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Summit Racing EFI ?

Started by Midnight_Rider, September 08, 2017, 06:16:35 PM

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Midnight_Rider


c00nhunterjoe

Still dont see the need to go efi in 90% of the cases it is used. I can think of alot of other things to drop a grand on. But to each his own i suppose

68CoronetRT

haha looks like they ripped Fitech right off with their stand, screen etc...  :smilielol:

will

Too bad none of them lets you use your air cleaner unless you buy a spacer.

flyinlow

Quote from: c00nhunterjoe on September 08, 2017, 06:24:35 PM
Still dont see the need to go efi in 90% of the cases it is used. I can think of alot of other things to drop a grand on. But to each his own i suppose


After having it for a couple summers and about 7K miles, I am not arguing with you. It's closer to $2000 by the way. (fuel tank with pump,  relays , PTFE hose return set up, gauges for testing fuel system, FITECH system ,etc.)

I have learned a lot about EFI.  Some people on this site fork over big $ to have 1 of whatever cars.  I like to Hot Rod stuff .


JR

Quote from: c00nhunterjoe on September 08, 2017, 06:24:35 PM
Still dont see the need to go efi in 90% of the cases it is used. I can think of alot of other things to drop a grand on. But to each his own i suppose

Depends on how you use the car. If you're just making passes down the drag strip at wide open throttle, EFI is a waste of money.

But if you regularly drive on the street, or have a pro touring build, EFI is great.

Better midrange throttle response. Exhaust doesn't smell like unburnt gasoline. No more engine stalling out around fast corners. Almost no chance of vapor lock. The computer automatically adjusts for elevation/air density/temp changes, instead of having to rejet a carb.

My only regret with EFI is I didn't try it sooner.

70 Charger RT top bananna /68 Charger RT triple green

Mike DC

 



IMO carbs get a bad rap for low/mid-RPM throttle response because the old car scene is focused on drag racing.   

alfaitalia

Sorry boys much as much as I love the simplicity (sort of!), character, old skoolness and stand alone nature of a carb they really can't do anything better than computer controlled injection. Whether you want to drag it or pose down the local cruise, EFI can be set up to outperform any carb. It will be crisper, more efficient, less emissions..at least in the form of unburnt fuel going out of the exhaust which at the end of the day is wasted power. Just some of the many reasons you cant buy a new car with carbs these days. If I was restoring by the numbers I would certainly have a carb (or three!) but on a fast street restomod where I want it reliable to start, hot or cold and drive crisply any time, it had to be EFI for me. To be honest with the way I'm going with my build carb setup would be very difficult anyway...at least for my ability. Easy to map the EFI computers in the dyno . My guy and me (mainly him!) can even set a different injection map for each 100 rev increment and overlay that on a map for each few degrees of throttle position. You will never get such perfect fueling on a carb at low/medium revs.......a real carb export might get close but drive up a mountain and it will be all wrong. Each to his own though...still loving carbs....and the smell of unburnt petrol!
If at first you don't succeed, skydiving is not for you !!

RCCDrew

The Street Demon is the best carb for drivability I have ever tried. The only reason I'm going FI is for the power adder capability. That and the price keeps going down.

John_Kunkel

Quote from: Mike DC (formerly miked) on September 09, 2017, 03:35:34 AM
IMO carbs get a bad rap for low/mid-RPM throttle response because the old car scene is focused on drag racing.   

I feel the exact opposite, carbs are fine at WOT but the starting/idle/cruise is where they're lacking.
Pardon me but my karma just ran over your dogma.

justcruisin

I love my carb, personally I wouldn't bother with a TBI system, MPI is a different story. Only advantage with a TBI system over a well tuned carb is self compensating for altitude and weather, it's certainly not a performance move - at least not from what I have seen. I have a friend with TBI on a 360 pulling his hair out trying to tune out a flat spot - due to manifolding IMO. But as Joe said - each to there own.

alfaitalia

Quote from: John_Kunkel on September 09, 2017, 04:25:45 PM
Quote from: Mike DC (formerly miked) on September 09, 2017, 03:35:34 AM
IMO carbs get a bad rap for low/mid-RPM throttle response because the old car scene is focused on drag racing.   

I feel the exact opposite, carbs are fine at WOT but the starting/idle/cruise is where they're lacking.


Is that not what he said!? :shruggy:
If at first you don't succeed, skydiving is not for you !!

alfaitalia

Quote from: justcruisin on September 09, 2017, 04:40:21 PM
I love my carb, personally I wouldn't bother with a TBI system, MPI is a different story. Only advantage with a TBI system over a well tuned carb is self compensating for altitude and weather, it's certainly not a performance move - at least not from what I have seen. I have a friend with TBI on a 360 pulling his hair out trying to tune out a flat spot - due to manifolding IMO. But as Joe said - each to there own.

