L28E vs. RB30E

[Azon]

Which engine has more potential as an NA fuel injected single cam (so no rb25 head) setup? I would think that RB30 will be a better choice since itss 200cc bigger, but then L28 was designed and tuned as a performance engine when the RB30 as a family car engine. I am particularly interested in power charcteristics of eaxh engine with some minor mods: extractors, exhaust, CAI+POD filter, port+polish head and may be a mild cam.

Any information on how these engines compare is welcome.

[Zeddophile]

The L28E is rated at 127kw at the flywheel, the RB30E as fitted to VL commodores and R31 skylines is rated at 114kw at the flywheel (Stock figures) The head design on the RB30 is apparently nothing short of crap.

 

Besides, to fit an RB properly requires custom engine mounts, and some stuffing around. You can bolt it in on existing mounts, but it will sit forwards and higher of the L series position, therefore changing handling characteristics.

 

My L28E revved to about 6000 rpm freely (Badly tuned, running quite rich), and by just bolting on a set of 6 into 1 extractors, it revs freely to a bit past 7000. (The stock exhaust manifold is crap, first thing on the list should be a set of extractors to allow it to flow better.

 

When you fit an L28E, you find that the air flow meter sits so far forwards that you have to put the filter in front of the radiator (this is actually where the airbox on a 280zx sits, across in front of the radiator). I have a pod filter dangling through here at the moment, it needs to be neatened up a bit, but basically cold air intake is not an option to fit the L28.

 

With a cam (and the computer reprogrammed to suit), they go pretty damn quick - my mates 280zx had extractors, pod and a moderate cam (somewhat lumpy at idle), and it picked up very quickly. I'd say for about $1000 of mods (max), theres a pretty decent powerplant there.

 

I don't know that you'll find it easy to get performance parts for an RB30E powerplant, as most people swap them out in favour of an twin cam RB. The focus for RB30s is definitely on the turbos....

[Azon]

The L28E is rated at 127kw at the flywheel' date=' the RB30E as fitted to VL commodores and R31 skylines is rated at 114kw at the flywheel (Stock figures) The head design on the RB30 is apparently nothing short of crap.

 

Besides, to fit an RB properly requires custom engine mounts, and some stuffing around. You can bolt it in on existing mounts, but it will sit forwards and higher of the L series position, therefore changing handling characteristics.

 

My L28E revved to about 6000 rpm freely (Badly tuned, running quite rich), and by just bolting on a set of 6 into 1 extractors, it revs freely to a bit past 7000. (The stock exhaust manifold is crap, first thing on the list should be a set of extractors to allow it to flow better.

 

When you fit an L28E, you find that the air flow meter sits so far forwards that you have to put the filter in front of the radiator (this is actually where the airbox on a 280zx sits, across in front of the radiator). I have a pod filter dangling through here at the moment, it needs to be neatened up a bit, but basically cold air intake is not an option to fit the L28.

 

With a cam (and the computer reprogrammed to suit), they go pretty damn quick - my mates 280zx had extractors, pod and a moderate cam (somewhat lumpy at idle), and it picked up very quickly. I'd say for about $1000 of mods (max), theres a pretty decent powerplant there.

 

I don't know that you'll find it easy to get performance parts for an RB30E powerplant, as most people swap them out in favour of an twin cam RB. The focus for RB30s is definitely on the turbos....[/quote']

 

Thanks a lot for the info, it explained a lot.

[gav240z]

The RB30 is a good motor but IMHO not a good choice for a Z unless your planning on turbo charging.

 

As Ben said they are a heavier motor and all the extra fabrication work and engineering to be done is not really worthwhile. The money would definately be better spent on an L28 in port work and a different camshaft profile.

 

The stock SU's are good for engines up to about 280HP. I don't like the standard ZX EFI mainly because I think it's messy and you need to spend $$$ on it to improve it. It's also a little dated these days compared with modern systems and OEM parts for it can be expensive.

 

The main advantage of an RB30E over and L28E is the extra 200cc and the crossflow head which in general allows for better port work to be done but not always.

 

I'm sure others would like to chime in. :wink:

[VertexZ]

The L28E is rated at 127kw at the flywheel' date=' the RB30E as fitted to VL commodores and R31 skylines is rated at 114kw at the flywheel (Stock figures) The head design on the RB30 is apparently nothing short of crap.[/quote']

 

thats not correct. The EFI L28E as in the 280zx is rated at 105kw (from memory). Remember in about 78-79 they changed from quoting gross hp to net hp, hence why the stock 260z motor is rated at 162hp (121kw)

 

I tend to agree though - for the effort required its probably not worth it considering the small gain.

