edelbrock efi

[hinoonaz]

How does this type compared to other efi's without fuel rails. I know cost difference and looks are a factor.

[twobjshelbys]

Have you read the discussions on EFI? There are probably half a dozen over the past 6 months. Search can be your friend.

But why??? What problem are you trying to solve? What do you hope to gain? I assume you are considering changing from carb'd. What do you think the gains will be vs the cost?

If you already have an older generation EFI system and want to upgrade then there have been many improvements that probably make it worthwhile, but even then cost is a factor.

If you are in AZ in the Phoenix area and only rarely go to higher altitudes EFI will do nothing a properly tuned carb won't do. If you put in an EFI system and don't "go all the way" to the MAF based system (utilizing full tuning feedback with O2 sensor) then you've got nothing more than a glorified electronic carb that cost you another 4K.

If you're considering the 8-stack the faux 8-stack with EFI is your only choice since the only thing below converting to EFI for the wrong reasons is a true Weber.

[hinoonaz]

Makes sense if not changing altitude to stay with c arb. Traveling now to altitude so down on hp. So what is what i shd say about altitude and HP. Mass flow is best i believe. Speed Density is what the older 302's had out of mustangs i think. Every time i explore efi i come to the same conclusion as Tony above. Apparently just want to spend money. Ouch

[eschaider]

Originally Posted by hinoonaz

How does this type compared to other efi's without fuel rails. I know cost difference and looks are a factor.

OP it does not matter whose EFI you are using, when you take the fuel rails off none of them work.

[mrmustang]

Originally Posted by hinoonaz

How does this type compared to other efi's without fuel rails. I know cost difference and looks are a factor.

I just listed a new in the box Holley Sniper here in the classifieds


Bill S.

[joyridin']

As a person who likes to drive his car a lot, I would never mess with a carb again if I didn't have to. With a properly tuned EFI system, you never have to worry about heat soak, vapor lock, floats sticking, high/low altitudes, hesitation, cold starts, hot starts, or any of the other of the millions of carb issues.

You hop in, it starts every time, and runs the same.

[twobjshelbys]

Originally Posted by hinoonaz

Apparently just want to spend money. Ouch

That is another justifiable cause. If the money is burning a hole in your pocket then just budget twice what you think (for the iterative tunes you'll need) and for the mods (e.g., return fuel lines and fuel pumps) aka "collateral damage".

As happened with me you'll become a EFI expert having learned much more about the subject than you'll ever use. If you're an engineer you'll love that part of it. If you understand "control systems" you'll love it even more.

[spdbrake]

MAF and Speed density will both be down on power at altitude.
The MAF is using intake air to trim fuel mixture, and in most cases also uses the O2 sensor to verify the MAF is correct. Speed density uses the O2 sensor to trim the fuel mixture. Not as quick or accurate (EPA doesn't like it) but it does work to achieve the correct tabled AFR mixture ratio. A huge plus for the SD over MAF (in my mind) is you're not stuck with a butt ugly snorkel intake.

Carb will be down on the power as well but will run rich and will get richer the higher you go.

Power loss for MAF,SD and Carb are 3% for every 1000ft of elevation rise.

The Sniper that Bill has for sale is an example of a system that will serve you well and make your life simpler once installed. The horror stories of EFI tuning have largely subsided by and large in the last 5+ years. They are still are out there though, especially on 8-stack systems (not just Speedmaster) and folks who want to self-tune thru Heath-kit type installs.


