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TPI adjustability

Discussion in 'The Injection Section' started by 77crewcab, Dec 5, 2006.

  1. 77crewcab

    77crewcab 1/2 ton status

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    I am new to working with fuel injection and am trying to figure out if a stock TPI system will do what I want or if I should look at an aftermarket setup. I am looking at building an engine for my Nova that will be a 383 with Vortec or Etec heads. I know Scoggin-Dickey makes a Vortec TPI base manifold. But I am not real sure how adjustable the TPI systems are and how it is done.
    1. Would it support this type of engine combination?
    2. Am I looking at hooking up a laptop to reprogram the computer or will I have to look at burning chips.
    Any suggestions and/or links to help me understand these systems would be appreciated.
     
  2. Russell

    Russell LB7 Tahoe Status Premium Member GMOTM Winner

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    www.chevythunder.com has all of the mechanical / electrical aspect down, while www.thirdgen.org's forums have all of the chip burning info you need :)

    You will probally need to consider going with a super-ram or something with a 383. A stock TPI intake barely breaths enough for a bone stock 350 to 4500 rpm, a 383 would be just that much more restricted.

    You will want a fairly mild cam with EFI, it should idle smooth, as EFI is better for making torque than it is for making super high horsepower. Make sure the cam has a lobe separation angle of at least 112 degrees to minimize valve overlap, esspecially at an idle.

    It can be done, and your engine will run very well once it is tuned up, but don't expect to just bolt a stock TPI on and have it run perfect right off the bat, expect to spend a lot of time and money on the swap, making it perfect. Make sure you do your research, and decide on the intake you want to run right away too.
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

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    Guaranteed a 383 will demand more than the stock injectors can feed. So for a "stock" system, no way.

    One way to get serious power out of the box is to just go with an LS motor. RyanB is one to talk to about this. Those motors put out serious power and still all the benefits of EFI. $3000 approximately so I hear, you'd be hard pressed to build a 383 and purchase the EFI that will support it for near that I'd suspect.
     
  4. 77crewcab

    77crewcab 1/2 ton status

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    I would love an LS but have yet to see one around here for less than $5K The reason I was looking at the 383 is because I already have a 350 I am rebuilding. Since I will be going with Vortec style heads I wanted to see if the TPI could support the 383 if I decided to stroke the 350 later on. So I will probably be running a 350 for a while. Other than injectors, and chip programming, what else would need to be done to support the 383? Larger Throttle body, runners, something else??? I actually can get a full TPI unit from a Camaro for a very reasonable price ($100) so no problem there.

    Honestly if I could find a LS1 for $3K or less I would love to go that route just haven't seen one local and am leary of buying something used like that online.
     
  5. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    I built a 383 with TPI and you need to run 24lb. hr. injectors and i installed a BBK 1050cfm throttle body and that thing ran excellent. I was running a roller cam that was special ordered from Comp Cams to work with the TPI. If you're interested in the cam specs i still have the cam card. Oh, you will need a chip burnt as well. I had Street & Performance do mine.
     
  6. 77crewcab

    77crewcab 1/2 ton status

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    Yes please give the cam specs/part number. And any info you may have on the chip. The writer at chevythunder states he is also running a 383, so I guess my the answer to my question of if TPI will work with the 383 is yes. Now I am starting to get a little excited about this new venture. While I have had FI cars in the past I have never been the one to work on them so this is all a new learning experience. BTRW what kind of power were you getting from that 383?
     
  7. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    Ok, here are the specs on the cam i ran. There is no part number since it is a custom grind. This is a hydraulic roller cam

    Valve lift In. .480" / ex. 487"
    Duration @ .050" In. 206* / Ex. 212*
    Lobe separation 112*

    ------------------Open----Close
    Valve timing In. -5 BTDC / 31 ABDC
    Valve timing Ex. 42 BBDC / -10 ATDC

    These specs are for cam installed at 108* intake centerline
     
  8. dyeager535

    dyeager535 1 ton status Premium Member

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    The reasonI suggest the LS series is because I went the whole Vortec/Roller/TPI route, and am less than pleased at what I'm getting for my money, compared to what the LS motors make out of the box.

    Don't get me wrong, a friend that is really into performance said my truck has a lot of power, but for a 355 and 3.42's, it runs out of steam QUICK. I guess it all depends on what you want to do, but I hated compromising top end for low end, which is exactly what TPI does. With an LS you get both.

    Go over to thirdgen.org and see what people have done with 383's. It seemed pretty universal before that without running some really high dollar parts, TPI just won't allow a 383 to do what it's capable of. Big difference between capability and what you actually get.
     
