Hey, it's cheap and more practical than slapping a huge carb on the motor. With hi po fuel injectors it should deliver enough air and fuel to support 400+ ponies. Im just not sure what kind of injectors to use. Stock 350 tbi injectors? Would those lil' things deliver? Any advice would be greatly appreciated. A stock 350 tbi makes 190hp, and that x 2 ''in my eyes'' would rule out the use of stock type injectors. I'm planning to build a 388 sbc, and am shooting for 420 horses at the least. Once again, any info or advice would be wonderful. Thanks!

 

i think Turbo city used to offer a packge like that back in the early 90's. It was two 2 bbl TB's , adapter plates, harness etc. and it had 2 computers IIRC. You had to procure your own dual quad intake too. Only thing was since it was FI and in its infancy back then, the setup was around 3000-3500 dollars

 

Do a search on this board, there was a long running post about doing this a while back using as many OEM parts as possible. I would like to see this done, it would be cool.

 

Thanks guys.......I'll keep you updated!

 

http://www.turbocity.com/EFIDualDtail.htm

The Kit is currently unavailable. I was looking into this about 2 years ago and decided to go with Holley Projection 4Di instead, since it is cheaper and easier to tune.

The intake manifold is made by Offenhauser and is available from Turbo City.



I don't understand why you think EFI would be cheaper than a Carb. A 750 Holley Double pumper is enough for a 500 HP 383 stroker. It may not be "high tech" but it gets the job done.

 

What im looking for is a setup comprised of mostly factory components. 2 stock gm throttle bodies wired to the same ecu.
Im just unsure of what Injectors to use.

I realize that a carb would be the cheaper route to take, and I could give a rat's *** about ''high tech'' but im also interested in emisions and gas mileage. Thank you for your input.

 

http://www.turbocity.com/EFIDualDtail.htm

Comprised entirely of stock components... Yeah it costs ALOT of cash, and is currently unavailable.

Ed Wright can take a stock ECM and modify it so it can fire 4 injectors instead of 2, as well as burn you a new PROM.

So then you need 2 stock tbis ...Bone Yard items and prob. not that expensive.

Get some new injectors from Turbo City, They can even 'blueprint" your TBIs

you WILL need the aftermarket intake manifold made by Offenhauser.

Upgrade fuel pump ...Turbo City

Fabricate adapter plates to mount TBIs to intake.
Fabricate Linkage to connect TBIs to each other.
Hack up your wiring harness to hook up the second TBI, You also have redundant sensors. TPS, MAP, IAC motors. etc. = BIG WASTE OF TIME.

Buy one Holley 4-Barrell TBI. Bolt Holley TBI to any 4 barrel carb intake of your choice. (Holley TBI has Carb mounting pattern)

Have Ed Wright modify your ECM so it can fire 4 injectors instead of 2, as well as burn you a new PROM.

Upgrade your fuel pump
Modify injector harness to connect Holley TBI.
DONE

700 CFM Holley 4 barrell TBI = 65 lb/h injectors 200-400 hp
900 CFM Holley 4 ballerll TBI = 85 lb/h injectors 400-500+ hp

Good Luck

 

Go here: https://www.thirdgen.org/techbb2/sho...light=dual+tbi

...then start with the questions.

Steve

 

Go there.... what for? That is all speculation and "wet dreaming" and in the end was the question answered??



Hate to be redundant or to sound cocky but my 2 solutions are rooted in reality...and actually WORK!!

1) Buy the dual TBI kit from Turbo City

2) Buy a Holley 4 barrell TBI -the 700 CFM model should work just fine for you.

 

Oops, sorry, I wasn't talking to you - you already know it all. That other post had a lot of good info in it about this idea. I thought I'd let HIM decide if he was up for it after reading all of the speculation and wet dreaming from people that don't know a damn thing. After all, he did ask about a dual TBI rig. One thing: "rooted in reality...and actually work!!", eh? Then what does "Yeah it costs ALOT of cash, and is currently unavailable." mean? Maybe I misunderstand the difference between "cheap and practical" and "ALOT and unavailable". My bad.

From now on I'll run all of my replies through you so you can edit for content.

Steve

 

All, that above link was my topic and I was just curious...

I am in the process of building a 400hp single-TBI motor, now. I will dyno test it with carb and TBI on both engine and chassis dynos as well, to verify my stuff. Already "engined" it once at 400hp+ on a carb, pondering my single 454TB options as we speak. spring project unless I can fix the heater in my garage. I also need ignition upgrades and am not sure what is good enough for a TBI-type distributor. Any experience would be helpful in my decision aking process.

 

Steve,

No need to act like a *****, I read the treads on the link you posted and honestly it was a waste of time. Maybe it means something to bunch of engineers who get off on such wet dreams, but to a drag racer , I don't want speculation I want something that works.

I don't know why Turbo City still Advertises the dual TBI kit if it is now unavailable. As I said I was looking into it several years ago but decided to go with Holley Projection instead. The main reasons being ease of tuning, and it's ability to support high horsepower applications.

Someone asked about dual TBI, I point them to a Vendor which actually made the damn thing in a Kit form, you send him a thread of BS and I'm the A-hole?

