25gt - Barra

[pavilionbucket]

Hello lads, a naïve p-plater here.

I've had an unholy thought of swapping the rb25 for a barra once it goes out (whenever that happens, sitting on 215k atm, i know these engines are resilient).

Has this been done before? Any tips or should i steer clear and buy a gtt, cheers

[GTSBoy]

It's as sensible as any other modification to an NA Skyline, You're going to need to put in an LSD, gearbox, tailshaft and brakes to make it happen, same as if you turbo'd or turboswapped an RB.

And then it will sound gross like a Falcon. But if you don't mind that, go ahead.

It has been done. You can probably search up some examples, although there won't be too many of them here. Just out there in other forums and the tubes and so on.

'twere me doing a complete engine swap.....I'd be looking at a Mercedes V12.

[Duncan]

Yeah I did hear of a few barra conversions starting....never heard of too many actually completing.

There isn't really much benefit of the engine they came with, and the barra is a big engine for a relatively small engine bay.

It will be far "easier" to +T your GT, that is a well worn route. Even then it will still cost more than you expect so start saving!

[pavilionbucket]

Hm, by the sounds of things I might just drive this till failure and buy a more powerful skyline later on...

I've done my reading and the consensus with any engine replacement for this drivetrain is bleak. Although it seems that with GTTs disappearing like dodos it is an actual viable option?

Edited March 31, 2024 by pavilionbucket

[Kinkstaah]

I thought about barra'ing mine when I put the LS in.

To be completely honest, there's no real way of it being sensible unless the car you want literally does not exist (mine didn't at the time.)

But for a barra to work, you more or less need the entire drivetrain and electronics and a lot of know how, not to mention if you want to do it right you're going to need specalist fabricators to do things like exhausts, aircon custom setups etc, including wiring. It's really not for the faint of heart.

In 2024, your money can go into far more sensible car places. It'd be SO simpler to get a FG and lighten it and call it a day, or get a Mustang. Or if you want something lighter, a MKV Supra is going to save you a lot more sanity for probably the same total price once you're all in.

A modern GTT is either the MKV Supra or something like a 240/440i with the B58 and ZF8. They can be had for outrageously cheap, relative to this thought experiment.

[pavilionbucket]

2 hours ago, Kinkstaah said:

To be completely honest, there's no real way of it being sensible unless the car you want literally does not exist (mine didn't at the time.)

It might not be sensible but my goal is to keep the r34 coupe body functioning as long as possible. A better question I should of asked is what is a sensible engine replacement once the rb25 goes? This could happen in 5-10 years and my thought was a barra initially because of its availability and rep.

2 hours ago, Kinkstaah said:

In 2024, your money can go into far more sensible car places. It'd be SO simpler to get a FG and lighten it and call it a day, or get a Mustang. Or if you want something lighter, a MKV Supra is going to save you a lot more sanity for probably the same total price once you're all in.

True, but I am keen to spend time working on a car - especially one I adore, i'm not that concerned with power output just the thought of engineering your own car seems awesome

[GTSBoy]

25 minutes ago, pavilionbucket said:

what is a sensible engine replacement once the rb25 goes? This could happen in 5-10 years

That is so far in the future that the question is meaningless. 5 years perhaps not so much, but 10 years is well into the possible territory of "how dare you try to register a car with a petrol engine conversion you environmental savage you!?!**"

**Won't somebody think of the children.

Also, I would not expect an NA RB25 to ever die. 1 million km is not unreasonable. I don't know why people keep expecting Jap engines to die.

[pavilionbucket]

25 minutes ago, GTSBoy said:

That is so far in the future that the question is meaningless. 5 years perhaps not so much, but 10 years is well into the possible territory of "how dare you try to register a car with a petrol engine conversion you environmental savage you!?!**"

**Won't somebody think of the children.

Also, I would not expect an NA RB25 to ever die. 1 million km is not unreasonable. I don't know why people keep expecting Jap engines to die.

