R33 Rb30 Conversion

[r33_racer]

brad can hook you up with some sweet cp pistons...great price.

free plug mate

Edited August 13, 2007 by r33_racer

[GTRgeoff]

Yep, this is your man. I used his gear.

http://www.skylinesaustralia.com/forums/in...hp?showuser=220

[Brentmcd12]

Okay! so it has taken me 1 entire month and a lil longer to read through this ENTIRE THREAD!!

so !

i have 93 RB25DE VCT in my R31 skyline..

i have a RB30 block all stripped apart and ready to go for a acid bath...

i will be usuing the 25de pistons so i should get around 10-5-1 comp ?

i am usuin tomei pon cams type b with exaust side adj cam gear...

also buyin harder valve springs and valves

i will have my VCT connected and working..

i will be usuing the RB25DE oil pump with the tomei oil restrictor...

i have a N1 waterpump

ummm std injectors DE afm extractors custom 3" intake 2.5hiflow cat back exaust

will be eventually tuned on my wold 3d V3... just need a loom for it..

i will get back with all the prices i have been quoted on for the gasket kit n piston rings n main bearings n all the other build parts...

anything anyone else can reccommend while everything is out and i am doing this conversion ?

it is staying NON TURBO... RB30DE

cheers..

brent

[Adriano]

Congrats on reading the full thread and not asking 100 dumb questions.

Youll need to dek the block to use the rb25 pistons, but thats no big deal.

I would look ino sppending a little more on the camshafts, and getting a pair made, Tighe Engineering in queensland are doing a pair for me $880 for whatever grind i want, just that the poncams wont give you the full benefit, as your NA You could easy go to 280-290 deg without dramas.

May be well worth trying something like the ebay greddy copy manifolds, with a Q45 throttle body, as you need to get as much air in as possible.

The rest of it looks great, and if you need to upgrade the injectors later on, det injectors willl be easy to source(i dont know if they are bigger though)

[mr_rbman]

Congrats on reading the full thread and not asking 100 dumb questions.

Youll need to dek the block to use the rb25 pistons, but thats no big deal.

I would look ino sppending a little more on the camshafts, and getting a pair made, Tighe Engineering in queensland are doing a pair for me $880 for whatever grind i want, just that the poncams wont give you the full benefit, as your NA You could easy go to 280-290 deg without dramas.

May be well worth trying something like the ebay greddy copy manifolds, with a Q45 throttle body, as you need to get as much air in as possible.

The rest of it looks great, and if you need to upgrade the injectors later on, det injectors willl be easy to source(i dont know if they are bigger though)

is this a typo? Tighe did mine for $290 for the pair!

[Adriano]

is this a typo? Tighe did mine for $290 for the pair!

No, these were new billets, not regrinds

[Godzilla33]

Who's good in Brisbane for crank work? need to get my collar fitted, crack test, balance etc.

[Spoolup]

Crankshaft Engineering.

They can fit it - or build up the snout.

[Alf]

Im after opinions on diff ratios, what do you guys use?

I have a 32 gtst with a soon to be:

25/30 with 9.2:1 comp

256 cams

33 GTR 5 speed converted to rwd

GT35R (0.82)

Aiming for around 330rwkw mainly for the street.

I'm looking for a ratio that is ideal for the street and is highway friendly.

With the current 20det the revs sit on 3k at 100ks, It'd be nice to drop that down to 2k or a bit less to save on fuel and engine wear.

Cheers Alf.

Edited August 20, 2007 by Alf

[r33_racer]

1000rpm is a big drop.

[BOOST ON]

you might get away with 2500 but i dont know about 2k, even with the 3l it will be abit doughy on the highway at 2k

[Cubes]

The 25t box has a slightly longer 5th ratio than the 20t box; unsure what the ratio is within the gtr box. But to give an idea.

(Ignore what your tacho says; they read high. Consult the pfc rpm display)

4.363 ratio at 100km/h is 2757 (146km/h in third @ 7000rpm)

4.11 ratio at 100km/h is 2597rpm (155km/h in third @ 7000rpm)

3.9 ratio at 100km/h is 2464rpm (163km/h in third @ 7000rpm)

3.69 ratio at 100km/h is 2332rpm (173km/h in third gear @ 7000rpm)

I went from a 4.363 to a 4.08 a noticed a drop in off boot torque; out of corners etc the car felt lazier and spent more time trying to accelerate through any lag. Essentially it made the car feel more laggier. Accelerating off the line the car felt much nicer in first gear and appeared to accelerate better even though it would wheel spin but second and third + didn't feel as responsive.