Air density drops with altitude, your only real fix is boosted with forced induction.

https://www.garrettmotion.com/news/n...r-air-density/
https://www.enginelabs.com/engine-te...engine-tuning/


But back to your original question. The Edelbrock Pro-4 EFI is an excellent system. Sequential Port Injection VS Throttle Body Injection, and Edelbrock is also highly rated in Tech support staff that A:answer the phone and B:know what they're supporting. Their kit is complete, Intake manifold, Gaskets, Dizzy, Pump, ECU, Harness, Rails, Injectors

https://help.summitracing.com/app/an...-style-mean%3F

[twobjshelbys]

If you're looking to EFI to keep the power in Payson the same as in the valley that problem won't be solved with EFI. Every engine suffers power loss as altitude increases. There's nothing you can do about it until they repeal the laws of physics. (Just ask the top fuel dragster guys at the Denver Mile High Nationals.) All a MAF based EFI system does is automatically keep the Air-Fuel ratio at ideal so you don't run rich. That's why the EPA loves this type of fuel injection - it's all about emissions. But without the MAF to sense altitude (air pressure) the other calibration systems are basically static and deliver the same results as a carb.

Like spdbrk says if you are looking to make a high altitude car like a low altitude car get a supercharger. But that's static too and can be dangerous. A friend put a Paxton on his 2006 Shelby Hertz. He set it for 8lb boost in Denver. Well, the 4.6L3v maxd out at 8lb. When he took it down to sea level and ran on a track the engine all of a sudden saw 10lb boost and literally exploded (piston through the wall)... (He replaced it with an Aluminator).

[hinoonaz]

Thanks! I keep learning about my car.. So many knowledgable people Goiong to stick with a carb even with low rpm stumble.

[Tommy]

If you want to rid yourself of that stumble, search for a carburetor tuning specialist in your area. Carburetors are not that complicated for people who know what they are doing. A good one can also tell you if the problem is coming from the carburetor or some other system (e.g., distributor).

[twobjshelbys]

Your low rpm rumble may be due to the cam than the carb. Do you have cam info? What is your idle speed? There are some engine guys that can talk about this and what you can expect.

[hinoonaz]

Lacking numbers on cam. Advised to idle at 900+ because of cam. It likes over 2000 and operates smoothly. Best description is nasty with a lope that is to love. The engine was built by dirt track machinist. 9.8 compression 347. no choke 650 holley.

[lnfletcher]

Before going full bore EFI to solve your stumble, try a different carb. I had a stumble I could not fully get rid of with my combination and ended up switching to a vacuum secondary carb and no more stumbling. Stumble is most often is fuel starvation. These are over powered light cars and exacerbate the effects of the feeling. Vac secondary helps with wide open rush of air because the secondary opens on need instead of foot force.

[eschaider]

Low speed engine stumbles (below 2000 rpm) can easily be attributable to camshaft selection, especially if it is one of the cams that provides a 60's style race car idle. Manifold vacuum is typically low with these cams. Additionally cylinder to cylinder charge reversion at idle (which contributes to the race car sounding idle) is quite common.

EFI might mitigate this undesireable behavior to a point, but it will not eliminate it. Sort of reminds me of something I read recently. It said, 'Duct Tape can't fix stupid but it can muffle it'.

To restore good low speed engine manners, you are going to need a camshaft change. The camshaft change will significantly reduce the 60's style race engine rock and roll idle qualities the current cam provides but the bucking and farting in higher gears at lower speeds will go away.

[hinoonaz]

Not worth changing cam. Want to keep the lope forever. Thanks for the info . The engine is running well within a couple miles here in AZ from cold start.

[joyridin']

Originally Posted by hinoonaz

Not worth changing cam. Want to keep the lope forever. Thanks for the info . The engine is running well within a couple miles here in AZ from cold start.

I have a friend that had an engine built by a shop that specializes in dirt track engines, although they do other builds as well. Hate to say it, but the engine is a bit of a mess. They ported the heads massively, stuck in a large cam, and did everything to make it not a streetable engine. He had the same problem as you. I guess they forget the difference between building an engine that runs continuously at 6800 - 7000 RPM for a specific amount of time in a race versus an engine that sits at stop lights and has to be driven in traffic.

What did help a lot with his stumble was going to a Proform main body for the carb and using annular boosters. I got rid of the stumble and increased performance. They were around $200 at the time.

[hinoonaz]

Will check out. Vic JR heads and intake. Intake and exhaust ports matched without porting head internally. The engine sure comes alive after 2 grand and hits rev limiter faster than my skills!!!