Carbs Or Injectors?

[Gecko71]

I have a bit of a dilema.

I'm currently running a weber'd up 4AC KE70 on my P's. It's a good little car, around 90hp, plenty to play with.

Despite of this, I will be upgrading to a 4AG when i'm off my P's and onto open in a bid for a bit more power. The question lies in whether I should go for Carbs or Injectors?

The two options I am tossing up is a directly transplanting a small port into the car (the usual 4AGE conversion), or to go with the 16v head (and block) with twin 40mm solex's/weber's/dellorto's. I know the biggest concern with the carbs will be the fuel consumption, but that is something that does not conern me greatly. Plus, I have a bit of a soft spot for Carbs, I'm a bit more proficient with them than I am with EFI engines.

I just ask for some feedback on what everyone's personal preferences and experiences are, and why?

Thanks.

[Trev]

For simplicity of the install and go the carbs.

 

EFI tends to be more of a pain with fuel lines and the wiring.

[parrot]

EFI will be a better car to drive as a daily, IF, and I mean IF it is wired in properly. This is not as easy as some people claim.

 

Carb is simpler to install, but not much cheaper by the time you buy all the bits and get them properly set up on a dyno.

[ke70dave]

as much as the sound and throttle response, and general old school'ness of carbys is appealing, i still love EFI.

 

i just have a (what some consider boring) 16V in my ke70, but its great! plenty of power, 100% reliable and EFI is great for daily driving, weather its sitting in traffic at a stand still or crusing along the highway at 110km/h it dosent miss a beat. starts first time every time and certainly takes a beating.

 

i don't know why everyone thinks that EFI is difficult to setup in a carby car, just do it once and do it properly.

same deal with wiring, there is not alot to it, but if your not electrically minded it can be difficult. either spend a few weeks learning about electrics, or pay someone good money to do it. or find a mate who you trust to do a good job.

 

EFI is like a "set it and forget". the tune isnt going to change in the computer, and on the 16V its such a simple (and somewhat primative) EFI setup there is very little to go wrong.

Edited October 5, 2010 by ke70dave

[jono1986]

Why does everyone claim that electrical is so hard, you have a wiring diagram and a loom, done. Carbies are so much harder to get right, and with my experience with carbies there a constant problem whereas EFI is just set and forget.

[parrot]

The hard bit with the electrics in an ECU controlled car, is that the ECU can only do its job based on the information it receives. Map sensors, TPS's, cold start switches etc are all easy enough. But how many people install the idle up circuit properly? And then they are always complaining about idle characteristics, too high, too low. Car cuts out at the lights, or you sit there blipping the throttle to keep it going.

 

I agree totally with KE70Dave, but as he says, you need to set it up right.

[ke70dave]

agreed that alot of the auxilary functions are never hooked up on these conversions. but then again you can get away with out an idel up for if you don't have A/C or power steer.

 

on my car i have no idle up, but i have gone about blocking up every port properly and i just use the butterfly to control my idle speed. and i have none of that water business up near the throttle body either.

 

ideal? nope, but it will idle at exactly 1000rpm all day every day ). and so long as i drive it gently when its cold i never have a drama. though its a different story if my brother needs to reverse it out the driveway at 6am, he will stall it a good 6times!

 

(can be slightly difficult to start on REALLY cold mornings, might need to help it out with a bit of throttle for the first couple of seconds)

Edited October 5, 2010 by ke70dave

[philbey]

Yep that's true you got to set it up right. And funnily enough, the same thing applies to carby cars, you have to set it up right.

 

I would vote carby's in this instance because Gecko71 has already stated that he's proficient with carbies.

 

Carbies are more mechanically involved, jetting, linkages, balancing etc. The work you put into getting those things right is akin to spending the time carefully wiring up an EFI motor, so it really comes down to what the individual feels comfortable doing.

[Gecko71]

My biggest concern lies in getting the wiring right (or the cost if I have someone do it).

The car in question will eventually become a forest car within the next five to ten years, essentially running the carb set up I mentioned before.

So I ask myself, why go EFI when it will soon be running Carbs anyway?

It is a daily driver, so I see the benifit of EFI, however, it only does about 100km a week, if that.

[ke70dave]

what do you mean by forest car? rally car?

 

and I'm not sure if 5-10yrs is considered "soon"!!

 

(assuming i understood your post correctly)

[Gecko71]

Yes, I do mean rally car.

Disregard the 5-10 years, for all i know the process could happen sooner or later. The car is a daily driver, but is already taking part in minor rally and touring road events as it is.

Edited October 6, 2010 by Gecko71

[Trev]

as much as the sound and throttle response, and general old school'ness of carbys is appealing, i still love EFI.

 

i just have a (what some consider boring) 16V in my ke70, but its great! plenty of power, 100% reliable and EFI is great for daily driving, weather its sitting in traffic at a stand still or crusing along the highway at 110km/h it dosent miss a beat. starts first time every time and certainly takes a beating.

 

i don't know why everyone thinks that EFI is difficult to setup in a carby car, just do it once and do it properly.

same deal with wiring, there is not alot to it, but if your not electrically minded it can be difficult. either spend a few weeks learning about electrics, or pay someone good money to do it. or find a mate who you trust to do a good job.

 

EFI is like a "set it and forget". the tune isnt going to change in the computer, and on the 16V its such a simple (and somewhat primative) EFI setup there is very little to go wrong.

 

 

Why does everyone claim that electrical is so hard, you have a wiring diagram and a loom, done. Carbies are so much harder to get right, and with my experience with carbies there a constant problem whereas EFI is just set and forget.

 

I never said that the wiring is hard

 

It is more of a pain to make a fwd wiring loom to suit a rwd conversion (wants smallport) and run a fuel system to to be compatible with the efi.

 

jono1986, I am not f@$king stupid when it comes to wiring, I have made looms before including converting my 82 fwd loom to rwd.

 

I don't know where everyone gets the 'carbies are unreliable' theory from, it is not a holley carb, if you go to a weber then all the tuning is on the inside of the carb.

[jono1986]

Dude, if it came across that i was having a go at you PM me OK, nearly every EFI topic has someone saying that it's hard to do. I wasn't having a go at you and I didn't say you were stupid, just calm down.

[Trev]

Dude, if it came across that i was having a go at you PM me OK, nearly every EFI topic has someone saying that it's hard to do. I wasn't having a go at you and I didn't say you were stupid, just calm down.

 

Putting a FWD efi engine especially the smallport is not as simple as plugging it in, the geometry of the loom does not fit the E7 chassis.

 

The drama I had to go through to make the FWD 82 harness fit my 71:

 

http://www.rollaclub.com/board/index.php?showtopic=12422&st=0&p=171090entry171090

 

Up to post 39.

 

easiest install I have done is a RWD wiring harness into a sprinter as it follows the engine and the car how it should.

[parrot]

easiest install I have done is a RWD wiring harness into a sprinter as it follows the engine and the car how it should.

 

This is true. However in an AE86, the engine loom is only one of three body looms that run the engine (ignoring the power feed to the fuel pump). In a rear wheel drive factory set up, the charge/headlight loom & underdash loom also contain wiring feeds back to the ECU - VSV's and idle up circuitry, speed sensor, fuel circuit relay and injector power etc.

 

The fuel circuit and injector power can be wired in easily enough, but I have seen a lot of really bad jobs I am amazed haven't ended up in a ball of fire.

Edited October 6, 2010 by parrot