Has anyone tried the M7 400mm injectors and if so are you happy and what mods do you have?

Showvan

 

First off I am a partner with M7 so take my post with that in mind. I have had the 400cc injectors in for about 9 months now and about 15,000 miles. Car starts and idles like stock and gives a great little series of snaps and crackles when backing off the throttle. My gas mileage has suffered a bit perhaps but that is more than likely because I am on the throttle a lot. As for engine mods I have at present , 15lb flywheel, Plasma Booster, jackson racing header, Borla race exhaust,15% pulley, Pipercross Viper CAI, Jackson 8.5 mm plugwires, M& device, 180d thermostat. Bottom line is the car runs like stock unless pushed then the mid range and top end pull quite nicely . Again my opinion is certainly biased but I noticed that you had not gotten any feedback so thought I would drop in.

Randy
Team M7

www.M7tuning.com

 

I have heard a few people who have used them, really like them. The one advantage is that they are the stock injectors reworked for a higher flow rate. Therefore the fit on them is much better than some of the other units out there. You probably won't see a notice unless you have some major mods on your car that may drastically affect the A/F ratio (i.e. extensive head work in conjuction with matched headers, NOS...). The stock injectors are pretty good for most mods such as a pulley and small head work, intake and so on. When the air really gets moving, the stock injectors can't keep up. I think that jlm has done some extensive tuning with a set of 400cc injectors (not M7's) with an Apex'i and had some really good results.

 

Does anyone else think that to get the full benefit out of modded injectors you'd need to tune the ECU software? Or do you think that the ECU is "smart" enough to adjust for the 400mm injectors and/or that an ECU upgrade like the PowerChip or Unichip would work just fine.

Maxmini,
What ECU software are you running? I did not see any ECU upgrade.
Also don't you have M7 rebored throttlebody?
Any upgraded spark plugs?
With the M7 lightweight flywheel did you reuse the stock clutch or put in a racing clutch? Any Quaife or other LSD when you put in the flywheel?

 

The stock injectors are also maxed out at high RPMs with the 19% pulley.

 

I have the JCW program at this time on the stock ECU.
Do not have the new throttle body at this time. Everytime one comes available we sell the damn thing. Will have a 62 by the end of the week or else
I use Iridium IK22
I am using our upgraded pressure plate with a stock mini clutch plate with our LW flywheel.
No Quaife but that will come with the head / cam uprgade in the near future.

 

I would agree completeley with maxmini, I have had Peter's injectors installed for about 3 weeks now on after his recommendation with the 19% pulley which is said to run a little lean on top. I also am finishing up the install on his Venom nitrous kit which I intend to use with great caution since I know next to nothing about the stuff but he did mention it's very important with NOS so I went for it.. I get the little burbles and pops off throttle as well which tells me it's a little richer than before but hard to say because I did a Miltek header and cat-back system same day I did injectors which where pretty easy to install by the way. I also use the densco IK22 colder plugs, other mod is alta intake, that's about it for now but would like to have head work done by Peter as well, He's been very helpfull with all my questions about mods and I p[lan on sticking with his products whenever possible and I basically plan to mod this car to the limit.

 

greatgo or SCCA,


Do you know at what rpm range it starts becoming lean with the 19% pulley? How easy was it to install the M7 injectors?

 

5500

 

wow thats quite a bit lower than I expected. Is that with stock internals or your high flow setup?

 

high flow head, header

 

How ar those RC440's? I tried contacting SPI, but they never got back to me.

 

I spoke with Eric at Helix13 and I thought that the MCS with 19% pulley ran rich until close to redline when it ran lean using stock injectors and head. 5500 rpm to start to run lean with high flow heads seems on the low side but maybe it is more like 6000-6500 rpm to run lean with stock injectors and head. Anyone check this out?

This means those with 19% pulley upgrades are loosing out above 6000 rpm range up to redline as the MCS is running lean. Could be improved with larger injectors and ECU tuning but when the high rpm range is improved gotta watch was happens in the low rpm range as well.

 

took the mini out after the latest mods and it shut down at the top of the rpm`s for a lack of fuel. It is a demon
had to order the injectors with rush shipment to which Peter at M7 did an excellent job.
Already install the injectors, however we are having some weather problem so I would not take her for a run untill Sunday (hopefully)

 

you got it, minihune. that's what the $350 Apex'i is for. using that combo, I could keep a very flat 12.5:1 A/F up to 5200, and then richen it a bit to 11.5:1 from 5500 to 7000, but also still flat. Before the injectors and Apex'i, it ran way rich and not flat (11:1 or more up to 5500,) and then started to lean out, reaching for 14:1 at 7000.

 

dont you also have a larger A/A IC? (thought I remembered reading that you welded one up from 2 smaller ones)

also, I thought "ideal" was 14.7:1 (http://auto.howstuffworks.com/question257.htm).

If so then at high rpm with stock setup, it lean-err but still not dangerously lean, heck not even ideal. of course I could be waay wrong on this one. confirm please?

 

The computer will compensate for the new injectors at part throttle. Thats why maxmini thought he was getting super milage when he first installed them (the ECU cuts back the fuel trim).

At WOT, you'd have to tune specifically for them like JLM does or just go with more is better (that seems to be MINI's philosophy with the stock programming).

You'd see benefits without additional programming if the injectors are blueprinted and matched as well as enlarged. That way you'd have uniform spray patterns and flow rates so the computer can make more accurate calculations without cylinder variations.

--
Cheese

 

forced induction engines want a richer mix at higher load and rpm; most people suggest 12.5:1, more or less. at other times, ie. partial throttle, when boost is low, yes, 14.7 is the norm.

I am farting around with welding up some larger IC cores. So far, I have made 2 units and found that they also need some creative ducting to force the incoming air through the core.

As far as the testing done to my car when setting the apex'i to control larger injectors, we did try it with a larger IC. Got 10 more hp (went up to 220whp!). next step was to replace the stock IC and put some miles on the setup. From the dyno runs and A/F we had set, there was a bit more to be had by further tweaking, but it seemed prudent to be conservative until the car had some miles on.

So far, after about 5000 miles, I have had no problems...just waiting for some wrenching time.

 

oh I had not considered that part of it. Still I wonder why? do the reaction dynamics change with increased pressure (I assume pressure is the relevent factor here)? I'm afraid I'm not much of a chemist (but I'm a reasonably good thread hijacker )