Learn Me - Drop on Carb replacement EFI, FiTech etc

Learn me?!

I hate carbs, we just don't get along. I grew up in EFI age, and I just have zero real experience with them. So these units (FiTech, Holley, Summit etc) that drop in place of the carb really appeal to me. The fuel system in this car needs to be redone anyway, so I can either swap a modern EFI tank of some sort in, or have the option to run a inline high pressure, or one of the little in the engine bay pressure tanks that are sold and reuse the low pressure system. The manifold is a spreadbore 

I know Mr Nohome said he wouldn't do it again, chime in as to why?

Anyone else use one?

I've got a FiTech on my 1969 Cougar.  Edelbrock carb failed and I wanted to try fuel injection.  Sniper wasn't yet available as it was installed two years ago.  Overall I'm OK with the system.  I did replace the entire fuel system (tank, in-tank pump, fuel line, and throttle body).  Car runs better and cleaner than with the carb (less unburnt fuel).  I could have done a replacement Holley carb for much less than the system I installed but I wanted to try something new on the cat. 

For most, it seems that an MS2 plus a salvaged TBI unit plus the necessary wiring and sensors and pump might be more flexible (wanna go TPI?  Add a blower or a Turbo?  Control the ignition or even the transmission?  MS can do all of that) and potentially less expensive (with careful shopping and reusing take-offs).

The issues I've heard of with most of the drop-in TBI solutions is all around the interface used for the setup and tuning.  Many are terrible, simply terrible and this kills the installs for most.

TBI has some issues with flow compared to similarly sized carbs, so for total power output they aren't great.  Their improvements in idle and drivability (not impacted by rapid changes in direction or angle for example) tends to be a good compromise for most.

The Holley Terminator Stealth on my friends Camaro has been amazing but I simply cannot recommend it for the price. It's close to 3 grand all in if I remember right. He only got it instead of some other options because of a hookup on price. I feel like the MS2/GM throttle body setup mentioned earlier would work 85-90% as good for 1/3 the cost or less. 

I have a TBI 88 Silverado. I've considered swapping it out for an aftermarket system if I were to repower with a heads and cam upgrade or 383.

Tuning the current system is supposedly possible, but I've never encountered instructions that seemed comprehensible to me. 

By contrast, the instructions for the aftermarket systems are dead simple, and they complete the final tuning themselves.

One concern is that some users have found that they may require a single plane intake to work properly.

My observation of the Fitech is that it is marketed as a solution for those that cant figure out a Carb. "Never buy a carb again"

The fact of the matter is that in order to set up a Fitech, you MUST know how to set up a carb as foundation knowledge.

If you are looking for a hobby, then by all means go ahead and buy any aftermarket EFI system, but they will neither install themselves correctly or tune themselves to your needs ( despite what Fitech advertises)

Another issue I have with the Fitech is that it is built down to a price; All of the components  like the injectors and sensors are China knock-offs.  Standard advice is to ditch the supplied temp sensor because it is a known random number generator. Not sure about the O2 sensor but I suspect it is also a knock off.

Fitech has no viable technical support, nor do they provide a manual of any kind with the system. Not a huge issue since the forums exist and you plan to become your own self taught authority on EFI.

The wiring harness is ridiculous if you like neat wiring. It could have been done with a single connector rather than the tangle of spaghetti that they have created.

Someone asked me where I am going to mount the little programing  dongle-box for the Fitech. "Why would I even want it connected" was my reply? If I can't trust it to stay tuned the way I left it, then I don't really want the thing do I? Once set-up I want to spend as much time with Fitech tuning as I do with my DD. NONE.

I still have not go the Fitech running right. It seems to have a new personality every time I start the car. The throttle is boggy and the revs are slow to drop, kinda hovering when I transition to off the pedal. NOT my preference. Also cant get it to stop backfiring through the throttle body on occasion.

Minor quip but mentioned by everyone who has operated the gas pedal on the Fitech: The return springs built into the throttle body throttle shafts are a berkeleying beartrap.  I removed the one on the secondaries, but the little bit of play in the linkage made this a bad idea; the second spring needs to be there to clamp the throttle blades closed firmly or the IAC goes mental.

A Holley street avenger is les than 25% of what the total cost of the Fitech is and you can have it installed in half an hour.

Does it have potential to be better than a carb? Yeah I think so, computers are good at dealing with a broader operating range, but it wont come easy and I dont know how long it will last.

