fuel injection question

[danny gabbard]

how hard or what's it take to build and wire something custom, what books? websites, any idea's

[Airspeed]

Its not that hard really, but you will have to 'get into it' like you have done with carbs way back then 
It is all different, but the rewards are huge too.

[Peter]

megasquirt has a great site! i m using it too
i think its www.megasquirt.info ....
prepare to read

[ian c]

danny
it can be as easy or as hard as you want it to be .
i've been researching it recently .

megasquirt gets you the electronics know-how , and the mechanical is basically as easy as bolting on a set of carbs .

cb sell a complete kit (one recently forsale for 1000) it is throttlebodies , inlets , filters , loom etc. and you control it by a 2 swich box .

there latest offering is a "self learning" complete kit . featured in hot-vws mileage project and mike lawless wrote a brilliant article on it .

the megaquirt and others have the learning feature , but they dont sell a complete bolt-on kit .

i'm still looking at the intricasies of fine-tuning an ecu only kit , so cant really offer advice off the top of my head .

[danny gabbard]

I'm just starting to put some peice's together, everything helps when I have nothing.plus  I want to make as much as I can. something streetrod like, wazzu  intake. but the electronics scare me!!

[Martin]

ive been using efi for years now. have been using DTA, but now im using an AEM unit and find that it so much faster to tune and its data logger is only a step away from motec stuff.

i now produce pulleys and crank trigers to bolt onto T1 motors to make it easyer.

dont be scared of it, the worst part is getting that base map in so the car can fire and run. as for the wireing the main thing is that the crank and cam sensors are wired in a shilded cable so it can't pick up interferance from the coils.

you dont have to use a cam sensor, but i do with my set up.

with the AEM setup it was about an hour of messing about to get the car to idle and drive the rollers and about another hour to get up to the 450hp level.

the car starts and drives like a moden day motor.

once you get into the EFI thing you'll love it.

[danny gabbard]

do you use any GM parts like fuel pump, injecters, whats better port style injecters or throttle body. thanks again guys.

[Martin]

you can use just about any sensors, you like.

I use Bosch stuff and a AEM map sensor.

as for fuel pumps you can use any that will flow enough fuel and at the right preshure. If you going to use 'production car stuff' then find a dona car thats about the same hp as what your wanting to acheve. then you know that the pump, injectors will flow enough fuel for your motor.


As for injector placement...

If you using block fire (all the injectors activate at the same time) then mounted in the throttle bodies is good, if your going to run sequential injection then get the injector as close to the valve as posible, this just stops the fuel hitting the side of the port.

but for ease and if your not after the last .5 hp then go for the injectors in the throttle bodies, makes that bit of the instalation easy.

Jenvey do real nice bodies, i have been using there 48mm bodies on a 2276cc N/A motor. this is a bus motor and pulles great. Or CB do a range of bodies and manifolds, never used them myself but they look good.

[Peter]

Hi danny , here s a pic of the mockup of my motor,
injectors facing inside and running jenvey 48s,
when you know the' basics it s not hard to understand how it all works, and the wiring is not that much at all
ill try to find a pic of the schematics...

[Peter]

here ya go!
every wiring harnass is about the same

 

[Lee]

how hard or what's it take to build and wire something custom, what books? websites, any idea's

You might want to try the 'Shoptalkforum' aswell 

[K-Roc]

I Run Megasquirt as well, and have been for the past 7 years,  with 48mm Jenveys, 32# Ford injectors, Bosch pump, and GM sensors,  The harness is a snap to make up especially if you use the relay board option.

My latest iteration is with a MS2 on the 3.0 pcb, and it runs awesome and the autotune feature really works well,
The only area I have had trouble with is nailing down the right settings (cranking pulse width's) and afterstart enrichment percentages. to get clean and consistant starting in all temperature conditions,

So if any of you Megasquirt users have some settings they would like to share with me to try that would be excellent.