So.. I dropped the 4.3 ratio back in and it is a much more enjoyable sporty drive.

I don't do much if any highway cruising so the drop in 100km/h cruise rpm didn't affect me.

Once making some decent power the longer ratio 'may' be worth while as it will help getting it hooked up. I noticed it felt as if it was easier to control wheel spin in first.

[Alf]

The 25t box has a slightly longer 5th ratio than the 20t box; unsure what the ratio is within the gtr box. But to give an idea.

(Ignore what your tacho says; they read high. Consult the pfc rpm display)

4.363 ratio at 100km/h is 2757 (146km/h in third @ 7000rpm)

4.11 ratio at 100km/h is 2597rpm (155km/h in third @ 7000rpm)

3.9 ratio at 100km/h is 2464rpm (163km/h in third @ 7000rpm)

3.69 ratio at 100km/h is 2332rpm (173km/h in third gear @ 7000rpm)

I went from a 4.363 to a 4.08 a noticed a drop in off boot torque; out of corners etc the car felt lazier and spent more time trying to accelerate through any lag. Essentially it made the car feel more laggier. Accelerating off the line the car felt much nicer in first gear and appeared to accelerate better even though it would wheel spin but second and third + didn't feel as responsive.

So.. I dropped the 4.3 ratio back in and it is a much more enjoyable sporty drive.

I don't do much if any highway cruising so the drop in 100km/h cruise rpm didn't affect me.

Once making some decent power the longer ratio 'may' be worth while as it will help getting it hooked up. I noticed it felt as if it was easier to control wheel spin in first.

Way back in this thread SK has stated that the ideal diff ratio is 3.7 for circuit racing. I'd assume this would be using a higher comp and different box than yours Cubes.

ps: I'll using a 33 GTR box (suited to 4.1 diff gears) with the 25/30.

3.9 is looking good.

Edited August 20, 2007 by Alf

[RB120WHY]

I have a clearance problem in my car... Does anyone know where to get a single belt pulley from to suit RB30/26 ??

I had to "modify" when i was RB20, but would prefer an off the shelf item if available. I have no a/c or power steer to run.

[shanef]

harmonic balancer?

i nkow the front pulley is rmeovable on the ross ones, not sure if the other 1 is or not, also not sure on the ATI ones

[RB120WHY]

harmonic balancer?

i nkow the front pulley is rmeovable on the ross ones, not sure if the other 1 is or not, also not sure on the ATI ones

You skyline drivers have a 3 belt pulley system off the harmonic balancer to run alternator/air conditioner/power steer belts. I only require the 1 for the alternator and need it to be only 1 as i have minimal room to play with.

I will google "ross" and "ati" and check it out.

Cheers

Steve

[Alf]

Found some gearbox/diff ratio spreadsheets that might come in handy, dunno how accurate they are tho.

R33 GTR

http://www.sol.co.uk/h/hugh/R33%20Speed%20...alculations.xls

R34GTR

http://www.sol.co.uk/h/hugh/R34%20Speed%20...alculations.xls

OS Giken

http://www.sol.co.uk/h/hugh/OS%20Giken%20U...al%20ratios.xls

Edited August 21, 2007 by Alf

[RB120WHY]

My list of parts so far for RB30/26...

HKS inlet cam - 264/10.0mm lift

HKS exh cam - 272/10.0mm lift

HKS step 2 valve spring set

HKS cam gears

HKS 680cc injectors

HKS fuel rail kit 11.0mm

HKS adj fuel pressure reg

ARP 2000 head stud kit

Cometic metal RB30 head gasket

Garrett GT35R 0.7in /1.06 ex

Engine goes into the builders next week and i'm undecided on pistons as yet, but i think i want about the 8.2 compression ratio. I'm in the hands of the engine builders expertise now. *fingers crossed*

[shanef]

maybe whack in some arp main studs, at a bit under 200 its a bit of safety with a build like that

also what size head studs u go for? 26 ones and re-tap the block? or 25's and live with the slop...

[RB120WHY]

maybe whack in some arp main studs, at a bit under 200 its a bit of safety with a build like that

also what size head studs u go for? 26 ones and re-tap the block? or 25's and live with the slop...

202-4207 to suit RB26...

Yeah i will fit it out with the arp gear down below. Better safe than sorry

Edited August 22, 2007 by RB120WHY