I am in the process of finally getting my car swapped over to tbi, and i'm trying to keep track of all improvements and changes as I go. As of right now the ecm is running the timing side of things and reading all of the sensors except for the tps iac. I got the timing curves smoothed out to where it's making good power and the part throttle drivability is great. Well as great as it can be with a carter 750. In the process of getting the timing maped out I had to richen the carb up in the part throttle end of things because the thing just plain wanted more fuel once I got the timing jacked up in the light load cruise area's. I'm trying to document everything in steps, kinda want to see exactly where the improvements or restrictions are. My setup is in my sig, I know its not a third gen but it's TBI so I hope it doesn't bother anyone. I'll have some gas milage averages by the end of the week and I hope to make it to the track this weekend. Early g-tech runs show about the same 0-60 times but traction is so iffy on the street I'm not putting too much stock in those. It feels like it pulls better. I ussually average 19 mpg with a 80% highway and 20% city commute. Max of 21 highway, low of 14 city. So we'll see how much just getting the timing right helps. O2 is showing rich just about everywhere. Can't really lean it out much more without getting into surging, gotta love the resolution of a carb, this is the primary reason i'm swapping to tbi, just found out what the limitations of the carb are. I also plan on getting a before and after manifold vacume reading at WOT to see if the 454 TBI is restricting my motor any more than a carb. I also plan on gettting track times with the TBI on as well. It might be a little later in the fall before I get the fuel curves dead on but i'll be sure to post. Let me know if there is anyting else you would like to know, or have me watch as I make the swap.



edit: just read my sig, kinda lacking here is some more info on my car.
84 monte carlo ss suspension mods ( mostly for traction)
3600 pound race weight ( me in it without the speaker box)
.030 over 350 4 bolt
crapy 305 heads with a head spacer shim to cut compresion
195 psi cranking compresion
9.5 static compression
255-50-16 falken ze-502 on iroc rims, see it wants to be a camaro
ohh yeah and thats a ford 9" rear end thats overkill not the gears

 

thats pretty cool. it should be interesting to see how the tbi finally stacks up against the carb. I think youll find that once you fully put things in the hands of the ecm the engine will get real flakey since it looks like you have a decent ammount of duration. You should be able to work through that though. The tbi wont flow as much as the carb but that probably wont be a problem, either as long as you dont stick a crazy engine combo unerneath it. Keep us posted... I want to see how it all comes out.

 

I was a little concerned about the cam my self, being that it had a 110 lobe seperation angle, but after "seeing" my motor through the ecm's eyes it basically idles like a lo3. At 700 rpm it idles dead solid in the 35 cell and doesn't move at all, i think it would have to be a pretty big cam to make it throw a fit but after messing with it I don't think it would take too much tuning to get it to behave with a cam that had 10 or 15 degrees more duration.

 

yeah, 216@.050 isn't very big at all for a hydrolic cam in a 350 with a carb, do you actualy have the TBI unit installed yet?

 

no not yet, just wanted to get the timing worked out while I got the fuel pump installed and got some numbers with just the ignition side tuned, I want to find out exactly were the gas milage and performance is helped or hurt by the TBI system and by how much.

 

Well gas milage numbers will have to wait till tomarrow or friday, the map sensor cam unhooked and really screwed my last tank of gas. This tank is looking promising should know hard numbers by tomarrow. It's really looking like I might make it to the track this weekend too. Any one near pitsburgh raceway park?

 

Keep us updated I amvery interested in this thread. I have a TBI motor I am considering swapping to carb, and getting rid of the Computer. I am just not sure yet tho.

I would love to hear how this turns out, good or bad I want the grimy details!