Hey wasap! I'm not about to do the swap or anything, but I had a general question about drivability when running baseline BIN's. When you guys swapped to a new ECM and began tuning, was your car driveable at all with the baseline BIN's? Did you have to spend alot of time tuning before you considered the car safe or reliable to drive? Or would it really vary with the application? I will be doing a 749 ECM swap ( using $58 code) into my 91 Z28 (HSR, injectors, heads, cam, and blower) and I'm curious how long the car will be down while tuning. Would I be dumb to drive it to work (no racing) and back on a untuned setup? Or is it a better idea to keep the driving very short (I guess as to avoid bad things happening) while tuning and trying different chips? Should I just make arrangements to have another car to drive in the meantime while tuning? I'm just trying to get an idea of how long the car will be down before I can consider it driveable (not causing damage to the motor). If you have any experiences, please share

Thanks!!

 

Swap in one heat range hotter of plug, and work out the idle.
Next is low speed drivibility.
Then back to normal plugs.
And complete your tuning from there.

Varies with car, and experience of the tuner.
Some guys have a knack and can get thru it rather quickly, some others struggle.

 

I swapped from 870 to 165 with little initial tuning except injector constant and lowering fan speeds a bit. I drove on it with a scanner and it was safe enough to drive like any stock prom in a stock car, further tweaking from there. The 730 took a bit more to get in the 'safe' area but still wasn't bad, I broke in an engine with a "guessed" 730 bin and close monitoring of a scanner (20 minute 2k-3k rpm break in).


I would guess the 749 would be even further out considering the obvious, either way if you're a competent tuner you can bring it into 'drivable' range in a day easy. Just make sure its got fuel and no knock, when you start venturing into boost just do it maybe 500-1k rpms at a time

 

Hey thanks for the info guys!! Appreciate it!! Before I start getting into it with the 749 swap in my 91Z I will be practicing with a 165 swap (L03 to L98) into my 89RS. Once I feel comfortable making tuning changes then I'll think about doing the 91. I'll probably need to read up on tuning speed density for the 749 swap since I'm figguring it will be alot different than tuning the maf setup on the 89. For the 749 swap I'll be pulling the .BIN off a friends 92 Typhoon in my car club. I'm guessing I'll need to edit it right away with tunercat, setting it for 8 cylinders instead of 6. And I'm also figguring I should get everything as close to the stock 91 settings as possible (as far as fuel/spark) for a baseline. So I guess it'll go like this:

Swap in one heat range hotter of plug and work out the idle.
Check the scantool logs and make changes.
Work out low speed drivibility, 20 minute 1k-2k rpm break in's.
Check the scantool log and make changes
Keep doing 20 minute tests untill it looks good.
Then change back to normal plugs.
20 minute tests with normal plugs 2k-3k break in's (pre boost)
Once its solid, short boost tests 500 rpm at a time.
Check the scantool log and make changes.

I'll have my girlfriend ride along and watch the knock sensor and laptop. Then once its running good with the stock heads/cam/intake I'll think about doing mods and starting the tuning process over again. I'm figguring it will take a long time, but if I do each mod individually (heads, cam, intake, etc) and retune each time before doing the next mod I wont get lost. Dosnt sound like overkill does it?

 

Ooops, I forgot the note taking part.
Lots of notes.
The more notes you have the easier it is to see trends forming.

From like TPS to maintain 65 MPH to how long it cranks to start, are all details to keep track of.

Once you get the main fuel and spark tables done, then you can hunt around and play with the finer settings to get the drivibility the way you want.

You'll enjoy seeing the difference from the 165 to 749.
Doing 2 different ecms will put you way ahead of the field once you get some clarity about tuning each.

Burn a million chips, test, and take notes, it really gets incredible what you can do. Did I mention small changes and notes, LOL.

 

Couldn't be more true.


Keep an 'archive' of scans with a .txt note along with it saying the driving conditions and what you were testing/results etc etc as well as the actual prom changes, that way you can back up easily instead of having to start over or go "way" back.