Injector Q. Options

[BudmannG]

I am wanting to know what injectors came in the 2G turbo manuals. I was thinking they were the 510's, is this right. I also talked to someone that thought they were 450,s.
Could someone answer this for me?

As it stands right now I am running 450's in the 1G motor, which is stock. I am just curious to know if I am running the right injectors for this swap to a 2G. Thanks guys!

[AWD DSM 1]

All the turbo manual cars had the 450's stock. the turbo autos had the 390's.

[BudmannG]

Thanks Rob!

[BudmannG]

So when I put my 3" GM Mafs on what injectors should I run then? I haven't made up my mind on turbo yet, But it is running a 14b right now.

[natedogg]

450's are fine for a 14b, unless you plan on boosting the piss out of it, which I don't recommend. 14b runs past its efficiency range at about 15-16 psi. Injector sizing hinges on how much air flow you will have, aka the size of the turbo. So once you figure that out, we can give you a better idea.

[BudmannG]

Thanks Nate! I will decide that when I have the cash in my hands. Thanks for the help guys!

[The Iron Goat]

450's are fine for a 14b, unless you plan on boosting the piss out of it, which I don't recommend. 14b runs past its efficiency range at about 15-16 psi. Injector sizing hinges on how much air flow you will have, aka the size of the turbo. So once you figure that out, we can give you a better idea.

Well, there are some on this board *cough,cough* that would believe it's perfectly fine to boost the piss out of a 14b, but understand the consequences of angering the 14b God!!! To directly answer your MAFT question, that little baby works just fine with whatever injectors you want. As Nate said, the turbo is typically the only thing that determines injector size.

[ncgalant]

Your very best bet would be to size your entire setup based on your goals and then get an EPROM ECU burned for the injectors of your choice and use the MAFT for the fine adjustments. Your best bet is to set a goal and base a setup around that goal. This should keep you from buying the same part three times and make your overall experience better.

[Hult250R]

Your very best bet would be to size your entire setup based on your goals and then get an EPROM ECU burned for the injectors of your choice and use the MAFT for the fine adjustments. Your best bet is to set a goal and base a setup around that goal. This should keep you from buying the same part three times and make your overall experience better.

I agree, I bought a 16G and 650's thinking id never go bigger. I got a DSMChips Eprom Chip burned for the 650s.
Then I found a T04E 60 trim for really cheap (From TurboWht) and maxed out the injectors, So I had to get 850's and have another chip burned too.

[natedogg]

You'll always end up going bigger. Its part of the addiction.

[SCCA Stang]

You'll always end up going bigger. Its part of the addiction.

then you have guys like me that are running 550's on a EVO III 16G and am too damn cheap to go bigger... partly depends on you budget on what setupp you will end up running.

[fastclipse82]

Injector size isnt dependant on the size of the turbo but the amount of boost. However, a turbo will determine how much boost you can run. In my opinion, you always want to go a little bigger then you need to. You can always take out fuel but you can only give it as much as the injectors will flow. And also, I personally wouldnt worry about the ECU issue. The MAFT is set to your injector size when you set it up and for a street/strip car, it does very well. Basicially, we need to know what turbo you plan on using for now. If you want a solid low 13 second car, then run high boost with that 14B and get all the supporting mods or go with moderately high boost with a 16G and the supporting mods. And dont forget, you can get 1000cc injectors and they wont do a bit of good without a fuel pump and rewire. Thats the first thing I would do, and maximize the 450's to see what you can do with them.

[akamiami]

you pick injectors based on hp. there are numerous calculators available online, but I'd avoid going over an estimated 80% DC.

what hasn't been mentioned in this thread is a common tuning trick used in certain situations. depending on what tuning device you're using (SAFC, MAFT, hacked MAS vs. ITC, EMS) it may be wise to select larger injectors than you truly need or anticipate the need for in order to gain indirect control over timing.

however, if you're running 1000cc injectors on a 14b on pump gas you'll pretty much guarantee that in order to get the car even running in the realm of stoich, your timing curve will be far too aggressive. This is of course more true on a 1g than a 2g due to the more aggressive maps on the earlier generation.

But, using 650 or 720's on a 16G may be a wise decision if you've got good 93+ octane fuel and desire an aggressive tune.

On a full standalone, this point is effectively moot, as anything with incremental and separate timing control will allow far better control than the crude method described above.

Hope this helps.

[natedogg]

Injector size isnt dependant on the size of the turbo but the amount of boost.  However, a turbo will determine how much boost you can run.  In my opinion, you always want to go a little bigger then you need to.  You can always take out fuel but you can only give it as much as the injectors will flow.  And also, I personally wouldnt worry about the ECU issue.  The MAFT is set to your injector size when you set it up and for a street/strip car, it does very well.  Basicially, we need to know what turbo you plan on using for now.  If you want a solid low 13 second car, then run high boost with that 14B and get all the supporting mods or go with moderately high boost with a 16G and the supporting mods.  And dont forget, you can get 1000cc injectors and they wont do a bit of good without a fuel pump and rewire.  Thats the first thing I would do, and maximize the 450's to see what you can do with them.

One really doesn't choose injectors based on boost. 15 psi from a 14b is a LOT different than 15 psi from a GT35 for example. Like Miami said fuel injectors are chosen based on the amount of power one plans on running. To get serious about more power on DSM's is to get a larger turbo, which is, as I said in my original post, capable of more air flow, the true deciding factor. One must choose injectors that will match the air flow (not pressure) the turbo is efficiently capable of. Tuning for power is all about the air/fuel ratio and the timing. The more air and fuel one can ignite in a cylinder at the right ratio, and at the right time, the more power one is going to make.

[The Iron Goat]

Miami and Nate both put it in better terms. The whole "turbo decides the injector thing" is kinda true, but only as an end result to the other factors that need consideration. My apologies for a very watered-down version of the intense knowledge these gentlemen presented.