R33 Rb30 Conversion

[r33_racer]

We went CP flat top pistons. But its upto you what pistons you want, to achieve whatever CR. Our tuner wanted us to go with a lower cr, while others tend to go for the higher cr.

The view is the lower cr makes the car less responsive off boost, while the higher cr makes it more responsive. However depending on tuning the lower cr helps with less knock and allows more ignition advance and boost without the knock, while the higher cr helps with more low/midrange power but in alot of cases ends up with more knock....but it all comes down to the tuner in the end or so everyone says. Prob abit in it with fuel economy and other bits and pieces, but .5 difference is like either choosing to run rb26 cr or running rb25 cr...in the end its upto you cause its your engine your building.

But then again it depends on what application your building this motor for.

Edited September 19, 2006 by r33_racer

[humz]

howdy just about to order some pistons for 30det.

can get a good deal on acl rebuild kits and the new forged pistons they've produced.

does anyone have any experiance with these suckers? are they any good? or shall i pay a few hunj more and buy eg arais??? dont really wona spend teh extra dollars coz i will also be getting Hbeam rods.

also these acl forged pistons apparently produce a comp ratio of 8.5!

is this ok for a daily driver which will cop a bit of shit with about 420rwhp???

the car is a r33 is thats gona help.

[humz]

http://www.aclperformance.com.au/NissanRB3...rgedPistons.htm

[Spoolup]

they will work just fine

[r33_racer]

except those pistons are suited for a rb30ET not DET. I think it will give a shithouse CR something like 7.1:1 its been said. You need the NA pistons to give a better CR around 8.2-8.5 or thereabouts.

[Spoolup]

No they are 8.5:1 in the RB30ET engine, so when used with the RB25 head they come in around 8 depending on combustion chamber size. I have used them in my RB30 with R34 Neo head ( it has a 58cc chamber ) and comp has worked out at 8.4:1

You are correct in what you said if you use the std oem turbo piston from the VL RB30ET. They were around 7.5:1 std I believe.

Best to use the CP pistons like I sell.

Edited September 22, 2006 by Spoolup

[JMCY]

No they are 8.5:1 in the RB30ET engine, so when used with the RB25 head they come in around 8 depending on combustion chamber size. I have used them in my RB30 with R34 Neo head ( it has a 58cc chamber ) and comp has worked out at 8.4:1

You are correct in what you said if you use the std oem turbo piston from the VL RB30ET. They were around 7.5:1 std I believe.

Best to use the CP pistons like I sell.

So what compression do you get with your pistons SPOOL

[r33_racer]

I stand corrected then. I figured that since std pistons would give that so would the forged equivalents. Ahh well, my bad.

But i agree use the CP's.

[Spoolup]

CP make two types

8.5:1 and 9.0:1.

One has a flat top with zero deck height and the other has an 11cc ( from memory ) dome.

[JMCY]

CP make two types

8.5:1 and 9.0:1.

One has a flat top with zero deck height and the other has an 11cc ( from memory ) dome.

Thanks for that spool, just wondering Is their any issues using oil restrictors with VVT.

Edited September 23, 2006 by JMCY

[Spoolup]

JMCY - are to talking about oil restrictors in the block ?

[JMCY]

JMCY - are to talking about oil restrictors in the block ?

Yeah sorry about that Spool in the BLOCK.

[Spoolup]

Why would you be using restictors with the RB25 head ?

[JMCY]

Why would you be using restictors with the RB25 head ?

I read earlier in thread that Sydneykidd suggested it, but on nengun sites says shouldn,t be used with VVT?

[Dahtone Racing]

seeing as ive got this motor apart

should i use restrictors if im using an RB25DE head and RB30 oil pump?

the isnt going to be raced very much at all, just a weekend cruise and a dyno run here and there

[Spoolup]

I have never used restrictors on RB25 VCT heads as I have never experienced any issues, but definitely use them on RB26 heads.

[shanef]

yes on an RB26 head block off one and use a restrictor in hte other, size depends on oil pump

i picked up my sump adapter on thursday and i'm going to install it this week, so i'll document the whole process (with pics) and post them up here

[r33_racer]

rb25 head with n1 oil pump and one blocked off and 1.5mm in other and we have oil problems. Circuit racing is a bitch for exposing problems.

oh and we have vct as well.

Refer to the table from SK's oil control problems in rbs info.

Edited September 23, 2006 by r33_racer

[FROGGAH]

Hey guys been reading this thread for a while now almost an hour lol

just a few qik questions...

i have picked up an rb30 complete do i need a n/a rb25de head or can i use an rb25det head as there is one that has been ported and polished? vct or non vct

also this rb30 has been rebuilt to std specs like 400kms ago is it worth just fitting the head and fix it if it breaks. I work in a performance workshop so rebuilding it is no problem i was just curious if anyone has pushed the std n/a 30 bottom end to breaking point?

cheers

[Adriano]

I would just bolt them together with the restrictors and remote oil feed to the vct. Cc your chambers and pistons( you dont need to pull them out) and chech your deck heights to find out your comp and squish, i would go for high 8's:1 comp amd about 35 thou squish, so you may have to deck the head or block of fiddle with head gasket thickness, get a steel head gasket and your done. Dont try to get 1000hp, and it will hold together. You may wish to put a good set of big end bearings in it though. This should be good for a safe 550hp if tuned well, as above this the rods go