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454 tbi swap questions

Discussion in 'The Garage' started by noalibi, Feb 24, 2006.

  1. noalibi

    noalibi Newbie

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    hello, i'm new to this forum and am in the starting stages of a 68 swb fleet build that is gonna get a 454/350 or 400 combo. i have a complete tbi setup from a 90 chevy van and a 454 throttle body from a 90 454SS. i know that i'll need a 454 chip and a higher flow fuel pump to make things happen. my questions are how much over stock can i get with a mild cam (what size, brand)?, if i go with a hi-perf chip (what brand)? got some shorty headers and an edelbrock tbi manifold. hoping to get 300 to 325 hp with these modifications. is this realistic? would love any help i can get. this is a planned 3 year project that my 13 year old son and i started about 4 months ago, and will be a ground up build. it's not my first build, but this will be my first tbi build, and i'm looking for a real streetable setup that "could" be driven if i choose. i did a search on tbi swapping and read all the posts i could find, and gained a wealth of info from them....thanks to the posters and your knowledge.
     
    Last edited: Feb 25, 2006
  2. 1-ton

    1-ton 1/2 ton status Premium Member

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    A COMP Cams part #255DEH will work for the kind of thing you are trying to do. I am sure someone will disagree with me, like they always do, but it is just my recomendation.
     
    Last edited: Feb 24, 2006
  3. dyeager535

    dyeager535 1 ton status Premium Member

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    Forget the "hi performance chip", and either have it tuned and a correct one burned, or learn to do your own. If this is a projet that is not restricted in time, and something that you'd like to learn on, I'd suggest learning to burn your own. You simply cannot extract all the performance out of an injected engine running with the wrong parameters, no matter what any aftermarket chip company says. (IE, hypertech chips, etc) Also, as a friend puts it regarding injection swaps, how do you know it's good if it's never been right? It may run ok on whatever chip you have (mine does) but improvement can always be had by doing it yourself.

    Comp is a good company, the only other one I would recommend for fuel injection cams is Crane.

    Also, as much as it is poo-pooed for accuracy, desktop dyno 2000 (or engine analyzer, which I believe is MUCH more expensive) will help on cam selection. If you can plug in accurate data, the changes a particular cam will make are pretty evident. The cam companies can also recommend cams, but from another fuel injected 454 thread, IIRC, they were recommending a cam that didn't sound like it would work very well.
     
  4. noalibi

    noalibi Newbie

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    i have no desire to experiment with or burn chips. i would like to have a good idling 454 with moderate horsepower over stock. the tbi is for driveability and to make cold start issues go away over the traditional carb problems, among other things. i would probably be content with a stock 454 chip, but i fielded the hi-po chip question to find out if anyone is running one and if it sacrifices driveability any. i also want something that is reliable and easy to drive as my son will be driving it sometimes. any input is greatly appreciated.
    on the Comp Cams DEH255 the specs say that it sacrifices some low-end torque for mid and high range, and makes most hp from 1200 to 5500 RPM. this may sound strange, but is this what i want to be shooting for in a cam if i am looking for max hp between idle(600 to 700) to 5000 RPM.
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

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    Reliable and easy to drive really comes down to stock. The entire engine from the ground up in trucks is made to make a ton of torque down low, and do it reliably for many years.

    The carbed and TBI setups were that way since their inception. Mid-upper end power was the sole domain of cars until the Vortec engines came out (along with the increased desire to drive SUV's and trucks in general) which expanded the performance over a larger range of useable engine speed. You start talking about higher RPM power in truck TBI setups, you start talking about bigger injectors, adjustable fuel pressure regulators, and so on.

    Any time you make engine changes to an EFI engine without tuning the PROM, you are in some way or another going to be hurting driveability. Whether it be mileage, performance or idle, modifying an engine from the baseline the ECM is programmed with, hurts. The smaller the changes, the less it's noticeable, but it's there. With your stated lack of desire to learn to burn your own, you will need to deal with someone like tbichips.com(?) or the like to get you in the ballpark.

