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TPI vs Vortec vs LS1 vs LT1 with a 4L60E

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 75K5, Apr 18, 2002.

  1. 75K5

    75K5 1/2 ton status

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    I already have everything needed to build a pretty sweet 383TPI. I even have a new Eaton M112 blower and intercooler that I plan on plumbing into the lower intake. I have someone locally that is just going to build a custom lower for it.

    Before I Start cutting and welding, I wanted to know if it would be better to start with a vortec or LS1 motor. I plan on using a 4L60E or 4L60E transmission and the 98-up electronic controlled push button transfer case.

    Ohh yea, I have a complete dash, steering colum, switches, vents, blower motor, a/c ducting, cluster, wiring harnesses, door pannels, and accessories from a 98 Tahoe. I plan on using all the wiring, air controls, dash, and switches in the newer dash. It looks like it is not going to need major trimming to fit. The wiring will be a PITA, but not that complicated. I am going to weld/blend the newer tahoe inner door skins in in my existing doors so the door pannels install correctly with minimal trimming.

    Now to my question.
    If I use my tpi setup, how am I going to control the 4L60E/4L80E transmission and transfer case? Does anyone make a stand alone transmission computer and wiring harness?

    If I sell all my TPI stuff, I have a local yard that will sell me a complete 98 Vortec 350 with everything (all accessories, wiring, everything under the hood) AND a 4L80E transmission with transfer case. I started thinking this might be easier to deal with, because the wiring from my dash and the engine/trans wiring will all interchange.

    Ohh one more question. The TPI I have uses batch injection. What year did GM switch to sequential? My TPI is speed density, so at minimum I would want to convert it to Mass Air for simpler tuning.

    I am not really worried about which motor will perform better. I'm sure with 9lbs of boost and heavy head porting I will have enough power to be happy.

    Thanks for the input!
    Brian

    Thanks,
    Brian
     
  2. 75K5

    75K5 1/2 ton status

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    Re: TPI vs Vortec vs LS1 vs LT1 swap questions

    mkkay, guess I should have used google first. Looks like I can use the 4l60E, Just have to do some splicing and run both ECM's.

    "If you have a 1993 and up truck and want TPI it is a little tougher but we can still do the conversion.The harness still gets removed as mentioned above and still will be modified however we leave the stock ecm in the harness to control the 4L60E. We then set up the harness to accept another ecm (1227730) which will share some signals with the stock ecm so we have both TPI engine control and 4L60E control.When we do this we provide a second ALDL so the TPI system can be scanned with a scan tool and your other DLC plug under your drivers dash now will remain the same for future use by GM.There is enough room for the 2nd ecm behind the glove box.This harness mod cost $300 "
     
  3. 87GMCJimmy

    87GMCJimmy 1/2 ton status

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    It's looks like you've already answered you on questions but here is a couple of this to think about. I'm currently in the middle of installing a 99 vortec 5.7/ 4L60E into my 87 blazer and contiplated the same questions when I pick this motor. The problem with the TPI is that unless it it modified from stock it doesn't pull much passed 4600rpm. Where as a stock vortec truck motor will pull up to 5400-5500. I would rather not run 2 ecm's, just more expensive parts to go bad. The LT1, LS1 and vortec truck motors are SMFI. If you were choosing betweeen these three, the question would be where do want the motor to make power. I would have loved the LT1 on the road but the vortec has awsome lower end grunt for towing and wheeling. I never considered the LS1, it was a little pricey for what I wanted to do. If I had the unlimited cash......454 vortec and a 4L80E.... Gee it bolts right in....

    The electric shift transfer case from the newer trucks is drivers side drop so this will not work unless you want to change out your front axle. Good luck!

    Mike
     
  4. 75K5

    75K5 1/2 ton status

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    I am not worried about the low end pull, because after we get the heads ported and the supercharged installed the motor should have a much nicer powerband. I really wanted a twin turbo, but a friend practically gave me a brand new eaton M112 and intercooler off a lightning, and I started thinking it would be a cool setup.