 

torque is 202Nm vs. 247Nm in favour of the RB30, which is a significant gain

 

There is/was a white 260Z 2+2 going round with an RB30 in it...

[sid280]

I know this is an old post, but i need to say the L28E is better than some of you are saying, for starters i've had a $35 pod filter dangling out the front of my engine bay for over a year now without a problem, i havent even cleaned it and its still running sweet.

 

As for 105kw ? are you serious?

 

 

Thats at the wheels doing 5500rpm, completely stock, with a dodgy clutch and 2 deg advanced timing (factory is 8 deg adv). Since then I've fixed the timing problems, put the pod filter on, muffler (stock pipes still), big leads / plugs and leaned out the mixture a little on the AFM. Now it chirps my 235/45/R17's into 2nd without a problem.

 

Also, for those interested, at dyno time it was running standard 7/11 lead replacement petrol (blue line), but on the 3rd run we added the NOS branded Octane Booster that came with some injector cleaner pack i bought, its the green line and if you look REAL close you can see its actually made a 0.02% increase in power - wow.

 

Go the L28E its a great motor, its (mostly) reliable and it will bolt directly into your car so there is more potential for performance because you wont need to engineer it and can spend your cash on go fast bits. If you are going to use an RB30 avoid the GM models, they overheated more due to design flaws (GM stamp on head, radiator mounting position).

[lambs]

As for 105kw ? are you serious?

 

There are L28's and there are L28's. The figures quoted by others are about right for a 'local' L28, but some Japanese domestic models got higher performance engines, which is not uncommon for Nissan (JDM S15 vs local S15 being another example). There was a version of the L28 sold in Japan only that had flat top pistons standard. There was a local Z specialist in Melbourne who was using those engines as the basis for performance L28's. It might be you have one of those, or perhaps it's not as standard as you think.....Also induction and exhaust have a big effect on performance.

 

I've done head flow work on L28's and RB30. Cross-flow head is worth about 5% in terms of flow straight away. With minor cleaning up and some re-shaping RB30 head flows extremely well compared to L28 with similar work (actually a bit more).

[sid280]

Its got an F54 Block / N42 Head, and from the best of my knowledge Waz @ Zworx has been working on the car most of its life, until i started tampering with it...

[Zeddophile]

Thats at the wheels doing 5500rpm, completely stock, with a dodgy clutch and 2 deg advanced timing (factory is 8 deg adv). Since then I've fixed the timing problems, put the pod filter on, muffler (stock pipes still), big leads / plugs and leaned out the mixture a little on the AFM. Now it chirps my 235/45/R17's into 2nd without a problem.

 

The problem I have with that is that dyno graphs are so variable. For example, what gear was that in? What correctional factors were input? Many dyno shops will use a number of correction factors to give the biggest number they can. Much as I would love to believe that number (it would translate to the 127kw flywheel figure I had been going on, and would mean that 100rwkw is easily accheivable in mine - exact same L28E, F54/N42), its just to damn easy to screw with dyno charts.

 

And by the way, I really wouldn't rely on a $35 pod filter to keep my engine clean - it probably filters more out now its full of bugs than it did new.

[Natez]

dyno sheets mean jack all

 

i had my silvia on 2 dynos.....

 

both nearly same weather, 2 weeks apart... same petrol even, and 4th gear

 

one had 165rwkw, another had 184rwkw...., the one with 165rwkw was the one i usually go to. btw....

 

dynos are good for tuning.... unless its done on the same day and comparing dyno runs between differant car clubs for say a club dyno day, that would be more accuarate to see what differance both motors have

 

but back to topic....

 

Rb30e, is a good motor, but most likely not worth the effort to install into a Z, unless with de head, and some work, with new computer and better injection as the injection setup on a stock vl Rb30e is comparable to stock L28e, ie shit

[VertexZ]

sid280 - thats what they were quote ex factory when new.

 

 

mine pulled 81.6kw peak on a stock motor (N42/F54) just 2" exhaust, and pod filter out the front, and standard 280zx injection.. Allowing for 25% driveline loss, 105kw standard would seem right....

[Zeddophile]

mine pulled 81.6kw peak on a stock motor (N42/F54) just 2" exhaust, and pod filter out the front, and standard 280zx injection.. Allowing for 25% driveline loss, 105kw standard would seem right....

 

Yep. Thats about the figure i would expect if the standard figure is 105kw, considering you have pod and exhaust. My alfa pulled up 55kw on the dyno at tafe, and was flywheel rated at 97kw. It was streaming black smoke at higher rpms though, since the carbies were a bit worn and very rich.