Jump to content
SAU Community

Recommended Posts

me neither :-)

I sell two types now for RB30. the original design and a PHAT rod for serious power.

PHAT'S are heavier but they have a thicker beam, more steel around the bolt area and across the bottom cap.

Ive used both and cant really distinguish any noticable difference in response.

Anyway thats my two cents worth

Link to comment
Share on other sites

hmm so we switched the turbine housing over to the modified one by kyle and it holds boost perfectly now with no fluctuations, however its not making power. Before when it was spiking, it was making 290kw now its down to 220kw.

I tell ya i feel like driving the whole race car straight into the brisbane river and letting it sink...starting from scratch, then i can use a 32 like i originally wanted.

Oh Brad did you get my message last night?

Edited by r33_racer
Link to comment
Share on other sites

Problem solved.

Looks like the cat or middle muffler has collapsed and blocked most of the exhaust.

Got it to 1 bar after I dropped the exhaust at the dump pipe flange and went for a blat up the street.

Whoo hoo, now to just replace the cat or muffler and back to the dyno.

Think Ill have a few beers tonight.

Link to comment
Share on other sites

Hey Spool, you got any specials on your RB30 CP pistons coming up? have the 9:1's got a 6cc dome? My 26 head seems to have 65.5cc. It would seem that using flat tops would give me a comp ratio of 7.88:1 with a .0 deck height, 1.2mm head gasket, 0.5mm oversize. taking the 6cc dome of the 9:1's (if im right) I would actually end up with 8.5:1. Any extra info would be good.

Thanks, Matt

Edited by Godzilla33
Link to comment
Share on other sites

Hi Matt

From memory _ I will confirm. The CP's have an 11cc dome on their 9.0:1 pistons.

Ill also calculate your comp from the figure you have given and see what we turn out.

Cheers

Hey Spool, you got any specials on your RB30 CP pistons coming up? have the 9:1's got a 6cc dome? My 26 head seems to have 65.5cc. It would seem that using flat tops would give me a comp ratio of 7.88:1 with a .0 deck height, 1.2mm head gasket, 0.5mm oversize. taking the 6cc dome of the 9:1's (if im right) I would actually end up with 8.5:1. Any extra info would be good.

Thanks, Matt

Link to comment
Share on other sites

assuming your head gasket is 87mm in diameter , and using the other figures you have given.

1.2mm gasket

86.5mm bore

11cc dome

65.5 cc combustion chamber

you will get 9.1:0 with the cp 9.0:1 piston

Your calculations using the 6cc dome are correct though.

Link to comment
Share on other sites

From memory _ I will confirm. The CP's have an 11cc dome on their 9.0:1 pistons.

Gday Spool,

Hmmmm I got an email from QRI and they assured me CP 9.0 were 6cc dome?!

I thought you would be the best person to ask!

Arias apparently have a 13cc dome on one of their pistons which would make even higher c/r :wave:

I had a quiet day at work today so did a bit of emailing and ringing around to find out about pistons....

CP Quantum Racing Industries

All compression ratios are based on zero deck height, 1.2mm head gasket (7.13cc), RB25 @ 62.5cc, RB26 @ 64.5cc. They assure me they have done alot of work to make sure the facts are correct.

p/n= CP-RB30/26-.20

Flat top with no valve pockets

8.2:1 compression with RB25 head and bit less with RB26 head

21mm pin

1.280" compression height

Only stocked in 0.20 thou oversize but can be custom ordered in any size.

p/n= CP-RB30/26-.20-9.0

6.0cc dome top,

9.0:1 compression with RB25 head and bit less with RB26 head

21mm pin

1.280" compression height

Only stocked in 0.20 thou oversize but can be custom ordered in any size.

*Care must be taken when using on RB26 with more than 11.5mm valve lift*

Link to comment
Share on other sites

Also, I thought with RB30ET std 7.8:1 pistons the c/r with a R33 RB25 head is about 7.1:1, so using 8.5:1 (quoted off the ACL website) ACL forgies might make it approx 7.8:1?

Even if the R34 NEO head has smaller chambers, it surely does it reallywork out to be 8.5:1?!?

Or was it all CC'd?

Edited by VHR32
Link to comment
Share on other sites

I have the chance to buy a GT30 .82 with custom wheels in it, which apparently made 367rwKw @ 24psi boost (C16) on a RB25.

I'm aiming for 350rwKw on 98 fuel.

Would this be a bit on the small side on a RB30/26 street/track car??

Link to comment
Share on other sites

Have a good look around here...

http://www.turbobygarrett.com/turbobygarre...bochargers.html

GT30R is listed as GT3076r

GT35R is listed as GT3582r

Have a look at their wheel sizes. The multiple listings of the same GT3076r and gt3582r is off the top of my head just different turbine housing configs (T4, T3 4 bolt etc etc).

