Maxing out a small 16g?

[chanley talon]

Ok i want to max out the potential in my small 16g i was wondering how much injector this would take ? I was wondering how much boost it can make as well? Will 550s be enough or do i need 650s ? Thanks in adavnce for your comments and help.

 

[v8killerr1]

you should be able to do it with the 550s. If you want to make sure you have a little more room get the 650s.

 

[biglady112]

We have a set of 660 nippondenso's that flowed 690cc's on the bench. They are maxed out at 21psi on pump gas. Dsmlink tuning the car as well. Car runs 12.7's on pump gas at 5800ft.

Steven

 

[Mike1992]

I've had my 780's to 70% idc around 23 psi with 37 psi base fuel pressure. I'm sure 650's will meet your goal.

 

[NewB2dsm]

550cc injectors, 25psi on 110 made 338awhp and i ran 12.1@112 with my fullweight 2g. Id say this was pretty much maxing it out.

 

[wishihadatalon]

30 psi falling to 24psi ran 12.3 at 116mph with 550s and a big 16g. I don't think there was anything else left in the car.

 

[SolidBoostTSi]

the S16G is pretty under rated, I remember when it was hot sh!t way back in the day. But... back to the topic, 550's will max out rather quickly especially on a good tune. Just to give you some head room too, increase your base fp according to the Injectors you are running. Enjoy!

 

[LA97GST]

I say get 650's at least. The sm16g is a very very underrated turbo that tends to max out more than expected.

 

[ivanr4g63]

A good tune, zero leaks, and some race gas will allow you to run good on 550's, but most likely you'll max'em out anything over 20psi, plus you'll get power hungry (believe me, we all do) so, for the sake of future power, you're better off with a bigger injector... don't go too big though, you'll have a hard time controlling it.

 

[SolidBoostTSi]

as ivan said... Power Hungry. I'm guilty as charged for that. I went from a FPRed to S16G, 18G, 5031E, T04B V-trim, and now....6152SP Tuning is Key!!!!!!! no matter what you're setup is built for. 300 or "shep" horsepower a good tune will get you more consistent than a turbo ever will.

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-Solid

 

[Dark_Horse]

550cc injectors are at 80% IDC at 31lb/min.
550cc injectors are at 100% IDC at 39lb/min.

If I were you, I would run some 650cc injectors or larger.

 

[spyderturbo007]

http://www.dsmtuners.com/forums/showpost.php?p=151048611&postcount=1

 

[Steve93Talon]

550cc injectors are at 80% IDC at 31lb/min.
550cc injectors are at 100% IDC at 39lb/min.

If I were you, I would run some 650cc injectors or larger.

At what AFR and pressure? We've gone 11.05 @ 123 on 550s and a 20g on C16, pretty sure it was well over 40 lb/min.

I'm not disagreeing that bigger injectors are worth buying nowadays with chips and DSMlink being able to compensate so well.

 

[Dark_Horse]

At what AFR and pressure? We've gone 11.05 @ 123 on 550s and a 20g on C16, pretty sure it was well over 40 lb/min.

I'm not disagreeing that bigger injectors are worth buying nowadays with chips and DSMlink being able to compensate so well.

11:1 AFR. Fuel pressure is not part of the equation. With C16 and 12.5:1 AFR, 550cc injectors still max out at just about 45lbs/min. That's figuring that the injectors flow exactly 550cc. It's highly possible that you had a set of injectors that flowed over 550cc. As Biglady112 pointed out, his injectors are rated 660cc, but flow 690cc.

That being the case, it's still better to play it safe than to push the 550's for all they are worth and hope for the best.

 

[Smokin80]

i have a s16g and ran 12.803@106mph while running 23psi on 94 octane with meth/water injection. I think the turbo still had some more in it. I weighed 3170 at the time of the run. My 880's are usually around 56% idc at 11.4-11.5 afr's. If i dont go to a GT3076R before the next races i think i could get a 12.6ish run out of this turbo at 108 or 109mph. I like this turbo for everyday driving but i want something bigger!!!