Haha true, if that's the case im a happy camper with my n/a

[admS15]

@MBS206 has or is still doing this conversion into an R33, similar enough. I'm sure he can let you know more about the process and requirements.

[admS15]

If I was you, I'd bolt on a turbo to the de with supporting mods, dial in enough boost for around 280-300kw and enjoy. Deal with gbox replacement if or when it blows.

[morboost]

https://www.gumtree.com.au/s-ad/somerton/cars-vans-utes/nissan-stagea-barra-swap-engineered-/1317457589

would be much the same as this stagea just buy it

[morboost]

my mistake I read 250gt

[morboost]

like i tell all p plate na owners just buy a turbo engine and put it on a engine stand and build it up till full licence with the view to swap it in, the thing about doing this way is when people give you crap for having a slow skyline you get to tell them about this mythical phantom engine you have in the build.

[Kinkstaah]

2 hours ago, morboost said:

https://www.gumtree.com.au/s-ad/somerton/cars-vans-utes/nissan-stagea-barra-swap-engineered-/1317457589

would be much the same as this stagea just buy it

@pavilionbucket this ad with it's last two images is a good insight into how much a barra swap would cost. Once you get started, and if you have a mind to do things 'correctly', this is the outcome.

[MBS206]

The low down on this is, it's not terribly hard.

Mine isn't finished as I don't have money to drop, or when I have money, I don't have time (I don't pay people to play cars for me).

 

But if you have the money:

Engine mounts are available off the shelf. I made my own, to get the engine even lower. The mounts aren't expensive.

Gearbox mounts for 6 speed ford box are available off the shelf.

For about $1,500 a custom wiring loom can be built for you (I modified my own factory Ford one) - Hootons Harnesses is my recommendation here.

For about $400 someone will unlock the ECU for you.

For about $100 you can get a bolt in accelerator pedal bracket.

You will need a new radiator, or to modify an alloy skyline radiator.

You need good thermo fans and a shroud made (electric fans).

You'll need a custom tail shaft made. $1000-$1500?

You'll need custom intake made, and a custom exhaust.

You'll need a FMIC setup and intake piping to suit as part of the above.

Custom PS lines, few hundred $$$

Then you need an engine and gearbox, these are not what they were worth when I bought mine, and I haven't looked super recently, but for an FG XR6T with Y speed manual, plan for a minimum of $5k, for second hand, 200k km + motors. Yep, expect to be looking at rebuilding the motor.

Oh, and if you've gotten this far, and spent probably close, or over $10k in parts (before an engine rebuild, of which you should do a few mods to that motor even if you don't rebuild it) if you can't do the work yourself, throw another $10k in labour in, and then expect to have lifelong issues.

Personally, the Barra fits and is easier than an LS swap.

However, if you're looking for the "best" motor you can swap in, and not a budget limit, no BS, I'd 100% start looking at crate EV motors... Until you drive a decent EV, you've no idea how quickly they'll obliterate an ICE engine in a straight line and around a curve. However, don't expect to be able to do heaps and heaps of laps at a track day, as batteries will warm, and the control unit will lower power output when they get hot. However, daily driving, long term ROI, and avoiding potential issues with old ICE car tax in the future, it's a great plan!

 

But an EV swap will suck the life and soul out of your skyline...

 

[Kinkstaah]

1 hour ago, MBS206 said:

Personally, the Barra fits and is easier than an LS swap.

However, if you're looking for the "best" motor you can swap in, and not a budget limit, no BS, I'd 100% start looking at crate EV motors... Until you drive a decent EV, you've no idea how quickly they'll obliterate an ICE engine in a straight line and around a curve. However, don't expect to be able to do heaps and heaps of laps at a track day, as batteries will warm, and the control unit will lower power output when they get hot. However, daily driving, long term ROI, and avoiding potential issues with old ICE car tax in the future, it's a great plan!

But an EV swap will suck the life and soul out of your skyline...

