first off MERY CHRISTMAS AND Happy NEW YEAR so I have decided to go with fuel injection in my 70 skylark, just to update you guys, i just got a ton of TA parts to hop up with stage 1 se heads, roller rockers and all the goodies and a new front cover oil pump setup, along with an SP 1 on my big block, looking at some of the stuff thats out there, I like the MSD setup 'cause it will interface with the distributer and 6AL box I already FAST is what a lot of guys see to like including the guy that builds TA's system. I already have the tank and pump installed, currently running a quick fuel 850 dp. What are you guys using, any input thanks Jim
If you look at the Atomic Throttle body you will notice that it looks like a standard Carburetor with Annular discharge boosters using the injectors to supply fuel to the rings. Not much different than the Carb you have now. Here is a quote from MSD "The annular rings on the Atomic throttle body are designed by MSD’s engineers to work as special injector nozzles. The rings are not in a venturi and at no time does the fuel get pulled out because of low pressure. They help to spread the fuel out and have been shown to improve per cylinder fuel distribution. Even cylinder distribution, like that from a carburetor, helps make more consistent high rpm horsepower." That's fine at WOT but at partial throttle (where you spend most of the time) the fuel dumps on to the back side of the throttle plates. Not the best for fuel distribution. I would prefer the FAST Throttle body that has the injectors below the throttle plate that inject directly into the intake manifold plenum. Just my opinion. All EFI systems will interface with any MSD ignition box so don't let that be a deciding factor. By "472" cam do you mean the TA C113? Paul
If youre gonna do it...spend the money and go MPFI (its really not that much more expensive than the TBI unis and its infinitely tuneable and scalable for any future upgrades). Get the injector bungs added to your SP1 now before its on the engine and everything else is just as easy as the TBI units. You can do self learning on the MPFI units too or fully tunable, which isn't as hard as you might think.
All systems out there work with the MSD distributor and 6AL box. Don't let that be a sticking point anywhere. The MSD distributor likely outputs a square wave signal any ECU can take (and if its a VR most will take that signal with no work, some might require a filter), and what ever ECU you get that can control timing will output a square wave for the 6AL to control timing (via the white "points" wire of the 6AL). I'm the token MegaSquirt guy if you go that route. I'd only recommend MS if you are going multi-port injection. The MSD one isn't below the plates?? I cannot find a googled picture that definitively shows one way or another.
They use the rings that look just like the annular discharge booster rings in a normal carb. See the MSD quote in Post#2. They have a 3D view on their website. http://www.atomicefi.com/Atomic_EFI_-_3D_View.aspx
Yeah I know what it says about the annular rings, but that doesn't mean they aren't more "marketing" than function, or simply straighten out the air flow at WOT with the injector spray still under the plates. And of course their damn "3D" advertisement skips the bottom uzzled: Hmm, looking at some install pictures folks have taken, it does appear the injectors are near horizontal, which means, yeah, they are going right into the rings. Interesting concept. I doubt there is fuel puddling due to the small quantity, but it certainly is working more like a carb than an EFI system.
Actually you have that backwards Paul. Injecting ABOVE the plates is better. Injecting "directly into the intake manifold plenum" will only add to puddling at part throttle. The MSD unit is self contained, meaning any repair and it has to go back to them. And their spark control is limited. I'm with 61636, go multiport with a system that allows full control. Let me know if I can be of help.
284-88h cam, someone had asked. I did look into the TA Multi port setup and talked to the guy that builds them, he uses the FAST BBC system and just machines the manifold ect. he said that the mp system is little more efficient but in my setup I probably wont notice a difference, and the cash is 1500 to 1800 more. are any of you guys running any of these systems?
Using a throttle body injection will be fine for your setup. There are some concerns. For idle quality and partial throttle opening operation like cruising, a throttle body that injects directly into the intake manifold plenum should do a better job of distribution. Self learning EFI systems do a better job with cam profiles that have a wider lobe separation angle where the transition in torque from idle to peak power is smooth and the resulting fuel map has smaller incremental changes. The TA 284-88 is by no means radical with 6.5 degrees of overlap but it is not ideal for EFI either. Getting the idle perfect can sometimes be a chore where there are 2 very different idle loads, in neutral and in gear with the converter load. Sometimes that requires setting the closed loop mode so it doesn't activate until some rpm point above idle so the user can fine tune the idle with fuel map entries that stay fixed. In other words the user can do a better job tuning than a self learn system. The Holley Terminator TBI system can be upgraded to the user tunable HP software or you can use the full blown HP ECU with the Holley TBI FAST has recently gone that same direction and you can use their new User Tunable XFI Sportsman ECU with their throttle body injection. If you look at all the features you get with the upgrades especially data logging and ignition control, it's a no brainer. So Yes you can have TBI with all the other great software features of port injection. Paul
I agree with going MPFI, it's not that much more and way better in the long run, however, in my research on these TBI units, the Holley was my number 1 choice for the reasons listed above, upgrading to the HP full fuel/timing control ECU was most appealing. Second choice was the latest version of FAST XFI due to it's ability to handle boost and higher horsepower than the other units in case I ever wanted to do that. The others weren't even contenders to me. Not to thread jack because I think it still adds to the conversation, but does anybody know how much it normally costs to get a carb intake manifold set up for MPFI (machining/installing injector bosses) or how much TA charges for just an Edelbrock intake set up with the bosses already installed? I'm also looking to go EFI, but want to assemble my own setup with the Holley universal MPFI kit ($1890)...just need an intake, injectors, computer controlled HEI, and fuel pump/EFI tank with that one.
You need a local machine shop that has a milling machine. Look over these instructions pages 4,5,11 http://documents.holley.com/199r10510.pdf
imagine injection does the fi conversions for TA, they are also in AZ, talked to Bob over there, hes the man.
See answers above in (). I've done dozens of Muliport and throttle body applications. Anything with any amount of cam in it will benefit from a good multiport system, period.
