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Noob-ish TPI build questions

Z71paramedic

Z71paramedic

Wait....What???
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Ok so I have a build thread going in the first gen forum and I've decided to tackle everything at once (I'm sure it's not the first time you've heard it and it won't be the last). My current drivetrain is a 350 .030 over with a edelbrock intake and 4 bbl mated with a sm465 and 205. I've got the 12 bolt/44 setup with 4.88's turning 40's. I was planning on just rebuilding the engine when I got a $1000 quote from the machine shop just for machining:eek1: Sooo, I then decided I was just going to do the top end including a new cam/lifters and the TPI setup I yanked off a T/A a few weeks ago. Well the latest installment of plans-changing is the guy I bought my heads from (193's to mate with the 91 intake setup) told me he could sell me a completely dressed block the way I want it for 425 and I handle shipping (which is ok since I work for Fedex). So now my plan is full roller .030 over TPI... What I need to ask you guys is as follows

What's better 355 or 383? I know that displacement is great, so that's a given but what would I really gain from the 400 crank? I'm not looking for anything insane here, in fact I'm pretty happy with the power I'm producing now, just want to update to efi, get a one piece rear main etc... BUT, I do like power:D The truck will be 85% road, get dirty when I can type of deal

Also, I already plan to eliminate the EGR. I'm up in the air about knock sensor, VSS, etc. I want maximum driveability first and foremost. I don't know much about EFI at this point but wouldn't mind learning at the same time. I just want to make sure it's not going to be a finicky b*tch:whistle: I'm open to running as much or as little as you guys recommend (hence me asking). I also plan to cut down the factory harness and obviously have a new chip made. I'm also still acquiring parts so I'm not really in a hurry, I just want to ask as much as possible before I commit to anything.

If it matters I have a 1227730 computer.

Thanks in advance:bow::bow::bow:

and now some shameless pic whoring to keep you interested!

DSC_0011.JPG

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If I were you I WOULD NOT disable the EGR, knock sensor or the VSS. I built a TPI 383 for my last blazer and I forgot to hook up the VSS and it had all kinds of idle issues once you came to a stop (most times it would die or run rough), the ECM needs the VSS info along with the MAP sensor to let it know there is no load and the vehicle is not moving to allow the engine to idle correctly.

Why would you want to eliminate the knock sensor which is used to allow the ECM to adjust timing based on engine knock? If you disable it and the engine starts pinging and you don't hear it and back off on the throttle or do whatever it takes to make the pinging go away then you will destroy the engine in short order.

Also, the EGR helps to reduce cylinder temps which also helps to eliminate preignition. None of this stuff hurts fuel mileage or performance in any way.

Another thing, If you do build a 383 it will require larger injectors and also a chip burn. Back in the day when I did my build I bought a stand alone harness from Street & Performance and had them burn a custom chip for me.

Also, if you're going with a hydraulic roller cam I can suggest one that makes TONS of torque (I had it custom ground for the 383 back in the day and it finally became an off the shelf item which i'm currently running).
 
I love my TPI. The best mod was to swap over to run OBD2. A lot easier to tune. have a look through my build thread. I have a few pics and a video of the swap. Then grab a chair and go do some reading over on www.thirdgen.org. Lots of good info there.
 
IMO, keeping the engine nearly stock will keep the budget to a minimum. A 383 will be more expensive than a 355. Performance increases will almost always increase the budget. Personally I would not put a TPI on a 383.

I think a good place to start learning with a TPI is put together a test bench similar to the one I did on this post. http://coloradok5.com/forums/showthread.php?t=270085&highlight=tpi+test+bench The test bench mostly provides for electrical testing, using EFI diagnostic tools like an AutoXray, using TPI data logging software, and checking PROM programming.

One budget option for a TPI engine management is from Larry's Electric. http://www.larryselectricsite.com/TPIKIT.html The TPI kit from Larry's Electric is a real time saver, and competitively priced. The Larry's Electric TPI kit is set up for a nearly stock engine, because the PROM chip that is included in the TPI kit is programmed for a nearly stock engine.

dave w
 
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4X4HIGH said:
If I were you I WOULD NOT disable the EGR, knock sensor or the VSS. I built a TPI 383 for my last blazer and I forgot to hook up the VSS and it had all kinds of idle issues once you came to a stop (most times it would die or run rough), the ECM needs the VSS info along with the MAP sensor to let it know there is no load and the vehicle is not moving to allow the engine to idle correctly.
Click to expand...