There's no way it fits and is easier than a LS swap. It basically has exactly all the same elements of doing a LS swap though, though the Barra is a bit bigger and you have to worry about Turbo things (and rebuilding/looking at the motor to make RB power unless you get a late model barra).

I wanted to do the Barra thing, but the main reason I wanted to walk away from the RB was dealing with turbo problems at the track with turbo lines, overheating, space and all that. I told myself that if I really wanted a turbo I could have a turbo LS, and that doing the LS would be fundamentally simpler :p

I say ad nauseam:

Getting it to work is easy. Getting it to work well is extremely hard.

EV's powertrain is supreme, it's instant peak power all the time with no downsides. Around a curve though still a lot remains to be desired. However, if the weight issue becomes solved, I can imagine a track day where you do your 20 minute session, then charge for 40 minutes for your next session, and away you go again.

That said that is a niche situation for 99.9% of people. However a lot of the 0.1% are on this forum. :p

[morboost]

18 hours ago, Kinkstaah said:

@pavilionbucket this ad with it's last two images is a good insight into how much a barra swap would cost. Once you get started, and if you have a mind to do things 'correctly', this is the outcome.

so true in current year 30k to do and engine conversion, I don't know why they bothered could of just turboed a babf wagon i guess 40k is better than having a roof liner fall down, solid axle would get the power down and manual swaps are easy in falcon, not my car not my money not my brain, meh.

Ev r34 would be cool, I just looked at the tesla battery 20-40k weight 480kgs a 2ton skyline would need r35 brakes, te37s the floor cut out, tube/boxed frame and cage, 15k tesla engine, wiring, engineering, custom coilovers. A guess 100k with a range of a barra on e85 but instant toque.

To op if you change your oil regularly and carry out timing belt changes, dont over heat it, a na rb25 will do twice the k's you have now, the 2k barra meme is over you wont save more by doing a swap, reco it if you damage it, honestly your more like to crash it then blow it up.

[MBS206]

On 4/2/2024 at 9:36 AM, Kinkstaah said:

There's no way it fits and is easier than a LS swap. It basically has exactly all the same elements of doing a LS swap though, though the Barra is a bit bigger and you have to worry about Turbo things (and rebuilding/looking at the motor to make RB power unless you get a late model barra).

I wanted to do the Barra thing, but the main reason I wanted to walk away from the RB was dealing with turbo problems at the track with turbo lines, overheating, space and all that. I told myself that if I really wanted a turbo I could have a turbo LS, and that doing the LS would be fundamentally simpler 😛

I say ad nauseam:

Getting it to work is easy. Getting it to work well is extremely hard.

EV's powertrain is supreme, it's instant peak power all the time with no downsides. Around a curve though still a lot remains to be desired. However, if the weight issue becomes solved, I can imagine a track day where you do your 20 minute session, then charge for 40 minutes for your next session, and away you go again.

That said that is a niche situation for 99.9% of people. However a lot of the 0.1% are on this forum. 😛

It's easier to get the Barra to fit, than an LS.
There's more room to fit the exhaust past the steering column with a Barra, then there is with the LS.

Engine fits in with a radiator, it's "tight" but not really any tighter than some modern cars these days.

 

While you talk about making RB power, the part most people don't really notice, is the amount of torque they make. They make power lazily like the LS does.
IE, look at a Barra NA motor from a BA, makes only a couple of KW less than an RB25DET, EXCEPT, it also makes an extra 100nm of torque.

 

Barra makes power, lower in the power band.

If you make the same amount of power in motor A at 5,000RPM, as you are at 6500RPM in motor B, (Barra A, RB B in general), than that is already showing an additional 30% torque, as you're passing 5,000RPM. 
When you also match the barra gearboxes, and retain skyline diffs, you end up with even more fun, as you end up with some pretty short ratios

But yes, after having an LS in the engine bay, and a Barra in the engine bay of the same car, yep, the Barra is definitely easier to drop a Barra in.

