Skabidat

Ok, i really have searched this and i cant find what i am looking for, so i am sorry if this has been asked before.

Can the omp, ignition, and guages all be controlled by the stock computer if the fuel injection is removed? Is the ignition timing affected by the TPS signal? The intake mani and TB would all be removed obviously and replaced by a RB intake mani and a holley carb or something similar.
Any help is very much appreciated!

BigMike85

If you actually want to go down this path, get a dizzy/coils from an FB, a fuel pressure regulator (adjustable), and premix instead of doing omp. Havent ever heard of any other combos, although I'm no pro.

Jager

iTrader: (10)

Right on the dot actually.

Get a Malpassi regulator (to keep a stock fuel pump). Otherwise it's not all too hard !

SonicRaT

iTrader: (6)

why downgrade?

inflatablepets

I agree. It seems backwards to go carb to me.

Jager

iTrader: (10)

Some people just know carbs better, they can also ditch the shitty intake manifolds (if ported) and AFM. Also they can get a carb that can squeeze how some low-end torque.

That's just why I think of it.

Mechanic

well my fc is carbed and i dont got a dizzy, i dont know where my tps is... ignition is all ecu and then a carb.... lol even my manifold is home made!

RylAssassin

Hell yeah ive seen some of the fastest FC's carbed and the look is ******* awsome.
From what ive seen you gain a **** load of power by carbing if done right. But of corse the downside is the car is pretty much useless for emissions and gas milage

federik

I have a 89 gtu with a holley 450 ,60 and 62 jets aeromotive fuel reg and it is working fine now.

SonicRaT

iTrader: (6)

If you want better intakes, replace them. That doesn't mean you need to ditch the EFI and downgrade to a carb...

furiousbob

yeah i've also heard that carbing your engine will up your power like a **** but it costs an arm and a leg to get it done right.

SonicRaT

iTrader: (6)

I'm hoping that was sarcasm.

If not, the only 'gains' are from the intakes, there isn't a gain from the carb itself unless you've screwed up your EFI, or simply don't know what you're doing to use any sort of management system. All things equal, EFI is better.

Jager

iTrader: (10)

Better intakes just don't fall out of our asses. Tweak It has really the only one that is available for a price and availability that everyone can afford. Even Kahren's first manifold couldn't be used with a stock ECU. And not everyone has the resources or knowledge to make their own.

Btw, alot of FC's (even NA's ;o!) have made great power with a carb.

furiousbob

if ure talking to me, sonicrat, then no i wasn't being sarcastic. but then again i've only owned my 7 for about 2 weeks. i heard about the carb thing from an 84 rx-7 owner.

eastcoastdrift

Btw, alot of FC's (even NA's ;o!) have made great power with a carb.[/QUOTE]


You will never be able to get the same ammount of power you could with a correctly tuned EFI system than with a carb though.

Jager

iTrader: (10)

You will never be able to get the same ammount of power you could with a correctly tuned EFI system than with a carb though.[/QUOTE]

I doubt a stock ECU can hit 220HP all motor and can control a bridge. Comparing stock EFI to a carb is somewhat hard. Comparing an aftermarket EMS to a carb is different. That's where EFI is king. But for cost (dollar to HP) carbs aren't the worst thing in the world. Keep in mind megasquirt is fairly new and it's not 100% proven to alot of the "big" folks.

It all comes down to what you are familiar with.

SonicRaT

iTrader: (6)

The intakes can usually be used in either application, so that debate is rather useless.

Carbs are old and busted, simple as that. With EFI getting cheaper and cheaper, downgrading is just an excuse for ignorance (and being terrible at finding a deal on anything).

Jager

iTrader: (10)

Oops!

I do agree with Sonik on this, 5 years ago was one thing, but with MS now it's pretty pointless. But I still can see where a carb might still have its place. :o

Kahren

iTrader: (13)

my old intake setup just doesnt permit an afm to attach anywhere, there is just simply no space for it to go before the throttlebody. the new intake manifold will be compatible with the stock efi.