I was under the impression that the EGR was simply for smog purposes and only recirculated hot exhaust gases back into the intake, thereby slightly hurting performance. If that is not the case then I will run it by all means, doesn't hurt me either way, I have all the wiring and sensors already...

4X4HIGH said:
Why would you want to eliminate the knock sensor which is used to allow the ECM to adjust timing based on engine knock?
Click to expand...

Originally when I was going to run the TPI on my current block that is in the truck now I wasn't sure that I could use a computer controlled cam in it, so I was considering not bothering with those electronics. Again, I'm new to all this and am just trying to decipher though all that I've read so far. I haven't pulled the trigger on anything yet so I'm just trying to do my homework so I end up with the best setup I can.

4X4HIGH said:
Another thing, If you do build a 383 it will require larger injectors and also a chip burn. Back in the day when I did my build I bought a stand alone harness from Street & Performance and had them burn a custom chip for me.
Click to expand...

I knew I would need a custom chip anyway just based on the fact that the computer I have came out of a 305 car, plus I would be changing cam specs and various other things anyway. The harness isn't worrying me that much. I know it's a lot of wires to sort through but I have time on my side. I've got a nice pinout diagram for it and know where all the sensors terminate. Now I just need to sift through and remove all the crap I don't need on there. I'm probably not going to go 383 for a few reasons. First off is price. I know it's pretty negligible now, but I want to build something that will last a long time and not nickel and dime me down the road and with higher performance comes more wear on parts. I also don't need any crazy power or high RPM's. It's really going to be a street queen that I get dirty when the opportunity presents itself.

4X4HIGH said:
Also, if you're going with a hydraulic roller cam I can suggest one that makes TONS of torque (I had it custom ground for the 383 back in the day and it finally became an off the shelf item which i'm currently running).
Click to expand...

That I'll definitely take you up on. If I end up going with a newer block (which is really looking like the case) I'll be building top to bottom, so I'd definitely like to get the best package put together as possible.

Thanks again for all the help guys. I'm already reading through a bunch of stuff and seeing what I can scrounge up for must-do's...:popcorn:
 
bronc3buster842001 said:
I love my TPI. The best mod was to swap over to run OBD2. A lot easier to tune. have a look through my build thread. I have a few pics and a video of the swap. Then grab a chair and go do some reading over on www.thirdgen.org. Lots of good info there.
Click to expand...

So I read through the whole "411 swap" thread over on thirdgen but it didn't answer one of my biggest questions. It was mentioned that even if you have S10wildside make you a harness you still had to splice it into the original harness (at least that's what I pulled from it). I assume that's only referring to the ecm upgrade into a TPI camaro, right??? Obviously I just want to run the TPI setup on the engine I'm building and really like the idea of upping to OBD2. The harness I pulled from the T/A is actually in great shape. If I were to get the 411 ecm and the terminals could I just take the corresponding pins out of my ecm connectors and place it into the correct spots in the new one (and add the new wires for the 2nd O2 bank and CPS)? Or do I need to get a harness out of a van as they suggested and merge parts? I also know I would have to grab the vortec timing cover, dist., ign. coil/module etc. I don't have to worry about smog, the truck is a 72 and wouldn't have to pass anything no matter where we were to move. I just want something that once it's in is very driveable and doesn't require constant tweaking. I won't be running crazy HP or anything and want the engine to last a long time and be as friendly as possible. I love adding new parts but hate tracking down little bugs all the time.

Another downside is I know NOTHING about tuning efi systems, and am not too keen on dropping $500 or more on efiLive or something similar. I know it would benefit me, but I have already skewed far off of the budget I started with (like always). I'm interested in learning about it, but also don't know if I trust myself to set a tune on a brand new motor that will have never run before... I also know I'll need it custom tuned to get peak performance out of it. I'm not scared of the wiring portion, it's just time consuming. I'm more worried about once it's all put together:eek1:

I would prefer if I could make a stand-alone engine management system utilizing factory style OBD2 stuff and the TPI intake. I will be replacing the rest of the wiring in the truck at the same time, so let me know if there's anything that I should do now to make everything as pleasant as possible. Thanks again guys:waytogo:
 
bronc3buster842001 said:
best bet would be to just call S10Wildside and pick his brain. he should be able to build you a stand alone harness setup to run the '411 PCM.
Click to expand...

