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Welcome to TGO.

If you have to ask, then don't switch to EFI. I could type for the next 3 hours and begin to scratch the surface of the can of worms you just opened.

If you like the car, and want to buy, I would ask him WHY he suggest converting. Nothing wrong with a carb, in fact, they're a WHOLE lot cheaper and easier to work on (for all intents an purposes). There's nothing on that engine (carb related) that if broken, would be CHEAPER to fix by going to EFI. Now if YOU want to make the switch for whatever reason, then of course that's a different story.

If you like the car, buy it, and go through it top to bottom and give it a full tune up. Get it running good. Then read all you can on this site about adding performance and bolt ons, etc. etc. ....you'll find out for yourself pretty quick what the right questions to ask are, with regard to "which fuel injection" you should get.

 

If you're going to do EFI don't do that one, no spark control, and limited features.
Do multiport. I've done a few ZZ3's and they came out really well. And having a Chevy getting compatible pieces will be a breeze.

Jmo. Thanks.

 

when I called him, he said something about how if you are going down the highway at 55 mph and you are in 5th gear it seems like the motor wants to bough down and you have to say in 4th. He said it does best at between 2-3k rmp. Is this more of a gearing issue or is this something I would tinker with in the carb since I will be driving a lot of highway.

 

Well first of all, if it bogs with an out of tune carb, it can bog with an out of tune EFI system. No difference. No EFI magic.

Now for the record, my car runs like a champ, and at "only" 55 mph, I have to be in 4th gear too, or guess what? - It bogs. (kinda) I'm around 2200 at 65-70 mph in 5th. ...under "about" 1500 RPMs, it doesn't have too much grunt.

Doesn't sound like a problem to me, but if somehow you're on a road commuting at 55 mph a lot, and 4th seems to low, and 5th too high, then yeah, could swap ring and pinion gears out back to either a taller gear (numerically lower) to make 4th not rev as much, or, probably better, would be to go deeper (numerically higher) to give you few more RPMs in 5th. I have a 2005 Trailblazer, and it doesn't like to drive at 60 mph. 3 is too low, 4th is too high. Doesn't matter, all cars are gonna have spots. It's math and physics. There's no free lunches.

But to reiterate, EFI will do nothing for that problem.

 

Hello,

Go EFI. It's a whole new and different world. EFI doesn't break that much, and besides that you'll learn a lot. Even a TBI setup will run circles around a carburetor. Get a system you can tune by yourself and by all means, get a new wiring-harness. Check the guys at EFI Connection. They sell LS-engine EFI systems made up mostly of OEM GM parts. There are cheaper alternatives like systems based on TPI ECUs. All you'll need is a single-plane intake modified with injector-bungs, a set of injectors, a fuel pump and some sensors and as said before, once dialed-in EFI will give your engine that new-car feel.

Cheers!

 

I don't know that I could possibly disagree more. Anything is easy if you know how to do it. That being said, there's a LOT more that can go wrong with EFI, especially since the carb set up is already up and running. And carbs don't break that much either. I mean is there a problem with carbs breaking down that I'm not aware of?

....once dialed in EFI will feel Just like a carb that's been dialed in!!

On an average zz3 type motor, meaning nothing extreme, both systems will run fine, idle fine and perform just fine. EFI will give you better gas mileage, and it'll cost a whole lot more. ....if you know all the parts you need, how to swap/install them, what they do, how to trouble shoot and how to tune, then yeah, I guess it won't be that hard.

If the OP WANTED to switch, I would be 100% all for it. I mean heck, I prefer EFI too, but it sounds like the EFI was only brought up to possibly cure a problem. I think we've established that there may not even be a problem and it CERTAINLY isn't the carb set up. Given that info, I see no reason to switch to EFI. Now if later on the OP wants to switch for whatever reason, then yeah, I'm all for it.

 

Really? Not to be a jerk or start a war but this is one of the reasons I hate asking questions here. Nothing like a "if you have to ask don't do something answer". The guy has a legitimate question and another "holier than though" answer makes it way into the equation. I remember when the only stupid question was the one that wasn't asked.

 

I understand holier than though answers, but my advice was sound. In this case, it was suggested that the OP switch, so he asked what kit to look at. My suggestion was that maybe he didn't need to switch in the first place. If I had said and then just left it at that, then I agree it might've been holier than though. -but I didn't. I immediately explained my point of view as to why it was a huge can or worms that wasn't easily answered, and then why I felt a swap probably wasn't necessary.
The entire thread was a multiple post discussion with a few people where the options and ideas were discussed. Not just a one post "don't bother".

At no point did I refuse to answer a question, or suggest that it was a stupid question. I started with a quick tongue in cheek comment, but immediately discussed the question at hand. To simply take each and every question asked on TGO as black and white and not to discuss would be just as irresponsible, and UN-helpful as to offer a "holier than though" answer.

Sorry to offend.

 

I'm an EFI guy, but I don't know that I agree with that statement. My stingray with a quadrajet actually runs better than any TBI vehicle I've owned. It even starts quicker than my 2012 GMC with the 6.0.



