Have installed a 19%, cat back exhaust, CAI and plan someday to get a header. Currently looking to get an ECU "upgrade" whether MTH or GIAC, I have yet to make the decision. However, I am leaning towards MTH.
GIAC calls for larger injectors, MTH says it is not required. Question, is there any benefit of installing the JCW 380cc injectors and leaving the stock ecu programming or will it simply run rich as a pig. What about with the MTH tuning? At my HP level is there any benefit, at all. Piston, valve cooling?
Thanks,

 

I'd like to know this, too. I switched from 15% to 19%, then a few weeks later put in the JCW 380s, without ECU changes. Although I'm sure there is power to be had with MTH/GIAC, the injectors alone made a surprisingly nice power bump in the mid range. I really expected there would be idling problems or something, and that I'd have to limp up to Helix for a GIAC flash. But no, the car runs great under all conditions. Eventually I will do the flash, probably GIAC, since it has the 30 day satisfaction guarentee. I'm curious to see if the software makes much difference, since it seems most folks do all the mods at one time.

 

Yes. The 380s are a pleasent suprise. Better idle, smoother through all ranges.... What ever you do, IMHO, the 380s are worth a long look as an early upgrade.

 

Isn't the ECU programmed for the specific injectors used. Thereofore, in closed loop operation the ox. sensor would adjust the duty cycle for proper air fuel ratio. In open loop, wide open throttle, it would use the programmed maps and because I would have a larger injector, thus a richer than needed air fuel ratio? How is it that many report that their car seems stronger with the larger injectors, even without a "proper" ecu map? Do the JCW's have a better spray pattern? Am I missing something?

 

I agree larger injectors should give absolutley no performance gain unless you get a re-mapped ECU. I am sorry to hurt your feelings, but I think you guys are only feeling a placebo effect.

Not-so-rednwhitecooper and I have done a few side by side WOT powerband tests: Our mods at the time were almost identical except he had 400cc injectors. We had identical power from 2k-7k rpm.

My point is larger injectors will nicely compliment a 19% pulley and remapped ECU, but injectors alone should gain nothing.

 

That's basicaly what my mechanic told me. I don't need the 380c injectors since the maping programs they did in my cpu has the fuel/air flow at optimum. He basicaly told me I don't need them.

I felt better sisnce I can use the money toward other upgrades.

 

One element of the JCW kit is 380cc injectors. However, must get ECU re-map to exploit the mod in a stock MCS. The JCW engine kit includes intake, injectors, approximately 16% redux SC pulley.

The aftermarket modification trio of GIAC ECU re-map, 19% pulley and 380cc injectors together is a widely recognized MCS performance "package."

Many well-recognized NAM tuners have opted for larger injectors, though not ALL of them support the idea that they are "NEEDED". Dr. OBNXS runs 380's last time I noticed, and though I don't know what the numbers were that convinced him, Dr. O is pretty fanatic about requiring proof of added value of any mods. On the other hand, DMH Motorsports (see NAM vendor directory) has argued that the stock MCS injectors are sufficient to pretty high HP ranges. I don't remember specifics, but I think his site has details.

FWIW, my own next mod is an OBX header (as soon as it arrives from Helix) and 380cc injectors installed with a FBT Racing ECU tune, since they are located nearby.

 

Odd, I thought the JCW pulley was a 14.5% reduction?

 

It is.

 

For sure The injectors are only going to do what the ECU tells them. Nothing more.


With any pulley 380s are an improvment, even without the ECU re-map.
There are noticable small changes, idle, cold start, throttle responce & smoothness through out all ranges. With an ECU tune all the mods = more better.

 

I stand corrected. Thanks.

So would JCW's use of the 380cc injectors with a 14.5% redux SC pulley would appear to be an even stronger "argument" in favor of using them as a relatively early mod?

Don't remember where I got the 16% number, but it was here on NAM. Just shows you can't believe everything you read!!

 

The strongest argument, for 380s, is future upgrades. Helix has a trick 380 for less cost than the JCW. It could be better yet as it has a twin spray ( for the intake port design ) that the JCW does not.

 

Actually, JCWs have the twin spray as well. Eric acknowledges this in the thread where the new 380s were introduced. What I don't know is whether other injectors like the M7 400s are twin.

 

Are all the JCW 380s twin? Or just a new generation..... I don't remember seeing the 2 holes, then again I don't wear my reading glasses when I work on the car.

I didn't see the thread. I have seen the Helix video.

And No I did not sleep in a Holiday Inn.... shoulda..

 

Yup, the JCW 380s have two holes, at least the ones I bought this last Sept from Outmotoring, when they were on sale.

 

Thanks. Just looked up the JCW injector, there's only 1 PN.

Now I don't need to go to a Holiday Inn

 

Acknowledging that an ecu tune would fully exploit larger injectors, but what do you folk think if I move from 15 to 17 and not upgrade my existing AmD ecu tune? Do you think this scenario would be better than not having an ecu tune with the larger injectors?

 

You don't need 380s for a 17%.

If your budget fits then 380s are a good long term upgrade. The tune will be an improvment reguardless, 380s or not. 17% + 380s & tune = better.

 

When you guys say an ECU remap after adding 380 injectors, is that on the oem ecu or an add on like GIAC or Unichip?

 

Unichip, MTH, GIAC tune is what we are refering to. The factory JCW tune will work as well = least expense.