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Injector Recommendations based on Drivability/Tuning


f85stealth

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I am looking at upping the Legacy to a BNR 18G. I think that will require 1000CC Injectors for 93Oct fuel. I am looking to see who has upgraded injectors and how well they were able to be tuned in for drivability/Idle/Low throttle/all around performance.

 

I see the big name companies like Injector Dynamics make fuel Rail Adapters so Top mount injectors can be used.

 

Then you have companies like Five-O who claim to have a 1000cc side mount fuel injector that bolts right in and very cost effective in comparison.

 

Injectors is something I don't want to gamble on so I want to know I am buying quality and it will last.

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1000cc is way overkill for an 18G on pump gas. I'm pretty sure you could run E85 with those. :)

 

That said, ID 1000s run fine, so it's not a bad idea. I have their side-feed-conversion kit and my car idles without stumbling. I get a bit of stumble when the engine is cold, but I don't think the injectors are the cause.

 

I'm not sure offhand what you'd really need, but if you really want to know you should find some people with 18Gs and find out (a) what injectors they're running (b) what their max injector duty cycle is. I'm pretty sure 740s would be plenty.

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My question is more on what brand name injectors are available for the side feed legacy and some feedback on the good name brands.

 

Five-O doesn't need any sort of adapters which is appealing and offer the largest injector size in that configuration.

 

I feel better to have too big and run low duty cycle then not have enough for mods that may come later.

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I would stay away from DW850s, based on LittleBlueGT's experience with them. I had different injectors that had the same anomalies and it's a nuisance. It's not something that a tuner would notice unless they do pulls at varying boost levels and discover that they have an AFR issues that can't be fixed with MAF scaling.

 

http://legacygt.com/forums/showpost.php?p=2659311&postcount=54

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You won't need 1000cc with 93 pump and your turbo! 740cc will be plenty actually.

 

I don't know about DW850, but DW740 injectors have no issues. I am upgrading to ID1000 for E85. I have two sets of 740s for sale, one unused after checkup and cleanup by Deatchwerks. Haven't listed them yet, pm if interested.

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I have had both the dw740s and the 850s - both had no tuning issues. I do not think the problem lbgt had is widespread..I have not read many similar issues with the sti guys.

 

I personally know of 4 guys running 850s with no problems. And I suspect a lot of members here have had a positive experience. But there is no doubt lbgt was having serious leaning issues - I am not convinced it is an injector issue tho.

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His AFR issues went away when he switched injectors, and only injectors, and that's enough to convince me that injectors were the problem. Mine went away when I switched injectors + fuel rails, so I could be wrong, but I still blame the injectors.

 

People haven't noticed because people haven't looked. Or they just think it's normal to fix AFR problems by adding or subtracting from different spots in the fuel table. Show me data logs that include the actual AFR and the fuel-table AFR, with not just full-boost WOT pulls but also a few intermediate boost levels, for example 5psi, 10psi, 15psi, and then we'll talk. :)

 

With good injectors (and a good MAF scaling and proper injector scaling and latency), you will see the actual AFR matching the AFR in the fuel table, or at least it'll be off by a consistent and predictable amount. With injectors like the ones we had, you end up with AFR deviations in some RPM/load areas, which (a) won't be apparent in just WOT pulls and (b) cannot be fixed with MAF scaling or injector settings.

 

The thing is, if you only check AFRs in cruise and in WOT pulls, you'll never notice. If you dial in the MAF scaling at wastegate boost, and then tweak it again during WOT pulls, you might not notice a problem. Unless you go back and do a few wastegate-boost pulls and notice that your AFRs are screwed up again. And even then you might not notice, if the problem spots are somewhere in between wastegate and full booost, or in between vacuum and wastegate boost.

 

My ID 1000s do have a lean spot at around 4000 RPM and high vacuum. It's perfectly repeatable. Nobody else seems to have noticed that sort of thing. I wonder if it's because nobody else has that problem, or nobody else looked for that sort of problem. It doesn't show up in cruise, or WOT pulls, or wastegate-boost pulls. If I hadn't made a point to check AFR in all conditions I wouldn't have noticed it either. If I was getting paid by-the-hour or by-the-tune I wouldn't have bothered to go looking for it.

