silver_7

Does anyone know the process of swapping the rb26 motor in the rx7? Or is there a site or website that I can look this up? Thanks any info would help.

NOPR

someone did it, im not sure why you'd want to though. that engine is seriously heavy

KaoticFdR1

Search first.....i'll point in a company acosta motorsports look to spend around 72k

digitalsolo

iTrader: (2)

LOL, and if you want to spend that much money, supply the car, engine and 10K to me and I'll give you a RB26DETT 7.

rarson

You can probably pick up an RB26 for pretty cheap, less than 4k. Go for an RB25 and you'll probably knock up to a thousand off that price. Usually the 25 will come with a RWD tranny while the 26 won't (since it came with an AWD tranny) but I have seen quite a few places selling the 26/25 engine/tranny combo.

After that, it's just a matter of getting a custom driveshaft ($400-600) and making some engine mounts, then getting the thing to run.

It'd probably be a lot easier to use the RB25DET, since it's less complex and uses HLA's instead of solid lifters. The two engines, when modded, are so close anyway that there's no real advantage to going with the RB26.

It's not all that heavy; I'm assuming the engine weighs less than a 2JZ since it's got a smaller bore spacing. There's a lot of cool things going for that engine (stock COP, cam-on-bucket, etc.).

KaoticFdR1

but the parts for that engine from what i've heard aren't anywhere near cheep and difficult to source.

rarson

Well, not too difficult to find, but expensive since they're all coming from overseas and there is a smaller market for the parts. A 2JZ or even a 1JZ would probably be a better choice if parts availability and cost is a concern.

Nihilanthic

Id just like to step in and say the high deck height would probably make it a bitch (hello hood scoop or cowl or bump or buldge!), and 4-6 hundred for a DS is a little... high.

It would be a great drag/highway toy, but considering what you would have to do to it to make it really handle and shine in the kind of classes you would be put into (E-Mod) it would be kind of a waste of time to do anything but NASA type racing (thier classes seem more open), HPDE, and.. highway ****.

rarson

Sorry, I should have clarified, I was referring to a custom aluminum driveshaft (The Driveshaft Shop can make whatever you need). I mean, if you're going to do it, you might as well do it right.

I'm not just talking about the performance advantage of the aluminum driveshaft, but also of the twisting ability versus a steel unit.

Nihilanthic, I'm curious as to why you bring up classes, since no one else didn't. I'm assuming 95% of the people asking these sort of questions are planning on building such a car solely to drive on the street and have fun with. And probably 98% of those people will never actually do their planned swap.

I don't think deck height would be much of a concern for the RB26, at least not in an FC. I'm not sure, but I really doubt the engine is taller than a 2JZ.

wpg_gtr

correct in some respects, but the problem with the RB25, is that the intake manifold curls over the top of the engine, making a height problem.

incorrect.

the RB26 has a much more advanced cylinder head. also the bottom end is alot stronger, and alot more balanced. the water passages in the block and head are also alot more efficiant. there is also alot more availible for aftermarket.

in an RB25, to hit 400whp, you would need an aftermarket turbo, intercooler, intake/exhaust, and most likely better cams.

in the RB26, you can hit 400whp simply with intake, exhaust, and just turning up the boost on the stock turbos to 14psi.

i have a spare RB26 in my garage, so when a local was selling his FD shell for $4000, it was very tempting to try the swap.

i took the measurements, and i found that the RB26 engine would fit very easily. but i can imagine that the RB25 would not fit due to the intake manifold (but i didnt have an RB25 handy to measure.

i passed up on the FD shell. i think if i was going to do something crazy, i would try the RB into an RX8. nobody in my town would mess with an FD, but everyone knows that RX8s are slow, and cant be made fast. ultimate sleeper!

rarson

Right, but if a thing's worth doing, it's worth doing right. I'd go with a Greddy intake manifold and Q45 throttle body, which would alleviate the problem.



Yes, but all those mentioned things, besides the aftermarket, don't make a whole lot of difference for a typical project/daily driver. The RB25 can easily make numbers in excess of 500 whp, so why worry about all that other stuff? The RB25 head isn't that bad either.

Not such a big deal. For reference though, I've got a friend making just around 400 whp on the stock cams.