    I sure wish I could have SMFI on my TPI. That's the one BIG disadvantage I see to keeping my TPI.

    I hadn't though much about the transfer case with the electronic shifter. Is that thesituation with all the newer transfer cases? Which one did you use?
     
  5. 87GMCJimmy

    87GMCJimmy 1/2 ton status

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    Wow... Ok I'm jealous...... Why can't you use the SMFI computer and modify the harness to fit the injectors on the TPI manifold. The TPI and LT1 intakes are practically the same just much shorter runners on the LT1so I don't think this would be a big deal. They use the same type of sensors between the two systems and it wouldn't shock me one bit if half of them have the same part #. If you are capable/willing to rewire the entire dash I don' think the fuel injection harness would be a problem. Are you going to use MAF or MAP??

    Mike
     
  6. 75K5

    75K5 1/2 ton status

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    good point! And actually if I used an SMFI computer I could probably take the 4L60E transmission controls and not have to deal with the dual PCM problems. If I went SMFI do you know what years they werel MAF? I am a huge MAF fan.

    I was originally going to take a PCM from a 91-93 syclone for my TPI. They have an adjustable control that allows you to select 4, 6, or 8 cylinder motors. Those PCM's are supposed to be ideal for supercharged applications because it can read boost via a 2 bar MAP sensor. So the originally I was feeling forced to go MAP.

    I wish I knew more about GM PCM's, but I come from always running Ford's.

    Ohh yea, Have you decided on a transfer case for your 99 vortec?
    Edit: Just read your profile, I see you are using an NP208. Thanks!

    Brian
     
  7. dyeager535

    dyeager535 1 ton status Premium Member

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    SMFI really isn't that huge of an improvement over batch fire. Take that for what its worth, its a better idea, but the improvement isn't huge, and as you note, it sounds like a much more complex task. Nothing wrong with that, you are going to be doing a lot of work anyways, just that it *is* a further complication that doesn't net a whole lot of extra gains.

    IIRC, you can't get a 4L80 thats not an "E" variant, but you can get a 4L60, and not have to run the tranny on the computer obviously.

    Personally, if I had the time and money, I'd probably run the TPI, get Vortec heads, something along the lines of a mini-ram intake (not sure how that would all tie into your supercharging though) and run a 4L60. Then again, thats some serious power, but a standalone 4L80E harness (which I'm not sure who makes) would give you the insurance in durability that the 4L60(E) never will.

    I'm not a TPI expert, but I'm working on gathering a lot of knowledge on the system, by paying attention to what everyone is doing and using.
     
  8. 87GMCJimmy

    87GMCJimmy 1/2 ton status

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    I like the MAF systems better also but I've read somewhere that with a super charger you can go over the max flow of the MAF sensor. I do think the LT1 MAF's are larger than the TPI's. You can check out www.thirdgen.org or www.fbody.com for information on computers, tuning and using a supercharger. I think all the LT1's, LS1's and Vortec are MAF. A SMFI TPI would not be a huge gain in performance over the MFI TPI but I think it would be worth it to run just one PCM. By running aftermarket siamesed runners and plenum you can shift the rpm's up to match the heading porting and cam. This should be a bitch'n motor when put together. What kind of Hp/torque are you looking at and in what rpm range?

    Mike
     
  9. 75K5

    75K5 1/2 ton status

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    The TPI setup I have I got off ebay. When it arrived, I noticed larger cast runners that have been siamesed. But to tell the truth, I'm not even going to need them. The fella making my intake is going to put the blower on top of the lower intake, and sandwedge an air/water intercooler between the blower and intake manifold. So I am doing away with the plenum, runners, and stock Throttle body location. The biggest pita is moving the throttle body and intake plenum off to the side of the blower (instead of in the middle like the stock tpi). Look at the engine compartment of a 99-up lightning, that's similar to how this will be setup. I think forcing air directly into the lower intake will be more efficient than trying to stuff boost through the stock plenum and runners.

