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RB20 in need of modest love injection

QB6SAGR
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QB6SAGR Newbie

QB6SAGR

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Posted

Hey guys, 

I'm after some advice and this here is the best place to get it imo. I was a member a looong time ago under another account, with a lost email address. Its nice to jump back on and see some of the same names still giving good advice. 

I mothballed my car when i moved to perth in 2013, and after getting towed across the nullabor a few times it has officially done more km's on a trailer than under its own power.

Now that i have started the process of tidying up and modifying it, i see the fruit available (and the fruiterers selling the produce) is different than back in the day. hence my questions, as i used to 'know' what to get and now, i'm not so sure.

Engine wise the car (92 gtst) has a walbro 255, k+n, fmic, cam gears and and turbo back 3"exhaust.

Wish list is a Hypergear high flow or ATR43G1, Link G4x and some newer injectors before a tune up. My goals are modest, only low 200's power wise. i know i could achieve this with less, but i've been swapping out old for new where i can. Every cooling hose has been replaced, along with mani gaskets, WP, thermostat and radiator, fuel pump and timing belt, tensioner and idler, and i rebuilt the steering rack.

Regarding the injectors, the fruiterers all seem to sell what used to be considered quite large injectors. There are a lot of options for bosch 1000cc EV14's, and i would like to know if that is a suitable choice for my build. Is modern injector design good enough to run these at the low duty cycles that i likely would be? is there a downside to running a too large injector these days? or, would there be an upside to running a smaller injector at higher duty cycle?

I can see that there are smaller injectors still available, but the ones i have seen specifically marketed for RB's are pretty large (see: https://golebysparts.au/collections/fuel-rail-injector-kits/products/nissan-rb20-fuel-rail-bosch-980cc-1150cc-injectors-turbosmart-fpr800-regulator-kit), and i dont know enough about them to say one not marketed for RB's would fit or not. I have searched the forums, and amongst all the posts on older tech, I did see gtsboy recommend EV14's, but no size was mentioned... again, i'm not clear on if the smaller size bosch injectors are also EV14's as they do look similar. 

also, if someone can recommend a tuner familiar with RB's in the Geelong or West Melbourne area i'd appreciate it.

Thanks in advance guys.

Cheers, Rowdy

 

  • Like 1
GTSBoy Grand Master

GTSBoy

Posted
Posted

As you're looking at using a Link ECU, then large injectors are not a problem. But there's not really any need to go 1000s on an RB20 unless you're planning >>600HP on E85, which would seem unlikely.

There are other options for injectors. The Xspurt ones are available from a number of places and you can get them in the mid 600s and 725cc, which is probably a sensible place to be. These are all EV14 based.

If you are not using the stock AFM (at all, which would be the case with a Link) then a large turbo intake pipe to suit the ATR turbos is not an obstacle, so you should use one instead of a highflow. Results will be better.

QB6SAGR Newbie

QB6SAGR

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Thanks for the info GTSBoy, legend. If there is no downside i'll likely just get the larger bosch units because why not... I remember hearing stories about people washing their bores with fitment of too large injectors way back when, which i guess has made me shy about it now. But happy to know it shouldn't be an issue.

Ozdavroz, the little rb20 is a lot of fun- now that i have a little extra funds and time i am very glad to be tampering with the ol girl again, after so long. More RB20's on the road the better.

Cheers, Rowdy

MBS206 Grand Master

MBS206

Posted
Posted
  On 02/04/2025 at 10:10 AM, QB6SAGR said:

Thanks for the info GTSBoy, legend. If there is no downside i'll likely just get the larger bosch units because why not... I remember hearing stories about people washing their bores with fitment of too large injectors way back when, which i guess has made me shy about it now. But happy to know it shouldn't be an issue.

Ozdavroz, the little rb20 is a lot of fun- now that i have a little extra funds and time i am very glad to be tampering with the ol girl again, after so long. More RB20's on the road the better.

Cheers, Rowdy

Expand  

Personally, I'd stick to appropriate sized injectors if you're not going to go shooting for needing all of that fuel flow.

Even though ECUs have improved, having that less size still allows for slightly easier fine tuning.

Basically, an injector twice the size you need, means giving a small change, is still going to be about twice as big as you might want. Being able to make smaller and finer adjustments can make dial ins easier.

ECUs still have a limited resolution they can work with. Why give away 40% of that resolution to something you don't need?

  • Like 2
QB6SAGR Newbie

QB6SAGR

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  On 02/04/2025 at 10:40 AM, MBS206 said:

Personally, I'd stick to appropriate sized injectors if you're not going to go shooting for needing all of that fuel flow.

Even though ECUs have improved, having that less size still allows for slightly easier fine tuning.

Basically, an injector twice the size you need, means giving a small change, is still going to be about twice as big as you might want. Being able to make smaller and finer adjustments can make dial ins easier.

ECUs still have a limited resolution they can work with. Why give away 40% of that resolution to something you don't need?

Expand  

That makes a lot of sense. good info, point taken. Thanks Matt.

QB6SAGR Newbie

QB6SAGR

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Posted

Hey guys, so Golebys has good prices on Bosch injectors, and also sell an adaptor to go from 1/2 length injector to standard with the Nissan 10.5mm top seal. 

Does anyone know if that adaptor is to suit the 14mm or 11mm injector tops? 

And re. The bottom seal, to suit my standard RB20 intake, would I be right in saying I can just slip the 14mm square section O ring over the bottom of the new injector and done?

Thanks in advance guy,

Cheers, Rowdy

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