Jump to content
SAU Community

Recommended Posts

Thanks David

No worries.

Like I said that is an approximate. Know of several (four other members!) others who have cc'd their heads and got 62cc or there abouts. Its fairly accurate "approximation" to assume yours will be the same.

If you're shooting for 9:1, just make sure your builder/assembler knows this and machines the assembly accordingly.

I think its weird that its not more commonly known (the chamber volumes)

I guess it comes down to not many people touching the heads on RBs and simply throw a bigger turbo and more boost at it to make power.

This also relates to CP/Weisco etc labling the comp ratios for pistons straight out of the box.

No worries.

Like I said that is an approximate. Know of several (four other members!) others who have cc'd their heads and got 62cc or there abouts. Its fairly accurate "approximation" to assume yours will be the same.

If you're shooting for 9:1, just make sure your builder/assembler knows this and machines the assembly accordingly.

wildo, costing me enough as it is, dont want to risk phucking it up. . :thumbsup:

Rb25 & rb26 I've seen all varied from 62-67. Neo's from 52-56. The first 20 thou ground off an un machined 25 & 26 head removes exactly 2CC's and it always varies from there

piston to deck heights varied too,

rb30 with rb25/26 pistons 10 - 40 under

rb30de pistons 20 thou under to 10 thou above

5 thou above will usually add .25 to the comp ratio

a 1.8 gasket replacing a 1.2 can lower the comp by around 0.75

  • 2 months later...

My RB30DET is running,

modified r33 25 head, drilled oil returns, welded water and vct, 20 inlet cam, 25 exhuast cam, full reco and skim.

RB30 block, drilled oil returns, drilled & taped tensioner, 1.0mm oil restristors, deburred and honed.

RB30 crank, grub screwed & crank collar, linish and balance.

RB30E std piston and rod, new rings, acl race bearings,

Cometic 1.2 MLS head gasket, genuine nissan gasket set.

N1 oil & water pumps, dayco 94407 timing belt, 2x tensioners.

Garret GT3071r 3037s 56t .63. ebay hi mount, tial 38mm gate, nismo 750cc, Freddy, apexi pfc, 3x pumps.

Heaps of Torque & 12psi @ 2500rpm :whistling:

Next: E85, reposition wastegate & tune

Edited by RED513

So just as I finish sorting out all the teething problems of the new setup and was thinking of booking it in for a tune.. some dumbass P-plater tries to make the gap and failed hard :(

The old girls heart will beat again soon, hopefully in the body of a sexy young 34 :whistling:

post-31803-0-66439500-1324344558_thumb.jpg

post-31803-0-09321800-1324344625_thumb.jpg

  • 3 weeks later...

New engine has just been tuned. I have a nice 300rwkw tune for pump fuel as thats plenty for the street. And a 475rwkw E85 tune at only 24psi as that seems the be the limit of my exhaust system.

It makes 180rwkw @ 4000 and 360rwkw by 4500 so things get fun pretty quick.

Just need a 4" system and a less restrictive muffler and should make more but this will do for now :thumbsup:

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

    • Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
    • No those pads are DBA too  but they have colors too. I look at the and imo the green "street" are the best.
    • I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
×
×
  • Create New...