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injector and f pump recomendations for bnr 16g


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just got my used bnr 16g, i have DW 850 cc injectors (i know 850 is overkill but they were cheap and used) and was planning on ordering a DW65c fuel pump, but i am now seeing some horror stories about DW injectors and pumps causing stumble

 

im wondering if my current oem pump and injectors would be better or even enough for the 16g, im vf40 stage 2 now and inj duty cycle is currently 76% at wot 17psi

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How about you try reading the stickies first?

 

On a 16G the stock injectors are quite sufficient, provided the fuel pump can keep up with demand. If yours is a few years old, or you like peace of mind, swap for either a DW65c or a stock GR/GV STi pump.

Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs.
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Ease up, fahr_side. A 16g with supporting mods will come close to maxing stock injectors at the very least. Certainly not "uneducated" to explore fuel mods at that point. And to argue that mileage only has an effect on the pump and not the injectors is not terribly smart.

"Bullet-proof" your OEM TMIC! <<Buy your kit here>>

 

Not currently in stock :(

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i have read all the stickies man but some people have said the oem is not big enough esp on 05-06 like i have with 520 injectors as aposed to the 550's 07+ use

 

also the stumble i spoke of is mentioned in the post right below my post in the turbo power train section so clearly it is not something i made up or out of left field at all

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The side-feed injectors flow the same, they are just scaled differently... lower cc/min and lower MAF scaling to match. The top-feeds on the later models are variously scaled from 520cc to 565cc depending on the application, even they are the exact same injector. Unless you are running E85 they are enough.

 

The guys who get into very high IDCs are running boost too high at high revs. The 16G is way out of it's efficiency sweet spot by that point and you'll get more power by running less boost (like 16.5psi at redline) and more timing.

 

Most of the guys who are seeing AFR lean out at high IDC (at least on small turbos like this) have pumps that are falling down because they are old and stock, or aftermarket but worn out, or just fakes, or other fuel system problems.

 

I can't speak to your stumbling concerns as I've never encountered such a thing once injector scaling and latency is set up properly, tip-in recalibrated, MAF accurately scaled and compensations adjusted. There's a lot more to it than just typing in the numbers the vendor gave you for scaling and latency.

Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs.
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Damn I forgot 07+ was topfeed I guess I'll end up using the dw 850cc. My tunnerl said no way the 520cc will be enough if I want the most out of the set up

 

 

Your 'tunnerl' is wrong.

Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs.
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Ease up, fahr_side. A 16g with supporting mods will come close to maxing stock injectors at the very least. Certainly not "uneducated" to explore fuel mods at that point. And to argue that mileage only has an effect on the pump and not the injectors is not terribly smart.

Injectors can easily be cleaned and returned to full flow. Pumps wear and cannot.

 

Whether or not the injectors will come close to being maxed out is another matter. Those who think anything over 95% IDC will assume they are maxed out. Same for people who tune for AFRs in the low to mid 10s, and same for people who force the turbo to run at 18psi all the way to redline.

 

I have tuned at least a dozen cars with 16G turbos. My own test mule ran a BNR item for about three years, with supporting mods including different upgraded TMICs, EL headers, catless and high-flow catted downpipes. I also tested at least two other 16G turbos on this car for comparison to the BNR. Customer cars (WRX, FXT, 2.0 / 2.2 stroker STi models) have run 16Gs from several other builders. I can tell you categorically that the stock injectors are quite capable of supporting these turbos. Yes you can max the injectors by either tuning pig rich or by holding boost at 18psi out to redline. However, neither of these strategies will net you any more power. Running pig rich clearly does you no favors on the dyno. Pushing the 16G to hold high boost to redline pushes it far beyond it's efficiency range and forces you to run a few degrees less timing. I had tried this with the massive Spearco TMIC and still had to pull 2 to 3*. You gain a bit of airflow but charge temps go so high you're forced to pull a few degrees of timing to stave off knock. Forcing the turbo into overspeed and compensating with less timing is not a good tuning strategy. Tapering boost off to about 16.5psi at redline and adding some more timing gets you the same or more power, is kinder to the engine and turbo, reduces intercooling demands and lowers IDCs for the stock injectors to an entirely reasonable level, provided the pump can keep up.

 

People are welcome to spend their money on whatever they like, but don't expect more power to come from larger injectors on this turbo.

Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs.
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Your 'tunnerl' is wrong.

