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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

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

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.

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

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

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.

Thanks for the info, just using the std RB26 head gasket (think its actually 1.28mm) gasket is pretty close to 87mm I think, planning on O ringing. Think I might stick with the flat tops to be safe.

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*

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

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??

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).

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 :)

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?

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