DOUBT IT

iTrader: (13)

I got over to the dyno tonight to see what the car would do on the nitrous.

NA Best was 318/304

Nitrous best was 435/380 on a .051 post MAF shot controlled by the Interface.

The wideband that was being used is one that a guy with a 9 second car uses, but I don't know how much I trust it.

NA runs were 11.4-ish AFR, and one nitrous run dipped to 12.8-ish.

Never heard any detonation, plugs look fine physically, no melted anything ( BR6EF, btw ), and the car still runs perfectly fine.

This is an SI car running 93 octane. The AFR we finally got everything settled on was 12.3:1. Again, car runs strong on the juice, no pinging, no signs on the plugs of anything amiss, not down on power... Is this too lean to run at the track?

Didn't have any datalogging or anything like that, btw...

I'm just confused, 'cause I was shooting for a 11.8 to 12.0 AFR, but when we richened it up, it lost power.

Any insight?

Robert56

iTrader: (2)

You can get away with 12.8, but is close to the ragged edge for a street/strip set-up. My self, I would opt for lower 12's for safety. The rec 11.5 for the LSx is a little bogus, IMO. Check out the projected vs non projected thread for insight on really reading your plugs well. you are learning what is slowing being learned, the LSx can run leaner than most think, and make power doing so, safely.
Robert

venom ws7

iTrader: (13)

Robert So with Boltons/H/C car and 150shot do you think 12.0 AFR is the best?? of course with the right fule and timing??

I love reading your replies I learn something everyday from you
THANKS....

DOUBT IT

iTrader: (13)

Yeah, my friend watching his wideband slapped my arm to get me to cut out and said 12.8, but I didn't.

I have been paying attention to the various threads and kinda figured 12.3 *should* be safe, and I am running non-projected plugs after all.

Chris@NitroDaves

We try and shoot for 11.8AFR on nitrous. Unless i had a completely forged motor ( Which lets one get away with running the car on the lean side due to being forged internals) i wouldn't spray my car on 12.8AFR because you will have a greater tendency to hurt something at that level if something went wrong. I've seen to many stock motored cars let go with 12.4 and higher AFR.

buzz12586

iTrader: (17)

Read your plugs.

/thread

DOUBT IT

iTrader: (13)

It's actually set at 12.3 right now, and it only gets that high at the very top of the rpm band ( 6000+ ), at anything less, it's lower ( numerically ).

Plan to the next time I go to the track.

In fact, I should have my OWN wideband before I go next.

Robert56

iTrader: (2)

If you guys read through the projetced vs non projected you will see why the LSx is in a tuning land all it's own. The VE of these motors are higher than any other motor stock. low 12's on any LSx motor, that depends on a few things if you can do it safely, IE: plugs to match, and timing to match. The standard rec for these motors are for people whom are not going to be checking anything. If your really willing to read your plugs, which will get you your tune correct, then yes a low 12 a/f ratio will be fine. But like Chris said, 11.8 can be safer if your not going to follow thru with a complete nitrous tune. Some of us are now running mid 12's and leaner on the spray, we can do this on the LSx. Much more detail in the thread. Knowledge is your real key to power safely.
Robert