I was kinda hoping to do it myself just to save some $$$ if possible, but that's probably the best bet. I'll try and get in touch with him to get his opinion. Thanks
 
I'm going to do the '0411 conversion. This is not my first EFI conversion, but my first OBDII.

Let me cut to chase, solely based on my personal experience, save yourself lots of time / money and but together an OBDI EFI system.

dave w

DSCN3053.JPG
 
dave w said:
Let me cut to chase, solely based on my personal experience, save yourself lots of time / money and but together an OBDI EFI system.

dave w
Click to expand...

I'm not opposed to spending the money if it's worth it. Based on everything I've been reading (and common sense backs this up based on what current auto mfg's are using and have been since 96) is that OBD2 is FAR superior and will get you a much better tune that any OBD1 setup. I understand that even the OBD1 will be far superior to a single 4 barrel, but if I'm going to do it I really only want to do it once (assuming that I would want to upgrade later, which is my style...) My biggest concerns are 1) doing it right and 2)final product driveability. No I don't feel like spending a fortune, but from what I've read the parts can be had relatively cheaply, and everything is already going to be apart. I'm just trying to nail down what will be the best setup *within reason*:haha:

Thanks again guys.
 
EFI Equation

The more you know about EFI = The less you pay for EFI

Cheap EFI parts = Someone not know much about EFI ... Give up on EFI project?

dave w
 
Here are a few screen shots from the Demo Version of EFI Live. I installed the Express Van .tun file. This OBD II is something else!:eek1:

dave w

EFI Live 02 Parameters.jpg

EFI Live 03 Parameters.jpg

EFI Live 04 Parameters.jpg

EFI Live 05 Parameters.jpg

EFI Live 06 Parameters.jpg
 
dave w said:
Here are a few screen shots from the Demo Version of EFI Live. I installed the Express Van .tun file. This OBD II is something else!:eek1:

dave w
Click to expand...

Yeah, that's kind of what I'm picking up... I'd like to keep the cost of the system down a bit more than that (based on all the other areas of the truck I'm dumping money into), but I'm worried if I set up the OBD1 and get a chip burned etc. that I'll just wish I had done the OBD2 anyways. I bought a couple books that were highly rated on tuning. I'm going to be doing some reading before I make any decisions. That ought to help the ole bank account in the mean time:whistle:
 
Z71paramedic said:
but I'm worried if I set up the OBD1 and get a chip burned etc. that I'll just wish I had done the OBD2 anyways
Click to expand...

Well here is a link to some of my older TPI OBDI projects.

http://s239.photobucket.com/albums/ff290/buildabot2002/TPI System/?start=all

http://s239.photobucket.com/albums/ff290/buildabot2002/454 MPFI/?start=all

Anyway, if you get an OBDI engine management system running on your truck, you can recover your expenses (and more) by selling the hear it run OBDI system to help fund the OBDII system in the future. It's my personal experience, there are more potential buyers for a hear it run OBDI system than potential buyers of a pile of OBDI parts sitting in a dust covered cardboard box. Besides all that, a hear it run OBDI system sells for more $$$ than a dust covered cardboard box full of OBDI parts. Learn a few things, work a few hours, make a few bucks ... nothing wrong about that!:D

dave w
 
dave w said:
Learn a few things, work a few hours, make a few bucks ... nothing wrong about that!:D

dave w
Click to expand...

Good call. What should I do about chip burning if I go that route? I don't have a burner or any experience with it, and I've heard mail order tuning leaves a lot to be desired. I just want the f***er to run once I've put all this time and money into it.

Either way, engine is on the back burner for now (relatively speaking) because I need to start with the additional lift/body work. The engine in the truck runs fine, just leaks so it can wait. I figure I can work on stuff I know about and read about stuff I don't for now, and when I get some more $$$ I should have a little better knowledge base to play with. We'll see if that pans out or not:popcorn:
 
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