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what model acl race pistons as most of them work out with horrible compressions without serious block or piston work.

i spent ages researching that and ended up running a set of stockers with new nissan rings.

the turbo ones give about 7.6:1 the NA's are better

I'm running the RB25det wiseco's in mine, comps up around 9:1 from my calcs.

So far all is good 70,000km's on the motor, still perfect compression in all 6; no drop in compression since it has been rebuilt so the std ring pack appears to hold in quite well.

If I were to do it again I'd run with the CP pistons.

The wiseco's are not optimal either.

they are the pistons i was referring too before. which cp pistons would you go with? i take it 9 1 compression is ok judging by your build. what turbo are you running? i was thinking of gt35r from what i'v read. or a t04z

I wouldn't hessitate running 9:1.

Since I've dropped the larger (gt30 .8) turbo on the amount of ignition timing it can take is quite surprising.

Interestingly it takes quite a bit more than a blokes stock rb30 n/a bottom end (8.2:1) with stock rb25 head running a gt35 turbo with slightly more boost. Unsure why his was running so little timing compared to mine. Mine with less boost and running more ignition makes the same power.

Possibly the bit of head work I've had done? Im not sure.

The wiseco pistons require a bit of stuffing around + it messes with the squish/quench. So not optimal, but mine have worked fine. :(

Hey guys,

i was just talking about a standard piston, not forged etc

do acl do anything that will get the comp at 8.2-3 or should i just go with nissan. Though i thought i might have read a post in this thread that nissan arent making them anymore?

Will have to give them a call tomorrow

the acl im using were designed for the hybrid conversion, the engine builder that im using had them from a previous build that didnt happen, ill have to see what the comp works out at, but they are practially flat top, so ill have to post it when i figure out the comp

Just a quick one, Given the Engine is built right and maintained well. As it is basically a new engine once built what is the life expectancy on a RB25/30 DET??? Someone I have spoken too has lead me to believe that they dont last long. Ive been told I would be lucky to get 50,000km out of it. What are your opinions.

thats a load of bull, its just like any other engine, the reason they might not last is if they are punished or not built properly, they are like any other engine, if they are put together properly, all gaps etc are good and they are well maintained and not thrashed competely they should last as long as any other engine out there

Definitely a load of bull.

sky30 grabbed a 270,000km rb30e dropped an rb25 dohc head on it and drove it for a couple of years with 300rwkw. Then dropped it in his gts4 with a 26 head on it and drove it at 380rwkw for quite some time.

My own.. 70,000km's there are countless others. Head over to ct.com to see the 300-400 thousand rb30 turbo's still trucking.

Definitely a load of bull.

sky30 grabbed a 270,000km rb30e dropped an rb25 dohc head on it and drove it for a couple of years with 300rwkw. Then dropped it in his gts4 with a 26 head on it and drove it at 380rwkw for quite some time.

My own.. 70,000km's there are countless others. Head over to ct.com to see the 300-400 thousand rb30 turbo's still trucking.

Hey cubes, what is ct.com??

Since I've dropped the larger (gt30 .8) turbo on the amount of ignition timing it can take is quite surprising.

Interestingly it takes quite a bit more than a blokes stock rb30 n/a bottom end (8.2:1) with stock rb25 head running a gt35 turbo with slightly more boost. Unsure why his was running so little timing compared to mine. Mine with less boost and running more ignition makes the same power.

Possibly the bit of head work I've had done? Im not sure.

Ignition timing makes a big difference, even a couple of degrees is substantial. Likely that the bigger turbo has resulted in cooler intake charge and also more efficient exhaust scavenging (less restriction) so you've got a better charge.

Optimise the airflow and you don't need to throw more boost at it.

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