jlay

iTrader: (2)

Guys, I been having my 72 chevelle 5.3 swap running for a couple of weeks now and been taking it further and further from the house checking for problems. Question is should I get it tuned? The motor is basically stock other than the Z06 cam and long tube headers. It runs good but since it will be my daily driver I want to be sure everything looks good (a/f ratio, etc).

What does everyone think?

bczee

iTrader: (12)

You most likely would be ok.. but beleive me that a good tuner will do wonder with what you got and what you thought was good power and driveablity.

I had a mail order tune when I did the swap. .I though it ran good, but after years. I got a dyno tune.. he found 30 extra HP and up the MPG. Driving it was much better too.

But, if it seem good, you can wait until your can afford it. You might want to do more bolt on and other mod in the mean time.

BC

Sarg

iTrader: (6)

If the airbox and everything is all from a stock truck it will probably be just fine. If you had to change the maf tubing (most do) it can be way off. I just tuned one for a friend that had a ls1 in a 81 z28 and his tune was as much as 18% off on the maf tables and was going kinda lean up top. I would at least scan it and see what your long term fuel trims are looking like. If they are +-5% all through the maf htz then you are probably fine. Much more than that and I would get a tune.

roninsonic

iTrader: (3)

I'd say throw a few bolt-ons at it, THEN do a tune.

superbean

Always tune.. I did a stock 5.3 swap in my 81 Malibu. All it had was a 4 in cold air and long tubes. Made 252 whp.. with a cam unturned made 300whp and with a tune made 321 whp. Mine tune is also only running 25deg of total timing as I will be spraying it soon. A good tuner could probably find 20whp-30whp just in fuel trim adjustments and more timing. But more importantly is not the peak hp, but bottom end torque and drivability. It woke this thing up!

superbean

Here is what I mean.. under 3000 rpm that's an improvement of almost 50 lb ft tq and 15 hp..

jlay

iTrader: (2)

Thanks for the replies, it is not the same induction tube. The main thing I am worried about is it leaning out and burning up a piston. Going to be a daily driver so no bolt-ons, but that is what the 67 camaro and LS2 is for! Thanks again guys!

bczee

iTrader: (12)

I am currently running a stock LS1 with only a LS6 intake and header that was tuned. put down 330wrhp.. This winter I replaced the cam with with an LS6 (+03) cam and springs. I monitored the AFR and Fuel trim as I drove around, it drove fine and the PCM seem to make up an differents it needed. Going from Stock to a LS6 is not that great of a bump and it should be ok.

I do plan to get it retuned somewhere down the road.. but it seem find driving around and at the last Good Guys Autocross.

I would not worry until you got a few more bolt on's or upgradeds. For now.. get a monitor and watch it or capture it and review it later..

I have an Android tablet that I loaded Torque App on it and use an Bluetooth ODBII Wireless and use it as a scanner. you might look into something like this.

BC

Bowtie316

iTrader: (1)

Fuel is only part of the battle. I just swapped out the 4.8 in my s10 with a 5.3 with a small 206/212 cam. Flashed in a stock 5.3 file. Fuel trims were -10 to +15 depending on the RPM and MAP but it learned them quickly. The first test drive was disappointing. Felt almost identical to the 4.8. I checked the log for timing and found that I was only getting 18 degrees of timing at WOT. Looking at the timing map, it is obvious what happens. As you introduce more air into the motor, the pcm uses cells that are farther down in the map and have lower timing values.

It was perfectly safe on the tune it had, but was leaving alot on the table.

BLK02WS6

iTrader: (2)

You need a tune. There are far too many changes there to be running on a stock tune. The trims will take care of fuel for part throttle driving, but WOT will be off - both fuel and timing need to be optimized...

jlay

iTrader: (2)

Will probably be going to futral motor sports in the next couple of weeks for a tune. The car has been running better but hesitates and sometimes backfires at wot. I also have flex fuel injectors but don't know if it is set up for that.

jlay

iTrader: (2)

Got the Chevelle tuned yesterday by geoff at engine power systems EPS and damn what a difference! Awesome throttle response, smoother operation, and more power. I have to say, Geoff took his time with it and explained everything to me while he was doing it. Definitely would recommend him to anyone!

bczee

iTrader: (12)

"told you so !"....


Lol.....