ryanisfast

So I had been driving with all my mods in sig and no tune...Most things seemed ok, but obviously it would stumble up top because there wasn't enough fuel, and I was still running on stock rev limit and all that.

Update...Drove the car today for the first time with my new tune and Pulled all the way to rev limit set at 6600. I then did multiple runs on a long stright road shifting at about 6400-6500 and nothing broke. Obviously it's hard to say how the long term reliability is, but I can attest that they can in fact handle the lift of a mid 0.544, and it seemed to pull all the way without any stumbling that's normally associated with valve float. Hard to say though. I plan on hitting up a dyno to see the hp and tq curves as well as get a A/F readout.

Outside of heavy foot driving the car seemed toned down and not so choppy, However, I think my tune was a little messed up with DFCO because before the tune the car had engine braking at low rpms, but now engine braking doesn't kick in until about 3300 or so. And if I push in the clutch while rolling the rpms don't drop down as fast as they should. Unless I have a vacuum leak, but most likely I don't because I didn't touch anything but the pcm before I sent it out. And it was fine before...

Maybe I miss understood DFCO, but the way the tuner explained it was that that heavy DFCO would mean heavy engine braking off throttle.

SPEED#1

iTrader: (14)

What is DFCO? How are those proforms hanging out?

ryanisfast

I was told DFCO was the settings for engine braking. My tuner said that he programmed the pcm to engage DFCO at any rpm over 1600 and disable under 1400, but the thing is when I come to a stop when slowing down my rpms will hover around 2k rpm before it slowly drops back to idle. I do have 0154 bank 2 snsor 1 code for no activity in passenger side o2, but the car was fine before the tune and i didn't change anything since then.

As far as the proforms go. They are good, but not forgiving if you set the valve lash incorrectly. They are aluminum and if they are set too loose or get loose they will break easily if they smack against something. I have broken 2 because of 1 time I didn't tighten the locking allen screws tight enough and the other time I just completely f'ed up my valve lash by doing it "my own way" , My own way was totally the wrong way. Lol. Also, proform was really cool and sent me a free roller rocker, no questions asked when I was about to order 1 and pay they said "don't worry we got this one."

I've taken the rpms well past 6k rpm now for a few days. I just need to take care of the o2 sensor and see if that doesn't fix it.

If it doesn't rain this weekend, I'm going to run it down the dragstrip @ Pacific Raceways for the first time since the cam and tune. Last time was stock with 13.9. hopefully break 12's this time!

kolorzcars

dfco is deceleration fuel cut off...........i beleve

chavez885

iTrader: (12)

SO you're out romping on your car and you haven't even put it on a dyno? Nice.

ryanisfast

You're right, I should put the car on a dyno to check the A/F ratio. I've heard that usually the mail order tunes are on the rich side anyways, so I should be safe, but the dyno is on my list of things to do. just so you know though...plenty of people over the years, incuding racers, have never dynoed their cars and it worked, maybe not as effective, but more fun anyways.

New update: Fixed bad wiring on one of my front o2 sensors, I can finally drive the car in closed loop, and it seems to run pretty well. Really couldn't tell too much of difference, but I guess that means my tuner did a pretty good job with the tune. The DFCO still kicks in, just not very much at low rpm below 2k rpm. At higher rpm it kicks in just fine.

Will be recording fuel mileage on my next tank after I go to the drag strip this weekend. Let you know how everything goes and then I'll namedrop who my mail order tuner was, but I don't want to say anything too soon until I make sure I get all the bugs fixed.

boosted99camaro

iTrader: (3)

glad to see you got it all worked out.good luck and have fun!

Wicked94Z

iTrader: (26)

sounds more like an IAC follower issue on the hanging revs and lack of engine braking.

ryanisfast

Yeah, does seem like that. Seems though, that since I fixed the issue with the o2 wiring it isn't as bad. Going to the track tomorrow, so I'll post a new thread with my times. Crossing my fingers for 12.9 or better!

ryanisfast

Update on the setup:

Just went to track yesterday and out of three runs I got 13.9@101. then a 13.0@110 and a 13.1@109. My first run was horrible.. I missed third gear and spun all of first. Second run was ok, but only had a 2.2 60ft, when I was stock I was able to hook a 2.0, but temps we're very cool yesterday and my tires suck!! Last run was like the second one.

All in all, I'm happy. I know the setup is putting down a lot more power than stock. I also had a slight mis due to a crack in one of my spark plug wires. Probably held me back a couple of mph. I also was unsure how accurate my tach was and where to be shifting at.

But, I was able to manage to beat an c5 vette and a 2010 camaro SS!!!! That was really my whole goal in the first place! It was funny because the vette club was there and my car was getting better times than a lot of them because they couldn't launch at all...worse than me! And they had a lot of money and dyno tuning into their cars.

Btw, Solomon @ LT1pcmtuning.com is the mail order tuner I used. The tune isn't perfect, but it worked well enough to get me down the track safely, and faster than stock, so I'm happy!

I might go back today and try for 12.9 or 12.8. I know the car has it in it.