Rb25de Dream Engine

[sil25]

not saying you don't get advantages but there are much easier and cheaper ways to go about getting that extra response.

once those things have been done for sure look into it.

sorry to say lads but machineing and shimming buckets taking alot longer than they thought due to the increased lift. they a bit worried about bending valve shafts with the increased duration combined with vvt.

after a big weekend head will be back to me on monday, fingers crossed.

for anyone in the know what is a resonable price for a cam belt and a new set of bearings.

since the motor is apart anyway it makes sense to hit it all now.

[NA_R33]

Timing belt and idlers.. depending on who you know you will pay anywhere between 150 to 300 bucks. I want to see the results of this build.

What are you planning on revving it too?

[sil25]

obviously when you start running that sort of compression things wear alot faster if you don't do it right. thats why i've spent so much time on the head to get it right which left no money to balence the bottom end. with that in mind red line will probably be about 7500. if i can find a descent harmonic balancer i might stretch it out to 8000.

everything that i've done to date have been at a tune length. paid through the ass for tune length custom extractors. cams that have power band that line up with that and a port job that reflects that as well.

basically that means that it won't be the highest total hp i could have gotten but it will be the hardest accelerating and constatly be in power band when you drive it right.

I haven't seen an rb25 built to this extent and this quality so im interested to see what sort of power i get. i know that some of the boys here have ported rb30de's but lifting and machining buckets angel cutting all round and high compression to my knowledge hasn't been done.

if someone has seen this and can give me an idea of power to expect pleae let me no.

[NA_R33]

Sounds awesome mate cant wait for the results.

Performance Wholesales at slacks creek here in brissy sell speced up balancers for GTR's... pretty sure that it would be compatible, probably worth a look into.

[sil25]

yeah do you know what sort of price there talking?

not sure if it will be worth it at this stage. for longevity of the motor it probably is but outright speed i don't know it would be that benificial?

just got short shifter in and fitted it feels pretty nice. keen to see how she runs.

flywheel is now machined up and ready to go in. total weight 4.2kg. bit worried bout how she'll be driving around on the street but im sure once i learn how it feels it will be fine.

just checked up on head and its looking good for monday which means head goes on 20th tuned on the 23rd.

[sil25]

the exit runners on the head how important are they once you have a good set of pipes?

im tempted to tell the guy grind them out but not sure if its going to kill flow rather than help it.

has anyone here removed them and what sort of results did you see?

[Eug]

i hope you didnt machine the stock flywheel down to 4.2kg - that's asking for trouble

[sil25]

hell no thats just crazy. after market style all the way. started at 4.8kg just took bits and pieces out and balenced it with new clutch.

all the added power with such light weight fly clutch combo the short tail shaft of the sil big lsd and big tyres i can see my gearbox going boom if im not to careful.

[sil25]

sorry to disapoint boys but will be a few more days before engine is back together having trouble sourcing good quality idler bearing.

exit runners still causing concern with the flowbench readings.

looking to be back together and on the road by wed next week.

[BADR33]

have you thought about extrude honing or somthing. its where they force some hot abrasive stuff inside and it smoothes all the edges. i saw it quite a while ago in fast 4s or somthing similar

[sil25]

i looked into because it looked pretty good but the only real gains you get are in your air intake because they just can't do it anywhere else. ie your inlet manifold. so you still have to get a good porting job anyway. when i sent my head down i paid to get the inlet cleaned up anyway so any gains that extrusion honing would have gotten me i'll get, and then some.

i also wanted my inlet split to get more flow again which again you need to get done at a good porting shop.

if anyone has any more ideas like this please let me no. still keen to pick up any extra power i can and still a few days left to do so.

[BADR33]

twin throttle bodys? its been done on a couple of the rb30des on here. im just starting on it now.

or have you got somthing else planned? i cant quite rember now.

if you really wanted to try somthing totaly differnt. what about increasing the size of the intake runners? im not sure if that would be a gain or a loss. but its somthing i havnt heard about...

also what about a thin copper head gasket? to increas compression even more

oh and mb to avoid alot of blow by some oil restrictors? or mb thats just what you need for rb30s... i know i need some...

[monster]

Contact your local CBC Bearings, they do a kit which replaces your seals/idler/tensioner/belt at a great price, plus all the stuff they use is genuine... just not in 'nissan' boxes

I know, because I'm a Rep for them

Kit will set you back around the $250 mark (with racing belt)

[sil25]

damn monster your like a few days to late. grabbed a new racing belt the other day and idler bearing is on the way but thanks i'll keep that in mind, im sure i'll be building again in the not to distant future.

as for twin throttle bodies no have no plans as such, yet. seeing how this package goes then moving onto a twin throttle setup if i feel the need.

the inlet runners beind made larger was on the books but this will only be done if it shows up on the flow bench that we'll see gains. it still being played with and little things being changed and the gains are really starting to pile up.

as for the copper head gasket we've worked out all the comprension ratings to give her as much as she can handle with just a normal head gasket. bearing in mind that if an rb30 bottom end was to go on the compresion would increase again.

whats mb?

[Eug]

whats mb?

"maybe"

[johan.p.g]

what ecu u running and how are the fuel maps controled without the afm

im a bit of an idiot so prob pretty simple

[Eug]

it's not his car.

i'd expect that since the motor is in japan, it most probably would be using a d-jetro or something

[BADR33]

most people either use power fc dejetro or link if they wish to remove the air flow meter as they run map senser.

i have heard that they have stopped making dejetro though...