With my built motor and twins, we decided to go a different route in regards to fuel. Instead of doing 6 big injectors, we decided to try something old and true: secondary injection and of course, a fuel return. Pro drag cars have used it for years, and it has proven reliable.

The Greddy EU is capable of controlling 2 extra injectors, much like the Stillen SS box controls a 7th injector. So, I'm using 6 stock injectors and 2 850cc injectors. That should supply more than enough fuel for now until I build the 5AT. My tranny will become suspect way before I run out of fuel, but I plan to run high/low at about 500whp and 400whp, respectively.

Dyno sheet coming soon

Some pix attached for your viewing pleasure. Comments? Questions?

 

YUMMY!!

Now that is interesting. Is it running now with this setup? Please include a video with that dyno sheet.

 

Yea I was using the 2 extra injectors on my prelude. I didnt like it at all, but I was using the MF2 as a controller I think thats where the problem was.

 

Nice. What sizes are the primary injectors?

 

stock...The idea behind this is to retain driveability and avoid scaling injectors...we also found that the new EU firmware has a bug in it for scaling injectors. Yes, the Utec CAN scale injectors, but it's linear scaling, and injector pulse width is not linear so it's not a 100%. I just want to say that now so this doesn't become an EU vs Utec thread

The EU has full control over the 2 extra injectors and uses them as needed when it sees boost (obviously).

 

Another quick note, the shop has already done this with a TN kit and a built motor and it runs superb (even tracked a few times in the few short weeks after the tune), with around 450whp and 500tq

 

very nice!!! I have seen a few people do this before and was kind of suprised i haven't seen anyone ask about this on here. Where did you get the hardware to mount the injectors into the plenum? Looks very professional

 

Scott @ Ballistic Motorsports did all the work. He welded the injectors into the plenum, got the AN fittings, braided lines, and connected everything together. Top notch work

 

this idea would be good if u could evenly distribute the fuel to each cylinder. alas, you cant.

Some people say 'but the cylinder will suck enough in when it sucks the air'. lol.

 

Using throttle body injection in an intake manifold not designed for it is a no-no... I hope it doesn't cause you any problems.

 

Welcome to the 1980's band-aid solution to no larger sized injectors available.

Looks like it was well done, just kind of stepping back 20 years. Hope it works out for you.

 

A boosted car does not suck air, it is forced into the cylinder This would not be used for an NA car

Second placement of the injectors is key , hence why we fire against the air flow to help atomize the fuel better . If you have proper atomization anywhere the air goes the fuel will go :-) This is no different than people using meth injection to raise the Oct and cool the air ................ or Nitrous. If the injectors were stuck in the middle of the plenum or anywhere else I could see a problem, as the air would have to bring the fuel back to the back of the plenum. As long as they are in the intake track you are good .

speaking of cooling, there are benefits to secondary injection .


Pros:
Cooling of intake air without worrying of running out of water or meth .
Cleaning of intake plenum of all the oil that accumulates that can cause detonation
Better idleing than a piggyback or standalone with lager injectors
Prevents misfire codes on piggybacks with large injectors with super small pulsewidths
Better fuel milage
Will pass OBD testing
and most important added fuel for more boost

20 year old technology? Yes it is old school but still used by many today . If it is so old school why does HKS, Greddy , Stillen , Whipple , Hanns , Splitsecond, etc still support it? Hanns just got a innovation award for it 2-3 years back from Sema for the same design as Ballistic's s2000 system . Just because someone developed something different does not mean it is better.

 

Turbos and superchargers are old technology, why do we still use them? hahaha...

I think this is a very fresh approach and 617G's explanation of where they are placed and their function makes perfect sense in my mind. It really is no different than nitrous or meth injection on a forced induction engine.

 

Because it's cheap and easy. That's the only reason, not because it's the correct way to anything close to it. Not to mention all the companies you mentioned there are well behind the times in terms of new technology.

Like i said hope it works for you, just that it's odd to see such a backwards step.

 

I'd add to this that the reason they support this is typically for CARB approval. Since its EXTREMELY difficult to get cold start emissions under the pass line with larger primaries those companies resort to secondary injectors which aren't spraying at idle or when the emissions test is run so that there is no way for them to fail the emissions test.

 

Well, don't bag on the guy too much.... It's always nice to see people trying new things. You never know when his findings could come in handy. Once people start maxing out those 1000cc injectors, this information could come in handy...

 

Well they do make injectors bigger than 1000cc .
Anyone making enough power to max 6x 1kcc's will have a proper ems that will be able to handle low impedance injectors or run staged injection.

Never was bagging on the setup per se, it looks clean, in fact one of the better AI installs I've seen done. I was just commenting on how odd it is to see such an arrangement this day and age.

 

Well, the shop had been doing this on s2k's for a while now with great success, and after the 350z that was done, I decided to give it a try. I will report my findings soon w/ dyno sheet included

 

++++111111111111

glad to finally see some creative thinking around here! Lately i am sick of reading all the bickering between shops and there customers and ish. Finally some good technical debate .

 

good stuff bro.


I know Hal from Injected performance used this way back when he still had his turbo'd maxima. Dude made like 550+whp on stock block vq30 using 370cc injectors(i think) plus a auxilary injector driven by the emanage blue.