Rb25 Conversion Or R33

[FordyR31]

Hey guys,

I'm new to this forum but have been on R31skylineclub for almost 2 years. I have an HR31 GTS-X and am a bit tired of the way an RB20 drives and looking for an upgrade. I have tried unsuccessfully to find an RB25DET in good condition ( failed compressions tests includin a complete NEO 34 DET package for 3500 ) and have been searching for a whole package with loom ecu all running parts and 5 speed gearbox. Have had a few tested and the price was around $3500 or less however these engines have failed. I'm told a healthy engine should test at 150psi across all 6 cyslinders or within 10% os the 150. Since joining this forum I had a quick squiz in the cars for sale section and found an R33 with a rebuilt RB25 with 20,000km or til december this yr warranty that I am going to have a look at it if it doesnt sell, think the guys name on here is torus.... Any1 familiar with this car and its history? I have been told that the previous owner b4 the guy selling it now blew the motor and was told what things r on the reciept from the rebuild and it sounds like it would be a good buy for what he is asking. Anyways, my problem is I love my 31, worked and saved hard to buy it, 4 yrs, and dont particularly want to sell it but am quickly running out of patience with unhealthy RB25's.... Would it be worth spending the extra and buying the whole car, R33, or be patient and wait for the right 25 for my 31..... I may be bombarded by 31 owners calling me weak. I'm told 33's r for posers and ppl who 'just wanta skyline'... Now i'll be bombarded by 33 owners ..

Thanx

Liam

Edited July 6, 2007 by FordyR31

[Dale FZ1]

Easy.

Take a 33 for a drive. If you like it and the price suits, then buy it. If not, then don't buy one.

Any R31 owner/fan who reckoned you were weak/poseur would surely jump at the chance to be owning/driving your GTS-X; right? If not then they're talking crap and you should ask yourself some questions about listening too hard to other people's views.

[BHDave]

If it was a local 31 i'd say ditch it and get a 33, but you dont, so i won't.

Tough it out and find a decent rb25. I think you may be a bit harsh on your comp testing as an engine thats been sitting for a while isn't going to generate any decent numbers, particularly cold and consistency will be out the window.

All i checked was that there was no moisture under the cam covers, the oil in the sump was in reasonable condition (no silvery bits) and there were no aftermarket bits in the engine bay (or evidence that there ever were) and the thing turned over by hand and had a bit of compression based on feel.

But thats just me.

[The Mafia]

they're only giving you shit because they can afford to get one...

I love my r33, and I'm not owning it to be a poser, I'm owning it to run 11's....

[mad082]

a complete rb25 halfcut that is in good condition is going to cost you well over 3500. more like closer to 6000. take a 33 for a drive and see what you think. i bought mine to go fast rather than look good, that's why i kept the stock wheels, etc.

if you do convert the 31 then it still isn't going to drive as well as a 33. you would have to do brakes, diff, etc to get it to perform as well as a newer car. and then there is the changes in the dynamics of the handling.

[The Mafia]

ahhh shit

I forgot

go and get a dirty old RB30 bottom end, hone and re-ring it, and put your RB20 head on that.

Should cost you less that $500 and give you bucket loads more power. You'd only be off the road for a weekend.

I'm 90% sure the RB20 head requires absolutely no modifications to fit onto a RB30 block. Talk to cubes - he did it. Ran 300rwkw for about 12 months??

Edited July 6, 2007 by The Mafia

[1400r]

^ ah yeh no

r32 rb25de and 26 head goes straight on rest require some rejigging

[NateR31]

i was in the exact same boat as you (no 33 pun intended lol) but i droped in a series 2 rb25 into my gtsx, along with a power FC, and i wouldnt look back, but 33s are nice to drive, ive driven afew and they sure do handle nicely with out spending the big bucks on old 31s, but i say do the conversion as it will be cheaper and fun, just my 2cents

[Simon-S14]

FWIW i bought a complete RB25det package, with motor loom, ecu, tailshaft, loom, and everything i needed, including some rb20 engine mounts (mine were busted) for $3500 and it came out of the most mint half cut ive seen, this car was stock as a rock and the engine bay was so tidy and clean. so i bought it there and then after seeing it, was from japanese motorsports and its been in the car and running with not a single fault with it!

so yeah you can find good motors!

[Adriano]

For $3500 you could build an rb30 with 25 head with forged pistons

[dead32]

stick with your 31 and put a diff motor in it, or join the 10,000 other r33 owners in australia... choice is simple.

[discopotato03]

I was in a position of owning one of the cleanset DR30RS's around , the problem was always going to be the limitations that R0/R31's have in the suspension and brake dept . Sydney kid probably got sick of telling me about Nissans "Quantam Leap" from R31 to R32 . Mac' struts and semi trailing arm IRS have been overtaken by multilink designs like R32-4's have . Brake wise nothing readily available bolts on and when 5 stud hubs are a luxury the writing is on the wall . You can fit better engines to R31's but the package will be heavy and handling/breaks just so so .

