Injector question
 

OK, I'm a newb to this topic. I installed my FM2 back in the year 2000. Moved, got married, had kids etc.. car has basically been on the back burner for years. I recently rebuilt a 99 motor with forged rods and pistons (car is a 94), and ordered up an AEM ECU from trackspeed to replace the Link. I recently heard rumors that the RC 550 injectors that came with the FM2 back then are basically 'no good'. I had no idea. Never had any problems with them, but then, never really got a good tune in the Link either.

So: Is it 'worth it' to upgrade those?

Right now I'm shooting for a good running motor in the 250whp range. I may eventually upgrade the turbo and exhaust and try for somehthing in the low 300's.

Are the Injector Dynamics 1000's that Trackspeed (and others) sell overkill, or are they just a great injector that will allow nice idle, fuel economy, and have the flexibility to allow future upgrades?

If that's the case then it seems that a couple hundred extra bucks is a drop in the proverbial bucket, and well worth it (if I'm replacing the injectors anyway). One aspect that attracts me is that they are direct plug in's. The RC's I have now run through a resistor.

then get ID750s if you think 1000s are overkill :)

RCs work, but it's old old old news.

Valid point Scott! I guess I know enough on the subject to understand that there are other size options, but I noticed that several miata vendors sell those ID1000's. In the past I understood that too large an injector could cause problems, but I'm wondering if that's changed as technology has advanced.

It has to a degree, in that there are some high-impedance injectors available these days whose dead times (lag during the off-on and on-off transition) are comparable to or even better than the low-impedance injectors of a few years ago.


That said, I wouldn't call the RC550s from the FM Link days "junk." Frankly, they're not much different from any other of the aftermarket injectors of that size range of years past. They work fine up to the power level that they're designed for, and presupposing that your old engine ran fine and you don't expect to exceed maybe 250 HP or so, I can imagine no reason to replace them. Maybe send 'em to the sexy nurse for a good cleaning.

Absolutely.

The RC's are Bosch EV1 1970's technology. Deadtimes are slow and spray patterns are "meh." The newer Bosch EV14 (ID, FIC, etc) injectors are modern technology with night a day better spray patterns and significantly reduced latency. This means better atomization, higher efficiency and more power. Can you run on EV1s? Sure, they have worked great on a lot of applications for a long time. Keep them clean and they will continue to perform well for you for years to come.

I think Reverant has a video of a Miata idling steady on ID1000's with an Enhanced MS2 @ 14.7:1 AFR. They are impressive injectors to say the least.

While we're on this topic, I was lately wondering about the difference between the EV14 725cc vs 850cc vs 1000cc.

Assuming an ECU that has enough resolution to control any injector at idle, does ANYONE know of a SINGLE downside or up side besides peak flow to run the larger ones or the smaller ones vs the "others"?

I hope that makes sense, but just in case:
Meaning despite the EV14's being so cool that you can get either size to idle right, would the 725's idle at least a ---- hair better or easier to control at idle?

Hoping savington or other folks that deal with ID's every day can chime in here.
I've had no problems with 1000's but that's all I've used so far. Not the 725's or 850's.

Are ids the same as bosch? Like the ones deaschworks offers?

DW offers EV6 Crap. Which is denso not bosch EV14's that are ID...... iirc.

Deatschwerks are Denso EV6 injectors. 949Racing sells the RX8 ones new on their site. Nothing wrong with them at all. Mazda liked them enough that they used them as OEM in the NB Miatas and the RX8.

Injector Dynamics (ID) and Fuel Injector Clinic (FIC) both offer EV14 injectors. The fact that Trackspeed and 949Racing both sell the IDs says something about them. These guys usually don't screw around with cheap crap.

I bought my FIC EV14s through another vendor that supports this forum. I would advise against FiveOhMotorsports EV14s though, there are a lot of reports of inconsistency out there for that particular brand.

The ID1000's from TSE is the only acceptable injector set for you to buy. Since turboing my car in 2007 I have ran stock 94 injectors, RX7 460cc injectors, RC550's, DW1000's, and am now on the ID1000's. I wish the ID1000's were available when I started and I just bought them at the beginning. Yes they cost a bit more up front, but knowing you will never have to buy another set of injectors is amazing.

for what its worth i have ID1000's in my 1.6 and can idle fine at 14.2/1 more stable then i could on my rxy 460's at any range from 12-14. i havent played with having it idle leaner but sometimes when im heatsoaked it idles in the low 15's alright. if u look up my posts ive got a SS of the idle after 10min of messing about with them, im sure i could get smoother and leaner if i tried / knew what i was doing.

And *that* is where the newer injectors really shine. They allow you to run flowrates which were considered absurd 10 years ago while still maintaining the ability to achieve a smooth idle and allowing sufficiently fine control to pass a tailpipe emissions inspection. This is welcome news for folks wishing to run extremely high horsepower engines (> 150 HP / liter) while still maintaining a civil, streetable character.

Of course, older injectors still work just as well as they always did- the introduction of a new technology does not cause all of the existing hardware to magically cease to function. As an example, I ran some old-school 440cc injectors on my '92 which I bought from Five-O motorsports (they were re-worked Ford Racing high-impedance parts) and that car passed the CA taipipe test just fine. Not a huge amount of margin to spare, but it always snuck by on the first pass.

The 725s will tune just as nice as the 1000s, but since the 1000s idle perfectly there's really no reason to go big.

We'll probably do 725s standard with our turbo kit (with 1000s optional) just because the 1000s seem daunting on paper - no other reason.

1000s genuinely are the last injectors you'll ever buy. I'll get close to maxing them in Theseus, but that's going to be at ~500whp on E85.

So no difference then.
Gotcha. I've tuned 1000's at least 20 times now and completely agree: excellent injector.
But never had the opportunity to touch 725's. Seems to be a rare injector size (at least around here).
Follow up question (sorry for thread jack OP, and sorry for another silly question Sav):
would 725's be too small for 300-350 on a dw200 pump and e85?

I am le dumb with fuel calculators, but playing with a few on random sites seems they'd leave 0 room for more power than say 300.

I have the dumb with injectors, so have patience. Is there a difference between the Trackspeed-949-or FIC injectors? My understanding is they are all EV14's are the FIC's different? I also don't see a FIC option on their site for Miata's. Just curious. Might replace my RC's one day. Good to know to just get 1000's and call it a day.

They are all the same Bosch EV14's

hands down ID1000. Idles perfect on my 94 with a built bottom end at 14.7. Once you actually have them installed, you'll thank yourself that you didn't go through all the mistakes of buying other injectors, installing, trying to tune, uninstalling, selling them on mt.net and then eventually ending up with ID's

EV14's require a spacer/adapter thing for our rail right? Can't just put them in and bolt it up? I swear I've seen something about adapters for our use somewhere. Stand alone stuff aside, I has.

if you buy EV14's for a miata, they come with the extender

I don't have an opinion on the IDs, as I've never tuned with these (they are really expensive over here), however what I can tell you is that I've tuned all sorts of EV14s from FIC and fiveo (445, 550, 650, 775, 850, 1150) and I'm really happy with all of them.

Now, to be perfectly honest, if you want PERFECT, modern OEM-like idling quality, go with the 650cc. These idle better than the stock injectors. Above that, its starts to compromise a bit. For example, the 775, 850 and 1150 can idle perfect at 14.2:1, but above that they do begin to exhibit very tiny misfires (the ones you get with the stock injectors, when you try to idle above 15.4:1). Many people wouldn't even notice, but I do, and its there, just very discreet.