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Old 06-05-2016, 02:40 AM   #1
EmeraldFlame
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TBI on an LS motor?

I just had a weird thought what would happen if i used an LS motor like a 6.0 for instance and bought the carb intake from edelbrock or holley and put it on the LS motor then bought the adapter for carb to TBI and used that then put a way bigger throttle body ontop of it? with a stand alone trans controller using the 4l80? is that possible?
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Old 06-07-2016, 09:26 AM   #2
OutlawDrifter
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Re: TBI on an LS motor?

simply, yes, but you will also need an ignition controller for the ls/lq engine. can it be done, again yes, is it easy to do, no. it will be cumbersome and will require a lot of thought to do it correctly, including finding someone to tune a chip.

you would be better off to start out with something like the fitech tbi or one from fast, holley, msd, edelbrock, etc.
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Old 06-07-2016, 12:44 PM   #3
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Re: TBI on an LS motor?

Quote:
Originally Posted by EmeraldFlame View Post
then put a way bigger throttle body ontop of it?
Define WAY bigger? Last I knew 670cfm was as big as they go, which is stock on big blocks.
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Old 06-12-2016, 05:09 AM   #4
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Re: TBI on an LS motor?

Yes, it is possible and actually fairly easy. Use a Holley/Edelbrock/GMPP LS-to-Carb intake with a Squarebore-to-TBI adapter plate, and either a GMPP LS Distributor Conversion Kit and eliminate the LS coils and use your stock TBI distributor (easiest), or MSD 6LS controller and keep the LS coils (may require some work to play nicely with the TBI system).
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Old 06-12-2016, 05:40 AM   #5
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Re: TBI on an LS motor?

$600 for a kit to change back to a lesser distributor system?!
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Old 06-12-2016, 05:57 AM   #6
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Re: TBI on an LS motor?

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Originally Posted by 68C15 View Post
$600 for a kit to change back to a lesser distributor system?!
It's under $450 actually http://www.jegs.com/i/GM+Performance...FUVhfgodcoAK6g

And besides, I wouldn't call the distributor system "lesser". There are far more things on the TBI system that need serious upgrading before that distributor system becomes the limiting factor. It would be a great setup for someone wanting to put an LS engine in an 88-95 truck that wants to keep the engine fuel injected but the overall swap cost low, and with minimal modifications. Perfectly reasonable goal.
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Old 06-12-2016, 08:32 AM   #7
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Re: TBI on an LS motor?

I have the 98 spider injection , Is there a possibility something like this is possible in that scenario ? I have wanted to convert to a LS based engine for its better horsepower numbers and torque , but by the time you buy a engine , ecm for fuel and spark management , mounts, exhaust ,egr valve solution, dyno tune , the conversion can exceed 6000.00 dollars in the blink of an eye . That's just not doable on my budget when I'm just trying to breath new life into a old truck that I love .
And converting to a carb is not possible with the emission checks here .
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Old 06-12-2016, 12:48 PM   #8
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Re: TBI on an LS motor?

In your case, buying a complete donor truck and using everything possible from the LS donor would probably be the ticket. You can find wrecked ones for anywhere from $500 to $2000. Part the truck out and sell any body, interior, or drivetrain parts to make some money back. Buy a pre-wired Swap Harness and Dirty Dingo slider mounts, and if you do research, you can usually find a set of OEM manifolds or low buck headers that'll fit just fine. Use everything you can and try not to get bit by the upgrade bug, and you can get away fairly inexpensively.

Just for an example:

Typical donor truck cost: $1500 (Reuse as much as possible)
Dirty Dingo engine mounts: $200
Typical standalone swap harness: $500
eBay LS headers: $300 (Gen 5 Camaro manifolds usually work in most swaps and can be had for about $150 used)
Aftermarket fuel pump and lines: $300
Subtract any parts you sell from your donor truck: -$???

So right there, we have an engine, mounted in the truck with exhaust, fuel, and it's running on the factory PCM using stock truck accessories and intake for $2800, and that's before selling off any donor parts. The thing that gets most people is the need to swap parts out for "something better". The moment you change intakes, change accessory drives, or make any kind of mods, the swap costs jump significantly.

For my '67 Camaro, I picked up a 2007 Chevy 2wd dually box van off Craigslist, wrecked with 41,000 miles, for $1650. It had a 6.0L LQ4 and 4L80e transmission. I sold the complete van chassis for $900, which left me at $750 cost so far. Then I sold the stock 317 heads off the engine for $300, and traded a few other pieces for a set of 243 heads. So I ended up with a 6.0L with 10:1 compression and 4L80e transmission, both with 41K, for a mere $450. I still have more to sell off the van that I won't use, so it'll probably be even less. The deals are certainly out there if you look for them.
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Old 06-13-2016, 09:11 AM   #9
DarrellS
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Re: TBI on an LS motor?

That's is a great idea , thanks for the suggestion .
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Old 06-14-2016, 06:35 PM   #10
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Re: TBI on an LS motor?

If your only goal is more HP and torque thats extremely easy with your current small block. Just upgrade.
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Old 06-16-2016, 08:44 AM   #11
DarrellS
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Re: TBI on an LS motor?

I could be wrong , but I seem to have it stuck in my head that the LS based engines, even the small 5.3 have not only more horsepower , which I thought was due to superior heads even in stock trim , and superior injection so that I could get significantly better fuel economy at the 300'ish horsepower . I am lucky if I have 250 horsepower now , and with the low performance cam and compression ratio I was doubtful upgrading heads and cam could get me any significant numbers . The 5.7 I have now is a new GM crate engine with about 12,000 miles on it but I was afraid to attempt a LS swap before now because I have a manual trans and couldn't figure out if I could bolt it to a LS motor . I did switch over to the TPI conversion spider since the old spider with the poppit valves was worn out and that helped a bunch . So many of you guys are so much more knowledgeable on getting performance on a budget that I guess this is why I ask questions here that might seem silly . Maybe I had better start a new thread ?? hate to intrude on the original poster .

Last edited by DarrellS; 06-16-2016 at 08:47 AM. Reason: spelling
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Old 08-04-2017, 03:57 PM   #12
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Re: TBI on an LS motor?

I'm sure it will work. Might cost a few $$ but getting the right fuel maps is the problem.

I have a '95 2500/NV4500 ext cab long bed that I got cheap and the block ended up cracking and needed a engine QUICK to get to work.

I had a previously built, forged .060 over 283, self ported Vortec heads (machined for higher lift cam) Comp ex268 cam, "air assault" ebay intake for Vortec heads, TBI adapter (more than enough room for Intake valve shrouding/clearance, and it runs considerably WELL (pig rich, but 15+mpg with 3.42 gear and stock 350 fuel maps and aprx 8.7 compression)
Having a bud go through a Rochester for me to go back to a carb/HEI til I can get my 472 caddy built up. THEN going with FI-Tech injection w/HEI

I'd call Brian Harris who has TBI-Chips and ask him about what it may take to get it to run "right" with the stock fuel maps. The only reason I DIDN'T use him was that my build was soo 'different' that he wouldn't even know where to start in selecting the mapping process for what I have. Others have suggested the 4.3 injectors, BUT, wouldn't know if at 'load' if it would be leaning out or not..

What LS motor are you considering? 4.8, 5.3, or 6.0?

E

OOOpps.. Just saw the date he asked..
Well, good info anyway.
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