What can a carb do for you?

[303 Mopar]

The 850 Proform on my 505ci ran great, until you shut it off on a hot day and then tried to restart within 30 min.  Crappy fuel, hot temp and 5300' elevation causes vapor lock and I was tired of being stranded.  Changed everything on the carb, tuned, tuned and tuned again.  Same result.  Slapped the Sniper on, first full day out was 97 degrees.  Ran perfect, stopped for a quick bite and started again flawlessly.  Knowing that plus instant throttle response is well worth the money to me.

[c00nhunterjoe]

The 850 Proform on my 505ci ran great, until you shut it off on a hot day and then tried to restart within 30 min.  Crappy fuel, hot temp and 5300' elevation causes vapor lock and I was tired of being stranded.  Changed everything on the carb, tuned, tuned and tuned again.  Same result.  Slapped the Sniper on, first full day out was 97 degrees.  Ran perfect, stopped for a quick bite and started again flawlessly.  Knowing that plus instant throttle response is well worth the money to me.

Was the proform fed by a mechanical or electric pump?

[303 Mopar]

The 850 Proform on my 505ci ran great, until you shut it off on a hot day and then tried to restart within 30 min.  Crappy fuel, hot temp and 5300' elevation causes vapor lock and I was tired of being stranded.  Changed everything on the carb, tuned, tuned and tuned again.  Same result.  Slapped the Sniper on, first full day out was 97 degrees.  Ran perfect, stopped for a quick bite and started again flawlessly.  Knowing that plus instant throttle response is well worth the money to me.

Was the proform fed by a mechanical or electric pump?

Electric - Mallory 110

[c00nhunterjoe]

Interesting that a 110 couldnt refill the bowls after a hot soak.

[69wannabe]

My gripe is as i said before, its not the carbs fault you cant tune. And its really not rocket science"

My case could be just the opposite....

I tried a 670 street avenger on my 383 years back and I wasn't that impressed with the street avenger carbs. The double pumper carbs are way more responsive and easier to tune IMO. I did get my 670 running pretty good with some jetting but after going to a 750 double pumper carb I tossed the street avenger and never looked back. My 850 DP holley runs fine any time I get ready to go anywhere with my charger. It can sit for a few weeks at a time and I can pat the gas pedal two or three times and hit the switch and it will fire off. By the time I pull it out of the garage it will idle on it's own (no choke on the carb) It will idle a little low for a few mins but it will idle and once it warms up it idles the same at every stop light and stop sign. Very minimal hot start issues now and it actually starts up good in hot weather after sitting 20 or 30 mins. If the Fi tech worked as good as my carb or better than my carb it would still be on there so i'm just not sold that EFI is 100% better than a good running carburetor.....

[Challenger340]

I've owned some pretty dam fine runn'in carbs..... and I have one right now.
2 pumps cold.... vroooom.... runs on high idle, kick it down and go.
NO pumps hot.... just turn the key and 1 rotation... vrooom.

I have a buddy going NUTZ trying to get his Sniper tbi on his 454 anywhere even close ? I think he "tunes" from his driver's seat as well ?

[John_Kunkel]

Some people can't open a box of crackers without help; no wonder the folks on the tech lines have little patience.

[c00nhunterjoe]

Wait, i thought they were plug and go, self learning....   

[69wannabe]

So did I.....

[Challenger340]

Wait, i thought they were plug and go, self learning....  

In a perfect world they are supposed to be.  Myself and many, many others have gone over Buddy's Sniper installation and can't find anything wrong there, even as far as Voltage drops.  

The system runs fine for a couple weeks, learns, good response, etc., etc., then just when a guy is getting fairly impressed with it, and thinking "it's all good now"..... then NO START !    

You have to crank & crank & crank with the pedal partially depressed until fires and revs to the moon, then slowly try to back off down to an Idle during multiple restarts, as it dies again each time, until a guy can get it to come down to Idle.
Then it seems to start it's 150 km "re-learn" process again.
No amount of re-plumbing, re-wiring adding grounds, new hand held controllers, and $400 donaro's twice now at the local FI guru's shop have been able to cure it, a couple weeks in it will die again.  Fuel logs were uploaded to Holley by the guru.... no help.... "software" problem.... update after update.... another 2-3 weeks and NO START with mr ugly to get going again.