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His AFR issues went away when he switched injectors, and only injectors, and that's enough to convince me that injectors were the problem. Mine went away when I switched injectors + fuel rails, so I could be wrong, but I still blame the injectors.

 

People haven't noticed because people haven't looked. Or they just think it's normal to fix AFR problems by adding or subtracting from different spots in the fuel table. Show me data logs that include the actual AFR and the fuel-table AFR, with not just full-boost WOT pulls but also a few intermediate boost levels, for example 5psi, 10psi, 15psi, and then we'll talk. :)

 

With good injectors (and a good MAF scaling and proper injector scaling and latency), you will see the actual AFR matching the AFR in the fuel table, or at least it'll be off by a consistent and predictable amount. With injectors like the ones we had, you end up with AFR deviations in some RPM/load areas, which (a) won't be apparent in just WOT pulls and (b) cannot be fixed with MAF scaling or injector settings.

 

The thing is, if you only check AFRs in cruise and in WOT pulls, you'll never notice. If you dial in the MAF scaling at wastegate boost, and then tweak it again during WOT pulls, you might not notice a problem. Unless you go back and do a few wastegate-boost pulls and notice that your AFRs are screwed up again. And even then you might not notice, if the problem spots are somewhere in between wastegate and full booost, or in between vacuum and wastegate boost.

 

My ID 1000s do have a lean spot at around 4000 RPM and high vacuum. It's perfectly repeatable. Nobody else seems to have noticed that sort of thing. I wonder if it's because nobody else has that problem, or nobody else looked for that sort of problem. It doesn't show up in cruise, or WOT pulls, or wastegate-boost pulls. If I hadn't made a point to check AFR in all conditions I wouldn't have noticed it either. If I was getting paid by-the-hour or by-the-tune I wouldn't have bothered to go looking for it.

 

I trully respect your opinion and the fact that you have facts to back it up. But at the heart of your arguement is the fact that no one notices it unless you are an avid datalogger; there are no symptoms such as knock or hesitation (and if there were we would be hearing more about them). I just don't think that is enough to make the leap in saying that all DW850 are bad injectors.

 

Truth is - if it is not noticable, does not effect performance/drivability and it is not dangerous to the engine it ceases to be a problem IMO.

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^ what most assume to cause these problems is poor atomization and poor combustion caused by it. Which, you are right isn't a problem until it causes a lean condition that ruins your engine.

 

I will re-iterate that injectors are your first and last line of defense against knock.

 

I just ordered a TD06 20g and am trying to figure out which way i'm going for fueling.

 

FIC now makes STI top feed conversions (which i think fit our cars) and they tend to scale higher than the ID injectors do (1100cc for the 1100cc injectors... not 5-15% less)

 

i'm just really paranoid about running my own fuel lines (probably for no reason)

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It's not that you won't have problems, it's that you won't know the injectors are causing your problems unless you do a lot of logging and study the data. My car was running lean wastegate-boost pulls - not something that many people tune for, but if you've ever accelerated at half-throttle you've done it. If your tuner didn't look for that kind of thing, you could be knocking there every time you accelerate moderately. How would you know?

 

If your tuner looks for this kind of thing they can tune around it, but that takes time, and it's time that your tuner could otherwise spend giving you a better tune rather than working around the quirks of your parts.

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Who started this rumor that any stage 3 setup needs 1000cc injectors on pump? I have been seeing this far too often. I have yet to come across any setup in which has required 1000cc injectors period.

 

but whats wrong with getting injectors that are too large? Not much of a price difference. Might as well go for it and have room to grow in the future, right?

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but whats wrong with getting injectors that are too large? Not much of a price difference. Might as well go for it and have room to grow in the future, right?

Depends on your tuner, but there is a big price difference when refering to sidefeed injectors.

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but whats wrong with getting injectors that are too large? Not much of a price difference. Might as well go for it and have room to grow in the future, right?

 

A lot. You should be using the smallest injectors appropriate for your setup. Bigger injectors = less control. If you're going to grow that much why get an 18G? It's a waste of time.

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The only reason i ask the 1100cc on pump question is i'm debating on going 850s with meth injection, or 1100s with OCCASSIONAL E85 use.

 

and i'm worried about a DD on 93 with 1100s being able to idle and control correctly just cruising around.

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