In reply to NOHOME :

Seems like a case of getting what you pay for then. The Holley setup instantly ran great on the mild, stock iron head, low compression 350 my buddy had before and then later ran good on his 383. He still wants to take it to somebody to get a good tune on it because we don't trust the self learning algorithm to get it completely right. It runs good enough to start putting break in miles on the clutch though. He had the back fire through the throttle body issue but I quickly traced it down to a loose fuel line fitting letting air into the line, as far as I know it's never happened again after I tightened that fitting. 

I still would never pay the full cost of the Terminator Stealth and only end up with TBI though. 

A friend has FiTech on his Mustang, works pretty good, but he had to have it more finely tuned by a shop. FiTech wouldn't let him get the software to access more of the computer, so he had to find a shop they would work with.

To Floating Doc, you can tune the GM TBI systems pretty easily. Gearhead EFI site helped me a bunch on the tuning. Also, since you have a small block, just need to get the 454 TBI unit for more flow (670 cfm, 2" bores). Can use your injectors or the 454 ones with tuning.

Thanks Everyone

In reply to Stefan :

MS2 and a TBI is interesting, but I have never tuned anything before. What pattern is the GM TBI? I have a spreadbore.

In reply to Daylan C :

Looks like the steath basic are just over 2k now.....

In reply to NOHOME :

Thanks for chiming in!

So why do you say it wont tune? What has your issue with it been? And why would you need carb knowledge? I do see they have no real support.... But it self tunes right? :) /sarcasm....

Too bad to hear the quality doesnt look great, especially for the $$ they stil charge. I figured that was more what I would get with a Summit branded one.

In reply to 81cpcamaro :

Do you know what the tuning issue was? Not what i like to hear..... 

GM TBI is a 2 barrel pattern that I think is unique. As far as I know, adapter plates do exist though.

In reply to java230 :

https://www.diyautotune.com/support/tech/install/chevrolet-gm/carb-to-efi/

In reply to Daylan C :

Cool, I see the adapter plates now. Only two injectors vs the 4 on other drop on units. 

In reply to Stefan :

Thanks! Handy. Not doing SBC tho, but it should be the same more or less.

In reply to Daylan C :

You need carb knowledge because a carb is just an analog computer. If you are not familiar with what a carb does and how it does it, you are not going to have a clue why or how the Fitech works.

A big complaint with the Fitech is that it needs a glossary ofr terms. You have several menus to work through and there are many words that will mean nothing to the uninitiated. Intimidating  ( infuriating more like it) to me because I need to go searching through on line forums to find out what some tuning function does as far as the Fitech is concerned.

I know that we live in a world where we just expect our technology to work without any comprehension from the user. Cell phone society. But the Fitech aint that.

As to the people who claim it worked out of the box? I am a bit skeptical. The fact that the car is drivable might seal the deal for a lot of people.  I would say that the Molvo is perfectly drivable, and in fact might not complain if it was an old carb that I had rebuilt. But it is not a quantum leap forward. It does idle well, does not stink like an over-rich carb, ( i do have cats)  and it does wake up when you trod on the pedal, ( Lordy does it ever!) but it sure does not feel good just puttering around where you have frequent transitions on the pedal, and that is where we all live.

I am not  quitter by nature, but I do have the Holley Street Avenger bookmarked. This and a mechanical fuel pump on the 302 seems pretty idiot proof at this point.

In reply to NOHOME :

This is going to be a cruiser, so that middle pedal range he's going to be 99% of its life. What feels so bad about it? Just a lack of RPM drop off throttle? Combined with the heavy spring?

FWIW, Fitech seems to be the bottom feeder out there. I'd feel better paying another 10 percent and getting a Holley. 

In reply to Kreb :

The Holley is considerably more than 10%. The basic fitech runs about 850 it looks like

In reply to java230 :

Non linear response. It behaves like a bored kid in Church who needs to take a piss.

That all said, my reaction is based on very short drives around the block while destroying transmissions. It may or may not self tune itself out of this phase and in fact my previous observation about how it seems to have a different personality every time I start the car, might just be the thing in transition. Like I said, it is quite drivable and I have bigger fish to fry at this point, so I am going to give it a few miles and see what I think of it then.

Pete

I’m not sure anyone should buy an aftermarket efi for a diy install that does not give you full access to tune it. 

Seems pretty shady to me. 

Lots of people here know how to calibrate efi, if you are worried about that. It’s mostly about knowing what you want the engine to do, and then making it do that. 

The bolt on TBI systems haven't evolved enough beyond the early Holley Pro-Jection systems to be worth the extra coin IMO.