    The ultimate goal is to have 400 RWHP in a streetable blazer. Between the supercharger, larger valves, diffrent heads, a conservative cam, and a 383 with lowered compression it shouldn't be difficult. I am one of those fools who will be taking this to the track between car shows and occasional outings /forums/images/icons/smile.gif

    Hopefully you can use an aftermarket MAF and reprogram the computer for the new transfer function. I definatly do need to read up on these computers and see what their potential is.

    The other thing I have been looking at this since this thread started is the Accel DFI for LT1's. Looks a little pricey, but has a serial interface.

    Thanks for all your help. Your input has made a difficult decision easy.

    edit: OHH, I just read that the Accel DFI for LT1's will support a widband 02 and can run in closed loop mode at higher throttle/rpm's. It's now looking verrrry tempting.

    Brian
     
  10. BurbinOR

    BurbinOR 3/4 ton status

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    Wow, you are ambitious............cool stuff.

    What are you doing for the added fuel needed for the supercharger............? I assume you will also be making a complete new chip with all the new variables. Guess if you go DFI maybe it has those capabilities.

    Whatever way you go, please keep us informed. Haven't seen such a hybrid setup as your's - TPI w/Supercharger.

    I'd go LT1, it will flow the air that the TPI will NOT. Just remember the Opti spark is down near the crank and will get wet, tho sounds like you won't be in the mud/water.

    On the other hand, if you got the $$, LS1 is way cool.........

    Have you posted over on www.thirdgen.org ? Good source for info............also, Dorian has a friend in NM that is very sharp on this stuff.
     
  11. BigJohnson

    BigJohnson 1/2 ton status

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    How is the vortec swap coming? I have some of the parts I need to put the fuel injection back on the vortec I have in my blazer. I am a bit hesitant about doing the swap though. It seems it will be very expensive. Have you run into any problems so far? Are you using an aftermarket harness or the factory harness? What about your fuel system, are you using your tbi tank? Fuel pump in tank or external pump? Sorry for so many questions but I this info will greatly influence my decision on what to run. I almost had myself talked into a TPI setup and vortec base from Scoggin Dickey. But I still would like to go with the vortec.
    Thanks
    Jordan
     
  12. 87GMCJimmy

    87GMCJimmy 1/2 ton status

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    The swap is going good. The main problem I'm am having is getting large enough chucks of time to work on it. I figure stuff out and then let it sit for a week and forget what I'm doing.

    As far as physically putting the motor in the truck it is a true bolt in. The NP208 bolts right to the 4L60E without a hitch. I am using the factory harness. The engine tranny harness for the vortec is pretty much stand alone system. I unhooked the NP243 transfer case and plugged the connecting wires with RTV. The stock fuel tank works perfectly. The 96-99 2-door tahoes and yukons use the same style of fuel pump and is a direct replacment for the stock TBI pump. The rest of it is just mounting the PCM, evap canister, oil cooloer, tranny cooler. underhood fuse block. I do need to get a Vss generator to run off of the NP208 for the computer. The wiring is pretty simple hook up the wires you need and seal off the ones you don't. Due to the 87 having a passenger drop t-case and the 99 having the drivers side drop, I will have to tow it to an exhaust shop and have them build it. This is probably the most expesive part.

    Just for a cost comparison I picked up the motor/tranny/t-case with all accessories, computer, wiring harness, exhaust cut behind the cat's and intake with 35k miles on them for 2k. So far the only other part that I have purchased is the fuel pump 71.99 at autozone. I still need the Vss generator, an exhaust system and parts to build a custom intake.