  9. 77crewcab

    77crewcab 1/2 ton status

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    Okay I see what you mean. On this build I am putting it into a car that is about 3000lbs maybe a little over and what I am looking for is just a good daily driver that isn't totally boring and it would be nice to have fuel injection. Honestly I have ridden in a few TPI Vettes and F-bodies and been very pleased with the engine performance and fuel economy which is why I am looking at going this route. I figure that putting the TPI on a stock 350 rebuild and having the Vortec heads and a aftermarket cam would probably do very well for what I want and if I see the need for more power then I could look at going to 383. Is there an aftermarket MPFI that you would suggest that might fit better, maybe the Edelbrock, Holley, Accel units. Again I would love the LS1. But when I start weighing the cost LS1 vs TPI the TPI is a hands down winner. Even if I had to replace all the sensors I would still be under the cost the aftermarket systems much less a LS1. As for the performance I think just by comparing riding and driving TPI F-bodies and Vettes I have experienced that I would probably be satisfied.
     
  10. Russell

    Russell LB7 Tahoe Status Premium Member GMOTM Winner

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    Well, I can totally understand how you feel about this injection system, it is definitely way cool, and I didn't totally believe that I would be dissatisfied with my system either. But, we are being totally honest with you, and don't want to you make an uneducated decision on this swap. Back in the day, when we started, LS engines swaps were super uncommon, heck, those engines were basically brand new. But there are a ton more of them out there, and as Dorian mentioned, they have everything that TPI has to offer, plus a whole lot more.

    All that said, if I was to build an EFI 383, I would build one with a compression ratio of about 10:1, aluminum aftermarket heads that have a traditional intake runner pattern, and an LT1 intake machined to work with a traditional small block. I would then toss the old ECM, and buy / build a MegaSquirt ECM. You then have a far more user friendly ECM that is way easier to modifiy, and has support for many of the aftermarket equipment that you may want, such wideband 02 sensor, built in emulating, internal flashable prom etc.

    Not only that, but then you can also retrofit in a DIS (Distributerless Ignition System), and run sequential fuel injection.

    Then, all of a sudden, you are on a much closer playing feild as the LS engines are on. You will suffer in low end torque with the LT1 intake, but your engine will be able to breath up to it's full potential, and you will have the same excellent ignition systems available on the newer engines, not to mention the economy of a sequential injection system.

    You could easily make a crapload of power with an engine like that, if you built the engine to match. And while you do loose low end torque as compared to the TPI intake due to the loss of the tuned runners, dyno tests have proven that the gains outweigh the losses to a fair extent.

    However, once all is said and done, you'll probally have pretty close to the cost of an LS engine, and will still not be totally up to par to what a 6.0L engine has to offer in terms of a smooth idle, and insane low end torque, with the ability to run off 87 octane.

    However, all this said, I've often thought that a mildly upgraded TPI system could potentially keep both the insane low end torque, and pick up some major ponies in the top end by means of forced induction... You might be able to pull that full 6500 rpm out of a TPI if you are running a bigger turbo that spools just as you come out of the range of the tuned runners at about 3000 rpm... You would again need to build the engine to match, including a strengthend bottom end (all forged, not cast), pistons made for boost, a lower compression ratio, and a cam for boosted EFI applications, not to mention a set of aluminum heads bolted on with head studs, and an intercooler... Again, still cost more than an LS engine in the end, lol

    So, take it how you see it, we really cannot totally convince you one way or the other, but I must admit, I'm with Dorian in feeling that while the engine is great in the lower RPMs, it certainly runs out of steam in a real hurry.
     
  11. 77crewcab

    77crewcab 1/2 ton status

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    Well after a little time spent over on the thirdgen site and a few others I think I have made a final decision to go forward with the TPI. I know the LSx engines start with more to offer but that also comes with a price tag that I can't justify right now.

    Once I figure in the cost of the engine and swap parts to put it in a firstgen nova I am looking at around 5-6 grand. With the TPI setup I will have less than $2K including swap parts. The engine and rebuild kit I got for free with machinging already done and ready for assembly. The TPI set up origional to this engine I got for $100 with SVO 24# injectors, buying Tunerpro RT and an Ostrich emulator would be about $200. I already have the swap kit for early novas including engine mounts, front sump pan, oil pump, pickup and drive shaft. So I am looking at $300 invested before picking out cam and heads.

    I will probably just keep the .030 over 350 for a while before looking at stroking it. From the thirdgen site it looks like there are several guys running this combo that are getting 300+hp/400+tq which would be fine with me. Knowing the limitations of the TPI sit around 4500-5000 rpm is fine with me as I am looking for more of a good strong daily driver rather than a race type setup.