I ran the 2BBL setup on my Scrambler simply because it was a quick and dirty way to get away from float bowls.   It didn't make as much power as it did with my Holley carbs, but the freedom from fuel starvation and flooding on extreme angles made it worth it.  But the inability to find parts away from home for it when it failed was a headache until I cross referenced and made a list of the stock parts that I could use in place of the injectors, fuel pump, and TPS.  (And carried spares of each)

There are a lot of new parts to cross reference on the new setups, and aside for a "smarter" ECU and possibly a better interface, not much of an upside to the "new" TBI systems that mostly bank on marketing to people that have been taught for a generation that all carbs are horrible.   Factory FI, , decent carb, or a MS with factory components are about all I will use anymore, and in that order of preference.  The new TBI systems simply don't match the hype.

I have the Holley Sniper on my restored 75 k10.  It was installed by the shop during the frame off restoration,  along with a new FI ready tank with in tank pump (from Tanks Inc)  and all new lines.  The truck runs great and it’s a very clean setup.  The shop mentioned liking the Sniper system and said it was a simple and straightforward install. 

I also have a 55 Chevy two door wagon with the Holley StealthRam multi port setup.   Very nice but also a lot more expensive.  This is an older unit and Holley continues to support it.  I just recently upgraded the old joystick controller to the new large touchscreen controller.  A laptop is also an option and is what I used before switching to the touchscreen.

I suspect that the answer for me to get more modern fuel injection will ultimately be to sell the truck to someone that wants a rust free 88 and buy a newer one.

I've researched this topic a lot.  If I had to pick a system I'd go with the Holley Sniper too.  Their tech support alone is worth it based on what I've seen.  Holley has many EFI systems for many different power goals and engines.  I've considered this for a Ford based Monster Miata.  This is way easier than integrating the 30 year old Ford EFI and probably a lot better.  I've also thought about a Holley EFI LS system for Porsche 944 swaps... 

You could do the MS, but a Holley Sniper is easier to wire, has options for timing / spark control, and tech support.  It's also more affordable than a lot of PnP MS systems.  You can always go old school and build your own MS though.  I had a Navy buddy do that while taking the electronics soldering class. 

If you are looking for options to the Holley, I'd consider the MSD Atomic EFI before FITech.  FiTech seems to have the most issue of any of the systems based on my research. 

Thank you all! I appreciate the discussion. 

So it boils down to your steering me away from fitech. Holley sounds to be well Supported. 

I can't do an intake with injection, no One makes one for this engine.... 

Anyone have experience with the summit system? Probably a fitech knockoff if i had to put $ on it. 

Used fitech with the fuel commander seems to run around 750-850 locally. 

We put a Holley Sniper 650 EFI (about $1200) on Jack's CAM-T Falcon Wagon.  We changed from the stock gas tank to a fuel cell and put a Holley in-tank pump conversion in the cell (I think about $300 for the pump setup plus $150 or so for a cheap cell).  The car had a tired pickup 302 with a Torqstorm centrifugal supercharger that we previously ran a Holley double pumper carb on.  We only got a few hundred miles on the setup before we pulled the engine to freshen the bottom end, put a cam in it, and put some good heads on it.  But we loved the Sniper.  It self-learned very quickly and driveability was very good.  We then put it on a DynoJet and did find more power without hurting driveability.  Tuning via laptop vs. spilling fuel while changing jets and power valves is a game changer.  

We've started working with a new dyno shop and they do a lot of Sniper work with turbo drag cars, so that validated our choice for us.   The LCD programmer is pretty good but we pretty quickly switched to using a laptop to get a little deeper into things more quickly.  We did have some issues connecting with the laptop we were using that we haven't completely resolved.  So our report so far is we're pretty impressed, but there are things to deal with.

The new engine will be done in a few days and we'll be back on the dyno soon, so we'll report back in the build thread and this thread as well.  The car is going to the CAM Challenge in Grissom in August and Solo Nats in September, so we hope to have it all dialed in for those events.  You'll also be seeing some stories in GRM about the whole project and the EFI in the future.

java230 said:

Thank you all! I appreciate the discussion. 

 

So it boils down to your steering me away from fitech. Holley sounds to be well Supported. 

I can't do an intake with injection, no One makes one for this engine.... 

 

Anyone have experience with the summit system? Probably a fitech knockoff if i had to put $ on it. 

 

Used fitech with the fuel commander seems to run around 750-850 locally. 

I have heard the fuel commander setups are problematic.  I’d go with an in tank or traditional external pump and avoid it.