Jump to content
SAU Community

R33 Rb30 Conversion

JNR24

By JNR24,
in Engines & Forced Induction

 Share

Recommended Posts

Cubes Grand Master

Cubes

Posted
Posted
i got my heap of junk dynoed for a bit today, just a quick check to make sure it was OK. fixed the AFR's back to 12:1 and didn't play with timing much at all. total of 1.5 hours on the dyno, 225rwkw at 9psi. graph and stuff can be seen here --> http://www.skylinesaustralia.com/forums/in...howtopic=104332

Looks good stocky.. Any plans to get that s/c providing a little more boost in the low end?

  • Replies 7.2k
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Popular Posts

Duncan
Duncan

Just thought I would bump this 20 year old thread because the Skid Factory have just posted up a video summarising a lot of the content, format might be more familiar for newer members

JNR24
JNR24

fyi guys, Well yesturday i picked up a RB30 for my conversion into my R33. I will be using my RB25DET head on the RB30 block. So i started stripping the motor down, pulled the crank, pistons, girdle

Cubes
Cubes

Here is all I have at the moment: http://www.geocities.com/r32_jjc/ Unless you are on broad band make sure you right click then save as. The file is around 120kb. If there is anything I have got w

Posted Images

Sydneykid Grand Master

Sydneykid

Posted
Posted
Does anyone know the formula for working out what the compression ratio will be with a standard 30e block & r32 RB25DE head with a 1.0mm metal head gasket??

Simple high school maths (Pi x R2 X H), 0.2 mm reduction in head gasket thickness = 0.1 to 1 increase in compression ratio. So if you had no head gasket at all, you would end up at 8.7 to 1 using RB30E pistons with an RB25 cylinder head.

An alternative (if you have a decent machine shop close by) is to mill the cylinder head 0.3 mm and reduce the combustion chamber volume by 2 cc's. Then install new (unmilled) valve seats which will reduce the combustion chamber volume by 0.8 cc's. Head gaskets of 0.8 mm are available, but to use one you will need to o'ring the block. Do those 3 things and you will end up at 8.65 to 1 which is the best you are going to get while still retaining the standard squish, which is important.

:( cheers :(

StockyMcStock Proficient

StockyMcStock

Posted
Posted
Looks good stocky.. Any plans to get that s/c providing a little more boost in the low end?

nup - it's perfect just as it is. the boost isn't important, it's the airflow that it's providing. it REALLY doesn't need any more bottom-end torque that's for sure. full boost (on the street) is a little later than i was expecting, simply because it goes through the gears so quickly. there's just no time. it mashes first gear and you can destroy 2nd if you really want to . yet to drive it on a cold night :O

it needs to have the cam timing checked to see why the power is dropping off past 5200. hopefully it's just the timing and not something else. pretty f**king happy with it at the moment that's for sure. name me any other RB30 engine with that response, power delivery and peak power on such little boost. i can't think of any.

Cubes Grand Master

Cubes

Posted
Posted
nup - it's perfect just as it is. the boost isn't important, it's the airflow that it's providing. it REALLY doesn't need any more bottom-end torque that's for sure. full boost (on the street) is a little later than i was expecting, simply because it goes through the gears so quickly. there's just no time. it mashes first gear and you can destroy 2nd if you really want to . yet to drive it on a cold night :O

it needs to have the cam timing checked to see why the power is dropping off past 5200. hopefully it's just the timing and not something else. pretty f**king happy with it at the moment that's for sure. name me any other RB30 engine with that response, power delivery and peak power on such little boost. i can't think of any.

Well thats just it, I haven't seen one... But I am greedy.. :(

You are pretty damn close to the same power I had with the rb20det turbo at 2400rpm but with a lot more top end.

I'm certian the issue is with cam timing as you have just disabled the vct and not adjusted the cam timing to suit yes?

I'm curious as to how its all setup.. I'm sure youve mentioned it before.

Where is the turbo's wastegate getting its boost reading from?

