Decapped Injectors
Thread Starter
Instructor
Joined: May 2013
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Decapped Injectors
I have a set of 60lb injectors that came with my A&A supercharger kit. I'm thinking about decapping them based on a conversation with one of my friends. I thought it was a joke until I went online and and did some reading. Just curious has anyone one else seen or used this technique on their ride.
Safety Car
Joined: Sep 2005
Posts: 4,226
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From: Orange County Ca
I have a set of 60lb injectors that came with my A&A supercharger kit. I'm thinking about decapping them based on a conversation with one of my friends. I thought it was a joke until I went online and and did some reading. Just curious has anyone one else seen or used this technique on their ride.
Thread Starter
Instructor
Joined: May 2013
Posts: 184
Likes: 2
Decapped
After a little more reading this seems to be a regular alteration on injectors. I've also seen a lot of the big injectors with no caps. At this point my only concern is idle. Since I have to get bigger injectors I will decap 3 of them and send them off to be cleaned and flow tested since its pretty cheap to do so. At this point I'm just curious.
Race Director
Joined: Dec 2013
Posts: 12,502
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Understand that you need not only the injector to atomize the fuel, but need to know the balanced amounts that the injectors are producing as well.
So what happen on uncapping, is that the injector just end up just garden hosing fuel in that is not atomized, and worse, fuel rate flows all over the map on what each injector is producing a well.
So you end up with this to start with,
And when you go to flow test the injectors, all over the map against each other as well. Hence without the actual flow rates of the injector, don't even have the info to plug into the ECM tables to begin with.
So what happen on uncapping, is that the injector just end up just garden hosing fuel in that is not atomized, and worse, fuel rate flows all over the map on what each injector is producing a well.
So you end up with this to start with,
And when you go to flow test the injectors, all over the map against each other as well. Hence without the actual flow rates of the injector, don't even have the info to plug into the ECM tables to begin with.
Last edited by Dano523; Jul 8, 2018 at 11:26 PM.
Thread Starter
Instructor
Joined: May 2013
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Decapped
That would be a nice video if it actually had decapped injectors. The first video you trash it as it explained nothing. Just showed a bad injector. The second was a set of new non decapped injectors with a little grain of evidence. Now, I have a quality set of injectors that have been flow tested prior them even being sold with the kit (FIC), I have all the injector data and there are a ton of YouTube video that show the exact opposite of what you tried to articulate. Like I stated in my previous post injectors will be sent out and flow tested as it is super cheap for this service and I don't mind d the water hose effect as long at it runs correctly at low throttle. Thanks for the advise but I'm really reaching out to the audience that has actually done it.
Le Mans Master
Joined: Apr 2011
Posts: 7,821
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From: Montreal
St. Jude Donor '13
If you want that info head over to "sloppy mechanics". Those guys do that and also change out junkyard motors every month. I seriously doubt to many vette owners are going to risk their motors by saving a few bucks using crap injectors.
Thread Starter
Instructor
Joined: May 2013
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Decapped
Yes, I agree with that statement and I've seen the video. I'm just amazed that this was even an option. I'm still going to purchase new 95lbs injectors I just want to know if anyone has tried it. There maybe be a use for them later down the road in another project
Safety Car
Joined: Feb 2016
Posts: 4,448
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From: SC
I've never heard this term "decapping" before but from a little googling, it appears this means removing the orifice plate. The orifice plate is what controls the static flow rate and spray pattern. Removing it will certainly increase the static flow rate but they will be all over the place. You will probably need a dozen or more and a flow stand to find 8 decapped injectors that flow close enough to make a decent set. Engines that are only trying to produce max power care very little about spray pattern but if you have to pass any sort of emissions test then spray becomes very important. Spray pattern will also have a big impact on cold start and drivability. Again, not a consideration if you are only looking for big power.
Personally, I would never do this but since I work for an injector manufacture I can build the exact flow rate I want any time I want.
Personally, I would never do this but since I work for an injector manufacture I can build the exact flow rate I want any time I want.
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Thread Starter
Instructor
Joined: May 2013
Posts: 184
Likes: 2
Decapped
Totally understand and low idle was my main concern. I just wont chance myvette engine but I do have another project that is drag strip only I think would be great. I hear all the comments and I could have posted the set I was going with on my vette and it would have been the same response since most people are brand loyal. If I wasn't going with what they know to be true they would have start trolling on the organization vs what is true. Thanks for the feedback and your assessment on the screen was correct. I will say this though you will be surprised at how close they come in comparison to their flow rates but like you said this can be a gamble.
Burning Brakes
Joined: Jul 2008
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From: Green Bay Wisconsin
Burning Brakes
Joined: Mar 2011
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From: Tampa FL
St. Jude Donor '13
Years ago I de-capped Ford 47lb/hr injectors and used them on my turbo Mustang I was building at the time: http://www.angelfire.com/fl5/qa1/ --about 1/2 way down shows my injector test data. The flow pattern looked horrible de-capped, and the flow varied from injector to injector quite a bit. However, I was using an AEM stand alone so I could electronically balance the injectors. Surprisingly, the idle quality was just fine and even passed emissions probably more a result of the idle tune. My methods were crude but the results were pretty good.
It is a direction you could take but be prepared to do some additional homework to balance the injectors and deal with a finicky idle tune. The car ran the True Street program for years and was a 9 sec capable 1/4 mile car with a single turbo, a 306 engine I built in my garage, and tuned myself.
It is a direction you could take but be prepared to do some additional homework to balance the injectors and deal with a finicky idle tune. The car ran the True Street program for years and was a 9 sec capable 1/4 mile car with a single turbo, a 306 engine I built in my garage, and tuned myself.
Last edited by MickVette; Jul 10, 2018 at 11:31 AM.
Safety Car
Joined: Jan 2001
Posts: 4,387
Likes: 691
From: Boise ID
Years ago I de-capped Ford 47lb/hr injectors and used them on my turbo Mustang I was building at the time: http://www.angelfire.com/fl5/qa1/ --about 1/2 way down shows my injector test data. The flow pattern looked horrible de-capped, and the flow varied from injector to injector quite a bit. However, I was using an AEM stand alone so I could electronically balance the injectors. Surprisingly, the idle quality was just fine and even passed emissions probably more a result of the idle tune. My methods were crude but the results were pretty good.
It is a direction you could take but be prepared to do some additional homework to balance the injectors and deal with a finicky idle tune. The car ran the True Street program for years and was a 9 sec capable 1/4 mile car with a single turbo, a 306 engine I built in my garage, and tuned myself.
It is a direction you could take but be prepared to do some additional homework to balance the injectors and deal with a finicky idle tune. The car ran the True Street program for years and was a 9 sec capable 1/4 mile car with a single turbo, a 306 engine I built in my garage, and tuned myself.
