SKiT_R31

Hey All, I'm after an ATMO bov, to bolt directly to the stock RB25DET crossover pipe. I dont want anything special and expensive, just a replacement unit, as my stock bov is causing serious vacuum leaks, as i can no longer plumb it back (flutter isnt an option). Thanks,

Will do after the weekend. I would have gone the Jun route, but i had a Greddy style and nothing to do with it (was initially for an S13 with an RB30DET, as the stock plenum didnt clear the bonnet, but went R32 head instead). Mine was <$500 for the plenum and 80mm billet TB, almost half what the JUN style inc TB's cost, not sure how much performance difference there would be, but the JUN is definately more ideally suited for N/A due to the bellmouth's, longer and identical length intake runners. I had a look on a plenum calculator, and for peak volumetric efficiency at 6000rpm i need 12" intake runners with a 2" diameter - somthing ill make at somepoint, until then the greddy should keep me happy. Mainly wanted it for the larger TB, and to get the intake away from the hotside of the engine, as well as the benefit from a much shorter intake pipe to CAI. Not sure what it will do for VE gain, as i think the runners may be too short, time will tell . ECU is microtech LT12S, GTR loom, 550cc injectors (low duty cycle for better efficiency taking advantage of the sequential injection) fujitsumoto jasma tuned length extractors, 3" mandrel exhaust (1 centre offset mandrel glass packed perforated muffler, straight through resonator, no cat) 1.5mm gap 7 heat range plugs, upgraded coilpacks, 255, 8.3deg cams & >11.5:1 compression ratio. once its together, should be quite angry. Had this in the works for a while, but i got distracted with yet another car (30e+t) made some big numbers with it, got bored, its done now so i'm back to my N/A ways on this old project.

Ask me in a week when i get my microtech on. But a Greddy rally wouldnt be the best choice, somthing like a JUN style (with the bellmouths) would be better, as the runner lengths are identicle, its like haveing Trumpeted ITB's at WOT

Just a heads up, im guessing you've had the head welded to block the VCT oil feed? Because an rb30 headgasket and block will join that hole up with coolant.

It wont hurt the engine, it doesnt got between the plenum and the runners is goes between the head and the runners, so you would have to unbolt the whole intake manifold. It will lengthen your runners slightly, changing the effects of 'velocity-of-sound' volumetric efficiency gain, making you runners longer, will probably push your peak torque down, by how much though, i dont know, possibly 200rpm.....? Main change obviouysly is less heatsoak, which is a benefit, but the problem is, RB's have coolant flowing through the plenum, which is hot (~80 degrees) so thats where all the heat is coming from, not the fact that its bolted to your head. Cant reember how RB25's are off the top of my head, but i think they have section coolant flows through which you cant avoid, so there is probably no point adding the spacer. RB30's on the other hand, i always used to remove the coolant lines from the plenum, which would turn a too-hot-to-touch plenum into mildly warm, with a gain in performance & responce after the engine warms up. Also, cooling the plenum/runners, means your fuel wont atomise as well, colder injectors and colder fuel means more will also be injected, with the end result being increased fuel usage at light throttle/rps/ lower injector duty cycles. It's all fairly trivial, but for the ~$90 i think the money could be better spent

yeah on a 3L, and not still exactly streetable power... i just reckon you'd have more luck selling it to a bloke with a falcon

Turbo would be well suited to a high power XR6, tad laggy though

210RWKW off 9.5PSI, RB25DE+T, FMIC, 3" exhuast stock 33 ecu & injectors, highflow T3. 2500rpm full boost. Because of the high compression, it makes more power per PSI boost, so 210rwkw with no R&R (used to R&R after 10PSI though)

is the 2.25" mandrel bent? If not, I wouldn't change it just for the hell of it, do some other stuff first and when its tuned, your tuner should tell you if there is too much backpressure, and if its whats choking your engine. Can emanage ultimates alter VCT? As that will definately need adjustment for cams with that duration. But yeah, in a nutshell, your car will love those cams with the gear it has. When you get it tuned, you will see if its being choked from the intake or exaust. If i was you, as a next mod i'd put twin throttle body's on your intake manifold, shouldnt be too hard since it has the twin input Y peice as it is. Granted its higher capacity, but with alot milder cams (255/8.3), my 30DE with twin 60mm throttle's, uses every last bit. Also, with exaust, it had 2.5" press bent, with a 2.25" section (decat pipe), it made 150rwkw, but tapered off quickly, it always felt flat after peak power aswell, after i fitted a 3" mandrel exhaust (2.75" wasnt available) that was no longer an issue and it held power strong until limiter.

RB25 neo's already have solid lifters, not sure how much lift they can handle though. They also have crappy exhaust cams, i reckon you'll get a decent amount out of it with some cams. As for exhuaust, its really depends how much power you think you'll get out of it... a free flowing (mandrel, good mufflers) 2.5" really should be enough to be happy at ~ <160rwkw N/A (mandrel, good mufflers etc). Not sure how much you can get out of 2.25", but i'd guess if you were making much more than ~ 135rwkw, you'd want to increase the size. If you have future intentions for nitrous, boost, or some more serious N/A work, 2.75" wont hurt anything, just for that extra resolution (car will be happy <200rwkw). What other mods do you have? Done anything with intake? What about management? Cams like that are going to feel fairly flat without a tune, either a piggyback that handles ignition (like emanage ultimate) or full management.

In what? Hydrolic lifters wouldn't find it amusing, should net a nice amount of power extra though, eith larger TB and free flowing exhaust

ignore, free bump

uhk, ill be using the RB26 loom, so rb20 have the same as the 26? As i have an rb20 silvertop ignitor sitting on my fridge...

