walhan_qtr

I finally got my 10s slip N/A. went to Pueblo Motorsport Park last week. 4900ft elevation. managed to do 2 real runs. first was 11.0@128 with a 1.73 60ft and 2nd run was the 10.9@127 with a 1.76 60ft where both my belts came off mid/end of the run. it sucked. 12hours for a total of 2 runs took me a while to fix it there because it was Hot. so had to let it cool down. made it back to a friend's place at 5am


the car still need to be tuned right. it was knocking through all gears. wasnt too bad. I was at 17-18 deg through the whole run.

car only made 495whp N/A. uncorrected. elevation sucks.

I think the car has a 10.7 in it or even faster with a 1.6 60ft.

this run was in a ~7600+DA which is the only reason why it went 10s especially with it being knocking all the way. my shifting wasnt that great too which you will see in the vid....




I am thinking about spraying it this weekend... or maybe try and get a 10.7 N/A I will think about it.

obzidian

495rwhp out of a 441ci Head/Cam car? Do you have a N/A only tune? If it's knocking with that less then 20*'s than you might want to have that tune looked at.

Good luck.

Mopar Jimmy

CONGRATS, anytime one gets a 10 second time slip its a heck of an acoomplishment on a street car!

walhan_qtr

Yes in a 5500 elevation. SAE it made 615whp. I don't think its real knock. Probably just because of the sleeves and my internals. I think its just picking up noise from the engine. We need to adjust the knock sensitivity I think. I will get the tune checked hopefully tomorrow. And yes this is N/A. I have a timing box to pull timing when on the spray.

obzidian

I would look into other area's before touching the knock sensors.. it could easily be something else.

tail_lights

Congrats again on your 10!

walhan_qtr

What should I look for you think? Car is at 11.8-11.9 and only 21deg of timing on E85. I am thinking the knock sensitivity is setup for a stock engine. With darton sleeves, forged internals, and short travel link bars and everything else I am thinking the noise is a lot different than stock. I don't really know if this makes any sense.

LS9Drew

Need to post Speedo vids on spray in SR&K

HeadTurner

Good work with that elevation

heavyhitter

Are you logging the afr via a in car wideband? Its easier to look at lambda when tuning E85. Also that somes a tad lean for E85. Next time at the track if you have editing software multiply your PE table by 1.05 and see if the knock goes away and look at your MPH. I have had success running between 0.79 and 0.82 lambda. Make sure you rename your file so you ca easily revert back to your other tune.

Sébast19X

11.8-11.9 are refference to AFR ?
You are way too lean for E85
If I remember, the stoich for E85 are 9.76
So a PE of 1.20 bring you to 8.1 AFR or so

Best way is to only change the stoich point in the tune (14.62857 for 9.76) and the tune fall right in place for E85 setup
Start from there, don't touch to knock sensor for now. I have tune some fully built engine and the sensitivity was left stock . I think that the probleme was a real knock because you are way too lean !!!

Hope this help.

Seb

walhan_qtr

Thanks guys. yes 11.8-11.9 AFR. this is using the dyno wideband which is setup for pump gas. I was told that I can go up to 12.6-12.7 without a problem at sea-level (pump gas readings) and 20-21deg of timing. usually at this elevation we can add 2-3deg of timing to what sea-level guys do. not on my car though. we have it tuned at 20-21deg and richer than what Carlos@vette-air and other tuners close to sea-level.

is that still lean for E85?? I dont think so?

heavyhitter

No that is really lean for E85 my blown cobra runs at.67 lambda. another factor it's what blend the E85 is I always tune on the rich side to account for variances in alcohol content. I would suggest throwing some more fuel in it and see what happens I think your gonna be surprised. do not mess south the knock sensitivity.

HOXXOH

Congrats on the first 10.

walhan_qtr

what about N/A?? what would you shoot for usually??

EDIT: just did a little search and found this. N/A on E85 you would want it between .80-.82 lambda, or 11.0-12.0 gas AFR. and it says you can go up to 12.7 but that would be the max. which is exactly what Carlos@vette-air told me. 12.6-12.7 max (again Gas). if you dont know, Carlos does a LOT of those high compression E85 setups. so I would think he knows??

I am not saying you are wrong or he is. just give me your opinion of what you think. Only reason I am mentioning Carlos is I have his heads/Cam setup and he does those all the time.

my old setup (heads, cam, intake, stock ls7 short block, 13.3 to 1 compression) was tuned around 21deg of timing and 12.0 AFR with Zero knock. so I dont see why it will knock with this new setup. only thing I can think of is the new rotating assembly, lifters, and the sleeves that causing more noise that the knock sensor picks up??

walhan_qtr

Soon I have been busy lately but I will try to get one here probably this weekend.


Thanks guys....

SIC_C6

thats way rich

heavyhitter

12.7 is really lean for an ls7 using gas afr. 11.8 is good but I would try throwing a tad more fuel in it and see what happens

walhan_qtr

hmmmm ok I will talk to Carlos and see what he thinks. thanks

Sébast19X

You want to know that stoich point for E85 are 9.76 or so
Not 14.67.

So, 14.67*0.80 lambda or 1.25 PE equal to 11.7 AFR with 93 octanes gas . Understood ?

IF you run E85 you have to change the stoich setting to 9.76.
That bring us to: 9.76*0.80 lambda or the same 1.25 PE equal to 7.80 AFR with the E85.

Nothing less nothing more !!! Right ?

0.80 lambda for 93 = 11.7 AFR
0.80 lambda for E85 = 7.8 AFR
If you run E85 gas with 14.67 in the computer setting for the stoich value, you are way OFF. And that is why you experience knock.

I hope you understand !

Seb