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What size injectors to go with...

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Old Nov 26, 2005 | 10:07 PM
  #1  
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What size injectors to go with...

I will be installing a new turbo and manifold in the spring along with a 3" dp and exhaust. I am trying to decide what size injectors to go with. I will be using the rtek 1.7 and most likely an safc. Here are the specs on the turbo

Garrett T04 60-1 Turbo
.62 TRIM
.60 A/R
.86

any help would be appreciated.
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Old Nov 27, 2005 | 11:45 AM
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nobody really sure what to go with? also the .86 is exhaust side
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Old Nov 27, 2005 | 12:05 PM
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720 primariees and 860 secondaries would be what i do
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Old Nov 27, 2005 | 12:14 PM
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ok sounds good i was thinking 720 primary and 920 secondary but that should work is there anyway i could get away with not changing the primaries?
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Old Nov 27, 2005 | 12:16 PM
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920 secondaries would do it too
i would change the primaries...
it takes no time anyways
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Old Nov 27, 2005 | 12:52 PM
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Originally Posted by Xbladr
I will be installing a new turbo and manifold in the spring along with a 3" dp and exhaust. I am trying to decide what size injectors to go with. I will be using the rtek 1.7 and most likely an safc. Here are the specs on the turbo

Garrett T04 60-1 Turbo
.62 TRIM
.60 A/R
.86

any help would be appreciated.

Check out this link. It should help answer your questions
http://www.pocketlogger.com/index.php?pid=rtek7feat
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Old Nov 27, 2005 | 01:43 PM
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Originally Posted by Ruffryder_29
Check out this link. It should help answer your questions
http://www.pocketlogger.com/index.php?pid=rtek7feat
if you are impling he shoudl run 550cc primaries and 720cc secondaries
you are dead wrong
d-e-a-d-w-r-o-n-g
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Old Nov 27, 2005 | 02:25 PM
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Yes I know that i need atleast 720cc secondaries... so that is not an issue the question im asking ruffryder is how much larger over the 720cc's would be necessary. The reason I dont want to get bigger primaries is because that is another 150 or so and i dont want to have flooding issues which i hear can be a pretty common with larger primaries. Do you think the 550 primaries would really be a prob or restrict my setup too much? Also what do u think a realistic hp goal for that turbo would be
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Old Nov 27, 2005 | 03:06 PM
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flooding isnt because of large primaries
it is because they have problems with getting their car to run properly

i had 780cc primaries
it starts just fine
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Old Nov 27, 2005 | 03:24 PM
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Ok Ill look into that then I was hoping to save a little money and stick with the 550 for primary but that doesnt seem to be an option... thanks anyone else have any ideas?
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Old Nov 28, 2005 | 06:20 AM
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Uh, doesn't the RTEK 1.7 require you to run 4 x 720's?
If you have questions with their ECU, why not ask THEM?


-Ted
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Old Nov 28, 2005 | 06:39 AM
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Originally Posted by RETed
Uh, doesn't the RTEK 1.7 require you to run 4 x 720's?
If you have questions with their ECU, why not ask THEM?


-Ted
Hense the weblink I had included......technical info and support
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Old Nov 28, 2005 | 07:00 AM
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Originally Posted by slpin
if you are impling he shoudl run 550cc primaries and 720cc secondaries
you are dead wrong
d-e-a-d-w-r-o-n-g
Im not impling anything...if he wants help then he can call and ask. Who would know better than the people who make them...
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Old Nov 28, 2005 | 07:12 AM
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Originally Posted by slpin
flooding isnt because of large primaries
it is because they have problems with getting their car to run properly
Nope, big primaries with the stock ECU does cause flooding. The ECU uses preset fuel values for cranking. You can't adjust them with an AFM interceptor because the AFM is ignored. Cranking mixtures are always very rich to aid starting and bigger injectors means even more fuel and a much greater chance of flooding.

This problem is easily solved though, since it should be pretty obvious that if you're at a point where you need to upgrade the primaries you shouldn't be mucking around with the stock ECU.

Injector sizes should be selected based on your expected power level. If you don't know that, you can't size properly the injectors.
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Old Nov 28, 2005 | 07:17 AM
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the v1.7 only requires bigger secondaries, but yeah, you are going to need more than that.

(pocketlogger.com)
Minimum Secondary Injector Size:

This is the size of the secondary injectors that the ECU is expecting.

The secondary injectors MUST be the same size or larger than the minimum injector size for the chip version you have or engine damage will result.