[Challenger340]

Some people can't open a box of crackers without help; no wonder the folks on the tech lines have little patience.

And I believe some the people on the Tech Lines ? actually ARE the same people who can't open that box of crackers without help !  that found "jobs"

[c00nhunterjoe]

Wait, i thought they were plug and go, self learning....  

In a perfect world they are supposed to be.  Myself and many, many others have gone over Buddy's Sniper installation and can't find anything wrong there, even as far as Voltage drops.  

The system runs fine for a couple weeks, learns, good response, etc., etc., then just when a guy is getting fairly impressed with it, and thinking "it's all good now"..... then NO START !    

You have to crank & crank & crank with the pedal partially depressed until fires and revs to the moon, then slowly try to back off down to an Idle during multiple restarts, as it dies again each time, until a guy can get it to come down to Idle.
Then it seems to start it's 150 km "re-learn" process again.
No amount of re-plumbing, re-wiring adding grounds, new hand held controllers, and $400 donaro's twice now at the local FI guru's shop have been able to cure it, a couple weeks in it will die again.  Fuel logs were uploaded to Holley by the guru.... no help.... "software" problem.... update after update.... another 2-3 weeks and NO START with mr ugly to get going again.

I was kidding. Lol.

[John_Kunkel]

update after update.... another 2-3 weeks and NO START with mr ugly to get going again.

Stand by for the shock of your life...............some products come out of the box bad and the makers are often reluctant to admit it and replace them. Don't condemn the concept because of that.

And, BTW, the self-learning feature is in addition to the need for initial programming.

[Challenger340]

Another 3 weeks seemed GREAT this time, now Mr. Ugly reared it's head again.

I'm having a BLAST !
it is afterall a 454 Chevy, so as you can imagine I am having a field day with common car-guy reliability commentary ?

"more miles on it vertically up & down on the hoist for repairs, than it has horizontally going down the road under it's own power"

Does "GMC" stand for Gotta Mechanic Coming ?

[alfaitalia]

Not mine....but here ya go.

TBI Fuel Injection Advantages
•It is less expensive than using other types of fuel injection systems.
•It is easier to clean, maintain and service because there are fewer parts.
•It is cheaper to manufacture than a port injection system and simpler to diagnose. It also does not have the same level of injector balance problems that a port injection system might have when the injectors are clogged.
•It greatly improves the fuel metering compared to a carburetor.
•You do not have to make any changes to the TBI intake manifold. You also do not have to change the throttle linkage. Instead, use the existing linkage, air cleaners and carbs to install the system.
•It is also capable of logging data and can be programmed for ignition and fuel. The TBI system is that it learns and understands your habits when driving so it can easily map out your actions and the performance of the engine.

TBI Fuel Injection Disadvantages
•It is almost the same as a TBI carburetor wherein the fuel is not equally distributed to all the cylinders. This means that the air/fuel mixture injected differs for each cylinder.
•It can cool the manifold much faster causing the fuel to puddle and condense in the manifold. The possibility of condensation is much higher since the fuel travels longer from the throttle body to the combustion chamber.
•It is a wet system and the mixture of fuel is still based per cylinder.



There is nothing wrong with a well set up carb....ive owned many carbs cars and bikes (many with multiple cards to balance) myself and yes I was not always playing with the setting to make it run. The problem to me is that its very old tech. It does the job (like that horse and cart).... but TBI is a better more accurate way of getting the fuel in......in a more metered and demand matching way. And lets face it....you would not take the horse over the Charger....why? Because its very old fashioned and there are better ways of getting places now. You pays your money....you takes your choice.

[BSB67]

.....no wonder the folks on the tech lines have little patience.

I've been enjoying this thread.  I have nothing meaningful to add, but I couldn't let this one go.

