Carbs Vs fuel injection

wannabfast

wannabfast

Thai with a 78 in MN
what do you guys think is better for an x?
i like them both, but for different reasons

carbs-
pros- you just can't beat the sound of a set of dcnf's at wide open throttle... altho the 32 datr is pretty nice sounding too, plus the mild adjustment on the carbs is nice for some fine tuning
simplicity, takes most of the guesswork out of what is going on.. as long as the bowls have fuel.. its probablly gonna start
cons- might be finickey when its cold if you dont have the choke/fuel enrichment lever installed or set correctly, syncronizing twin carbs might be interesting if youve never done it before, and if you dont drive it often the fuel in the bowls might cause it to gum up the jets

fuel injection-
pros- very reliable, fairly easy to get parts for, tuning is a snap with megasquirt, more exact tuning, easier to turbocharge
cons- lots of wires, computer boxes(weight), more sensors, more stuff to go wrong,

well im sure there is more stuff, but being the purist(sorta) that i am, i prefer carbed x's cause its era safe for modding, and the sound of them can be very nice, but it can be iffy for daily driving, but i think the x should be basic and vintage.. so fuel injection doesnt cut it.. but i honestly wouldnt mind an injected one for daily driving
 
Thai: you hit nail on the head...

...one other pro for carbs.
There ain't nothing sexier looking than dual carbs.
And nothing more retro-pure than single carb.
FI plenum looks like Rabbit motor.
For those who don't lift engine cover...no biggie.
But for those who appreciate sexy motor cosmetics...

I've found single carbed LesesigX to have all the manners
and most of the power of FI.
Attributed to Lezesig mod of drilling carb body for proper PORTED vac advance,
and ability to prime fuel pressure with electric fuel pump.
Les stated proper jetting helped the power as well.
I don't recall the jets I found in Les' carb,
but they weren't radical.
Jeff in Gig Harbor, if'n you're listening,
highly recommend you mod your 32 DMTR for proper vac advance!

Merely one opinion...formed after many smiles/miles
with single carb, dual carb, and FI Xs.
 
6 dozen of one...

...1/2 of another.:laugh:

Carbs are fun for fiddling with, always some leak to fix, some jet to clean, some linkage to adjust, an o-ring or gasket to replace, some nipple to refit, a bushing to lube or replace. Float levels and choke gaps to set, oh and fast idle too. Lots to mess with when you are young and single and have no other obligations.

Bosch L-Jet is steady and reliable, and simple to work on. Set it and forget it, if it runs poorly give it a tune up and change the filter, repeat as necessary. Parts are simple and easy to test with a VOM or test light. Better economy and power than stock carb, not quite the throttle response some say. Quieter, cleaner engine bay, late models have the dead-sexy™ stainless cover on the intake manifold, nicely compliments the optional stainless coolant tank and stock stainless exhaust.

I guess my preference is obvious; I'm getting old I guess. :shh:
 
FI forever more

I'll throw in a vote for fuel injection. Comparing a single carb to OE Bosch, better power, better fuel economy, better drivability in all climates. As for dual carbs, you could always spend what you X is worth on programable fuel and throttle bodies and have the same sound, similar esthethics and more power, drivability, and economy again. (shameless photo wh***** below)

P1020988.jpg
 
Another vote for FI

I learned in the "old school". That is, I learned to tune Webers the old fashoned way; by ear, plug color, throttle response, etc... Then on the dyno.

I put a programmable FI system on my racecar in '91. I will never go back. Sure my '74 had dual DCNFs, but its an old school car and that's the way I want it for now. Some day I may upgrade to DCNF TBIs and a programmable ECU but until then, I am happy with the Webers.

For the racecar, FI is the only acceptable solution. Performance, reliability, throttle response, driveability, etc... are all vastly superior to a carb.

And FI gives you so many options:

Intake06.jpg
 
I like carbs for power..but

I think carbs are easier/simpler to deal with if your trying to get a lot of power out of the engine. Using a hot cam with the Bosch airflow meter just doesn't cut it, nor does the L-Jetronic give enough fuel.

Programmable injection would be the way to go to get the best, clean power, but unless you buy a ready made system, I think there's a steeper learning curve.

With the right carb, you can jet it, etc and get it where you need it to be. I'd love to tune a carb with the new wide-band O2 sensors they have now. That would be a lot easier to do now than 30 years ago.

However, for a normal enjoyable weekend/ daily driver, the Bosch setup is hard to beat. Just set it and forget it.
 
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Ohh, looky there Mable. That dar is one of them slide plate throttle assemblies. Highly jealous. I'm guessing the runner length was chosen for maximum torque within some desired window?
 
Time out. I've seen that picture somewhere before. And there were some specs with it. My memory is shot these days.
 
Yep. Its been posted here before. That's the slide throttle intake on my old DSP X1/9. Yes, the runners were sized to make max torque at 4250 rpm.
 
Given a Choice, EFI

for a host of reasons. No worries about fuel starvation around hard turns, if the EFI is programmable tuning is direct and instant, Feedback loop helps correct a number problems while running, good ones are reliable, better fuel atomization and reduced fuel condensing out of the intake tract and etc...

Carbs are pretty darn reliable and mostly fool resistant, multi-carbs makes interesting sounds (specially on a 12 cylinder, like Ferrari, Lambo, etc) and makes good power if done properly.

It really depends on what the goals are. There is no real correct or wrong to intake choice for a given car/driver/roads/personal perferences...
 
olerascal said:
I've found single carbed LesesigX to have all the manners
and most of the power of FI.
Attributed to Lezesig mod of drilling carb body for proper PORTED vac advance,
and ability to prime fuel pressure with electric fuel pump.
Click to expand...

Tried to search the forum for above info.
Couldn't find it.
Always wondered what to do with the vacuum advance of the electric ignition :confuse2:
...it seems someone knows.
Anyone know where I can find it :help:
Thanks.
 
Well Said Bernice...

That is why my personal preferrence is carburation. One of the charms of a street X-1/9 is the ability to beat the beans out of it on public roads and the only nusance is the noise. Try reaching 6k rpm in second and third in any "modern" sports car and you'll have more smokies on your tail than the Bandit. In my X, the worse I get is a few looks due to the glorious sound of that Weber sucking air!

Ah, the simple joys of life.

:laugh:
 
[FONT=&quot]Thanks, Pete.
That’s exactly what I’m looking for.
Spring is coming and I'm getting that itch again :)[/FONT]
 
Call me lazy...

...but right now I like the no fuss FI in my X. Reliable, great driveability and easy to work on. My first X was carb'd... less power, more fussing, more emissions... And besides, in addition to my FIATs I've got several British rides... each with twin SUs or Zeniths... those give me all the tweak time I desire. The X (and Spider) I just get in and drive...
 
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