Will 550c injectors allow a stable 1.8T idle?
01-05-2003, 01:48 PM
#1
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Will 550c injectors allow a stable 1.8T idle?
wondering about the feasibility of using 550c injectors with my T28 kit, seeing if GIAC has appropriate software...and in conjunction with a FMIC.
Thoughts? Any ideas on the performance improvements? Ive seen 550c injectors mentioned on more than a few cars...
Cheers,
Sameer
Thoughts? Any ideas on the performance improvements? Ive seen 550c injectors mentioned on more than a few cars...
Cheers,
Sameer
01-05-2003, 04:49 PM
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For one, the 550's for our cars are a low imp which wont work without a fuel controller.
You should not be anywhere near running the 440's at their max not even at 1.7 bar of boost.
01-05-2003, 06:04 PM
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One of my DSM pals had a weblink that calculated required injector size.....
depending on what size your engine was, what boost you were running, fuel pressure, and what hp levels you wanted at the crank. 510cc was the majic # for something like 450 hp, which would be pretty close to running 450cc injectors with a 5 bar regulator. I agree with 2ptzero, and you might want to think about strengthening the bottom end of your engine running that much boost ;-)
01-05-2003, 07:36 PM
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interesting, then why cannot i simply turn up the boost?
Why not a chip that runs 20psi in winter, 23-35psi in summer? If there is fuel overhead...and if the T28 has overhead...and with a FMIC the EGT/IATs stay manageable...isn't that a recipe for more power? I understand detonation is always a concern...what about this on 94 octane, i have 93 octane here, but could enrich the mix a bit if needed.
Cheers,
Sameer
Cheers,
Sameer
01-05-2003, 09:44 PM
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You can run what ever boost you want
but the chip has to be tuned for that boost level from the start. Talk to PES, the non dbw cars have 2 different chips, 1 runs 1.4 bar of boost and the other runs 1.6/1.7 bar of boost. Each chip is tuned for the set boost level, remember your running a non dbw car which does not adjust the injector pulse at WOT using the maf. That is what audi did different with the DBW car.
01-07-2003, 09:47 PM
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Are you maxing the 440s out?
If you're not, then why bother? Check out your injector on-times, I think 16.8ms is the max for a non-DBW. If they aren't maxing out, you've got some room to play with.
Plus, like Mike said, 440 is the largest high-impedance injector that is a direct plug in.
Do you know what type of injectors you have? Are they Bosch green tops? This is just a curiousity.
Some 1.8Ts have problems with fouling out plugs when completely stock, what do you think will happen when you try and tune it for 550 injectors?
Plus, like Mike said, 440 is the largest high-impedance injector that is a direct plug in.
Do you know what type of injectors you have? Are they Bosch green tops? This is just a curiousity.
Some 1.8Ts have problems with fouling out plugs when completely stock, what do you think will happen when you try and tune it for 550 injectors?
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01-08-2003, 12:01 AM
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I think he has the RC's, if he is close to the edge with those
he can always try switching to the Bosch green tops, but I think those will have to run on a different chip since they flow more fuel.
01-08-2003, 12:54 PM
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just musing out-loud, that's all...
I was informed that there is significant headroom with the 440's, which is good to know.
I guess the whole reason for this is why not turn up the power a bit more if the injectors have headroom, and the turbo had headroom as well. What is the limiting factor, fuel detonation? Why not run the same boost in winter as summer? I know the tuners say the car can make the same power with less boost (cold air) but why not let the kit make more power in winter?
Cheers,
Sameer
I guess the whole reason for this is why not turn up the power a bit more if the injectors have headroom, and the turbo had headroom as well. What is the limiting factor, fuel detonation? Why not run the same boost in winter as summer? I know the tuners say the car can make the same power with less boost (cold air) but why not let the kit make more power in winter?
Cheers,
Sameer
01-08-2003, 01:10 PM
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Because after a point the turbo then starts heating up the air at a higher rate.
The 1.7 bar is about as far as you want to push it for street driving. But I will tell you what, I will tell you how it goes when I put a big turbo on my car and turn the boost up between 26-30 psi. Lets also remember that more boost makes your CR go up and since your running 9.5:1 at 23psi I can take my 8:1 compression motor up a little higher in boost and still end up with the same CR as you.
Also, if you turn the boost up too high you will end up hitting the max air flow of the turbo. You want to make sure you dont do that before you hit redline. Best thing to do is to log the maf and see if you ever hit a point where the g/s drop as your still at wot.
Also, if you turn the boost up too high you will end up hitting the max air flow of the turbo. You want to make sure you dont do that before you hit redline. Best thing to do is to log the maf and see if you ever hit a point where the g/s drop as your still at wot.