Cheers

Darren

[Peter]

hi Darren,
unfortunately my afterstart enrichments werent too well tuned either when i had my 1700, else i would be glad to help

[haldex201]

Hi
My input is too use and omex600 with weber 50mm thottle bodydies.
Engine T1 1998CCM
The ms2 with 3,0software was in the my head but after this it´s out again.
I am still in the design fase. Feed back for the projekt is welcome.
Haldex201



 

[danny gabbard]

WOW cool stuff ! this is very cool stuff and guys thanks  for the time and effort posting. One more question. runner lengths? I want to use 911 fan and make shroud and cylinder tin but a little bit narrower and bring intake a little closer to fan houseing, The reason being so I can get to manafold hardware and change plugs a little easyer. Im not building racecar and the older I get the less of a headeck I need. so back to the question, can intake runners be inboard a little more maybe 1-2 inchs max? and how do you determine the lenght or is it critical

[haldex201]

Hi
After i have use 911 fan, i want dont want to do it again,  the normal coling tin is better if it fits on the motor with no leak.

Is there some one in here, who can help to find a place to buy injektors for 250 Hk.

Best regards

Haldex201

[Austin Larsen]

always put the injector as close to the port as possible

[Peter]

http://www.autospeed.com/cms/article.html?&A=0102&P=1

in this list you can find injectors and rated horsepower....
hope this can help you?...

[Austin Larsen]

another thing to watch out for with injectors is some of the old ones
the bigger they get the crappier the spray its like fuel just flows out instead of like a fine mist
this isnt much of a problem with new injectors they have that mostly fixed to my knowledge

[K-Roc]

always put the injector as close to the port as possible

Not always the case... I know that when Darin Morgan was testing EFI on a Pro Stock engine at Reher Morrison, top end power was increasing as they moved the injector away from the heads. If I remember his own words were.." we couldn't get the injector far enough away.."
They never matched the peak power output of carbs, but only did a minor amount of EFI testing just for fun.

K-Roc,

[Austin Larsen]

where they using a intake designed for a Carb?
if so then in that case the injector would work best up there because that intake is designed for fuel to be injected there
thats why u wont c much horsepower gain when u switch a  VV8 motor over to EFI without changing the intake
ill rephrase my statement
on a intake with EFI in mind injectors are best close to the valves
on a carb intake its kinda hit or miss but id still put mine close
hell if i could id put my injectors in teh chambers like the diesel guys got
another thing
its good practice to use a common ground on all your sensors and the system to help reduce emi along with making sure u avoid coil wires or any other iteams that may cause interfreence
another thing
i forget which way u want to set up the tps sensor but i think u want to set it up so at wot u have the 5V going straight through
because the TPS is more acurate at that end because there is less potentiometer

[Roman]

According to Jenvey: http://www.jenvey.com/~Tech_QA.htm
Where is the best place for the injectors?
Where one injector is to be used per cylinder the best compromise position is immediately downstream of the butterfly. This gains maximum advantage from local turbulence and gives results surprisingly close to the optimum at both ends of the rev-range. This is the recommended position for most applications
For performance at low RPM, economy and low emissions the injector needs to be close to the valve and firing at the back of the valve head. This is the favoured position for production vehicles.
For higher RPM (very approximately 8,000+) the injector needs to be near the intake end of the induction tract to give adequate mixing time and opportunity. The higher the RPM, the further upstream the injector needs to be. As a result, use of speeds above approximately 11,000 RPM may give best results with the injector mounted outside the inlet tract altogether (see our remote injector mounting). It is common to fit both lower and upper injectors in such a system to cover starting and low RPM as well as high speeds.

[Austin Larsen]

http://www.hotrod.com/pitstop/hrdp_0704_pitstop_fuel_injector_location/index.html
"With good atomization, the nozzle can be located downstream, close to the valve."
"High-capacity injectors generate a relatively poor spray pattern with a large fuel-droplet size. As Duttweiler puts it: "You're practically just spraying raw liquid. If you put a big injector too close to the valve, there's not enough time for the fuel to mix with the air.""
that was back in the day
but now that we have good big nozzles that will spray lots of fuel in a fine mist there is no need to put them high to get good mixing because the mist already creates that mixing

[danny gabbard]

thanks austin and all the input

[Austin Larsen]

NP

do u know what ecu your going to get?
i am probab;y going to get the new fast with traction control

[danny gabbard]

It's still up in the air