    The added plus is that this is still a gen I SBC, and I have some good friends that give me some great deals on parts. Yesterday I was offered my choice of some older AFR 190 or some Trick Flows about the same rating. (I was driving down the road at the time and couldn't write the details down) I can get the AFRs for $800 and the TFs for $500. The owner is upgrading both his cars to the newer AFRs. Will be going with the AFRs for the nova. Deals like this make it very beneficial to me to stay with a genI SBC since I can get very good parts on a very tight budget.

    Now I am also considering getting the TFs and putting a TPI setup on the Burb I recently got for a little added power. Any of you with TPI on your truck want to tell me what kinda mileage your getting. I know most here will have 4WD lifted and big tire combos but figure that extra weight and resistance on a Blazer might equal out to the weight of a 2WD burb.
     
  12. dyeager535

    dyeager535 1 ton status Premium Member

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    First off, I'm not sure I'd go with the older AFR's. No offense, but Vortecs probably outperform them. I say this because I don't believe the early AFR stuff had the improved combustion chambers. For probably $400 more(?) you could get heads with better potential, and since you plan to build up later, why not get something worthwhile for another build? Just my opinion, I shouldn't have spent my money on Vortecs with the TPI swap. Live and learn. :)

    Mileage-wise, my sole economy test was pretty poor. I was going up and down a mountain pass at 65MPH, and also climbing logging roads all day. I averaged 13MPG in those conditions, a bit more than the carb managed around town in the same rig. Of course, my vehicle isn't tuned right, but I expect to eventually squeeze 18MPG+ freway out of the truck, which is what I had managed as a best in the same vehicle, but carbed.
     
  13. 77crewcab

    77crewcab 1/2 ton status

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    I think these AFRs are only about 2 yrs old but I haven't seen them yet. What would you recomen say in the $1100 or less price range for a pair of complete heads? I have heard good things about the Trick Flows but not sure what else to look at. The Edelbrock E-tecs seem to have really good reports as well. Just a little uncertain since there are so many to choose from.

    I was hoping to maybe get 18-20 Hwy on the burb, with the TPI, TF heads, and a good low to midrange cam with lots of torque. But I guess I'll just have to wait and see.
     
  14. dyeager535

    dyeager535 1 ton status Premium Member

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    If the AFR's are that new, then I think you'll be alright. One of the real advantages to the newer designs is more compression EASILY, without having to go up to a higher octane rated gas. I'm at right around 9.2:1 and don't have problems with 87, and could probably go higher. With AL heads I'd probably shoot for around 10:1 on 87.

    18-20 might be a stretch, but it IS possible I think. With the right gearing, engine combo, and tune, it is a worthwhile goal. What's your weight? Mines about 5000, I suspect aerodynamics to be similar enough for rough guessing. With highway mode enabled TPI, it would be interesting to see what further could be gained. You'll have to read up on "highway mode" on thirdgen, probably best in the diy-prom forum.
     
  15. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    Just to let you know, a 383 stroker can not use the Chevy II front sump oil pan. The crank counter weight will hit the oil pump on a Chevy II oil pump and a regular oil pump will not work with the front sump pan.
     
  16. 77crewcab

    77crewcab 1/2 ton status

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    Weight on the burb would still be stock. Not sure what that was but probably around the 5K mark maybe a little over. I figure that if I can get at or above the 15mpg of my old van then I am doing good and as a plus I can actually tow something with the burb whereas the old minivan couldn't. gearing will be 3.73 with 237/75R15 tires and 700R4. I have really thought about getting a GearVendors overdrive unit for the burb the help the mileage and that might be just what I need to hit the 20mpg mark.
     
  17. 77crewcab

    77crewcab 1/2 ton status

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    Didn't know that about the oil pan but by the time I start looking at going with a 383 I'll have probably swapped in a rack and pinion steering so could use a standard oil pan with no interference issues.
     
  18. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    Just thought i would throw it out there for you. I know it sucks to be buying parts twice. You could always buy the rear sump pan thick has a notch for the steering linkage. I don't really like them though because they do sit kinda low and i like my cars to sit low and that means tearing a pan off at some point from hitting crap in the road.
     
  19. 77crewcab

    77crewcab 1/2 ton status

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    Yeah I'm not too keen on those notched pans either. Especially since once the steering is upgraded I wouldn't need one. I got the V8 swap kit (pan, mount etc) with the car so I am not having to buy the kit.
     
  20. dyeager535

    dyeager535 1 ton status Premium Member

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    I have a feeling that with those gears and OD already, a GV unit might be overkill. Running right around 1500-2000RPM seems to be the "sweet spot" for the SBC, I suspect your burb is there already at 60-70MPH on stock tires and OD.
     

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