Plus, not many twits on this forum would put an LS in and then not add two turbos into it
However, there's also less twits on this forum who'd put a Barra in and not turbo it either.... But I think we found both of them

[MBS206]

On 4/2/2024 at 9:36 AM, Kinkstaah said:

There's no way it fits and is easier than a LS swap. It basically has exactly all the same elements of doing a LS swap though, though the Barra is a bit bigger and you have to worry about Turbo things (and rebuilding/looking at the motor to make RB power unless you get a late model barra).

I wanted to do the Barra thing, but the main reason I wanted to walk away from the RB was dealing with turbo problems at the track with turbo lines, overheating, space and all that. I told myself that if I really wanted a turbo I could have a turbo LS, and that doing the LS would be fundamentally simpler 😛

I say ad nauseam:

Getting it to work is easy. Getting it to work well is extremely hard.

EV's powertrain is supreme, it's instant peak power all the time with no downsides. Around a curve though still a lot remains to be desired. However, if the weight issue becomes solved, I can imagine a track day where you do your 20 minute session, then charge for 40 minutes for your next session, and away you go again.

That said that is a niche situation for 99.9% of people. However a lot of the 0.1% are on this forum. 😛

Also, meant to say, on the EV side of things, the weight part is definitely an issue regarding EV acceleration, but oddly, if you're smart, you can get the car to handle REALLY well. All that weight, is mounted stupidly low. Also, how awesomely you can get a 50/50 weight balance properly! And you might not have all the power in a straight line, dayum, you can make some ground up in a corner with low CG and better weight balance!

Oh, add to that, companies now starting to do EV Cars with quick swap batteries, like the way bike companies have done EV bikes. Would be a good setup for track days, and even endurance races, just need some better cooling for longevity of power...

Also the 10/15 minute session and charge for 45/50 minutes could work if the race tracks had some normal 3 phase chargers. Even better if they had a HUGE charger like the BP Servos do...

[Kinkstaah]

12 hours ago, MBS206 said:

It's easier to get the Barra to fit, than an LS.
There's more room to fit the exhaust past the steering column with a Barra, then there is with the LS.

Engine fits in with a radiator, it's "tight" but not really any tighter than some modern cars these days.

While you talk about making RB power, the part most people don't really notice, is the amount of torque they make. They make power lazily like the LS does.
IE, look at a Barra NA motor from a BA, makes only a couple of KW less than an RB25DET, EXCEPT, it also makes an extra 100nm of torque.

Barra makes power, lower in the power band.

But yes, after having an LS in the engine bay, and a Barra in the engine bay of the same car, yep, the Barra is definitely easier to drop a Barra in.

Huh! TIL I guess. I found that the LS fit easier than the RB does. There was questions about getting around the steering side of things, but in the end there's plenty of space, even though it looks like there's no way before headers actually get made up.

I remember sitting in a XR6T at a tuner when we were getting fuel, and hearing the BOV do it's thing at like 8kmh in 3rd gear and thinking "This is just absolute bullshit, this is a whole nother level than a RB"

But hey. I also wanted less transient lag. A barra still has _some_

But generally speaking, you need to do the same things with a LS swap that you would need to do with a Barra swap.

I'm with you on EV's, and they all handle great for what they weigh.

However, they still outweigh their ability to carve up a track, especially for say an interval that's longer than a 5 minute session which is still a non-starter for track people. Nobody would accept a 5 minute session for a full track day.

However on a single hot lap, can't really argue that a Model S Plaid being in the same conversation space as P1's, 918's, Huracan Track specials is incredible. And that's as is.

In a world with lighter batteries, a scenario where a car makes 3000KW if you use its battery charge like now, but it's restricted to "only" dispense 1000kw max, and weighs half as much, put in a sports car chassis? That "next step" is amazing, potential wise.

We're all oldies riding harleys now, in a world full of better performing sports bikes, putting around in our vintage cars. Pick up your hats, fellas.



(side note, wore one of these and people were offended how good it looked on me, so I'm ready)