Skabidat

Well, it wouldnt be down grading! It will make more power, and cheaply. A carburetor is not better than EFI, but EFI isnt always better than a carb.

A carb and aftermarket intake is going to flow more air and more fuel extremely cheaply in this situation. I will be able to get rid of the AFM, and all of the old inaccurate, unreliable, and worn out FI stuff from 20 years ago.
To replace this stuff with new EFI stuff and a well designed intake mani would cost me well over $2000 to do it the correct way with a real EMS system that i am familiar with. Just the EMS will be $1000-$2000 and thats not including all the supporting sensors and parts, my time installing it, or my time tuning it. It would take 10 or 12 hours to completely tune an EMS system, fuel and ignition for all the part throttle and midrange crap that you do when you daily drive a car. Not that i dont plan on doing it to the car at some point, i would just like to have the money and time to do it right before i go there.

I am actually not as familiar with carburetors, but it will cost less than $1000 to convert to carb and emissions arent a problem for me and gas mileage isnt going to be that bad. It should still be in the 20s on the highway, if i have mechanical secondaries its ususally possible to feel them being opened through the throttle cable. If i can force myself to leave the secondaries closed when i am worried about gas mileage it should be very decient. Tunning shouldnt take much more than just an afternoon or two of piddling, and i have friends that do know carbs. Plus i have a spare wide band and gauge sitting beside me that needs a home, so there should be very little guesswork.

Carbs will never make for better driveability, or the largest powerband, but they can make just as much or more power, and in my case its just cheaper to do this first. I will probably convert to Microtech or Haltech with one of those holley footprint TBs with like 8 injectors mounted in the base or something like that later.

NZConvertible

The only way a carb can "squeeze some low-end torque" is by choking the top-end.

Comments like this (every carb post hase several of them) are just based on ignorance. Power and speed are not determined by the fuel delivery method, they're determined by airfow into and out of the engine. Carbs and EFI are simply the method for getting the fuel into that air, which is something EFI is considerably superior at. Anybody can make a carb'd engine powerful (i.e. high peak power) and use that engine to make a car fast. That doesn't prove anything in the carb's favour.

Aftermarket EFI manifolds have been available in the form of IDA-style manifolds and TB's for many years. And anybody who thinks these systems can't be used with stock EFI is clueless. You put a plenum on top of the TB (instead of a filter) and connect a duct and AFM to it. The question would have to be be why would you bother? Why handicap a performance intake system with a stock ECU?

Kahren

iTrader: (13)

carbs will never make more power then EFI. the reason a lot of people think that there is some magic power to be had from going carb is because a lot of the carburator setups are made just like individual throttle bodies would be with fuel injection. when you get an aftermarket carb over your plain stock one with not so great flow design and airbox attached to it with more restrictions and then you swap out for an aftermarket carb that has the individual runners with horns on them you end up with something that flows much better then the stock carb system would. now even with this aftermarket type of carb there are still more restrictions inside it then its EFI ITB counterpart, since the carbs need to have the bowl and all inside its intake runner. the EFI ITBS only have a throttle plate to let the air into the engine. efi also has a much greater ability to be tuned precisely for all of the engines powerband and load at any given point. i hope this clears it up for those that think carbs can make more power then ITBs.

Nihilanthic

Im sure youve heard the carb guys play the fuel atomization card before... is there any truth to that?

Obviously upping the fuel pressure could help, as well as moving the injectors further upstream, but I was wondering if anyone really in the know would have anything to say about that arguement.

RylAssassin

Hey look all im saying is that its an alternative, not that its better. The FC i saw with a custom carb setup was supposidly pushing 350hp from what the owner told me and he said he spent about 1500 bucks to get it done (the carb and fuel mods that is).

NZConvertible

Since that must've been turbo, you need to spend considerably less than $1500 on fuel mods to get 350hp with the stock EFI set-up.