If it was set up correctly and the right unit on the right inlet for the right engine then there is absolutely no reason it shouldn't be a preference move.......sounds like he either has some incompatibility issues or needs some professional help on the setup and mapping....assuming it's a system that can be properly mapped for an individual motor.
If at first you don't succeed, skydiving is not for you !!

justcruisin

It's an MSD atomic, 360, procomp heads, mild cam, headers and an RPM manifold. My opinion is there is something going on with the signal at a certain RPM - 2200. Modified the manifold to more along the lines of a big block rpm, made it better but still there. I think the next move is to try a 1" open spacer and then a low rise single plane. Sorry didn't want to hijack.

flyinlow

I have a Quick fuel 780VS that I removed to install the FItech. Out of the box it was tuned pretty close. Accelerator  pump and four corner idle mixture adjustments in the spring and fall. Nice carb, got you down the road, some tinkering required.

However....the EFI cold starts much better, I would not go thru the change over ,just for that reason on a hobby car. The EFI idles better and leaner for a good idle , with less fumes. Once you learn how ,it is easier to tune. (still learning)  It self learns on some things. It does not know what vapor lock is. The throttle body bores can flow 900-1000 cfm. This would be over carbed for my engine. The EFI does not seam to care. By the way all four bores open at the same time right from idle. No primary/secondary. It seams to make more low/midrange WOT power (butt meter, no dyno for proof) It does not seam to make anymore WOT power. You get an Air /fuel ratio gauge with it. You can data log runs with it and get more info than you know what to do with. Being a throttle body injection it does have to wet the intake walls like a carb, but it has programing for that.
People with Multi Port look down on People with throttle body injection. People with Direct Injection look down on people with Multi Port Injection. I can live with throttle body  for $2000 less (half price and  most of the fuel injection advantages)  Todays gasoline is blended for F.I.
So far the EFI  has not leaked or blown a power valve. Dependability in the long term will be one of the big deciders on whether it was a good choice to do. I kept the carb and a length of fuel line in the trunk for a year.

c00nhunterjoe

When tuned properly, a carb will fire right up and be crisp and responsive throughout the rpm range. As far as the exhaust not smelling anymore- bs... the only way to stop that is install catylitic converters.  If your exhaust smells that bad, then your carb is not tuned properly.

alfaitalia

I think the smell people are referring to is the unburnt fuel.....not the exhaust fume per se. And since there is less unburnt fuel there is less smell. Cats wont affect the smell of the exhaust anyway (apart from that egg smell if you use high sulphur fuel...!)....but of course cats will run with EFI so there are less petrol fumes to start with. You are right about carbs but what is a crisp running, fast starting engine at see level is a (relatively) overfuelled and gutless dog in the hills. No amount of carb setup skill will overcome that.
If at first you don't succeed, skydiving is not for you !!

JR

Quote from: c00nhunterjoe on September 10, 2017, 07:46:40 AM
When tuned properly, a carb will fire right up and be crisp and responsive throughout the rpm range. As far as the exhaust not smelling anymore- bs... the only way to stop that is install catylitic converters.  If your exhaust smells that bad, then your carb is not tuned properly.

Sure, a carb can be tuned to do those things.

But next time the weather changes, or you drive the car over any significant elevation change, or you change the cam, or anything, you're right back under the hood rejetting the carb and starting over.

With EFI, at worst, you can change parameters on the computer to account for hardware changes, and let the computer self tune for all the other stuff.

I'm not saying anything is wrong with a carb per say, but it seems silly to be close minded to the advances in tech.

I imagine somewhere there's a pre war car forum, where similar sounding topics are being discussed.

"Why would I want a syncromesh transmission? Those are for wimps who can't double clutch!"

"Why would I want a distributor with automatic timing advance? I can manually set timing as I drive just as good as one of those complicated Doo hickeys."

"Interchangeable parts? Real men forge their own replacement parts in a blacksmith's shop!"

;D

70 Charger RT top bananna /68 Charger RT triple green

Kern Dog

That is some funny stuff.   :2thumbs:

c00nhunterjoe

Quote from: JR on September 10, 2017, 09:34:46 AM
Quote from: c00nhunterjoe on September 10, 2017, 07:46:40 AM
When tuned properly, a carb will fire right up and be crisp and responsive throughout the rpm range. As far as the exhaust not smelling anymore- bs... the only way to stop that is install catylitic converters.  If your exhaust smells that bad, then your carb is not tuned properly.

Sure, a carb can be tuned to do those things.

But next time the weather changes, or you drive the car over any significant elevation change, or you change the cam, or anything, you're right back under the hood rejetting the carb and starting over.

With EFI, at worst, you can change parameters on the computer to account for hardware changes, and let the computer self tune for all the other stuff.

I'm not saying anything is wrong with a carb per say, but it seems silly to be close minded to the advances in tech.

I imagine somewhere there's a pre war car forum, where similar sounding topics are being discussed.