    If you have anymore ?? let me know.
    Mike
     
  13. BurbinOR

    BurbinOR 3/4 ton status

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  14. 75K5

    75K5 1/2 ton status

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    I thought about the LS1, but it really dosen't excite me. My Mark VIII is all alluminum, and although it's nice It dosen't justify the cost for a project like this. I looked more seriously at the LT4, but sheesh... those are really pricey. If I was swapping it into a 50's vette I'd think about it, but it's a bit extravagent for the old blazer /forums/images/icons/smile.gif

    I hadn't gotten to the fuel system yet, but that will probably be larger rails, and if the stock fuel lines aren't adequate I know someone that can easily make custom ones. I think a 255lph pump should take care of it. Haven't calculated injector size yet either. I have an extra set of 42's laying around, so they might be used because of convience.

    do you know what year they switched from having the transfer case drop on the passenger side to the drivers side? Does it have any correlation to when they switched to IFS?
     
  15. jmd

    jmd Registered Member

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    First, I think that your goals are attainable w/ the Vortec motor, so going LS1 would add unnecessary expense. I love the LS1 and there are some positively obscenely wicket options for it (420cid / turbo) it's just that budget for budget, you can do what an LS1 can do for less $.

    What I have heard about the 4L60-E & 4L80-E is that they speak differently w/ the PCMs so they cannot be swapped directly for one another. There is available (from GM I believe) a standalone controller to run them separately from the engine. Don't have my GMPP catalog w/ me though; I'm sure it's on Sallee or somebodies site. I have no idea if the pushbutton transfer cases are operable via the standalone tranny computer I was talking about, but wouldn't there be a 94-9? 4L60-E or 4L80-E that had a "mechanical" shifter to the transfer case, yet still have the -E tranny? That would be another option.

    Personally, I think your best bet overall is to go for the complete 96-up Vortec 350 & 4L60-E trans. since you can use the PCM to control it. However, if the aftermarket on the aftermarket for those PCMs is limited, you might be better to go w/ the Gen I SBC & speed density TPI.

    On the TPI... The guys who are hard core into programming it (burnin' chips, as they say) say the speed density is the way to fly. Not only does it have a MAP sensor (which can be upgraded to 3bar; stock is 1bar) which is better for boost. The speed density is also easier to program than the MAF according to those who know. If you went w/ the SD TPI, I'm sure that it could support your goals, including blower, and for simplicity, you'd wanna go with the non -E tranny & 'case, even though the standalone controller & -E tranny could be used. Again, the batch fire is *not* even a 15hp gain; just run it and forget about sequential at this point. I'm happy I did :-D

    As far as TPI being limited in RPM.. the electronics & system are not limited to any 4600rpm at all; the intake is what does that. Switch intakes and be good to go /forums/images/icons/smile.gif The Mini-Ram is a great intake for a big inch or high rpm EFI small block and is available for Gen I or Gen II (LT1) SBC's but if you're looking for low end torque, there are likely better options. Unless you're building a 6500rpm SB, I'd look for something a little milder like the Super Ram. Especially in the case of a truck, you want torque under the curve, not just "big numbers."

    As far as the wideband, I would run that separate from the computer and use it for tuning, and use regular Delco O2's, the cost of the wideband stuff isn't worth it at this level.

    Also, about Ls1's, they make Iron blocks; the 6.0 and 5.3 and the other one in trucks is iron /forums/images/icons/smile.gif

    Frank, I hear your VSS is working well; glad to hear it.

    Okay, time to go do some clutch stuff.

    Matthew in Albuquerque
     
  16. BurbinOR

    BurbinOR 3/4 ton status

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    VSS is working great, and was well worth doing. No question!

    I knew you'd have some good insight on this, thanks for helping out.
     
  17. 75K5

    75K5 1/2 ton status

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    I thought I would share this info, I just recieved it in an e-mail. There is a fella I found through the search engines that makes TPI harnesses. He sells a custom harness that uses both processors so you can run a 4L60E with your TPI. I'd prefer a 4L80E but I didn't ask him originally about that. Here's what he e-mailed me:

    "well, yes, we have a harness and ecm to control a 4L60E and it would just need to share some info with the TPI ecm to work.... the trans ecm would need to know TPS(in which you would slice a blue wire into your tps blue) and it need to know engine rpm(in which you will splice a purple wire into a purple at your 4-way dist plug ) and you have a system.. The system including ecm,prom and harness is $475.jim/jimsperf."
    his web address is www.jimsperformance.com

    as far as the MAF/speed density argument, I'll need to learn more about it. All of my fords use MAF, and although they are difficult to tune I really like how well they respond to modifications on their own. Plus I understand MAF much more in depth than I do speed density.