This has been my experience, 100% of the time.  I call the tech folks only to figure out that I know more than they do.  I'm sure it is simply a reflection of their experience and compensation.

[Challenger340]

Not mine....but here ya go.

TBI Fuel Injection Advantages
•It is less expensive than using other types of fuel injection systems.
•It is easier to clean, maintain and service because there are fewer parts.
•It is cheaper to manufacture than a port injection system and simpler to diagnose. It also does not have the same level of injector balance problems that a port injection system might have when the injectors are clogged.
•It greatly improves the fuel metering compared to a carburetor.
•You do not have to make any changes to the TBI intake manifold. You also do not have to change the throttle linkage. Instead, use the existing linkage, air cleaners and carbs to install the system.
•It is also capable of logging data and can be programmed for ignition and fuel. The TBI system is that it learns and understands your habits when driving so it can easily map out your actions and the performance of the engine.

TBI Fuel Injection Disadvantages
•It is almost the same as a TBI carburetor wherein the fuel is not equally distributed to all the cylinders. This means that the air/fuel mixture injected differs for each cylinder.
•It can cool the manifold much faster causing the fuel to puddle and condense in the manifold. The possibility of condensation is much higher since the fuel travels longer from the throttle body to the combustion chamber.
•It is a wet system and the mixture of fuel is still based per cylinder.



There is nothing wrong with a well set up carb....ive owned many carbs cars and bikes (many with multiple cards to balance) myself and yes I was not always playing with the setting to make it run. The problem to me is that its very old tech. It does the job (like that horse and cart).... but TBI is a better more accurate way of getting the fuel in......in a more metered and demand matching way. And lets face it....you would not take the horse over the Charger....why? Because its very old fashioned and there are better ways of getting places now. You pays your money....you takes your choice.

You forgot one TBI Fuel Injection disadvantage in the list ?
You LOSE HP & Trq when you remove the Carburetor and install the TBI System

Not alot,
but on the Engine Dyno we typically see a 15-20 HP and 20-25 Ft/Lbs Trq LOSS on a 500" Stroker using 230-240 @ .050 Cams, versus whatever Carburetor we remove.

[69wannabe]

Yep, Bob is right about the HP and torque loss. I don't have a dyno or know anyone around here that does but when you know your car really well you know when it doesn't feel the same. I could tell I had lost some HP when I had the Fitech on there. I knew immediately when I put the carb back on it that it got some of it's grunt back. 20 to 30 HP is alot to lose when you are spending upwards of 2000 bucks for something. I would rather spend that much on a good set of heads and gain 30+ HP and torque myself......

[c00nhunterjoe]

[quote author=alfaitalia link=topic=132783.msg1651866#msg1651866



There is nothing wrong with a well set up carb....ive owned many carbs cars and bikes (many with multiple cards to balance) myself and yes I was not always playing with the setting to make it run. The problem to me is that its very old tech. It does the job (like that horse and cart).... but TBI is a better more accurate way of getting the fuel in......in a more metered and demand matching way. And lets face it....you would not take the horse over the Charger....why? Because its very old fashioned and there are better ways of getting places now. You pays your money....you takes your choice.

[/quote]

What transmission is in your car? I hope its not an old fashioned 727 or rh-od cause there are better ways of getting places now.

[303 Mopar]

You forgot one TBI Fuel Injection disadvantage in the list ?
You LOSE HP & Trq when you remove the Carburetor and install the TBI System

Not alot,
but on the Engine Dyno we typically see a 15-20 HP and 20-25 Ft/Lbs Trq LOSS on a 500" Stroker using 230-240 @ .050 Cams, versus whatever Carburetor we remove.

That is a huge drop that I don't believe is typical. There was only 3 hp and 4 ft/lbs tq difference on my 505 with a Lunati 231/239 @.50 cam switching from an 850 Proform to a sniper. 

https://youtu.be/R2F_d9_NoZY

[alfaitalia]

Not mine....but here ya go.