 

Well let me see I now have a vf40 with 520cc running 16 psi of boost and the injectors duty cycle is 76%

I'd like to run more boost, so I will need more duty cycle, it's also going be a larger turbine so even at the same boost it would raise the duty cycle

20% more power requires 20% more fuel. That would put me pretty damn close to 100% duty cycle! And that's just estimating. 550cc would probably barely get it done. But I have the 850cc in hand

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I think you missed the post where I stated the injector scalings from the factory are somewhat arbitrary and chosen to work with particular MAF scalings. The same injectors will have different scalars in the factory ROMs on different model cars.

 

The TD05H turbine is not much larger than that on the VF-52 and power potential is very similar. Though the 16G holds boost better at high revs than the VF-52 does, it doesn't necessarily flow more air. It's mass airflow that makes power, not boost. More boost does not necessarily mean more power. If you're replacing a VF-52 with a 16G with the view to getting more peak power I think you're going to be disappointed.

 

Increases in power do not call for identical increases in IDC. The math is a little more complex than that.

 

You can run the stock injectors at 97% all day long without any problem as long as the fuel pump can maintain system pressure. Fuel flow actually still increases beyond 100% IDC because this does not actually mean the injectors are static. IDC is a calculation based on injection window.

 

Go ahead and install your 850s if you want peace of mind from lower IDCs but I promise you it makes not one iota of difference at this power level. I would not run any turbo larger than a VF-52 or 16G on stock injectors alone but they are just fine at this point.

Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs.
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The TD05H-Evo16G is superb little turbo and Bryan's fitment of that CHRA into the VF-40 housings is flawless. MHI TD05 turbos are only available in 7cm2 or 8cm2 housings* but the VF-40 has a P18 housing which is about 7.5cm2 and gives the best of both worlds. I prefer this turbo to the VF-52 but which one makes more peak power depends on your tuner, engine condition etc... there's not much in it. I just like the way the 16G holds on a bit better past 6k0rpm compared to the VF-52.

 

I'm still using most of the one I bought. After nearly three years and 60,000km it developed a small leak on the exhaust side seal so I had it rebuilt with new seals. While we were in there I decided to install new bushings and a proprietary billet 18G compressor wheel. The original turbine and bushings were in perfect shape when it came apart. Another advantage of not running the thing overspeed just to meet some arbitrary boost target ;)

 

You will btw find an equal-length header a really good compliment to your build... far more useful than those injectors. Mine was worth a solid 20whp on the 16G.

 

* Kamak 8cm2 housings actually measure out around 8.4cm2

Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs.
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The TD05H-Evo16G is superb little turbo and Bryan's fitment of that CHRA into the VF-40 housings is flawless. MHI TD05 turbos are only available in 7cm2 or 8cm2 housings* but the VF-40 has a P18 housing which is about 7.5cm2 and gives the best of both worlds. I prefer this turbo to the VF-52 but which one makes more peak power depends on your tuner, engine condition etc... there's not much in it. I just like the way the 16G holds on a bit better past 6k0rpm compared to the VF-52.

 

I'm still using most of the one I bought. After nearly three years and 60,000km it developed a small leak on the exhaust side seal so I had it rebuilt with new seals. While we were in there I decided to install new bushings and a proprietary billet 18G compressor wheel. The original turbine and bushings were in perfect shape when it came apart. Another advantage of not running the thing overspeed just to meet some arbitrary boost target ;)

 

You will btw find an equal-length header a really good compliment to your build... far more useful than those injectors. Mine was worth a solid 20whp on the 16G.

 

* Kamak 8cm2 housings actually measure out around 8.4cm2

 

I am curious what size injectors and at what duty cycle% you were at with the 16g?

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I was using the stock top-feeds (variously scaled from 550~565cc) and a stock GRB pump to back that up. I found best power at 16.5psi @ 6k4rpm, with AFR of 11.2:1. At that level, on the coolest day of the year (ambient temp 8*C) I'd see IDC peak at 97%.

If I set a target AFR of 10.8 I'd still hit that, so it's enough headroom.

Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs.
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  • 10 months later...
hey fahr side now that i have it all installed and tuned i figured id let you know you were very wrong with the bnr 16g and dw 850cc installed at 22psi i am running 80%inj duty cycle, if i had left tje 520's in i would have had to cap the boost at 18 which is lower than i ran with my vf40....
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I never said you can't run a 16G past 16 or 17psi at redline, just that there isn't any point.

 

 

Sent from my iPhone using Tapatalk

Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs.
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Headroom is always nice (as long as you aren't giving up resolution at low load), and I believe firmly people should be able to spend their money on whatever makes them happy.

 

 

Sent from my iPhone using Tapatalk

Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs.
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my 16g was happy with 740cc injectors and walbro pump, however during the first tune years ago, Chris from EFI (RIP) said the stockers had the room to run the 16g safely

 

I was tuned to `19psi tapering to 15/6 on the 5eat shift.

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