StockyMcStock Proficient

StockyMcStock

Posted
Posted

yeah VCT is disabled - but the cam timing is probably out due to the fact that it's a completely non-standard cam belt setup. i basically aligned the notches as best i could by eye, which wasn't very good at all.

DSC00174-1.jpg

as you can see the tensioners aren't in the "normal" place for an RB30DET, because i started with a series 1 block. i like my setup better though, the belts have less length between tension points so there's (theoretically) less flap in them.

turbo's wastegate is reading boost from before the intercooler, but this doesn't really matter. not much would change if i referenced it to the plenum, or after the intercooler. it might run 1-2psi more (pressure rise equal to pressure differential across the cooler) but that's it. the real magic is happening at the 2nd wastegate which is the blower bypass.

i really wish i had a dyno vid to show you guys, not because it looked cool but because of the noise it made. just insane.

Cubes Grand Master

Cubes

Posted
Posted

As you have the turbo's wastegate boost feed after the supercharger wouldn't this essentially cause the turbo to lag as the supercharger will be making boost; IF the supercharger makes enough boost to hold the turbo's wastegate open then the turbo man never really get up on boost?

Is that right?

Have you tried taking the turbo wastegate boost feed from the compressor cover or at least the pipe that runs from the turbo to the supercharger?

StockyMcStock Proficient

StockyMcStock

Posted
Posted

totally true, except the supercharger doesn't make enough boost (straight away) to open the gate. it only makes 5psi on its own, with no positive inlet pressure.

if i took the gate's pressure feed from the turbo-blower connecting pipe, it would likely cause plenum pressure to go up to around 16psi, which i don't want. this is because the blower multiplies the pressure, not adds. so the pressure differential stays the same at, say, 1.4x, so you might only get 5psi out of the blower with no turbo hooked up. connect the turbo and pressurise the inlet, and the final figures might be something like 7psi from the blower and 2psi in the blower-turbo connecting pipe.

if i had to guess (haven't measured it yet), i would say that there is only 2-3psi of pressure in the connecting pipe at full boost. so there is certainly a *bit* left in the old GT40 :O

gtst25 Proficient

gtst25

Posted
Posted
bah come on, yours would be heaps quicker from the info i've seen posted?

It sounds a lot more torquier than most with that supercharger - especially when compared to a mere rb25 like I have.

Can't wait to see how it goes with big injectors + big boost - you'll have some major traction issues!

Cheer

r33_racer Grand Master

r33_racer

Posted
Posted

i think he has some major traction issues now...if he tried i reckon it could nail first three easy. That charger really seems to kick it in the ass down low to get it all started. It looks and sounds wild as from that video.

StockyMcStock Proficient

StockyMcStock

Posted
Posted

yeah it starts spinning 1st gear at about 3500rpm if you keep your foot down, then 2nd it will turn them again when you hit full boost :) shift too quickly like i did in the video and it's all over as far as the tyres are concerned. i'd love to do this to an RB25 to show you guys how easy it is to make huge power out of a twincharge. it would really transform a 2.5 litre engine that's for sure. even better would be a GTR that could cope with the power. the 3 litre bottom end helps a bit, but when you have boost delivery like i have it's not really necessary.

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • oHBoy.
      Starter motor replacment teeth count.

      By oHBoy. · Posted

      I had 3 counts over the last couple of weeks once where i got stranded at a jdm paint yard booking in some work. 2nd time was moving the car into the drive way for the inspection and the 3rd was during the inspection for the co2 leak test. Fix: 1st, car off for a hour and half disconnected battery 10mins 4th try car started 2nd, 5th try started 3rd, countless time starting disconnected battery dude was under the hood listening to the starting sequence fuel pump ect.   
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      This. As for your options - I suggest remote mounting the Nissan sensor further away on a length of steel tube. That tube to have a loop in it to handle vibration, etc etc. You will need to either put a tee and a bleed fitting near the sensor, or crack the fitting at the sensor to bleed it full of oil when you first set it up, otherwise you won't get the line filled. But this is a small problem. Just needs enough access to get it done.
    • suko
      J50 clock date suddenly reset to January 1