-- Joe

 

Abubaca,
I appreciate your response as well as the PM. I also did not intend to offend. You are truly a gentleman and an asset to3rd Gen. You have shown there are still people that are willing to help as well as clarify a statement. Thank you Sir.

 

I disagree with a few of points Abubaca made, and I agree with others.

EFI will give you better mpg, yes. It will also make more torque/power along the way. But typically a bit less peak hp, apples to apples.
And yes EFI can be daunting, but also fun.
And EFI WILL help drivability over a carb, even the best carb, ESPECIALLY if you have a larger cam. A good EFI system, with spark control, offers distinct advantages. Whether or not it's worth the time and money is your call. Hope this helps.

Thanks.

 

The one thing that EFI still doesn't have the edge on, regardless of processor speed is tip in throttle response. Somehow, an accelerator pump and venturi's respond to throttle movements faster than the TPS and MAP sensor can react. The aftermarket stuff is way better than the stock stuff in this regard (anyone with a stock speed density TPI car shoul d be familiar with the dead spot I'm speaking of) but still not perfect.

This is probably why the electronic throttle cars drive so much better. The delay still somewhat exists in the pedal, but the ECM can get the fuel charge ready and then electronically open the throttle blades, rather than trying to react to a blast of air that's already half consumed.

-- Joe

 

Hate to say it but you're way off base here. Ever heard a Formula 1 engine rev? It's EFI'd. NASCAR? EFI'd. And I have videos of EFI appications I've done that rev quite well too.
The processors today are wicked fast. I'm sorry but you're either grossly misinformed or your experience is only with subpar systems and/or tuners.
Thanks.

 

... this was uncalled for. But to settle the argument, if both systems, whether carburetor or EFI, are able to cause a "bog" upon tip in from too much fuel, then there is no one is faster than the other, because that is how you tune tip in, pull just enough fuel to eliminate the bog, with the result being and instantaneous tip in without delay. If there is a delay, then too much was pulled. Doesn't matter if the processor is slow, if its' able to add too much or too little, then it is able to add just the right amount when tuned correctly.

 

Not at all. Maybe a friend of a friends' father told him this or that. You have no idea where he got it from, hence the reason why I said he was misinformed. I could have called him an idiot or any other name, but THAT would have been rude and uncalled for for sure.

Simple truth is a good tuner can make either a carb or EFI run well. But my money is on the EFI outperforming the carb on a daily basis.

Thanks.

 

I don't normally do this, but apparently it's called for here.

Let's compare our credentials:

I'm a software engineer, with a minor in electrical engineering.

I've been director of R&D (Research and Development) at an engineering company for over 10 years, and I've been with the company as a whole since 1997.

I recently took over as acting CTO (Chief Technical Officer).

Software written by myself and my team runs on high end security appliances, and analyzes data at millions of packets per second.

My software is used globally, and some things I've written are in the Linux Kernel.

This developer experience along with an interest in hot rodding for over 20 years makes me qualified to discuss these EFI systems.



You on the other hand sell products developed by other companies. Your expertise is based on reading sales literature.


The point I was getting at, which soared far far over your head was that the combination of TPS and MAP sensor response time is somewhat slow, and even a fast processor on an aftermarket computer cannot read a change and command an injector as fast as air moving through a venturi and over a jet. That's just physics.

The average latency of a production quality (wells, delco, etc) MAP sensor is between 80 and 100 milliseconds.

To put that in perspective, 1310nm fiber optic cable has an average latency of about ONE HALF a millisecond per 100 kilometers. So I can send a packet of information 100 milometers almost 200 times faster than the map sensor can tell the ECM a change in manifold pressure has happened.

This stuff is soo simple to me it hurts to argue with you. I suggest you alter your tone and delivery before I'm forced to evaluate your value to this forum.

-- Joe

 

Don't assume you're dealing with a novice. I did the training video for Accel back in '08 and have done dozens and dozens of tunes before and since.
And as far as being an engineer, that means nothing to me. I'm glad it does to you however.

 

Thank you for that well thought out technical response.

Move along and have a nice day.

-- Joe

 

300* of cam duration is a BIG cam for a street 350. If that is what is REALLY in the engine, then it should idle very poorly, or at 1500 rpm. Compare these specs and see why the 300* cam won't work very well at 55mph in 5th gear based on its operating range.
- Comp XR264HR = 1200 to 5200 = 212/218 @ 0.050 and 264/270* (close or 0.006" lift)
- Comp XR276HR = 1900 to 5600 = 224/230 @ 0.050 and 276/282*
- Comp XR300HR = 3200 to 6200 = 248/254 @ 0.050 and 300/306*

As for your question about carb-to-FI; It is cheaper to stay carb, and can be made to be comparable to FI. If you want to go FI, go for it. You could even collect the factory parts from a yard, off the classified boards, craigslist/ebay, etc.

 

I like my fuel injected zz3