550cc secondaries are stock so no change has been made to the fuel map in version 1.5. For version 1.7, the fuel map has been corrected to compensate for larger 720cc secondaries without the need for external fuel control, like an AFC, to keep from running very rich. If you have an AFC, it will no longer have to trick the ECU to compensate for the larger injectors. The AFC can be used for fine tuning. This also means that you CANNOT run version 1.7 in a car with 550cc secondaries or you will run lean

Last edited by red87tll; Nov 28, 2005 at 07:20 AM.
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Old Nov 28, 2005 | 09:24 AM
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I know that the rtek 1.7 just means larger secondaries it is made for stock 550 cc primaries. I am just trying to decide what size secondaries to go with and even if I need to upgrade the primaries.
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Old Nov 28, 2005 | 10:05 AM
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Are you like stubborn?
RTEK recommend 720's in the secondaries.
Why are you asking if you can run a size different than this???


-Ted
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Old Nov 28, 2005 | 10:31 AM
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Originally Posted by NZConvertible
Nope, big primaries with the stock ECU does cause flooding. The ECU uses preset fuel values for cranking. You can't adjust them with an AFM interceptor because the AFM is ignored. Cranking mixtures are always very rich to aid starting and bigger injectors means even more fuel and a much greater chance of flooding.

that is not my point
if the car runs properly, it will start with large primaries no problem.
it had been proven that on a properly running car, it would start with big injectors
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Old Nov 28, 2005 | 11:33 AM
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Ted... I dont think you understand. Rtek recommends a minimum of 720cc's in the secondary slot read again it says a MINIMUM Im asking how big I should go for the turbo that I will be using I am going bigger than 720 possibly even up to 920cc but im not sure what size. My main concern right now is can I use stock PRIMARIES!!!! I was hoping to use stock primaries for tuning purposes as well as saving me about 150 bucks which is the cost of the SAFC.

Ted this is right off of the site
The secondary injectors MUST be the same size or larger than the minimum injector size for the chip version you have or engine damage will result.

I am not trying to start a fight or **** anyone off I am just asking for some general opinions on what size injectors to run.

Last edited by Xbladr; Nov 28, 2005 at 11:36 AM.
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Old Nov 29, 2005 | 04:00 AM
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Originally Posted by slpin
that is not my point
if the car runs properly, it will start with large primaries no problem.
it had been proven that on a properly running car, it would start with big injectors
I didn't say it wouldn't start, I said it increases the chances of flooding. If you upgrade the primary injectors with the stock ECU, more fuel will be injected during cranking. No piggyback can change this. More fuel during cranking will increase the chances of flooding. Simple as that.
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Old Nov 29, 2005 | 06:10 AM
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Originally Posted by Xbladr
Ted... I dont think you understand. Rtek recommends a minimum of 720cc's in the secondary slot read again it says a MINIMUM Im asking how big I should go for the turbo that I will be using I am going bigger than 720 possibly even up to 920cc but im not sure what size. My main concern right now is can I use stock PRIMARIES!!!! I was hoping to use stock primaries for tuning purposes as well as saving me about 150 bucks which is the cost of the SAFC.

Ted this is right off of the site
The secondary injectors MUST be the same size or larger than the minimum injector size for the chip version you have or engine damage will result.

I am not trying to start a fight or **** anyone off I am just asking for some general opinions on what size injectors to run.
You're still asking questions which the RTEK people can answer.
Why gamble asking a bunch of people and getting random answers when RTEK can answer them properly for you?


-Ted
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Old Nov 29, 2005 | 07:44 AM
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Rtek with a full t04 turbo and you will blow your motor guaranteed. Get a standalone or get a rebuild then the standalone. With the price of megasquirts these days I am not sure why people are not jumping all over them. Did you know they are a direct plug and play now!
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Old Nov 29, 2005 | 01:01 PM
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I did not know megasquirt was plug and play... What does megasquirt cost and buck do you have any links of places I can check it out in more detail?
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Old Nov 29, 2005 | 01:16 PM
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pm a member here named tofuball
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Old Nov 29, 2005 | 04:26 PM
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Ted so you know this is what digital tuning told me

Setup questions are best answered by guys on the message boards since you'll
probably find someone that's already tried the setup you have. Every car is
different so every car's fuel requirements is different. For liability
reasons, we shy away from telling people to run this setup or that setup.
You need to run a setup that is going to provide enough fuel for your mods.
Fortunately you have message boards where you should be able to get a
baseline setup for that turbo/mods. As with *ANY* setup you choose, proper
tuning and monitoring of A/F ratio is imperative and the only true way to
know if the injectors you are running are big enough.
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