What injectors should i run with this setup?

272 Cams (in/ex)
Cam Gears
Injen Downpipe/Straight exhaust
255 fuel pump
Injen intake
Borla header
Greedy BC
Injen FMIC
Forge BOV (recirc.)

I was thinking 680s from Buschur but was wondering would 720s hurt???

I plan on upgrading the turbo down the road so i think 720s would be better. Or is there really not a big diff. between the two?

 

This is really going to depend on what you are using to adjust/handle them. EMS or piggy back. An EMS can handle much larger injectors so I would say atleast 720's I prefer bigger though. If you are running a piggy back I would check to see what they can handel because usually they have issues with driveablity if you go to big. Most of they time they can handle 680s and probably alittle bigger but it is all depending on what you go with.

 

i was just planning on getting a re-flash for the mods i have. is that gonna be good enough???

 

I know that a few of the people that offer the reflashes can do some pretty good recaling but I would still ask who ever that is to make sure you get what they recommend. But with the flash you should be great.

 

who do you recommend?

so are you saying with a re-flash 720s will be fine with my current setup?

 

If you're planning to upgrade your turbo down the road, I'd go with the 720s. I've got the 680s with a BR440 turbo upgrade and at 22psi I'm running duty cycles in the 73%-75% range. If I run 100 octane and crank up the boost to 24 or 25 psi, I'd probably be seeing IDCs close to the 80%+. Safe, but not a whole lot of head room.

Pretty much any of the flash tuners should be able to scale 720s with no problem. I'd choose a tuner that is close to you or at least makes somewhat regular road trips to your area. Both Dynoflash and Vishnu make road trips. I've had pretty good service with Dynoflash so far. Many others swear by Vishnu and Turbotrix as well.

 

thanks for the quick replies. i'm probably gonna use Dynoflash. was gonna use Vishnu but they are hard to get a hold of plus they didn't return my call. Dynoflash did!

only reason why i would replace (upgrade) my turbo down the road is that i have a feeling my stock ones gonna take a crap. i have no confidence in it cause my first evo the turbo went out after 8k.

 

If you are staying with the stock turbo 680's should be big enough for you all around (Best bang for the buck). But if you can go with 720's it isn't going to hurt, the lower the duty cycle the better honestly but anything over 720's on the stock turbo is probably going to be a bit over kill. Just remember buy good name brand injectors usually you pay for what you get and fuel is nothing to hold back on. , Also if you are going with dyno flash send him a pm just to make sure he doesn't see any downfall in 720's over 680's on the stock ECU Reflash just to be sure this way you know that you are getting exactly what you need and you can get the best flash possible for everything all around.

 

Ok.. these discussions remind me of the carburetor debates I used to see all the time..

Bigger is not better.. You want injectors big enough for your application but not so large as they are difficult to adjust.. If you are getting a good tune on 550 CC injectors, but running at over 85% (75% or more I would consider it) under full volume/full load.. Then I would take a step up.. But only enough to accomodate the needs of the engine.

I understand that injectors are necessessary in most uprades, but with a stock-is turbo, 700cc's or more would likely not be worth the additional time it would take to get them to idle without surging(assuming your not using an EMS which makes it alittle easier)

Keep in mind the bigger the injector, the harder to meter small amounts of fuel, so unless you REALLY need 800cc or 1000cc injectors, I would stay away from them.

My combination is going to be using the Buschur 660cc injectors, I may have to go to 720cc or so, but for the time being, I don't see it necessary.

if you have a very specific plan for your upgrades, and you are certain of what you need, then getting the size you need for the ultimate endpoint is certainly a good way to save money (not replacing them as you exceed the volume) but again like I always say, set a realistic goal and stick with it.. bigger isn't always better.

Most of the guys with difficulty getting their cars to idle are using larger injectors, oversized cams, and other mods that lower airflow rate (not volume) through the MAF, the endresult is idle that surges up and down as airflow changes due to the large injectors swinging back and forth between 0% duty and 1% duty which generally means it will swing between too lean and too rich and the idle will surge up and down, hence affecing airflow more.. etc.. etc..

Keep all this in mind..

 

I'm not trying to get 720's cause i think it's better for my application, it's cause i'm pretty sure down the road i will go with a different turbo. i don't want to spend the extra money to have to switch them out if the 680's aren't gonna be suffice when i do make the change. but if the 720's are gonna hurt my current combo than it won't be worth it cause who knows how long it'll be before i do get a different turbo. it may be tomorrow or it may be next year. like i said it all depends on if the stock one grenades.

so are Buschur injectors any good? what others do you guys recommend???

anyway thanks again for helping a newbie!

 

Thanks for stepping in a clearifying I really appreciate it. If you notice at the bottom of my post I said to contact Dynoflash to see what would work best for the reflash.

 

opps! btw, i meant 660's not 680's

 

It's funny. Buschur lists 660s on their website catalog, but when I purchased my fuel pump and injector upgrade, they sent 680s. At least that is what was indicated on the sales invoice.

 

YEah I noticed the same thing.. I also recall reading somewhere that although their 680's, their probably in reality rated closer to 660 for whatever reason.

And I wholeheartedly agree with the previous post about contacting the vendor you intend to use.. They have combinations and recommendations for a reason, its best not to try to reinvent the wheel if its already been done umpteen times. Best bet is to contact your intended tuner as mentioned earlier.

I always say this.. but look at what your realistic goals are.. If you drive the car every single day, rarely drag race, occasionally hit a track day hosted by PCA or SCCA, then a stock turbo and basic bolt-ons, and a piggyback or reflash will make a night-and-day difference with the car.. Big turbos are fun for dyno numbers and bragging rite, but there are sacrifices you make for improved performance, many may not be able to tolerate the compromises of big cams, complicated engine management, downtime, or drivability compromises.. Take all these things into account when you set your goals.

 

in all honesty i don't want to replace the turbo but if it blows why not replace it with something bigger and better? that's how i look at it. i hope it doesn't happen but with my last one giving way i just have a feeling it's gonna happen again. the car i'm building is not intended for street use. it's strictly for open track days and local autoxing. but of course it'll see the street when i feel like hunting down a STi or two. j/k street racing's for kids.