I don't regret having my S2 R33 mainly because the bolt on potential leaves any R30/31 for dead , just about everything has gone through major evolutions and it shows in every way . Drive wise the R33 is light years ahead of the DR30 .

Your call .

[Al]

For $3500 you could build an rb30 with 25 head with forged pistons

Must be a pretty shit build.

[Roy]

If you know what you are doing (i dont) you could do a lot for 3,500. Labour will be the killer. Say

$250 - RB30 Bottom end

$1300 - Forged Pistons

$1200 - bearings and machining, balancing

$400 - Gasket kit

$600 - RB25DET head

Dont get too carried away with fancy oil and water pumps, ARP head/stud bolts. Forged rods instead of balanced RB30 rods etc etc and you can get it done on a budget. I wouldnt do it that way, but everyones different

[FordyR31]

Just reading a dew things there makes me think... I know u can get R31's to handle well coz a few mates of mine have done so, brake apgrades are as easy as R32 Mspec callipers being the import HR struts and hubs etc. Wieght wise its lighter than a 33, my coupe comes in a 1300kg and has all the stock trimmings. Diff wise, isnt the RS200 longnose stronger than 32 and 33 diffs? bit of a mixed reaction.

It doesnt have anything to do with what any1 else thinks. I do like how the 33's drive but they r just so common but that makes parts easier to come by. HR31 fuse box assembly from Nissan Japan cost me $160 and it is a piece of bloody plastic!

Dunno about halfcuts being 6 grand, all the ones I am priced r about $4500-$5000, $3000 for an auto half cut. I am a bit impatient sometimes and have some half decent suspension lined up for the 31 should I choose to keep it, not coilovers.

Think i'll take the 33 for a drive, I know i'll like it coz I prefer the 25's lol... seems very neat and tidy, just depends if i hear any noises that i shouldn't or find anything I dont like the look of lol.

Thanx guys

Liam

[aDrew_C]

The main problem with HR31's is the money you'll spend when it comes to specific parts, suspension being harder to upgrade etc. Luckily when once you do a conversion for the engine, you're set in that department. But personally r33's are boring and fat and too many people have them, so I went with the RB25 conversion. Any r33 I've driven with the same mods as my HR and similar power, doesn't do anything for me.

[Adriano]

Must be a pretty shit build.

Oh yeah, how many have YOU built smartarse

Im just doing a motor for a customer, RB30, ACL forgies, crank collar, r33gtr pump, cometic MLS H/G, r34 GTT NEO head, mild port job, GTR inlet cam, HKS 256ex cam, adjustble camwheels, and guess what the bill is...$3500. but i guess that is just a shit build

Edited July 7, 2007 by Adriano

[R31Nismoid]

The R200 is tough as mate. I drove mine into the ground, then simply rebuilt it. Good as new and better than it ever was (basically a Nismo diff really)

RB25 into the HR31 is a piece of cake, get a front cut then you can use the brakes and sell off any parts you dont need to cover some costs

R33's feel heavy, the GTR's even more so. My GTS-R feels a lot lighter and responsive compared to them.

It will cost about the same as buying a 33 (to get suspension/brakes/conversion etc etc). But the car will be different.

To each to thier own in that. Im HR31 all the way so im totally bias

[Al]

Oh yeah, how many have YOU built smartarse

Im just doing a motor for a customer, RB30, ACL forgies, crank collar, r33gtr pump, cometic MLS H/G, r34 GTT NEO head, mild port job, GTR inlet cam, HKS 256ex cam, adjustble camwheels, and guess what the bill is...$3500. but i guess that is just a shit build

So that $3500 includes the purchase or the NEO head, rb30 block, prepping, machining, blueprinting, bearings, gaskets, labour, etc? If so can you please provide the cost of each component listed above.

Here, i'll start it for you:

rb30 block - $100

Forgies - $800-$1200

Crank Collar - $180

Neo head - $1000 (not sure but doubt they are cheaper than this)

Prep/machining - $1200

Cams - $400

Total so far: $3700 without labour, porting, bearings, pump, gaskets, etc.

I have built none, but my rb30det build is way more than that; i guess you get what you pay for

[Adriano]

So that $3500 includes the purchase or the NEO head, rb30 block, prepping, machining, blueprinting, bearings, gaskets, labour, etc? If so can you please provide the cost of each component listed above.

Here, i'll start it for you:

rb30 block - $100 $60

Forgies - $800-$1200 $700

Crank Collar - $180 $120

Neo head - $1000 (not sure but doubt they are cheaper than this)$600(recently recod)

Prep/machining - $1200 Bore/hone, crank linish crank collar fiitting, deck, port $900

Cams - $400 $150(ex) had a spare gtr inlet

Total so far: $3700 without labour, porting, bearings, pump, gaskets, etc.

I have built none, but my rb30det build is way more than that; i guess you get what you pay for

Total $2530 + labour full kit HG 33gtr pump.

I agree, my rb30 det is a lot more than that, but im building for 450rwkw. As for the discussion, the guy is upgrading from a stock rb20, so many of the items on the above list arent even needed for 200rwkw