      By suko · Posted

      The time is always correct. Only the date is wrong. It currently thinks it is January 19. Tomorrow it will say it is January 20. The date and time are ( should be ! ) retrieved from the GPS navigation system.
    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      Buy yourself a set of easy outs. See if they will get a good bite in and unthread it.   Very very lucky the whole sender didn't let go while on the track and cost you a motor!
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      Well GTSBoy, prepare yourself further. I did a track day with 1/2 a day prep on Friday, inpromptu. The good news is that I got home, and didn't drive the car into a wall. Everything seemed mostly okay. The car was even a little faster than it was last time. I also got to get some good datalog data too. I also noticed a tiny bit of knock which was (luckily?) recorded. All I know is the knock sensors got recalibrated.... and are notorious for false knock. So I don't know if they are too sensitive, not sensitive enough... or some other third option. But I reduced timing anyway. It wasn't every pull through the session either. Think along the lines of -1 degree of timing for say, three instances while at the top of 4th in a 20 minute all-hot-lap session. Unfortunately at the end of session 2... I noticed a little oil. I borrowed some jack stands and a jack and took a look under there, but as is often the case, messing around with it kinda half cleaned it up, it was not conclusive where it was coming from. I decided to give it another go and see how it was. The amount of oil was maybe one/two small drops. I did another 20 minute session and car went well, and I was just starting to get into it and not be terrified of driving on track. I pulled over and checked in the pits and saw this: This is where I called it, packed up and went home as I live ~20 min from the track with a VERY VERY CLOSE EYE on Oil Pressure on the way home. The volume wasn't much but you never know. I checked it today when I had my own space/tools/time to find out what was going on, wanted to clean it up, run the car and see if any of the fittings from around the oil filter were causing it. I have like.. 5 fittings there, so I suspected one was (hopefully?) the culprit. It became immediately apparent as soon as I looked around more closely. 795d266d-a034-4b8c-89c9-d83860f5d00a.mp4       This is the R34 GTT oil sender connected via an adapter to an oil cooler block I have installed which runs AN lines to my cooler (and back). There's also an oil temp sensor on top.  Just after that video, I attempted to unthread the sensor to see if it's loose/worn and it disintegrated in my hand. So yes. I am glad I noticed that oil because it would appear that complete and utter catastrophic engine failure was about 1 second of engine runtime away. I did try to drill the fitting out, and only succeeded in drilling the middle hole much larger and now there's a... smooth hole in there with what looks like a damn sleeve still incredibly tight in there. Not really sure how to proceed from here. My options: 1) Find someone who can remove the stuck fitting, and use a steel adapter so it won't fatigue? (Female BSPT for the R34 sender to 1/8NPT male - HARD to find). IF it isn't possible to remove - Buy a new block ($320) and have someone tap a new 1/8NPT in the top of it ($????) and hope the steel adapter works better. 2) Buy a new block and give up on the OEM pressure sender for the dash entirely, and use the supplied 1/8 NPT for the oil temp sender. Having the oil pressure read 0 in the dash with the warning lamp will give me a lot of anxiety driving around. I do have the actual GM sensor/sender working, but it needs OBD2 as a gauge. If I'm datalogging I don't actually have a readout of what the gauge is currently displaying. 3) Other? Find a new location for the OEM sender? Though I don't know of anywhere that will work. I also don't know if a steel adapter is actually functionally smart here. It's clearly leveraged itself through vibration of the motor and snapped in half. This doesn't seem like a setup a smart person would replicate given the weight of the OEM sender. Still pretty happy being lucky for once and seeing this at the absolute last moment before bye bye motor in a big way, even if an adapter is apparently 6 weeks+ delivery and I have no way to free the current stuck/potentially destroyed threads in the current oil block.
×
×
  • Create New...