jayz28

iTrader: (3)

I've been tracking down reasons why my beefed up LT1 doesn't run like similar setups across the internet and realized in a datalog all timing is pulled at WOT do to knock retard.

Can this hurt performance? How can I desensitize the knock sensor.

The engine is a fresh 383 with Roller rockers, custom cam, TFS heads, true duals, with an A4 Edge stall.

And it has a mail order tune from PCMFORLESS

redbird93

Did you replace your knock sensors. Whats your compression ratio and what octane you running? you may just need higher octane. WE get shitty fuel here in KY

shbox

ALL timing? That would be pretty drastic. It would absolutely kill performance. You need to find out if the knock is real or not Try some higher octane fuel and see if it changes. Sensitivity adjustments to knock can be done in the tune.

jayz28

iTrader: (3)

11.5-12 to 1 and I run 93 all the time.

And probably no all timing lol. It goes from 38 down to 31 I think.

It's a new sensor.

mark97ta

iTrader: (1)

I don't know much about tuning but ... that is alot of timing for that compression ratio and that octane

jayz28

iTrader: (3)

I checked tge timing to get a correct number. I'm not sure which table to check but I'm thinking 36 degrees is tge actual timing at WOT and it retards to 31.

Icematrix69

Not sure which logging program you're using but you need to look at the knock retard and see what it's pulling that way.

jayz28

iTrader: (3)

Using datamaster.

Says spark is 31 and knock retard is 5.

speed_demon24

iTrader: (6)

I was randomly pulling 12 degrees of timing on my pcmforless tune. Got a dyno tune and no more knock retard.

jayz28

iTrader: (3)

Could you tell a huge difference in performance? I was wondering if this could be the reason my car didn't run like I expected.

I'm chasing down other problems so I can't get a dyno tune anytime soon. But I have been emailing Solomon at LT1PCMTuning.com. I think I'm gonna get him to modify my tune a little until I get it dyno'd.

1bdbrd

iTrader: (12)

This is why you shouldn't waste your money on a mail order tune. I have never understood the point.

RamAir95TA

iTrader: (2)

Try driving a heads/cam 383 with 42lb. injectors on a stock tune 2 hours to a dyno-tune.

Not to mention not everyone NEEDS a dyno-tune. A mild street cam-only user might not need every ounce of power. Many people aren't willing to pay $400 for a dyno-tune for an extra 10 HP.

speed_demon24

iTrader: (6)

That was on my old gm846 setup. I gained 30rwtq at 3k rpm's and huge gains all over, so yeah I noticed a difference. Not to mention the tune had way to much timing in it to be even remotely close to safe.

jayz28

iTrader: (3)

I agree. But sometimes its all you can get.

I'm just not ready for a dyno tune. Seems like I'm having tons of problems everywhere else. The car is a weekend hot rod and I don't have alot of time to work on it. Mail order is the way I had to go to get it driveable last year.

Now I have oil leaks and a belt alignment problem to work on, not to mention my rearend is spinning one freaking tire. Gotta get another posi unit now.

I don't think the dyno tuner will appreciate me pulling up with a rolling pile of junk to start with.

jayz28

iTrader: (3)

That's what I figured. Dyno Tunes are always better. I just haven't been able to get it done. The dyno tuner in the area is about an hour and a half away. I'll have to haul it down. But its just 250 to get it done.

After I fix a few issues I'm having with the car, I'm making an appointment at the local dyno shop. Hopefully next month during vacation I will make it happen.