Friday Night's Runs - After Thoughts
Thread Starter
Safety Car
Joined: Apr 2001
Posts: 3,525
Likes: 2
From: Houston TX
Friday Night's Runs - After Thoughts
I finally got the chance to review the runs yesterday evening. There were quite a few cars at the gathering (probably 200+). I datalogged several runs. The only really full pass was made against a fully built C5 stroker with spray on DRs. The run looks perfect in the datalog.
First... I was noting if you take off the time before the throttle was hammered and then until I hit 5800 in 4th, the time clock (scale on the x axis of each datalog) indicates 9.6. The car was running well, but I've never thought it was as quick on the street vs the track (no really good burn-out or slicks used. Those with FAST knowledge, are the clocks accurate?
Second...I have now pushed the timing up to 28@10 psi (11.7 AFR) and to 24.5 @ 15 psi (11.2 AFR). I had no spark knocks during the hard run. I did have some very slight spark knock when I was just gradually giving gas and between shifts on other logs. Thoughts?
It's great to live in TX where the weather stays decent for driving pretty much year-round.
Thanks for your thoughts.
Aaron
First... I was noting if you take off the time before the throttle was hammered and then until I hit 5800 in 4th, the time clock (scale on the x axis of each datalog) indicates 9.6. The car was running well, but I've never thought it was as quick on the street vs the track (no really good burn-out or slicks used. Those with FAST knowledge, are the clocks accurate?
Second...I have now pushed the timing up to 28@10 psi (11.7 AFR) and to 24.5 @ 15 psi (11.2 AFR). I had no spark knocks during the hard run. I did have some very slight spark knock when I was just gradually giving gas and between shifts on other logs. Thoughts?
It's great to live in TX where the weather stays decent for driving pretty much year-round.
Thanks for your thoughts.
Aaron
Drifting
Joined: Aug 2001
Posts: 1,500
Likes: 0
From: Holliston MA
Cruise-In VII Veteran
The time scale is dead on.Tough one on the spark knock. The area you're talking is where engine movement could be causing "false" knock, but it's also where transitional changes that bring on real knock happens.
You ever get that tip in stuff straightened out ?
Thread Starter
Safety Car
Joined: Apr 2001
Posts: 3,525
Likes: 2
From: Houston TX
Originally Posted by SloRvette
The time scale is dead on.Tough one on the spark knock. The area you're talking is where engine movement could be causing "false" knock, but it's also where transitional changes that bring on real knock happens.
You ever get that tip in stuff straightened out ?
That tip in stuff and the smoke issue has disappeared as I added more timing. I used to run 19° adv at max boost because I was seeing such incredibly high IATs. My IATs even on the hard runs were maxing at 195° the other night. I think the engine just was not having complete combustion due to the late ignition in the combustion cycle. This engine really likes advance!
The car is running very good, and I have been tempted to even add maybe 1 - 2° more advance, but was looking for others thoughts on the adv being used.
Aaron
