Jump to content
SAU Community

Recommended Posts

That depends what cams it is running.

Bigger cams allows higher static comp and higher boosts to be run.

Run a too high static comp and you will actually loose power due to the fuel being too volatile for the setup.

There is a graph laying around some where on the net that explains boost vs comp ratio vs octane..

  • Replies 47
  • Created
  • Last Reply

Top Posters In This Topic

straight turbo swap, depending on the boost u run, i would recommend a fuel pump anyway, saves hassles. Walboro intank pumps are my choice for mild setups anyway, fitted one to a mates cefiro with rb25det in it. Had to chop the wires and use connectors but that was not big deal

yeh i was planning on doing the fuel pump anyways...all this talk about rb25 turbos makes me wanna go out and do it...wat would be the expected rwkw with a setup like this:

3" turbo back zorst

POD

14psi

Fuel Pump

FMIC

Will be interesting to see if it really makes 200rwkws. Thats pretty good power

We Just - well midnight - jerked on of our little RB20's off the dyno...

PFC, 3", xtr(RB25) turbo, spitfire coils, 550's, X GT-r FMIC.

Tucked her into bed with 235rwkW.... 1.2bar boost. 79 runs in a space of 31/2 hrs and top temp was 93degC

Now rush out the shed and think, I got one of them...

TT

PS Oh yeah and good fuel.

i've looked into both the rb25 and vg30 turbos as a cheap upgrade for my rb20det, what figures i seem to get as to rwkws is around the 180-190 for the rb25 (14psi) and 200-210 for the vg30 (14psi) these figures are with the following other mods, good fmic, full turbo back 3" exhaust, POD, remapped ECU or piggy back system (safc), maybe upgrade the fuel pump to...the good thing is these turbos on the rb20 can run 14psi of boost all the time, set 14psi as low boost and 16-(18psi on the vg30) for high boost and your laughing...pulls all the way to the red line too...anything above these power levels and your going to need to look for larger injectors but now i'm going too far...

I would forget about the vg30 turbo as it has an exhaust a/r too large for the rb20t.

You loose heaps of mid range accelerating power.

The rb25 turbo is the better bet.. Has a more suitable exhaust a/r which gives you much more mid range power hence average power.

A Rb25 turbo making say 180rwkw and a vg30 turbo making 200rwkw..

I had a VG30 BB Ceramic turbo on my RB20DET running ~ 13psi. The RB20det stocker turbo felt much much quicker on 1bar. I ripped off the vg30 and put back on the rb20det.

The VG30 also has a smaller compressor wheel compared to the rb25 turbo.

yeh i was planning on doing the fuel pump anyways...all this talk about rb25 turbos makes me wanna go out and do it...wat would be the expected rwkw with a setup like this:

3" turbo back zorst

POD

14psi

Fuel Pump

FMIC

would imagin u should get 180rwkw easily. Do not know whether ur engine is healthy or not. Putting a high flow 33 turbo on would see higher results :P

We Just - well midnight - jerked on of our little RB20's off the dyno...  

PFC, 3", xtr(RB25) turbo, spitfire coils, 550's, X GT-r FMIC.

Tucked her into bed with 235rwkW.... 1.2bar boost. 79 runs in a space of 31/2 hrs and top temp was 93degC

Now rush out the shed and think, I got one of them...

TT

PS Oh yeah and good fuel.

What is good fuel? :P

That looks to be the figure im settling for with my TD06-20G. The guy tuning it seems to think it will make that power easily at 15-16psi basd on the power it has been making on lower boost levels in the intial stages of the tune.

180 something rwkws at 8psi. But if you are making the same power out of a low mount hi-flow which i imagine is more responsive based on other ppls experiences with the XTR Turbos...well i may just change the setup:(

PS i like your avatar Joel, putting the new RB20 in i see:)

Anyone in melbourne with an RB20 with a RB25 turbo makign 200rwkws: or a 2530 or any aftermarket turbo for that matter. Im very intersted in sampling a few RB20s, i went for wat i thought would be the biggest turbo a std RB20 could handle/use, but if ppl are seriously making 200rwkws out of small turbos?!?!?!? :bananaman

Ok helped do this convo last night and with RB25 turbo on a R31 ECCS RB20det

- We found out that the R31 oil line is the same and fitted the RB25 turbo

- Used the R31 oil drain on the RB25 turbo

- YOU NEED EIETHER THE R32 OR R33 WATER LINES FOR THE RB25 TURBO

- Used the R31 dump on the RB25 turbo

Update.