Link to comment
Share on other sites

Like I said - it was from memory. You could be correct. I think I have a set here, Ill check them and also ring Quantum on Monday to confirm for you ( and me ).

Gday Spool,

Hmmmm I got an email from QRI and they assured me CP 9.0 were 6cc dome?!

I thought you would be the best person to ask!

Arias apparently have a 13cc dome on one of their pistons which would make even higher c/r :)

Link to comment
Share on other sites

The NEO head is approx 10cc smaller than the R33 ( I cant remember the exact cc's - I should keep all this info somewhere ). The head was also surfaced when reconditioned and ported, so that decreases the comb chamber a little also.

I cc'd everything when I built my engine, combustion chamber, piston valve reliefs, etc

Also, I thought with RB30ET std 7.8:1 pistons the c/r with a R33 RB25 head is about 7.1:1, so using 8.5:1 (quoted off the ACL website) ACL forgies might make it approx 7.8:1?

Even if the R34 NEO head has smaller chambers, it surely does it reallywork out to be 8.5:1?!?

Or was it all CC'd?

Link to comment
Share on other sites

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

    • I'm pretty sure it's just this specific Dorman one. I checked it with the hub by itself and even then it was already shedding plastic. It's only once I ran into all these issues with assembling the clutch that I decided to be skeptical of the plastic alignment tool as well and found it to have a notable amount of slop as the clutch is heavy enough to allow the plastic to bend. 
    • The "one cylinder is 160 while others is 180" part of the compression test sounds bad. That's 12% lower than the others. I would bet something has happened there.
    • Does it do it at light throttle as well as high throttle opening? Only large throttle opening? If the answer is "No, it doesn't do it at light throttle opening", then (part of) the answer is as it has always been. Don't stamp on the throttle at low revs. Open is with some discretion. Roll into it. Now, because it's not a turbo, it shouldn't demand the highest octane fuel....but even 91 MON (equivalent to ~95 RON in the metric world) is only so-so for NA Jap engines. The 10% ethanol won't make any difference forwards or backwards. 10% is just filler. OK, actually, it is a little bit bad. Ethanol adds some (effectively) free octane. It allows the blend to reach the 91 octane rating without the petrol it is mixed with being that high octane to start with. But ethanol needs less air to burn than petrol does. So when a blend has ethanol in it, the fuel-air mix will always be a bit lean (except when running in closed loop cruise where the O2 sensor will add fuel to bring the stoichiometry back to target). When yo stamp on the throttle, you are not in closed loop and so a lean condition may well exist. Lean can (and will) cause pinging. The low compression cylinder may be a concern. If the rings (and in particular the oil control ring) are poor, and it is ingesting oil into that cylinder, that can cause it to ping. Oil reduces the effective octane rating of the fuel that is squirted into that cylinder, and rattle rattle rattle is the result. It's unlikely to be a bad MAF. You should make sure that the harmonic balancer is not in the process of failing. The outer hub can slip around relative to the inner. This makes the timing marks on it wrong. If you set the timing to a target, as read with a timing light from those marks, then the timing can be very wrong. You need to take out #1 spark plug and use a screwdriver or similar rod as an indicator and turn the engine over (which will be easier with all the plugs out) by hand so that you can see the screwdriver rise up, dwell around TDC and start falling again. It is difficult for the uninitiated to accurately find TDC that way, but it will do in a pinch. When you are pretty sure you know where TDC is, you need to check the timing marks. If it is not real bloody close to TDC, then you have to question the health of the balancer. Another thing that can go wrong is carbon build up on piston crowns or on the combustion chamber face of the head. These can glow hot and cause pre-ignition, and will tend to do it on light throttle as well as heavy.
    • Hello again so I blew my motor long story short one of the cams journals wasn’t getting oil and the cam stopped rotating and jumped timing on exhaust side. It’s a built r32 rb25de+t non vct so my questions are. 1. Can a r33 rb25det s1 head work on my r32 rb25de non vct block I still want to use it because forged internals. My r32 rb25 head is toast and I can’t find anyone with one. 2. Will my non vct parts work on the vct head which are cam gears, gear back plate, front gear cover, cas, cas bracket, and cams (rb20 tomei 256 cams). I will be deleting the vct because I don’t feel like it lol also I reached my hp goal on the dyno before it blew.   3.Last question I know I’ll have to switch up my manifold and fuel rail because no vct head is very similar to rb20 and ik vct head is different but I want to make sure that tps, water sensors, and idle air control valve connectors will be the same. I’ve read tps and water sensors should be the same just don’t know about the idle air control. I don’t want to have to modify my harness.   
×
×
  • Create New...