    For the hi-po chip specific question, a "generic" chip like hypertech typically increases the timing so much that to keep out of detonation, you need to run premium fuel, and run a colder thermostat. In essence, timing changes in a very small window are what they change, and charge you money for.

    Edit: for some reason I'm thinking you might feel as if I'm being condescending or something towards you, which I'm not trying to be. Just trying to be somewhat brief while making points and suggestions that may help. :)
     
  6. noalibi

    noalibi Newbie

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    thank you dyeager, those are the things that i need to know. i'm not really concerned about mileage, but i'd hate to have to pump premium in it to be driveable for a few extra hp. the quirks that you mentioned about hypertech and detonation problems are not what i desire, and being in hot louisiana summers just amplifies the problem when detonation comes into play and driving with the a/c on. i'll probably go with a stock chip and if i get more power hungry later, i'll re-evaluate my options. for now the only upgrades from stock will be headers, edelbrock tbi manifold, true-dual exh., and a hi-flow air cleaner. in other words the safe modifications for now. thanks again.
     
  7. Thunder

    Thunder 3/4 ton status

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    If you are going to get a edelbrock intake manifold. You should give Edelbrock a call. They make a cam to match it and may also have a chip programed for the combo to make everything work together. I have used their TBI stuff on SBC and it works good. Their TBI cams are pretty mild. And give very good driveability. I have ran them on a stock chip no problem.

    What Dorian said about comercial aftermarket chips is pretty much right
    You can get the same gains by simply increasing the base timing 4 degrees and running preimium fuel.

    I also highly recomend you get an adjustable fuel pressure regulator. You can get them in either a manual or a engine vaccum controled type. Check your TB. The one out of that SS may already have a vaccum type FPR in it. If the FPR has a vaccum port on it you have one. If not you can get one from GM they used them on BBC marine ans some vehicle apps. Basicly they run a lower pressure for normal driving. When you accelerate the vaccum drops and the regulator gives full pressure to the injectors. besides better performance. They help get better fuel milage
    When you get a fuel pump make sure it is for TBI. MPFI pumps put out too much pressure and can blow your injectors if something goes wrong with the regulator.

    From what you are doing I think you will have no problems reaching your 300-325 HP goal. The stock TB with a few minor mods will easily support that.
     
  8. eagle mark

    eagle mark 1/2 ton status

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    Lot's of good advice. Most cams now have EFI recomendations. We have chips that we have tuned on hundreds of motors that are very close to dead on when we do these. They are also guarenteed so run your laptop and record data with WinALDL and we will re-burn one no cost.

    When doing the swap you have to think of what else you changed too? If you leave out the VSS then it has to be changed in the chip as well, same with auto trans to manual or one with no ECM controls.

    Here's a link to a harness for that swap that will make it a little easier for you.
    http://www.affordable-fuel-injection.com/tbi-wiring-harness.htm

    CK5 discount can be found in the vendor section! :D
     
  9. noalibi

    noalibi Newbie

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    no offense taken dyeager, and i appreciate your honesty. if i knew it all i would'nt have asked you, and being the guy i kinda read into your replys you don't beat around the bush much and tell it like it is, ...thanks.

    i will check my FPR, thanks Thunder, but i don't think it has a vac port. who carries this type.
     
  10. Land Yacht

    Land Yacht Registered Member

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  11. Thunder

    Thunder 3/4 ton status

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    You can get a vaccum regulator from your local GM dealer. I believe this is still a good part number. P/N 17113186 it gives around 20 PSI max.

    I am not sure about the SS TB you have. But I know that some of the regulators used on BBC TBI were set to give around 30 PSi But those were on the last few years BBC TBI 95- 96 ? GM P/N 17113079. Those years also came with a higher PSI fuel pump.

    I will also give a plug for eagle mark and his company Affordable Fuelinjection. They do good work and can help you out. Plus you get a 10% discount if you are a CK5 member. They have done some injector work for me in the past and I was very pleased.
     

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