 

[Kevin Jewer]

The small 16g is good to around 36-38 lbs/min, and I saw nearly 40 on the big 16g once. The EVO 16g consistently does 42. The small and large 16Gs can easily get away with 550s unless you plan to really max it out on pump gas, which is rarely ever done on a 2 liter. A 2.3 makes it a no brainer though. At any rate, I would personally be perfectly comfortable with 550s, especially if this is an AFC or similar tuning setup. If you run DSMlink or an injector compensated chip and have a high IDC phobia, go for the larger injectors just because you can.

 

[DSMunknown]

11:1 AFR. Fuel pressure is not part of the equation. With C16 and 12.5:1 AFR, 550cc injectors still max out at just about 45lbs/min. That's figuring that the injectors flow exactly 550cc. It's highly possible that you had a set of injectors that flowed over 550cc. As Biglady112 pointed out, his injectors are rated 660cc, but flow 690cc.

That being the case, it's still better to play it safe than to push the 550's for all they are worth and hope for the best.

So it seems that you have answered one of my questions in the thread that Nathan gave above:

I can't have everyone's injectors flow tested, so we have to assume that if you bought 550cc injectors, that they flow 550cc/min.

Isn't it true that when Ben Franklin decides to buy (for instance) 550cc injectors, he is not actually getting what he pays for? In other words, the name "550" is just an "approximation", right? For example, when buying a set of four fuel injectors, could Ben recieve injectors that flow 547, 551, 552, and 555?

Obviously, the manufacturing company of the fuel injectors tested the flow rates of their products, but isn't this the reason why people have their injectors flow-tested, to determine exactly how well or poorly the injectors are flowing?

So if what you say is true, then when Mr. Franklin buys new injectors, he could be actually receiving 580s? Or would the flow rate of each injector be different (that each injector would be flowing slightly different from what they were labelled as)? In other words, if he is actually getting above 550cc injectors, does this necessarily mean that all the injectors will flow the same?

 

[Dark_Horse]

So if what you say is true, then when Mr. Franklin buys new injectors, he could be actually receiving 580s? Or would the flow rate of each injector be different (that each injector would be flowing slightly different from what they were labelled as)? In other words, if he is actually getting above 550cc injectors, does this necessarily mean that all the injectors will flow the same?

In order to know the true flow rate, you'd have to get them tested.

Retailers of injectors try to pair up injectors that are within a few percentage points flow with each other. It's pretty much impossible to have 4 injectors that flowed exactly the same cc. Each of the 4 will flow different amts...All be it, within a couple percent of each other.

It is possible that your injectors will flow more than 550cc, or less than 550cc. From all the data I've seen, usually injectors flow a bit less than they're rated to...But Steven had a case where they flowed more.

That's why the equation anyone uses to find theoretical max lb/min is just a good guess. You may have 550cc injectors, but they may be mutants and flow 580cc. Or you may have crap 550cc injectors that really only flow 530ish. Which is why most people recommend not running injectors over 80% IDC, because you never know exactly what they flow.
Well, unless you've gotten your injectors flow tested of course.

I still say, that if you have DSMlink, AEM, etc (not SAFC), buy the biggest injectors you can afford and that give decent drivability. If you can control them, you can never go too big IMO. Then it's 1 less thing you need to buy when you decide to upgrade from a 16G to an SC-6152. Buy big injectors, buy once. Buy small injectors for your setup, upgrade again and again and again when your turbo wants change.

 

[Kevin Jewer]

I've never found a FIC injector that didn't flow what it is rated at. Now the old skool Denso 660s and the X80 injectors are another story... I had a set of 660s that flowed everything from 700 to 820.

 

[90gst_sean]

B16g , 550's@38psi, 19psi, 35lb/min w/ 105%idc

Raise your hand if you can tell me were the problem is..?

I have to say; that my shopping of fic750's is what has brought me to this thread.

