Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

TBI, TPI, Vortec, etc what's the diff?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by laketex, Nov 10, 2000.

  1. laketex

    laketex 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    6,220
    Likes Received:
    0
    Location:
    North Texas
    TBI, TPI, Vortec, etc what\'s the diff?

    What's the difference in the systems? Which ones make the most sence for off roading and why in your opinion? How difficult is each to tune, to keep dry, and to destroy. What's everyone's take on the different injection systems? A lot of guys up here run projection but they have to tinker with that stuff all the time. I like the set it once in winter, once in summer kinda method. No problems there. Here's a pic of BlazzinOR's TPI setup: Anyone have any other pics?

    [​IMG]

    [​IMG]
     
  2. Bruiser

    Bruiser 1/2 ton status

    Joined:
    May 21, 2000
    Posts:
    320
    Likes Received:
    0
    Location:
    Caldwell,Idaho
    Here is a good site with lots of info

    www.fuelinjection.com

    Vincent Michels
    1978 Blazer
    Bruiser (Frost white/Black top/ Light Blue interior)
     
  3. BurbinOR

    BurbinOR 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    5,829
    Likes Received:
    0
    Location:
    Oregon
    Re: TBI, TPI, Vortec, etc what\'s the diff?

    Laketex, thanks for the press! [​IMG] Not sure if you are asking for this, but here goes (from my limited knowledge) -

    TBI is throttle body, basically a fuel injected carburetor. TPI is Tuned Port Injection, with 8 individual injectors aimed at the intake valve (or close to aimed at it). Both will help your gas mileage. Both will run better on off-camber/uphill situations than a carb. Both [​IMG] should start easier in cold weather.

    My builder has a couple of Projection setups running from pre-TPI days. A guy was over last weekend getting ready to go through DEQ (emission testing) at his house, took a heck of a lot of continual tweaking to get it "right" (my builder has a 4 gas analyzer to check engine tune, etc.). I asked him about his experience with Projection (he has had this running for about 7 years) and overall he is happy, but wishes he could convert to TPI. As you said, he is constantly adjusting his in-cab controls depending on weather, etc. His gas mileage is about 10mpg on a 3/4 ton pickup with 4.10 gears and 33" tires with a T400 trans. This isn't the newer version of the Projection, so keep that in mind. I haven't driven mine enough yet to get a tank of gas through it to check my mileage (not that I care [​IMG]). As far as setting it, once you get the chip set, you don't have to mess with it at all. Set it and forget it...........I hope [​IMG].

    <font color=black>'79 - 406 TPI -<font color=orange> K5#5 - <font color=blue>See it at---&gt;http://www.blazzinor.coloradok5.com
     
  4. shum1

    shum1 1/2 ton status

    Joined:
    Oct 8, 2000
    Posts:
    270
    Likes Received:
    0
    Location:
    UTAH
    Re: TBI, TPI, Vortec, etc what\'s the diff?

    BlazzinOR: What would you recomend as the most hassle free engine swap for my 1990 tbi suburban, Im looking for at least as much performance as a 350 vortec engine. Thanks.
     
  5. Re: TBI, TPI, Vortec, etc what\'s the diff?

    Turbo city has a harness that will let you pigy back your old wiring and computer from a tbi in favor of tpi.

    IF IT AINT BIG IT AINT BAD!!!!!!
     
  6. realsquash

    realsquash 1/2 ton status

    Joined:
    Jul 12, 2000
    Posts:
    778
    Likes Received:
    0
    Location:
    SE WI
    Re: TBI, TPI, Vortec, etc what\'s the diff?

    Heya, what's the best? The absoulte best is a custom port injection intake with runners tuned to the cam and other engine specs. But that is a pipe dream. There is nothing wrong with a properly tuned TBI, TPI or vortec. But the vortec is voodoo at this point (not sufficiently hacked), TPI is better than TBI, both being hacked completely.

    Stock TPI (like in your pic) is very restrictive for anything over about 300hp. They can be upgraded to flow more, tho. Stock TBI is also restricted to about 300hp, but again it can be upgraded. You have many options for sure.

    There are some things that you are overlooking, also. I use a single-plane carb-type intake with injectors mounted in the ports for the EFI. It is the best of both worlds, and almost zero sacrifice in the low-end, but will allow flow to 8000+ rpm. Here is a picture: http://www.trailrunners4x4.org/users/realsquash/enginepix.html The site is a little slow right now so it might not come up...

    Squash
    http://www.trailrunners4x4.org/users/realsquash
     
  7. BurbinOR

    BurbinOR 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    5,829
    Likes Received:
    0
    Location:
    Oregon
    Re: TBI, TPI, Vortec, etc what\'s the diff?

