LTFT question.

[kwiktsi]

Hey guys, I am getting ready to start tuning my 05 Vette. I did some logging and my LTFT's at idle and cruise are +8 to +11. Is it normal for them to be so high stock, or should I look for a mechanical issue (like fuel pressure) prior to messing with the VE?

The car also has some knock (~4*) at times when I got WOT- this is on stock timing. Does anyone else get knock with a stock setup? Maybe I'm reading total retard or something showing the burst knock retard? I forget which histogram is the default knock histogram- the one that shows just knock retard or the one that shows total retard including burst knock. Been a while .
Joe

[kgb]

Hey guys, I am getting ready to start tuning my 05 Vette. I did some logging and my LTFT's at idle and cruise are +8 to +11. Is it normal for them to be so high stock, or should I look for a mechanical issue (like fuel pressure) prior to messing with the VE?

The car also has some knock (~4*) at times when I got WOT- this is on stock timing. Does anyone else get knock with a stock setup? Maybe I'm reading total retard or something showing the burst knock retard? I forget which histogram is the default knock histogram- the one that shows just knock retard or the one that shows total retard including burst knock. Been a while .
Joe

I'm in the same boat. I have an 05 as well and am involved in the tuning process.

[Sneakyws6]

IF the LTFT tables are that high then tuning the VE tables first then tuning the MAF tables will help with that.

Did you get the wideband option on your HPT?

[5_Liter_Eater]

Tuning the VE table on the '05 vette is a real PITA unless you have Marcin's (redhardsupra's) LS2VE spreadsheet. Do a search for it.

I don't think it is abnormal for the trims to be +8 to +11 even bone stock.

You'll need to pin down whether it's burst KR or regular KR.

[kwiktsi]

Thanks guys. I had done plenty of VE tuning when I had my TT GTO, I just didn't know if it was normal for it to be so far off or if I should be looking for an issue prior to tuning.

As for the knock- I had read somewhere on here that a lot of the C6's showed knock and had to have a couple of degrees pulled from the stock map to prevent it. Ever see this? Also, how do I differentiate between burst KR and regular KR (I forget ). I did all this last year with the GTO (you helped me a bit 5 liter ), but my memory retention is that of a sieve lol.

[5_Liter_Eater]

I have not had any problem with the knock sensors with their stock settings and had been running more timing than stock. You just need to log the proper PIDs. There are different PIDs for burst knock and regular knock. Burst KR may show up as regular KR but not vice versa.

What year was your goat? The LS2 VE ('05 and '06 GTO) is different.

[kwiktsi]

I have not had any problem with the knock sensors with their stock settings and had been running more timing than stock. You just need to log the proper PIDs. There are different PIDs for burst knock and regular knock. Burst KR may show up as regular KR but not vice versa.

What year was your goat? The LS2 VE ('05 and '06 GTO) is different.

Mine was an 05. 795/806 at the wheels. I tuned it using HPT 2bar SD with a 3 bar map, so it took quite a bit of tweaking!

What PID's do I log? Any way I can see your timing maps to see how they look compared to mine? Thanks.
Joe

[5_Liter_Eater]

My old NA timing tune? Only if I can see your Goat's 2 bar SD tune.

[kwiktsi]

My old NA timing tune? Only if I can see your Goat's 2 bar SD tune.

I would be more than happy to give it to you- but I had a hard drive crash and lost all my tunes that were on it . I sold the car about a month ago now, so I can't even go read it for you. Sorry .

[kwiktsi]

Just looked at your tune- lower load/RPM, you are about 6-8 degrees lower than my stock tune, but up top, you had a few more degrees. Was there a reason you pulled so much down low?

[5_Liter_Eater]

Can you be smore specific?