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Discussion Starter #1
Perhaps a foolish newbie question, forgive me I'm still a fairly recent transplant to the Toyota community.

About a year ago, the Subaru and Nissan guys found a neat trick with their injectors. By removing or modifying the little cap on the end of the injectors, they could drastically (and apparently safely) increase the flow of the injectors by almost 100%. Seemed to good to be true, but it has been proven to be reliable on hundreds of cars by now in the Subaru/Nissan communities. This topic was covered in one of the major Primedia publications also.

Here are a few links so you know what I'm talking about. The injectors themselves (240cc and 370cc) are identical except for the spray caps on the 370cc units have larger holes in them.
Basically, by carefully removing the spray cap on the Nissan 240cc or 370cc injectors they can be made to flow at 550cc.

http://forums.nasioc.com/forums/showthread.php?t=478921&page=1&pp=25

http://forums.maxima.org/showthread.php?t=324271

I know ghetto tuning isn't exactly what most supra owners are into, but what can I say I'm a junkyard racer at heart ;)

Now like I said I personally have no experience with the Toyota factory injectors, I've never pulled my injectors to look at them.

Has anyone tried modifying factory injectors for higher flow, instead of replacing them with aftermarket units?
 

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Discussion Starter #3
You'd still need to have some kind of aftermarket fuel control (AEM, SFAC etc).

The question is can we get more than 550cc of flow out of the stock njectors, or is the toyota design different and thus this little "hack" wouldn't work.
 

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Discussion Starter #4
Apparently the Camaro guys have also been using a similar modification on Bosch injectors to increase flow.
 

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ou'd still need to have some kind of aftermarket fuel control (AEM, SFAC etc).
Yes I know, I have a MAP ECU already, I am just wondering if the stock computer could handle a 10-15% increase in flow.

I also remember reading something about SP modifying a stock fuel system and getting around 6xx rwhp?
 

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Discussion Starter #6
BXR SUPRA said:
I also remember reading something about SP modifying a stock fuel system and getting around 6xx rwhp?
I believe SP made those numbers with a rising rate fuel pressure regulator (ie more fuel pressure going through unmolested injectors), but I could be wrong.
 

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could you modify the stockers (550cc) and get a stronger fuel pump?:scratch: i know mvp sells injectors for the stock rail, but i dont know if they allow more than 550cc. ???
ckc
 

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Discussion Starter #9
ckcdecks1 said:
could you modify the stockers (550cc) and get a stronger fuel pump?:
That is the question of the day. I'm surprised nobody has come forward with any info on this one so far. Surely somebody has had a good hard look at these injectors...

bump!
 

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Are we talking about removing the pintle caps??

If so, I accidentally broke two of mine once ran like that temporarily those two cylinders didnt run any richer then before and when I called fuel injector clinic they told me that it wont effect operation but they will replace them with a rebuild. I pulled the plugs a few weeks later those two cylinder werent running any richer then usual. If you want to bump flow on stock injectors you can always get a bigger pump and crank up the base pressure.

Maybe these guys are talking about something different here? I'm going to read through those threads.
 

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oops, looks like they are talking about removing the cap that pintle cap attaches to. I dunno about this mod man, seems ghetto and nobody seems to know what it does to spray pattern yet other then "looks good". On turbo cars like ours we're running effective compression ratios to the sky I wouldnt want a bad pattern. Maybe I'm just real skeptical because of that old saying "If something seems to good to be true, it probably is" I know I lost knock just by going from one brand of injector to another and I dont think you could see that difference on a tester.

The guy on the maxima thread said that in the end it was a pain in the ass took a lot of finding parts to make it work or something like that. Then I would assume you'd want to have them flow tested and all that before you use them, thats about $30 ea = $180

After all that trouble and you've spent just shy of what new ones cost risked damaging the injector as well. This isnt my cup of tea, at least until there becomes a tried and true process for this. Save $100 for hours and hours of work and if you damage one injector you have now overspent.

It says it doesnt work for top feed injectors and it also said he needed to have machining done on the injectors afterwards
 

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I used to own a STI and looked into this also. It works for the top and side feed injectors from the subaru community. They were machining the entire end cap off of those injectors making them flow an incredible amount. They also had a flow pattern similar to many of the aftermarket options available for those cars. Its worth looking into I think.
 
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