Interesting application,,,

For discussing injector selection,manifold modifications, throttle bodies, fuel supply system design and construction, and FIdle valves and IACs.
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SILVERADO355
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Interesting application,,,

Post by SILVERADO355 »

Well I have seen everything and some how have come to be known locally for my proficiency in tuning FI engines.
So a fella drives up with a very nice yet totally stock 66 Chevelle, at least body wise.
Except for the fiberglass hood with the old school snorkel and a 427 big block under the hood with a tunnel ram.
Figuring that I was in for setting up a pair of carbs I get my jacket on (as its cold here)and he pops the hood and removes the bug catcher and low and behold he has 3, 2 bbl throttle bodies on a custom plate.
The MS2 he has and a very custom relay setup as it has an RPM switch and relay to feed power to the 2 outside throttle bodies.
They used an aftermarket Holley 454 replacement TBI in middle to feed it normally and 2 of the same brand, sized for 305/350s outboard. I think it has some type of controll from the MS and the RPM switch to getit to come in at higher RPM and partial throttle opening then made the linkage progressive.
They had the ignition setup seperate from the MS2. The big problem I found was dead O2 sensor(s) and a wacked out fuel pump.
But honestly I am thinking of looking for a 3 duece intake for my 283.
He swapped out the O2(s) and got it running better and has ordered new pump and filter setups.
This was a unique setup and it really impressed me on the way the previous owner had it set up but had used old parts from what I deduced.
Just thought you guys might like to hear about some different uses for MS
65ShelbyClone
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Post by 65ShelbyClone »

Just another example of the extreme versatility of MS. :D
'68 Mustang notchback - roller 302, Edelbrocks, 650 pumper, etc
'84 Mustang SVO - E6 manifold, wet cartridge T3.
'83 Honda XL600R - turbo/EFI in the works.
SILVERADO355
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some more on this one,,,

Post by SILVERADO355 »

AS for me I never will admit I am the best in tuning MS but I kind of liked the way it was executed.
The big thing I see is that with simply pulling a relay or fuse the outboards can be dropped, say for the fact if you broke something and need to drive home without maybe activating the extra fuel, like if you have to keep working the throttle.
Will I try to get it running even better, yes will I change things ,maybe. What isnt broke I wont fix till I see I can do better.
The engine got on a chassis dyno and made over 548 hp at the rear wheels!
Blow me away. This idea i really like so I am really looking at a tripower intake now to be different.
More on this car later.
bimdub
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Post by bimdub »

yeah I have considered this type of setup in the past on a Mopar engine...using a tripower manifold, you can actually still get them and then using three of the 5.2 magnum throttle bodies and having the manifold machined for injectors....then you dont even need a relay! and it looks like the 5.2 magnum and even the 5.8 magnum and yes even the V10 pickup throttle bodies would bolt to a standard carter 2bbl manifold therefore they should bolt to the tripower as well!
fury fan
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Post by fury fan »

I'm in the midst of investigating this very idea on a Mopar 383 2-barrel intake. I believe this bolt pattern is a standardized 'large 2-barrel' pattern but don't know how it compares to teh Holley pattern on a 6-pk manifold.

The 5.9 throttle body (I think the 5.2 uses the same one during some of the years) does NOT fit the pattern on this intake. The bolt pattern matches side-side but is about 3/8" off front-rear, which means old and new holes are about 1/2 diameter off. It might be possible to re-drill the manifold and wallow the TB holes a little, but this doesn't look like a 'professional' solution and good clamp force is needed to prevent vacuum leaks. And there is problem #2...

The TB has 2" dia throats and this manifold has 1 5/8" openings, which means throttle blade interference. Enlarging one manifold hole would be relatively simple (it feeds the upper plane of a dual-plane manifold) but the 2nd hole would require about 2" of depth enlargement to gain the full 2" bore benefit. Possible with the right tools and a few hours, I guess, but daunting to the average home fabricator.

The 1 5/8" bores, according to the MS calculator, are good for 196hp. The 2" bores of the TB are good for 297hp. Being that this manifold originally fed 270-290 hp 383s (with carb venturis that restrict airflow) I think the manifold would work as-is (with a suitable adapter) on a mild 383, and hogging it out a little would help.
wojeepster
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Post by wojeepster »

Boring out the holes on the manifold is fairly easy on a mill if you can get the manifold "flat". (Or you could do the adapter plate route if you have enough room to raise the throttle body. I am guessing but with a 5/8 plate you coud solve both problems.) As far as the bolt hole location the easisest thing there is to weld up holes if manifold is aluminum and drill and tap new ones. If it is cast it becomes more difficult.
fury fan
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Post by fury fan »

No mill, only a drill press. Figured a carbide burr would do the trick or maybe a side mill in the drill press could be used to hog the manifold (followed by a flapwheel in a drill).

It's a castiron manifold, so welding isn't an option for me, I'll be going the adapter plate route. The TB is much shorter than a carb so I know it will fit. I already overlayed teh 2 patterns in CAD and have all the holes centerpunched onto an aluminum adapter plate. Need to get the right size holesaw to match the manifold and then do some blending with a burr to meet the TB bore size.
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