fastcars95

iTrader: (9)

I've been raising my rev limiter 500 rpm everytime I take it out. Last night it was at 5500 and I noticed the a/f was getting as high as 13. Will a couple pulls do damage. Its a forged 383 9.5cr with a d1sc at 15#. I've only seen 10 lbs because I've been shifting early.
It cruises at 14 or so off throttle and goes to 10.5 as so as soon as I mat it. But it starts climbing around 4700-5000rpm to around 13 . I did not notice it and I've put on 50 miles like this.
Should I be concerned about damage. I'm not going to drive it until I throw in the second pump and a little meth kit.

98Z28CobraKiller

iTrader: (17)

10.5 is too rich and 13's is too lean. What you need is to tune the car before you blow it up.

fastcars95

iTrader: (9)

Ya I know that but is it possible to detonate and do damage that fast. I have a mail order tune from bryan to get me started. I was just going to break the motor in then go get a dyno tune.
I have a little stumble sometimes at 2000rpm and I was worried I could have hurt the motor already.

98Z28CobraKiller

iTrader: (17)

I wouldn't try it too often in the high 12's AFR with 15# on pump gas.

Old Geezer

iTrader: (3)

"But it starts climbing around 4700-5000rpm to around 13".
When this is happening, where is the fuel pressure going??

Johnv

Sounds like your running out of fuel pump.

Just get it tuned,
late model engines don't really need running in, they just start wearing out from the day they were built lol..........

running to rich or to lean is going to do more damage to a fresh engine than will be gained by a careful run-in imo.

Gabbiani

iTrader: (20)

It is very possible to detonate and trash a motor in 1 revolution. Stay of it until it is tuned.

fastcars95

iTrader: (9)

I have not checked my fuel pressure but I also think I'm running out of pump. I'm going to put in the second pump this week on a pressure switch. I'll have the second pump and a little meth kit come on at 6psi.
We are going to the dyno this weekend so I'll see if my tune is close.