5th injector setup - why not?

[Encino Man]

I was thinking about what i'm going to do for fuel with my turbo kit. I
read up on the system that F-Max uses..(ERL MK-2??) Anyway, it sounds
like a good idea. Whats up with this setup? why isn't everyone using it?
Is it a bitch to program? I've been thinking about this all day and i
can't think of anything BAD about it.

Just wondering what some peeps thoughts were on this setup before i go any
further.

Also.. where do you mount the extra
injector(s)

[zip]

It was last month's issue of SCC and it said that the JR miata they tested had a fifth injector before the TB to inject more fuel during boost. I can't believe no one has posted a topic on that subject yet until now.

[Encino Man]

is that the same issue that sais the B16a is harder(or was it just as hard) then the h22a to install in a EF CRX/Civic? man. sometimes i feel like burning my SCC mags. i only buy 'turbo'

Ok people. lets talk 5th injector setup. i really really want to learn about this. could it be a better alternative then a Zdyne? a step down from the accel DFI? i want to hear what people have to say about there f-max kits.

[BodidoGSR]

I would imagine it to have the same downfalls as Fmax: The fuel isn't evenly distributed to all cylinders, fuel pooling up in the manifold, etc... Just what I've read though. This isn't firsthand.

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Painfully stock 2000 GSR

[SEFI8LO]

Also an auxiliary injector upstream of the throttle body would create the possibility of a very nasty nasty backfire situation.

[rjaffey]

Especially if you add Nitrous!

[JRCivic]

Why don't you just buy that killer STR set-up from TurboGSR and forget about all this other stuff ???


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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.68 at 110 mph

[sirg]

The 5th injector is mainly design for street racing, street racers in Japan loves these 5th injectors, sometimes they dont want to get 550cc injectors and deal with the rough idle. (tho most of cars that have 5th injectors are big dogs skylines, Rx7, you know the tough shiet) so they get the 5th injector instead and only turn that on when your racing someone next to you. it is a very good idea if you can find someone who can ture it properly, the injector and the computer that controls the fuel cost about $900+ i think. unless if you use domestic fuel controller.

its pretty difficult to tune the 5th injector properly. unless if you or someone that know how to do it then go ahead, if not, its a better idea to save the money and not waste time with those setup. or there may be a pre-programmed computer for the 5th injector, i am not sure about that.

unless if you know that you need that much fuel, its a better idea to get an ECU and bigger injectors.

[SEFI8LO]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by DirtyLude:
The only problem with a secondary injector driver is even fuel delivery to each cylinder. This is more of a problem on our Honda's, because of the bad plenum design. Fuel spraying in the throttle body can get thrown to the back of the plenum and starve some cylinders while over richening others.

Without that problem, the secondary injector controller is superior to an FMU as it's programmable by RPM and boost. To stop tip in detonation I have the injectors kick in just before I hit positive pressure. I can also program it from the cabin if I need to. Run the car close to the edge when dragging it and give it plenty of safeguard fuel for daily driving.

I have an F-Max kit on my Prelude with an ERL MF2 secondary injector driver and it works well. Because of the fuel delivery issues I'm debating whether to go full EFI or make an adapter to run 4 injectors directly into the runners.

I saw this adapter on a Civic last summer and I think I might try and make something up that's similar. I'm waiting for a new intake manifold, when that comes in I'll start taking measurements.



He's running the stock injectors in the adapter and the secondary injectors where the stocks used to be.

EFI Systems makes a secondary injector controller as well. http://www.efisystems.com/sid.htm $400 for everything you need, except the injectors. HKS makes one, but it's much more expensive. I think www.carparts.com sells it.

<HR></BLOCKQUOTE>

Its not because fuel injected hondas have poorly designed plenums that theres fuel distribution problems with AIC units.. Its because fi cars in general arent designed to carry "wet" airflow. fi and carburation manifolds are designed alot differently. its like asking a airplane to fly under water.

[DirtyLude]

Even though it's not designed to carry wet airflow, my point is still valid. The standard Honda plenum is not the most efficient design with the airflow coming in from the side and carrying a fuel enriched intake charge only compounds the problem.

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DirtyLude
Toronto Prelude Club