Just finished putting a Series 1 RB25 turbo on a Series 2 R32 RB20det.Put the RB20 acuator on RB25 turbo for higher boost(11-12psi)

Easy just unbolt Rb20 turbo and put the Rb25 in it's spot.If you don't have the elbow on the RB25 turbo we used the RB20 one and drilled out the holes.Very easy people and it goes so much harder on 11-12psi than the shitter RB20 one.

When you say much harder.

I still think the rb20t turbo has more low/mid range power than the rb25t turbo.

It gives the feeling of a quicker car. I've been in a Rb20det with an rb25 turbo and to be honest it felt slower than the rb20t turbo up to around 5000rpm. Then the 25 turbo pulled harder especially from 6000-7000rpm.

Overall on the street I still think my ol rb20t would have given it a real good run for its money. BUT I was running an extra 2psi than the rb25 turbo was.

14psi rb25 turbo vs 16psi the rb20t turbo.

Jeol I was'nt driving and the tacho was'nt working so it's hard to say what rpm it was going hard at.

Of course down low it has suffered a little but it's not that bad.Up top(guessing by the speed)like you said between 5000rpm and 7000+rpm it just kept on pulling and stayed at 11psi-12psi,before the RB20det nearly sounded like n/a coz it had nothing after 6000rpm.

Ed G thats not safe :) but we all do it.Some go pop and some don't :wassup:

And the RB20det turbo feeling faster bit is true.Mine felt slow compared to it and I have a HKS GT2535.But then agian I had a plenum bolt missing and once another bolt was put back in i got boost 500rpm quicker rofl