I was also trying to state that by the time you are done cobbling all the pieces to make a "home made" dual tbi setup and then actually spend the time to fabricate parts, assemble it all, tune, screw up, tune again, screw up, tune again etc. etc. you'd be better off buying the kit from Turbo City, then spend your time installing and tuning.

 

Whatever.

Davieboy (not you, the drag racer) asked about a dual TBI setup. I sent him a link where us wet-dreamers were discussing the very same thing - a dual TBI setup using stock OEM parts; pros and cons, issues, problems, etc. He said "Any advise would be appreciated" Any - that means, well, ANY - not just yours. He also made it pretty clear that he wanted it cheap.

Apparently not clear enough for you. YOU point him to a picture and description of a setup that he can no longer purchase; and even if he could it is anything BUT cheap. Telling everyone that YOUR solution is "rooted in reality" is the only BS in this thread - because it ISN'T reality. Your second bit 'o reality is most definitely not what he was asking for either.

What could he possibly learn from the page you sent him? That it isn't available - that's about it. Oh, maybe that it looks nice because it has a polished intake manifold. Swell. I bought an Edelbrock dual quad intake for $75, linkage for $14, and used a piece of kydex as an adapter plate $8. You use all of the sensors JUST LIKE THE TURBO CITY UNIT DID. Upgrade your fuel pump with the Walbro HP version for <$90. A couple of stock 305 TBI's from a junkyard, what $50 maybe? Two of them'll flow at least 900 cfm. If you noticed in the other thread, we discuss adding two injector drivers because you can't drive four in parallel without them getting flaky. So far I'm bunches cheaper than the equivalent $2000 TurboCity unit. Once you do that, yeah, you're gonna have to tune. Bummer. Dang, going to have to tune your car. Sheesh. Whew. Have. To. Learn. To. Tune. Which means you're gonna have to learn to program your own chips. Over. And over. And over. Pulling this blurb off of the TurboCity page: Right. It's just THAT easy. Get a chip maker that "really knows how to communicate with a motor". From a thousand or more miles away. Without ever having seen said motor. Or maybe you're telling me that you don't tune, test, tune, test, tune, te...? You are just that good that you don't have to?

All of this was discussed. In that other thread. That I posted for him. To read. So that he could tell FOR HIMSELF if he really wanted that headache. If he decided that "Yes, I think I do want that headache" - well, he had a starting point to ask more questions. Had he decided "To hell with that" - then he had your most wise post to consider.

Steve

By the way, what do you mean "No need to act like a *****" - what does this say about you and your attitude: "Go there.... what for? That is all speculation and "wet dreaming" and in the end was the question answered?? " Like I said, you already know it all, that's why the post was for him and why you're the A-hole.

 

Why was the dual tbi kit dropped by TC? Anyone actually bother to ask??

 

That good yup...

12.4 @ 105 on my first pass with the "base line" fuel map I made to just drive the car around town to get the motor broken in. Haven't had much time to test and tune it. I Raced at NSCA events at Union Grove and Cordova, Broke the ring gear at Cordova on a test run so the car was down for most of the summer. Building a 9" over the winter and adjusting my fuel map based on my data captures of over 12 runs from this past
"cut short" season. Actually the fuel map is almost there, I need to fine tune my cold start, for those weekend cruise nights and based on my data captures my shift points are a tad too low, about 400-500 RPM too low, and in third I am hitting the traps at about 5400 rpm. So I need to tweak the TV cable or adjust the weights in the governor.

Once I iron that out I plan on putting the car on a small diet. front runners, pull the A/C, remove the Front Crash bar. The car will run 11s on nuts 10s when I spray it. But hey what Do I know...

 

If I recall correctly there was a post on DIY-EFI digest when I first joined around two years ago about that. Apparently all TC did was splice in a second set of injector wires into the original set in order to get them all to work. However, once the rpm got to a certain point the injectors would stop firing "correctly" and get flaky causing a poor running condition. Bruce Plecan, one of the original DIY wizards, has run a setup like that on his test bench and gotten the same results. He suggests pulling two drivers from a bad ECM and running them off of the good ECM in order to NOT run them in parallel, keeping them good to go at higher rpm. That is why I think it'd be a simple exercise to get a dual to work (simple being relative. As long as you don't get phreaked about electronics work and can understand what/why you're adding a second set of drivers.

Or something like that.

S.

 

Sheesh, guys. I'm having enough trouble tuning ONE TBI, I can't imagine why you would want to double those problems, although the idea is intriguing. Isn't it more feasible/practical to tune the hell out of one big TBI, than to use two?

 

I'll let you know if/when I get a frigging 454 TB... went to look ata nother one last night. Not good. Well, not good enough for me.

Looks like the ProJection TB unit with 85pph Holley injectors may get spliced in for a bit. Will the PROM made for the Holley injectors act the same if/when I put GM injectors in there? Same electrical-to-flow characteristics???

 

Fastbroker, I'm not sure what the pulse rate is for Holley/GM injectors. I would think they would be the same since Holley claims their unit is a bolt on replacement