"Why would I want a syncromesh transmission? Those are for wimps who can't double clutch!"

"Why would I want a distributor with automatic timing advance? I can manually set timing as I drive just as good as one of those complicated Doo hickeys."

"Interchangeable parts? Real men forge their own replacement parts in a blacksmith's shop!"

;D



So what did people do in the 60s and 70s when they took a road trip? Did they take jet kits with them and stop all the time? No, they didnt. Once its set properly, you are done. I never rejet or change my carbs. It will fire up in the winter or summer the same way. And at the race track, we see all kinds of weather variables and the carb is NEVER  touched. The et dial changes, not the carb but the car itself never loads up or has any issues. It see anywhere from 60 degrees and sea level to 4000 feet and 95 degrees and everywjere in between throughout the season.
     As i said, fuel injection has a place, and if you suck at carbs, then maybe its for you. But i feel throttle body injection is a waste of time and money. If you are going to do it, spend the money and go multiport with 8 individual runners and do it right. I see most conversions are to throttle body injection and it was done because of cold start woes and off idle bogs. Sorry, but in my eyes a 15 dollar squirter and 10 dollar pair of jets and possibly a drill bit would have fixed it vs 1000 dollars on a throttle body. But again, to each his own.

68CoronetRT

When debating to stay carb or go EFI, my friends had a simple answer for me.

"This is the 21st century, get with the times!"  :smilielol:

JR


No, back in the 70s most people drove around with carbs that ran "ok".  I'm not saying a carb won't run  in cold weather after being tuned in summer, but it's always compromised. Tune a carb in 90 degree summer weather, and it's probably going to run lean when winter hits and air is denser. Tune it in the winter, and it will probably run rich come summer time.

I'm not saying that you can't set a happy midpoint in between, but again, that's a compromise. The engine isn't running as well as it could be in either situation.

And coincidentally, (in the 60s-70s) most engines were due for a rebuild well before 100k miles. Id bet improper carb tuning had a large part in that. As soon as the crude EFI systems came along in the mid 80s, 250k mile engine rebuilds became the norm.

Sure, TBI is crude, but cost and simplicity wise, it's unbeatable. No crank sensors, only 5 or 6 wires to install, it can be installed in one afternoon, and it bolts right up to where the carb used to be. No welding injector bungs in the intake, or dealing with a ton of wiring, or programming your own tunes.

Of course, TBI isn't the ultimate in absolute performance, but then neither is a carburetor.
70 Charger RT top bananna /68 Charger RT triple green

c00nhunterjoe

The fine detailed maximum performance issues you noted have absolutely nothing to do with a street car. You are talking about a 5 horsepower max difference in tuning between cold and hot weather. Which brings me right back to what is the point on a street car unless you cant adjust a carb or just WANT fuel injection.
   Not knocking technology. I use plenty of it in my car. But to say fuel injection is the answer to carbs is crazy, especially tbi. I will put my idle throttle response and cruise to wide open crispness against any fi tech throttle body setup.

Derwud

Here is the bottom line as I see it..

Yes a Carb can be tuned to be "Perfect", but how many people have the time, patience, knowledge to properly tune a Carb, especially a Holley or it's many knockoffs..  I can tune a Carter, or it's many knock offs, but I no longer have the patience or time! If you tell me I bolt this on and forget it, I am all in!!
1970 Dodge Charger R/T.. Owned since 1981

JR

Quote from: c00nhunterjoe on September 11, 2017, 05:43:15 AM
The fine detailed maximum performance issues you noted have absolutely nothing to do with a street car. You are talking about a 5 horsepower max difference in tuning between cold and hot weather. Which brings me right back to what is the point on a street car unless you cant adjust a carb or just WANT fuel injection.
   Not knocking technology. I use plenty of it in my car. But to say fuel injection is the answer to carbs is crazy, especially tbi. I will put my idle throttle response and cruise to wide open crispness against any fi tech throttle body setup.

Isn't that line a bit needlessly confrontational? I could say what's the point of a carb unless youre uncomfortable with computers or just WANT a carb, right?

I can't speak for everyone, but the reasons I converted were better cold starts, self tuning over elevation and temperature changes, no worries about fuel starvation on hard cornering, no more vapor locking, and when I want to make adjustments I just pull up the handheld instead of disassembling the carb and smelling like fuel all day afterwards. And I went with the power adder version, so it controls timing retard for nitrous automatically. (That was a big seller for me.) And the lack or unburnt fuel smell out of the exhaust is great. I don't care how good a carb is tuned, they all have some fuel smell out of them.

I can tune a carb well enough to get by, (I had a Six Pack setup for years), I just don't want to tune it anymore than I want to set the dwell on points ignition, or adjust drum brakes, or anything else I don't have to when there's a more modern alternative instead.

But if carbs are your thing, have at it man. I'm glad they work well for you.


70 Charger RT top bananna /68 Charger RT triple green