    If I do processor and harness splicing, It looks like the lt1 harnesses and processors are easy to get a hold of. I woudn't just do that to gain sequential fire, but if I decide I want MAF and sequential, that'll probably kick me over the top!


    Still research to do on the transfer cases. I am thinking the only harnesses should go to the pushbutton shifter and maybe some speed sensors. The big problem is that it's on the wrong side. I don't know if the vacuum operated ones have the same problem.

    Very informative stuff. Thanks guys!
    Brian
     
  18. Bone85K5

    Bone85K5 1/2 ton status

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    Good friend of mine had thsi to say from your orginal post: (hes a regular on all the f body, z29 and ls1 forums...

    The 4l60e will NOT NOT NOT handle more than 450-500rwhp OR more than 430rwtq, whichever comes first. The 2-3 shift will die after a few full throttle runs.



    The 4l80e is where it’s at, that bad boy will take anything.



    And the ls1 is to the lt1 what the lt1 was to the l98 (tpi), if that makes sense. As much better as the ls1 is over the lt1 (a lot), the lt1 is a whole lot better than the tpi.



    Id’ do an ls1 and forget about the tp1 altogether. The 350 vortec would be nice as well but he’s looking at a SIZABLE project getting all this put together and working with the electronics, the tranny, and topping it with a blower is a huge project if the blower wasn’t built specifically for that application



    Cool though!
     
  19. BurbinOR

    BurbinOR 3/4 ton status

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    That is good info, and a lot of his opinion is right. However, and I'm not saying this to start a flame war, but the LT1 has one major DISadvantage over TPI for our trucks - the Opti spark ignition is down on the crank and that is not the place you want your ignition if you get into ANY mud or water. Not to mention a drip from the water pump. Yes, there are ways to change it, but from what I hear its about $1K for a new ignition. Hmm, I could spend that money on the top end of a TPI motor getting it to flow if I was so inclined.

    LT1's do flow air better but I'd still like to see the torque numbers for an LT1 vs a well built TPI in what I'd consider the usable 'for-a-truck' rpm range - below 5K. My 406 hasn't been over probably 4800 rpm ever, even running sand bowls, so tho I don't dispute the LT1 can make more HORSEpower, the value to our particular application is smaller, if there is any value at all. Torque is where it's at with our rigs.

    I don't think anyone on here has done or seen an LT1 in a K5..........one guy on Pirate has one in his YJ and commented to me the problems with the ignition are real and are a pain in the keester. Emmetology just bought an LT1 but not sure if it's going in a truck or a car project.
     
  20. Bone85K5

    Bone85K5 1/2 ton status

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    Also from my friend....



    He’s absolutely right.



    The opticrap iginition sucks big time.



    People with lt1’s have had them crap out after detailing the engine and barely getting it wet. They suck.



    I have heard that the l98’s / tpi’s are better at low rev’ing torque, so that is a very valid argument. The lt1’s flow better up high and the ls1’s even better. Maybe an ls1 with decent heads, a high torque’ing cam, and 1 5/8 headers would be a nice torquey combination?



    My lt1 made over 400rwtq from 2400rpm up, that was with 8.8:1 compression and an lt4 hotcam with nicely ported heads and matched intake. The boost really didn’t come in hard until 3500-4000 rpm knocking the numbers up to 532rwhp and 492rwtq (12psi non-intercooled vortech s-trim).



    My ls1 on the other hand makes a little over 400rwhp and 400rwtq with a nice heads/cam package on it. Similar combinations (I havne’t dyno’d mine on the spray) on a 100 hp wet shot have made 530rwhp and 700+rwtq. I figure that to be about right since mine blew of the et streets in all four gears the track right before my 10.8 @ 129 pass…
     

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