What about ignitor?

awesome, thanks for that. The car doesnt need a bullet proof race tune, just needs to be able to limp to tuner, and workshops

So the CAS is definately different? Does it have a different output, or is it just a different plug..? Can i put a GTR CAS on an RB25? I'm in tas, and my preferred tuner is good with microtechs, and i need a map sensor for my setup. To throw a spanner in the works, its for a 25/30, N/A... with fairly lumpy sticks in it, so vct isn't too much of a concern, but an external controller, or custom tuning one of the extra outputs and manually wiring it could be the solution for that. Knock sensors, fair enough, but once again, not overly concerned, as it is N/A, and i want it consistant. Car made 151RWKW with less compression, choked intake breathing hot air, and restrictive exhaust (2.25" press bent, triple chambers), crap headers, on stock management. It now has twin polished 60mm tb (mandrel 2.5" pipe) CAI's with no afm (OR will have jun bellmouthed front facing plenum with 80mm throttle body, ill test performance and output from each), fujitsumoto tuned length large primary headers, joining into a 3" mandrel single muffler (mandrel perforated centre offset) exhaust, had about 40thou taken off the head, spark plugs indexed facing intake valves, cam timing adjusted and accessories underdriven. so anyway, the injectors..., if i have the same injectors with different impedence, it will still work? Appart from that, the cas will be the issue? can anyone confirm? Also at somestage ill build another engine with a better bottom end (oversize lightweight pistons/rods, balance), and plonk on a 26 head (for the solid lifters) with some headwork and ITB's on it and push the peak power up 1000rpm or so... Meaning ill make adapters for the loom, so the whole 26 setup is neater. Cheers,

Hi, I'm looking at buying a Microtech ECU for my RB25, one has come up for sale cheap with a hand controller and loom, tuned for an RB26DETT. What issues will i have? Obviously the AFM's arent an issue, as microtechs run off MAP sensors, is the only other issue ill have with the injectors? Anything else that might be different? The ECU is mapped for 550cc injectors, which i have in my RB25, but i think the 26's would be low impedence, whereas my injectors are high impedence, this shouldnt be an issue on the microtech as its compatible with both?? So all i have to do is swap the injector plugs? Is the ignitor different, idle gear, cas? thanks in advance

anyone got redtop cams they don't want anymore ?

I think the 25det bottom end is reliable to around 7500rpm, lightweight pistons will reduce the pull on the rods giving you a few hundred more rpm. The stock cams will rev that high, but will be way out of their power range, so you will need some higher duration shafts, 270's ought to do it.... You may have issues with valve float, so to be safe you might want new valve springs. Past 8000rpm, esp with cams and increased lift, your going to have issues with the hydrolic lifters, which is something you don't want, do you will need to convert them to solids. If you are revving to 8500, it would be wise to balence the crank, fit new bearings, a higher flowing oil pump, some thinner oil, billet flywheel and aftermarket balancer, as well as under drive pulleys on all your accessories... You will encounter breathing issues with your cams and higher rpm, so twin throttle body's might be a good idea, or a front facing bell mouthed plenum (jun style, should feed them higher revs nicely) and 80mm throttle OR at least a 68mm XF jobby. quite an expensive excersize. Alternatively, you could drop an RB26DETT head straight on it, sfa modification (head studs, you lose vct, and will have to weld an RB26 header plate on your extractors - which you will need to purchase, but is definately you bang for buck, as it contains the cams, valve springs, ITB's (throttle flow) and lifters you require. On an N/A you might be able to getaway with another 1000rpm to standard, I'm not really sure what 25 bottom ends are good for, its not like you would be putting a lot of power down. With the 26 head there is no reason you couldn't run all the 25 gear. An RB25DE Mines ECU should have the limiter removed, or at least raised a lot, i know i never found the limiter on my mines ecu, but was never game to take it past 7400rpm (adjusted cam timing with aftermarket 256deg cams took me there) also any form of full aftermarket management will let you move or remove the limiter. OR forgetting all of the above, if you are just after rice points (which is fair enough, each to their own ) fit a mandrel bent 2" exhaust system (it can flow enough for a stocker 25de don't you worry) with a mandrel center offset muffler or 2 (pending req'd volume) AND NO CANNON, then simply fit an aftermarket tacho (or modify the stock one) to work in 4 or 5cyl mode, you will see your glorious high rpm, and your car will sound like it is screaming.

hey man, can you PM or post up some pics?

I've got an RB25DET........

The cast's mightr be made in china, but the assembly and balancing is done in aus, and thats what counts. it doesnt even have any rear wheel balancing, its a knock off of the original kkr design (with water cooling) i it wouldnt last one dyno run on my car. Not good for anything but the bin.

Item recieved in good time, packaged well, HOWEVER.... IT IS NOT A GENUINE KKR, IT IS A RIP OFF TURBO! Either you are lying about purchasing this from otomoto, or they have ripped you off. KKR's are an excellent turbo, australian blananced and assembled, and make good power, their only downside is they arent suitible for dosing or flutter (you need a BOV) as it dramatically reduces lifespan. Turbo's like the one is received however, are chinese (as in my case 'TRS', built in shanghai) peices of horse shit , made in sweatshops by children. Very few actually last more than a few thousand KM before they shit their seals, or if pushing high boost, shit a shaft/wheel.

$550 for thew KKR430 posted to tasmania

I'm interested in them though, you up north or down south?