I was about to post something similar to this, only thing different is age....37 here. Over the winter, I was Building my first Th400 and had many questions.... long story short, I had a guy "helping" me via the phone. He made the comment "maybe you should take it to a shop"......havent spoke to him since. Why pay a shops overhead...kids college.... and who knows what else, when you can do it yourself.

 

In this day and age with the technology around, there is little excuse for blowing **** up, especially on a low powered setup.

If you were pushing the ragged edge on something, then sometimes **** just happens but that is not the case here.

As for people over 50 not tuning EFI cars ?

It's almost the opposite in the UK. It's more common for people over 40, 45, 50 to be tuning cars and going fast reliably, and people under that thinking they're tuning cars ( as if it's a game on their laptop ) and blowing them up. The younger they get, the more are blowing stuff up !

Not in every case of course, there are some old guys that despite years of doing it...are still blowing **** up lol I'll never understand them !

 

WOW

Seems that "AFR in the low 10's when in boost" is not the case at all.

I don't think you should replace the O2 sensor. It's probably just fine.

I would however, get everything to a safe starting place. Lowest boost (maybe even pull the WG spring/s out altogether), low timing, and richer than commanded at all points.

Once you've got the VE table close, but still slightly richer than commanded per the O2 sensor at low boost and low timing, find a stretch of road with little traffic and put a fresh spark plug in #7 (you're gonna want to order a bunch of plugs).

No need to break the sound barrier, be safe. Make a WOT pass, maybe 1st, 2nd, and a bump into 3rd. Pull over immediately and turn the engine off. Pull the plug, inspect and take a couple close up pictures of it (helpful if you make each reading pic identifyable as to what pull it was from. Hash marks on your finger nail or a piece of paper that's in the photo. That way you know what's what if you need to review them later.), put a new one in, review data log, add a degree of timing back in, and make a run back up the road to where you started. Pull over and repeat the process, except make fuel adjustments this time.

Check spark plug, review data log, adjust timing, run up the road
Check spark plug, review data log, adjust VE's, run down the road
Check spark plug, review data log, adjust timing, run up the road
Check spark plug, review data log, adjust VE's, run down the road

Don't push it. Keep everything slightly rich and slightly conservative on timing for whatever kPa is the lowest you can muster.

Then put a light spring in the WG and repeat the whole process over again.

Every time you make a change, save the tune as a separate individual tune. And save the log for each tuning adjustment.
That way they're easy to review and reference. Or, if something goes wonky, it's easy to take a step or two back. Maybe even have the file name easily identifiable to the photos of the plugs. 1, 2, 3, or a, b, c... or whatever.

Slow, methodical changes. Starting from safe, staying on the safe side, and finishing with a safe and slightly conservative tune.


A dyno or track data is helpful in identifying gains produced with changes. Optionally, free accelerometer based "dyno" or "track" or "HP" apps for your phone can be used to identify and log gains/losses... if you can keep wheel spin to a minimum. (Might be helpful to short shift 1st & 2nd)

When gains diminish, back off a step (load the previous tune).

 

Under or over 50 ? lol

 

LOL
What's your guess?

 

From the sensible post...gotta be up near there at least lol

 

Im guessing at least my age (52), probably older by 8 or 10 yrs.

 

I'll take that as a compliment. And... you're right.

Old enough to know I don't know everything, yet young enough to not always know when to listen.

Young enough to have an ego that get's in my way at times, yet old enough to acknowledge that I have an ego that get's in my way at times.

Old enough to know, the world as I see it, isn't necessarily "the" way it is.

42... or is it 43? I guess I'm old enough to forget things. Better start writing stuff down. And next year I'll probably need some readers to read what I wrote down. Damn it!

 

Wisdom beyond my years. Nice!

 

I can relate ! and 43 too lol

 

52 here as well, I've yet to blow a motor in the tuning process, But I hunted down friends acquaintances and bought a lot of beer over the years for guys who were willing to share knowledge.

First ever solo car engine build for me was in High school in 1980, I built a RX3 with a friend and worked over his 12A rotary, built a intake manifold for a 1050 Holley, built a set of headers(Zoomies through the hood.. ) We had a blast in that deathtrap..

 

Haha I bet that sounded insane

 

Same age and built first cars in about the same time frame. Mine was a 63 Nova hard top. Had more holes than steel. I cut loose on any scrape pile I could find for sheet metal, and lathered the plastic on a little thicker than the recommended 3/16ths too. Built a .060 327 (337), hand ported the 461 heads, flat tops, good ol Reed cam and a Vic jr, even had a power shot 125hp kit on it (sprayin before sprayin was cool !) I got my hands on a set of home made traction bars to stop the wheel hop, and hade a set of JC Whitney 2 1/4" dual exhaust that turned out in front of the rear wheels. In a moment of genius, I cut the pipes off before the bend and they just happened to line up perfectly with the homemade traction bars. The bars were 2" square stock without any caps on the ends. To this day I have yet to hear another car that sounded so strangly cool. The pipes would echo through the traction bars (they sat about a foot behind the exhaust) . It made a hollow chirpng sound when the cam hit that made people walk across parking lots to ask what that thing had in it ! Never painted it and never found a gas cap for it. She rode in grey primer with a Rebel flag bandanna hanging out of its gas hole. Only car Ive ever owned that had a name, Rebel on the Rag !
Sorry OP, I havent thought about that car in years,

 

Thats what happens when ya wake all us old guys up from our naps..

 

i didnt just put an engine in and expect it to be better. i continued tuning and trying to figure it out myself before asking for help and i didnt say my tune was good. thats why it posted for all to see and get feed back to try to better myself and actually learn. i dont want anyone to do it for me i just want a little help and ive got quite a bit so far that i apreciate. i may be one my 3rd engine but im not scared. if i cook anouther so be it. i still have 2 more before im out. i have a whole bunch of rotted out plow trucks to give there lives for me to learn. it may only have a 4.8 in it now but im fixing things and learning alot and i know ill get it eventually. especially with all the help ive gotten so far. im not looking to become a pro tuner i just like to **** with stuff and see what i can make it do

 

Keep it up.

Just dial it way back and methodically sneak up on the tune from the safe side before starting to add boost. Pull several degrees of timing globally, get all the fueling richer than commanded, and slowly, cell by cell, make adjustments until it's within a few % on the rich side of the target before pouring in a little more timing and boost. And add those in slowly and methodically too.

Start safe, keep it safe, and leave it safe.

I'd highly recommend that you verify the timing and account for any offset, especially so if you're going to be street or strip tuning it.

And... take notes. Every change you make and every resultant change in data... write it down.

Ex: Adjusted VE from X to X at X kPa and X rpm, AFR went from X to X. It was X% rich of target and is now X% rich of target.

 

As everyone has said start low and work your way up noting what your last change was. Something that worked on another car is not guaranteed to work on yours even if it has the same parts. Look at your wideband, look at plugs, listen to the engine, use all tools available to give it what it wants.

Ringland damage is normally 100% tune, I've bent rods and even cranks and not torched a stock piston so they will hold some power. Don't get greedy and the stock bottom can live a long life.

 

I know it's been a bit now but I'm up and running with a 4.8 in the truck and I'm running around 11 in boost at the moment trying to get my timing tuned in. My question is where is a good spot to have the timing mark on the plugs. I guess I never did timing the proper way but I have some fresh plugs and ready to start over and do it right. My question now Is my timing table mass at 1.20 and I'm running up to 1.40 so how do i tune thay high. Does it just use the 1.20?

 

And does the timing mark show timing at peak power? It seems odd to me

 

get it on speed density!!!