drops to about 13-13.5psi

I have had a quick look at the ECU before but didnt open it up or anything like that, will get some pics up here for you

wholly!! 8500 rpm, talking about raping lol!! got cams????

Nope standard cams as far as i am aware haha, sounds nucking futs but im sure it cant be good for it haha

Yeh, RB20s are terrible! Here is a comparo from a few years ago ... The RB20 gives away 500cc, half a point of compression and variable timing on the inlet cam ... AND is an older engine. So on paper where you dont have to pay for things or get them registered it seems a no brainer. But in the real world where your folding stuff is what you are handing over, and you want to get the car registered with correct engine numbers etc

BassJunky R34: GCG Hi Flow, Poncams same tuner and dyno as me

Abo Bob R34: GCG Hi Flow, built engine, think he had Poncams as well. Different dyno, different tune

My setup: Std RB20, std plenum, a TD06-20G setup

Main reason for the difference is the R32s higher final drive ratio adn 17" wheel vs 18s of the R34...but all are 4th gear pulls. Even if you only compare BassJunky's result and mine as they are both from teh same dyno and tuner....you can readily see that when you open up the taps why the RB20 easily keeps pace with the RB25NEO with a Hi-Flow GCG turbo.

What difference does the 17" v 18" wheels make, just moves the power curve backwards on the dyno sheet? IE your doing less speed when making the same power, or does it add more/less power to your graph when it's not really there?

PS, sorry if this post is all over the place, just woke up from and big night haha

[SNOQPY]

Yeah I was just thinking the cheap way buy a neo and drop it in using all the 20 gear but yeah. Some people are happy with there rb20s

dam straight i had mine built, had a rb26 crank put it to stroke it to 2294cc aka rb23, i dont putter around in it. and she cops a thrashing once or twice a week on the old pac. bigger pistons, blueprinted, yes its a redtop. but for all of that comes a price when it goes bang it will go in a big way to make way for the rb31det

[iruvyouskyrine]

Okay, i got the turbo off, can anyone confirm that it is from a R34 GT-T? Im sure it is because of the OP6 rear housing, pics can be found Here!

After doing a bit more reading i can answer some of your questions, yes i am still running the stock PCV and lines. I was talking to one of my mates and he was saying that blowing the dip stick out is commonly cause by a blocked/stuffed PCV, and that i should check and clean the PCV. So i took it out and cleaned it with carby cleaner. Do i have to take the rocker cover breathers off and clean them as well? If so ho do you take them off, do they unscrew from the rocker cover? My PCV is still set up like factory ie;

PCV into intake manifold --> drivers rocker cover --> link to passenger rocker cover --> turbo intake after afm

Hopefully cleaning the PCV and lines will sort the issue, car is going in for a leakdown test on thursday anyway, gives me an idea of how healthy the engine is (:

[DVS JEZ]

Op6 = r34 gtt neo turbo

[zebra]

Or old 300zx turbo

[DVS JEZ]

Or old 300zx turbo

Really? This i did not know about.

[DVS JEZ]

Looking at the pics the 45v1 is the older type of 25 turbo's. But as zeb said it may be an old 300zx turbo

[TJR32GTS-T]

Feel free to jump in guys as I may be wrong but the oil in your intake pipe could be fixed by running a catch can?

[zebra]

Ye the vg30DET's (z31)

[iruvyouskyrine]

Op6 = r34 gtt neo turbo

Or old 300zx turbo

Ah so OP6 does not strictly mean its from a 34 GT-T? I have a feeling that this would have come off a GT-T thought because it has practically zero shaft play vertically/horizontally and about 1mm at the most forwards/backwards.

Feel free to jump in guys as I may be wrong but the oil in your intake pipe could be fixed by running a catch can?

Yeah thats what my understanding is, but what is causing it is more my issue haha.