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Can perhaps see how the R33 appreciators would think so.  
    • Thanks, I removed the fuse and the relay from the car and made my own circuit with them to test them with a test bulb.  I will look for the wiring diagram and go from there.
    • Jdm DC2R is also nice for a FF car compared to the regular hatches of the time.
    • Now that the break-in period for both clutch and transmission is nearly over I'd like to give some tips before I forget about everything that happened, also for anyone searching up how to do this job in the future: You will need at least 6 ton jack stands at full extension. I would go as far as to say maybe consider 12 ton jack stands because the height of the transmission + the Harbor Freight hydraulic platform-style transmission jack was enough that it was an absolute PITA getting the transmission out from under the car and back in. The top edge of the bellhousing wants to contact the subframe and oil pan and if you're doing this on the floor forget about trying to lift this transmission off the ground and onto a transmission jack from under the car. Also do not try to use a scissor jack transmission lift. You have to rotate the damn thing in-place on the transmission jack which is hard enough with an adjustable platform and a transmission cradle that will mostly keep the transmission from rolling off the jack but on a scissor lift with a tiny non-adjustable platform? Forget it. Use penetrating oil on the driveshaft bolts. I highly recommend getting a thin 6 point combination (box end + open end) wrench for both the rear driveshaft and front driveshaft and a wrench extension. These bolts are on tight with very little space to work with and those two things together made a massive difference. Even a high torque impact wrench is just the wrong tool for the job here and didn't do what I needed it to do. If your starter bolts aren't seized in place for whatever reason you can in fact snake in a 3/8 inch ratchet + 6 point standard chrome socket up in there and "just" remove the bolts for the starter. Or at least I could. It is entirely by feel, you can barely fit it in, you can barely turn the stupid ratchet, but it is possible. Pull the front pipe/downpipe before you attempt to remove the transmission. In theory you don't have to, in practice just do it.  When pulling the transmission on the way out you don't have to undo all the bolts holding the rear driveshaft to the chassis like the center support bearing and the rear tunnel reinforcement bar but putting the transmission back in I highly recommend doing this because it will let you raise the transmission without constantly dealing with the driveshaft interfering in one way or another. I undid the bottom of the engine mount but I honestly don't know that it helped anything. If you do this make sure you put a towel on the back of the valve cover to keep the engine from smashing all the pipes on the firewall. Once the transmission has been pulled back far enough to clear the dowels you need to twist it in place clockwise if you're sitting behind the transmission. This will rotate the starter down towards the ground. The starter bump seems like it might clear if you twist the transmission the other way but it definitely won't. I have scraped the shit out of my transmission tunnel trying so learn from my mistake. You will need a center punch and an appropriate size drill bit and screw to pull the rear main seal. Then use vice grips and preferably a slide hammer attachment for those vice grips to yank the seal out. Do not let the drill or screw contact any part of the crank and clean the engine carefully after removing the seal to avoid getting metal fragments into the engine. I used a Slide Hammer and Bearing Puller Set, 5 Piece from Harbor Freight to pull the old pilot bearing. The "wet paper towel" trick sucked and just got dirty clutch water everywhere. Buy the tool or borrow it from a friend and save yourself the pain. It comes right out. Mine was very worn compared to the new one and it was starting to show cracks. Soak it in engine oil for a day in case yours has lost all of the oil to the plastic bag it comes in. You may be tempted to get the Nismo aftermarket pilot bearing but local mechanics have told me that they fail prematurely and if they do fail they do far more damage than a failed OEM pilot bushing. I mentioned this before but the Super Coppermix Twin clutch friction disks are in fact directional. The subtle coning of the fingers in both cases should be facing towards the center of the hub. So the coning on the rearmost disk closest to the pressure plate should go towards the engine, and the one closest to the flywheel should be flipped the other way. Otherwise when you torque down the pressure plate it will be warped and if you attempt to drive it like this it will make a very nasty grinding noise. Also, there is in fact an orientation to the washers for the pressure plate if you don't want to damage the anodizing. Rounded side of the washer faces the pressure plate. The flat side faces the bolt head. Pulling the transmission from the transfer case you need to be extremely careful with the shift cover plate. This part is discontinued. Try your best to avoid damaging the mating surfaces or breaking the pry points. I used a dead blow rubber hammer after removing the bolts to smack it sideways to slide it off the RTV the previous mechanic applied. I recommend using gasket dressing on the OEM paper gasket to try and keep the ATF from leaking out of that surface which seems to be a perpetual problem. Undoing the shifter rod end is an absolute PITA. Get a set of roll pin punches. Those are mandatory for this. Also I strongly, strongly recommend getting a palm nailer that will fit your roll pin punch. Also, put a clean (emphasis on clean) towel wrapped around the back end of the roll pin to keep it from shooting into the transfer case so you can spend a good hour or two with a magnet on a stick getting it out. Do not damage the shifter rod end either because those are discontinued as well. Do not use aftermarket flywheel bolts. Or if you do, make sure they are exactly the same dimensions as OEM before you go to install them. I have seen people mention that they got the wrong bolts and it meant having to do the job again. High torque impact wrench makes removal easy. I used some combination of a pry bar and flathead screwdriver to keep the flywheel from turning but consider just buying a proper flywheel lock instead. Just buy the OS Giken clutch alignment tool from RHDJapan. I hated the plastic alignment tool and you will never be confident this thing will work as intended. Don't forget to install the Nismo provided clutch fork boot. Otherwise it will make unearthly noises when you press the clutch pedal as it says on the little installation sheet in Japanese. Also, on both initial disassembly and assembly you must follow torque sequence for the pressure plate bolts. For some reason the Nismo directions tell you to put in the smaller 3 bolts last. I would not do this. Fully insert and thread those bolts to the end first, then tighten the other larger pressure plate bolts according to torque sequence. Then at the end you can also torque these 3 smaller bolts. Doing it the other way can cause these bolts to bind and the whole thing won't fit as it should. Hope this helps someone out there.
×
×
  • Create New...