Um, have fun with that. The ceramic turbine wheels have been known to shatter at reasonably higher than stock boost levels.

Hehe... Yeah, I'm not saying that the RB26 isn't a great engine, and in a lot of ways, it is much better than the RB25. But for the average guy who doesn't want to mess with valve lash adjustment on a solid lifter setup, the RB25 makes a lot more sense.

That would be really awesome to see the RB26 in an RX8. A lot of people think the RB26 is just some overrated Japanese crap, but that's pretty damn far from the truth.

wpg_gtr

i dont disagree. but the amount of money you would spend to get a RB25DET to make 500whp, you could have an RB26 making 600whp, and with a superior powerband too.



for the R32 GTRs that are now reaching 13-17 years old, yes the OEM turbos dont like holding up in high temperatures, past 14psi. i have my 1990 GTR running at 14psi, along with nearly every other stock-turbo GTR in canada. and no problems, as long as you keep it under 14psi. and 400hp is attainable at that boost level


agreed, but should the 'average guy' really be attempting a money-pit swap. the RB25 certainly isnt anything to sneeze at, but you cant expect an RB powered car to be a reliable daily driver. and unless you had about $20k cash, i wouldnt dive into such a project.

and if 500whp is your goal, then the RB25 is the wrong engine to be looking at.

you would definately have to upgrade the pistons, rods, and all the fasteners. then you would need more aggressive cams, and valvesprings (for the higher lift). you would also need a better intake manifold, and TB (greddy + Q45 like you said). then you would need to upgrade the injectors, and pump. then you will need tuning. (that still doesnt cover the oilpump problem, it wont lube the engine fully at that power).

now if you allow for $1500 for a good turbo, thats about $10k ontop of whatever you paid for the RB25 itself.

if you wanted to spend the same amount on doing an RB26, watch this, i can even include the engine itself for that price.

buy a Mine's R34 Nur engine package (its a Nur-spec engine built by Mine's garage, its made from a Nismo N1 block) its $10,000. it comes with the engine, R34-N1 turbos, Mine's ECU, Mine's cams, and a Mines headgasket. now because the R34-N1 turbos only support 500hp max, you can sell these for about $3000 (going rate). you could probably also sell the Mine's ECU for $700. now take that money, and buy a pair of Garrett GT2860R turbos for $1500 (bolt right in, and good for 650whp). with the money left over, you can buy a standalone of your choice, and you have everything you need to make 650whp.

not only do you have a better powerband, more power, and quicker spool than the RB25 would have, you spent alot less. and the reason doesnt have to be that the RB26 was a 'better engine'. it is a better choice, because of how much more easily attainable higher power is, and about 50% of that factor is because of better aftermarket support.

there are many garages in Japan that put togather good-value RB26 packages. the reason they wouldnt do that for the RB25 is because it would cost more, for no advantage. people who build high power RB25s, its for a very specific reason.

rarson

Lots of good stuff, thanks for the info. And I agree completely. While the RB25 would be the RB of choice for a "budget" swap, an RB swap at all isn't really budget, which defeats the purpose.

Speaking of RB26 builds, is there any crazier privately-owned vehicle than the one at www.exvitermini.com?

wpg_gtr

yeh exvitermini have done some amazing things. going 2.8L (longer stroke too), keeping it twinturbo, and revving to 13,000 rpm... i can only dream

and yeh, i agree. the Rb25 is a great budget swap. its a great alternative for 240sx guys, who want to avoid the mediocrity of an SR20 swap. even the RB20 is a great engine for that purpose. but for an FD, you could do better with a Rotary.

theres a local guy here that has an R32 GTS-t with an RB20 running over 25psi from a fairly large turbo. he doesnt say how much power though. im guessing over 400whp.

rarson

That's pretty cool. I'd definitely go with an RB20 over the SR20, for the extra weight it's a much better engine (sounds a lot better, too).

silver_7

Wow...thats a lot to consider. Plus it would be a tight squeeze. Oh well something I was tossing around.

R.P.M.

iTrader: (3)

Here, check this out:

https://www.rx7club.com/canadian-forum-42/boring-night-shop-lets-see-what-fits-rx-7-a-601776/