TBI Fuel Injection Advantages
•It is less expensive than using other types of fuel injection systems.
•It is easier to clean, maintain and service because there are fewer parts.
•It is cheaper to manufacture than a port injection system and simpler to diagnose. It also does not have the same level of injector balance problems that a port injection system might have when the injectors are clogged.
•It greatly improves the fuel metering compared to a carburetor.
•You do not have to make any changes to the TBI intake manifold. You also do not have to change the throttle linkage. Instead, use the existing linkage, air cleaners and carbs to install the system.
•It is also capable of logging data and can be programmed for ignition and fuel. The TBI system is that it learns and understands your habits when driving so it can easily map out your actions and the performance of the engine.

TBI Fuel Injection Disadvantages
•It is almost the same as a TBI carburetor wherein the fuel is not equally distributed to all the cylinders. This means that the air/fuel mixture injected differs for each cylinder.
•It can cool the manifold much faster causing the fuel to puddle and condense in the manifold. The possibility of condensation is much higher since the fuel travels longer from the throttle body to the combustion chamber.
•It is a wet system and the mixture of fuel is still based per cylinder.



There is nothing wrong with a well set up carb....ive owned many carbs cars and bikes (many with multiple cards to balance) myself and yes I was not always playing with the setting to make it run. The problem to me is that its very old tech. It does the job (like that horse and cart).... but TBI is a better more accurate way of getting the fuel in......in a more metered and demand matching way. And lets face it....you would not take the horse over the Charger....why? Because its very old fashioned and there are better ways of getting places now. You pays your money....you takes your choice.

You forgot one TBI Fuel Injection disadvantage in the list ?
You LOSE HP & Trq when you remove the Carburetor and install the TBI System

Not alot,
but on the Engine Dyno we typically see a 15-20 HP and 20-25 Ft/Lbs Trq LOSS on a 500" Stroker using 230-240 @ .050 Cams, versus whatever Carburetor we remove.

Don't agree with that at all. Our local dyno guy says that a well set up TBI on and large capacity engine such as a 440 typically give between a 8 and 10 horse gain. This is due to more accurate fuel metering and better atomisation of the fuel.

This is from a UK shops website compareing carbs with TBI;

Power and performance. Again,its a win, because fuel injection and modern electronic controls are more accurate, fuel delivery can be tuned to match driver demand. Carburetors are precise, but not accurate, in that they cannot account for changes in air or fuel temperature or atmospheric pressure.

Why should is produce less power. If you choose the right size TBI it will flow at least the same air and will add exactly the right amount of fuel for that amount of air. At the very least it would be no less power.

[440]

The O2 sniffer doesn't lie..... usually....

[JR]

Here are some videos of Dyno testing carbs versus TBI.

Heres a TBI vs 750 Dyno test on a 427 Ford. The TBI made more power, but to be fair, I don't believe the carb was anywhere near peak tune.

https://youtu.be/kzbA5TsXJpY

Here's one tested on a Mopar big block. The carb makes 10 more hp at wide open throttle.

https://youtu.be/3Zj0RMPKquw

Here's a Fitech vs carb on 71 Chevelle. The TBI wins this round, and makes more power at mid-range. (Which is probably more important on a street driven vehicle.)

https://youtu.be/xyX39EX45Rw

Dual carb vs Holley dual TBI, on Hemi. TBI wins this one.

https://youtu.be/Teok9NATPTk

My takeaway from those is that in the real world, (for a street driven car), any difference in power is negligible and completely meaningless. Now if you live your life a quarter mile at a time, then by all means, I understand the hangup on power.

I'm two years into TBI, and I love it. Whenever multiport becomes more affordable, I'll try it out, but for now, im very happy with my setup.

[John_Kunkel]

The TBI made more power, but to be fair, I don't believe the carb was anywhere near peak tune.

So, the discussion goes full circle. Even if the carb did make a few more horses, what it takes to get it to "peak tune" compared to the TBI is noteworthy.

[JR]

I agree, John, see my edit on bottom. I'll take efi all day.