Having a hard time with my setup. I am running hot and think my timing is way to agressive for a boosted application. If you run a 730 or 749 ecm with code 58 or 59 it would be great to take a look at your timing tables to see how far off mine is.

 

lt1 my buddy adam has the same setup u might wanna PM him he's on this site as AC

 

I'm running the Holley commander & max boost is currently at 160kpa. At 5psi the a/f is set for 11.5-11.6 and at 10psi it's 11.3-11.4. I have the stock alum radiator & single fan setup and before I added a shroud to direct more air through the fan, I was seeing 15°+ higher in traffic. I almost never see temps above 200° even in boost.

 

wow that is pretty cool. You got any idea on how much power the car makes or how fast? I ran a buddies car friday night that ran 128 in the quarter on 8 lbs and mine on 5 lbs pulled him by a car so know this thing is making in excess of 500 rwhp. Just trying to get a idea if we are close in power range. thanks for the tuning help.

 

You are probably making more hp than me, but I honestly don't know. I only do street driving but it's more than enough for that.

 

I run less timing on my holley 950...
-9.4:1 static compression ratio
-Vortec heads (require less timing due to "fast burn" design)
-A little leaner mixture: 12.2-12.6:1 AFR
-tuned all the way to 195kPa, but trannys and rears don't last long up there.

EDIT: the crane powermax cam with 204i 216e@.050 and .427"i.454"e engourages a lot of cylinder pressure down low (to further reduce timing advance). It will roast the tires from a roll in third gear just by pressing the pedal to the floor around 2000rpm... with 3.23 gears. The worst is when it does it in fourth at 100 mph.

 

With the request for timing, NOTE the cams and heads in the setups. That has a big part of the timing as well.

 

Are those numbers in addition to your base timing? What is your base timing set at?

 

That is TOTAL timing including base timing advance of 10 degrees. note my edit above for cam specs. I was frequently getting loud pops out of the exhaust with just 2 more degrees of timing during boost conditions over 150kPa. 93octane.

 

I get those pops too at 10 lbs but not all the time. Is that from too much advance? well it pops and lays over really bad. I was thinking it was my 4 burnt plug wires i just found though with all the burnt and blown out header gaskets. I see this is going to be a trip trying to keep exhaust leaks away

 

I cured my pops by retarding timing and leaning the mixture. less unburned fuel in the exhaust to go boom, i guessed. mine doesn't slow up when it pops though i usually just shift.

 

The pops can also be caused by spark blowout(ignition not strong enough, plug gap too large).
What are you running for ignition?
My car would randomly do it sometimes over 4000rpm, felt like it hit a brick wall and sounded like a machine gun. I closed the gap from .028 to .022 and now it only does it over 5000rpm. I run stock ignition and I need a MSD box to cure this issue.

 

I have a msd blaster 2 coil with a msd billet distributor. I have a digial 6 for it and not on it yet. will be very soon. plugs are atb 30 ish. bet that was it. I remember it doing that on the nos with a 200 shot when the plugs were at 45. Felt the same. ok on 5 lbs with that gap but at 10 fell over flat. worse when hot and probably when coil got more heat soaked.

 

ttypecamaro, i have some afr heads, should i use the timing like yours or like the other guys. im only gonna be running 6-8psi, using the code59

 

you should use mine. Depending on combo might be able rto use my bin

 

whats your bin, where would i find it

 

I am doing this off my blackberry so can't give it now but I can send it to your email. Read my signature and see if your combo is close to mine. I have 42 lbs inj.also.I run code 59 on a 730 ecm.

 

I am doing this off my blackberry so can't give it now but I can send it to your email. Read my signature and see if your combo is close to mine. I have 42 lbs inj.also.I run code 59 on a 730 ecm.

 

If you're running a stockish cam (like mine), then you would do well with less timing like me. In theory, Aluminum heads can handle more timing than iron heads because of the lower, more evenly distributed, combustion chamber temps.