stack injection
 

I have a 427w built by world products billy mitchell its pretty mild but has an 870 holley dp I was thinking of switching to a stack system for iproved drivability starting etc. What is your experiences if any with this system.

I was running 2 /4 barrels on a 289 Hi Pro and installed a Eight Stack system , Rob Camp of Distinctive Motorsport's, Dallas did the install and now my car starts with the turn of the key, no gas smell , no missing, no problem shutting down, added a few more horses, etc It's great!!!! Expenses, Yep, worth it you bet.

I'm a huge fan of EFI. It is more expensive, and more difficult to tune. But it's far more accurate than a carb. Sometimes they make more power than a carb, and sometimes they don't.

an 8 stack system is essentially 8 different throttle bodies, and no common plenum. That's a different animal than most people are used to. There are some definate tricks to getting it tuned. And there are some engine build changes and tricks that can make the difference between success and failure.

Removing a single carb and bolting on an 8 stack system to the average SBF won't work nearly as well as you think it will. And getting good power from that system is not difficult, but it's different than a single carb.

Do your home work.

contact Dale at Eight Stack

dale@accuformmfg.com


Dwight

I am just finishing up a 410 W with an 8 stack. It's very high on the cool factor. Unless you can do EVERYTHING yourself, I'd stick with the carb. You'll save mega bucks.

I heard that some engines with a radical cam are hard to tune with efi just want the car to be more drivable does the 870 carb seem big for a 427w maybe I can just purchase a different carb I see alot of cars with the 427 running 750 carbs.

Actually, it's just the opposite. The problem with a huge cam is that at low rpm's the vacuum signal is low and erratic. In order for a carb to work well, it needs a good vacuum signal. That's why they have trouble idling, ad why you have to be careful about not putting on a carb that's too big.

EFI really doesn't care much about the vacuum signal. It will provide a solid fuel charge regardless of the vacuum signal or intake port velocity. Even with a huge cam and huge ports, the car can idle well and cruise down the street well without any problems at all.

If you have a radical engine in a street car, EFI will make it real easy to live with.

Thanks Bob maybe I will try a simpler efi like powerjection which is a bolt on.

One thing I would recommend is get a system that a local tuner likes, or get something you can learn to tune yourself. If you go with the latter, I would suggest Megasquirt. If you go for the former, avoid Megasquirt.

If you plan to hand it off to someone to tune, the last thing you want to do is have someone knocking it as he tunes it and using his bias as an excuse for his incompetence as he runs up a bill.

Good advice Luce

Well I'm no expert and don't have much experience working on EFI, but I have read a fair amount and have tried to learn more. There are some things that were said that could be true and could be false depending on the type of EFI system.

The early EFI systems were speed density. They use manifold vacuum (MAP) to estimate the amount of air flowing into the engine. They can be very accurate, but they cannot work with a radical cam where the manifold vacuum is very low at idle and increases a bit as the rpms go up.

A Mass Air Flow system measures the amount of air entering the engine directly, so manifold vacuum does not bother it. It is the easiest to tune because a direct measurement is easier to work with, however when the cam is so radical that air is pulsating back and forth past the MAF meter it falls down, too.

Some aftermarket systems you can select speed density, MAF, or Alpha N. Alpha N uses only throttle position and RPM to estimate air flow into the engine. It can handle the nasty cams, but it is less accurate and requires a lot more skill and knowledge to work with it.

The stack injections systems I have read about do not use MAF. They tie all the ports together under the intake to get a vacuum MAP reading for speed density or go Alpha-N.

You need to ask the right questions before you buy one, if you plan to do it yourself. Or you need to find someone who the manufacturer recommends or certifies to install and tune if for you.

There are a lot of claimed systems that tune them selves. Most work to some degree or another (not all). Most leave something on the table, Hp, mpg, emissions, drive-ability, etc.

I know less about this than anyone on the planet. I do know that it uses Ez tune that is a computerrzed system that turns it as you drive. My car was way over carbed and this fixed that issue. Call Dale at eight stack or Rob Camp at Distinctive Motorsports Dallas and I am sure they will be able answer any questions.


Eight Stack Injection- cobras

MrGeorge,
Is that your car Rob has down at the TCC meet?
The stack system looks awesome and seems to drive pretty well.
Love the 8000 series car too. Very nice.

Yep, he has it down there. I was going but something came up at the last minute so I let Rob take it down. Thanks for the complement, the system fixed a huge problem. Rob did a great job putting it all together, he's the man.Looking forward to meeting you guys at another event in the near future. George