 

[daren_p]

B16g , 550's@38psi, 19psi, 35lb/min w/ 105%idc

Raise your hand if you can tell me were the problem is..?

I have to say; that my shopping of fic750's is what has brought me to this thread.

Problem is you should be running 43.5 psi base fuel pressure, to get the 550cc of flow you paid for

 

[Splitpi]

Max flow according to the turbo maps is:
525cfm @ 19psi.

VE is pegged at the choke line with 60%

More than likely this wouldn't be attainable or sustainable. Figure 475 to 520 cfm @ ~15 psi as the max realistic flow. According to the turbo map.

http://www.ztechz.net/id6.html

According to my math on the assumption 11:1 AF and BSFC of 55%

525 cfm = 360 hp at the crank
475 cfm = 325 hp at the crank
520 cfm = 356 hp at the crank

NOTE: This is IDEAL mathmatical values. Don't expect to have the same values. But this is what the turbo could produce in an ideal environment. I would personally take 15 to 20% off to be more realistic in my guestimating of the real world. Either way though...not too shabby from the small 16G.

 

[Splitpi]

Problem is you should be running 43.5 psi base fuel pressure, to get the 550cc of flow you paid for

Yes running 550's (as measured from the manufactor at 43.5 psi) at 38 psi equates to a flow 514 cc or 7% less flow.

Anyone know if this assumption is correct?
On a side note: Can anyone shed light on the Injector calculations involving 1:1 matching AFPR to Boost pressure. Meaning that at 9.5 psi of boost (above atmosphere) on a static 43.5 psi fuel pressure, the actual fuel pressure should be 53 psi at that boost level... correct?

So If I take the equation:

hp = ((injector size)*(Number of Injectors)*0.8)/(BSFC)

and factor in the increased fuel pressure do to matching boost pressure:

hp = ((sqrt((New Pressure) / (Old Pressure)) * (injector size)) * (Number of Injectors) *.0.8) / (BSFC)

Is that correct to compensate?

 

[zippyshoe]

Yes running 550's (as measured from the manufactor at 43.5 psi) at 38 psi equates to a flow 514 cc or 7% less flow.

Anyone know if this assumption is correct?
On a side note: Can anyone shed light on the Injector calculations involving 1:1 matching AFPR to Boost pressure. Meaning that at 9.5 psi of boost (above atmosphere) on a static 43.5 psi fuel pressure, the actual fuel pressure should be 53 psi at that boost level... correct?

So If I take the equation:

hp = ((injector size)*(Number of Injectors)*0.8)/(BSFC)

and factor in the increased fuel pressure do to matching boost pressure:

hp = ((sqrt((New Pressure) / (Old Pressure)) * (injector size)) * (Number of Injectors) *.0.8) / (BSFC)

Is that correct to compensate?

The flow rate of the injector is determined by the differential pressure seen by the injector (Fuel pressure - Manifold Pressure). The purpose of the fuel pressure regulator is to maintain the differential pressure at a constant value, regardless of the manifold pressure. If you set your AFPR to a base pressure (vacuum line disconnected) of 43.5 psi, then your differential pressure is (43.5psi - 0psi = 43.5 psi). If you now build 10 psi of boost, your AFPR should automatically adjust your fuel pressure to 43.5psi + 10psi = 53.5 psi, assuming this is a 1:1 AFPR. Note that you still have a differential pressure of 53.5psi - 10psi = 43.5psi. Hence, the injectors continue to flow at the same rate REGARDLESS of boost pressure since they see a constant differential pressure. In the horsepower equation above, "injector size" will not vary with changes in boost pressure.

However, if you increase your BASE fuel pressure, then your injector size (flow rate) WILL increase with the square root of the increase in base fuel pressure.

 

[slipstream808]

I'd up that base fuel pressure to the 43.5. Or just round it off to 45. It should also help with power and mileage in that a finer mist SHOULD be produced. Don't quote me there though.

Make sure you can compensate for the extra fuel when not at WOT or else your Fuel Trims will start to hate you.