I am sorry if I am being repetiicious but I want to make sure I am not going about this wrong. Ran a 10.5 at 129mph on 20 lbs boost and 22 degrees timing on c16. I would like to turn up the boost to around 24 lbs to knock on the 9 sec door. If I do it in 2 lb increments and watch my a/f ratio where does the danger from knock come into play since I do not have a knock detector or egt. I will datalog each run and review. I really dont care to turn it up and then go woops thats too much and have to rebuild I will leave it at 22 degrees and use c16. Stage II motor Thanks
ready to turn up the boost?
- Thread starter rtviper
- Start date
- Joined
- May 27, 2001
rtviper said:
22* of timing on C16 is low considering you are only running 20PSI
What is your compression? What A/F Ratio are you running?
If you have enough fuel and considering the effecieny range of the turbo you should be able to turn things up a lot!
It is a 76 q trim turbo and I do not know the compression ratio. It was tuned on a dyno to get the new fast tuned and it has a a/f of 11.0 right now. I will try to stay at 11.0 in the a/f with the 22 degrees and turn up the boost. From what I read it sounds safe but I dont want to find out the hard way its not. I guess my question is as long as you have a a/f of 11.0 or close will detonation not be an issue? What method is available to detect knock when using the fast sequential?
ASSuming you have the WB 02, it will correct the AF ratio for you as you increase boost......you can then go back into the VE tables and zero the correction
you can use the stock knock detector with FAST......however, if you are running a "noisy" valve train, not much use.....egt is helpful also
you can use the stock knock detector with FAST......however, if you are running a "noisy" valve train, not much use.....egt is helpful also
- Joined
- May 27, 2001
Woody has some good points.
The timing and boost are very conservative unless you have a 10-1 Motor.
I am not suggesting that you run 30PSI but we have with twin 76Q Trims.
As long as your fuel system is up to it you should be able to turn things up a lot.
The timing and boost are very conservative unless you have a 10-1 Motor.
I am not suggesting that you run 30PSI but we have with twin 76Q Trims.
As long as your fuel system is up to it you should be able to turn things up a lot.
You should be able to run 11.5 A/F and 24 deg timing all day long with no problems, I have run this with over 10.0 :1 compression. To run higher timing and leaner A/F raito you need real good air temp. managment. Nothing over 100 deg at the very end of the run. Hope this helps.
Pull a plug or two after you turn it up each time and look very carefully at the ceramic insulator and the electrodes with a bright light and magnifying glass to see if you see any tiny aluminum specks from detonation. Should be able to see it there before any real damage occurs. Also, of course, any broken insulators or electrodes means you got a lot of detonation 
.
.Thanks guys I ran a 10.4 at 128mph with 17 lbs boost AND 22 degrees timing. Did not get to turn up the boost as my linelok went away and could not do any burnouts. These new M/T ET street Radials really hook as I ran 1.55 60ft with a 4lb launch,19 lbs air in tires. I will see what it does next week on the higher boost
- Joined
- May 27, 2001
rtviper said:
I have heard the tires like a little less presure like 16-18lbs.
Will more boost your car should scream!!!
ijames said:Pull a plug or two after you turn it up each time and look very carefully at the ceramic insulator and the electrodes with a bright light and magnifying glass to see if you see any tiny aluminum specks from detonation. Should be able to see it there before any real damage occurs. Also, of course, any broken insulators or electrodes means you got a lot of detonation
Just out of curiosity, with running C16, can you have lead deposits from the lead in the C16 on the plugs that might be mistaken for aluminum deposits.
I'm going to be in the same position as rtviper pretty quick as I have no knock detector on my newly built stage 2.
The reason I ask is, on my old 109 block, when I was running way too rich, I detected what appeared to be aluminum specks on the plugs, that dis-appeared after I leaned it out. Caused me a lot of concern for a while.
Thanks,
George
I've seen granular deposits from oil and lead but they were usually pretty big grains compared to the couple of times I've seen the aluminum specks, and they weren't aluminum colored. If Dale says you've already hurt things too badly when you see the aluminum I'll take his word for it. We turned things back down some and the motor gave the same times as before, but we never tore it down to see what the pistons looked like and we were in the 500 hp range, not where you want to be. I have seen rich knock with C16 on a stock block motor with stock ecm and knock sensor but we were definitely richer than 10:1; rich enough that there were puffs of black smoke from the tailpipes on launch and shifts. Got over 5 degrees retard at the 2-3 shift that went away when we leaned it back out.
ijames said:
That makes some sense, as the "grains" that I had on my plugs were like small round pellets. They were aluminum coloured though. I was running rich as I had black belches from the exhaust, say my race colleagues.
With what I thought was aluminum deposits on the plugs, I was very leary about leaning it out. The other clue was my EGT was way over 1650. I suspected I had fuel burning in the headers.
Nervously, I leaned the engine out and what a difference. The car ran strong and the EGT's went down to 1450. Car ran strong right up to the time I took out the engine for my Stage 2 project. We continue to learn daily
George