    My preference [​IMG] is TPI. I am sure TBI can be modified and improved, but my limited knowledge about it is, well, limited! TPI can be left stock (wonderful factory setups anyway) or "Frankensteined" pretty much up to well over 400 HP motors.........easily, and relatively cheaply. For example - my stock throttle body was 48mm, now it is 52........stock injectors were I believe 18, now they are 24 lb/hr.........computer chip was burnt for about $100 to match the 288 computer cam..........the rest is in the heads you use. That is the key area........gotta make sure the heads you use are compatible with TPI, as the manifolds must bolt up exactly. Someone told me you could use Vortec heads with TPI but the runners didn't match up "perfectly", which I want no part of. So the choices are yours, cost isn't that bad, did my entire motor rebuild, TPI upgrades (all above mentioned plus polishing, new Painless wiring harnes, etc.), LT-1 heads, and assorted improvements for $3000 COMPLETE. Doesn't have to be spendy, just have to find the correct parts and hopefully either you can do the work yourself or you find a local that is good at what he does with TPI. Not a "backyard mechanic" type guy, but someone who understand the systems. My builder has a lot of years experience with these systems, and understands them better than anyone I have talked to. He is the reason I stuck with TPI (was close to going back to carbs [​IMG]).

    <font color=black>'79 - 406 TPI -<font color=orange> K5#5 - <font color=blue>See it at---&gt;http://www.blazzinor.coloradok5.com
     
  8. realsquash

    realsquash 1/2 ton status

    Joined:
    Jul 12, 2000
    Posts:
    778
    Likes Received:
    0
    Location:
    SE WI
  9. shum1

    shum1 1/2 ton status

    Joined:
    Oct 8, 2000
    Posts:
    270
    Likes Received:
    0
    Location:
    UTAH
    Re: TBI, TPI, Vortec, etc what\'s the diff?

    Great summary BlazzinOr, How difficult is it to find a set up like this? Where should I start?
     
  10. BurbinOR

    BurbinOR 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    5,829
    Likes Received:
    0
    Location:
    Oregon
    Re: TBI, TPI, Vortec, etc what\'s the diff?

    realsquash - One correction - my unit LOOKS stock but is far from it.........upgraded throttle body, 24lb injectors, custom chip, puts out in the neighborhood of 400HP. Pulls like a RAT (yes, I had a 454 in my 75, so know how that ran), so yes, I am very happy with it.

    shum1 - first check the parts for sale board, there were I believe 2 or 3 available in the last few weeks, including one complete motor with the wiring kit! Other than that, boneyards will have plenty of good parts.......L-98 Vette motors with aluminum heads are probably the most sought after, but not sure if aluminum heads are the best overall idea (don't flame me for that, guys, I know aluminum transfers heat best, etc.). Painless Wiring sells the wiring kits, basically a plug and play application [​IMG]. Get a good book on doing this swap if you are doing it yourself, one with all the trouble codes, etc. Not kidding, it isn't a mammoth project if you have all the hardware and good sources of info (internet, books, etc.). If you lived anywhere near Oregon my builder could help you out big time..........he has done 108 Jaguar V8TPI conversions as well as over 45 (finally got the number out of him last night) others, including 3 K5's I found out. Let me know if I can help you in any way.

    <font color=black>'79 - 406 TPI -<font color=orange> K5#5 - <font color=blue>See it at---&gt;http://www.blazzinor.coloradok5.com
     
  11. BurbinOR

    BurbinOR 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    5,829
    Likes Received:
    0
    Location:
    Oregon
    Re: TBI, TPI, Vortec, etc what\'s the diff?

    Nice pics of your motor..........nice looking Blazer too! Love how those Boggers look.........how does your motor run? What kind of ECU controls your setup?

    <font color=black>'79 - 406 TPI -<font color=orange> K5#5 - <font color=blue>See it at---&gt;http://www.blazzinor.coloradok5.com
     
  12. BigJim85

    BigJim85 1/2 ton status

    Joined:
    Sep 7, 2000
    Posts:
    113
    Likes Received:
    0
    Location:
    Lakewood, Colorado
    Re: TBI, TPI, Vortec, etc what\'s the diff?

    Seem you guys know your stuff. I'm getting a new motor this spring, going from a 305 carb to a new 350. I would like to go to fuel injection, and quite frankly I'm lost. How should I go about this, what system is the best for a guy looking for better gas milage? Any help would be apreciated, thanks.

    Call my rig an SUV... And I'll tear your lungs out.
     

Share This Page