D16A6
Vitara 8.5:1
Eagle rods
Edelbrock mani
Ebay .63/50 turbo; 450HP
Cast Iron turbo mani, 2.5" long runners and good wastegate location
decent Intercooler
880's
Omni Map
ARP/ACL/gapped/torqued/built right.
Hondata S300


AFR's at 12.2 up until about 12 PSI... fattened it up to 11.8 till about 17-18 PSI. at 20-21PSI 11.4 rock solid through the powerband

tried to run 20 degrees of timing@20PSI and got a tiny, tiny bit of knock at about 5800-6200RPM (right after turbo spooling peak) so I backed off peak timing to 19deg@20.2PSI and let it drop to 17deg@redline. obviously I used a progressive declining curve for the timing; peak timing at peak torque. Timing curve was altered to cam/manifold setup

lets just say that

**** pulls hard as ****, no matter what the boost level is; for that amount of boost.

It has a very, very nasty camshaft. 268+deg duration

I heard the knock in the det cans at 21waaaaaaa19deg of timing. at 19waaaaaaa17 deg it was non-existent. think this sis a safe tun, or do I need to decrease boost???

 

Read your plugs & listen with your det-cans & you should be good to go.

 

While you may not be hitting the knock limit of the motor exactly...you may be getting close to what pump gas can handle.

I had a Z6 with a cam and Vitaras at 20 psi with some suspect looking plugs on 93 pump making roughly 300 whp...we added 5 gallons of Sunoco leaded 112 to the tank and did a pull and gained roughly 10 whp without any adjustments to the maps. This signifies that the pump gas was definitely at its limit at this power level...on this setup.

The thing about pump gas and tuning on the limit is that anything can change from day to day...including the ACTUAL octane of the gas at the pump, depending on the brand, mix etc...so tread carefully

 

What ecu and distributor you runnin?

 

Let me start off by saying you have bigger ***** then I do.... I now have a strict rule of 15psi for a non sleeved motor on pump gas (even if it has pistons and rods). The problem is no matter how good the tune is the customer (driver) can still put the wrong gas in it or decide to advance the distributor all the way or lower the fuel pressure when he gets home (or do whatever else they think will make it faster) and then you will have problems with no way to defend yourself.

Was all of this tuning done on a dyno or on the street? From my experience you can always squeeze a little bit more timing in on the dyno without the motor pinging but as soon as you get it on the street under a real load (like 4th gear) you need to pull a few degrees of timing or else it will ping. You can try to use the timing per gear compensation tables but I find the changes to the actual base tables are the most effective.

The other thing I tell people to keep in mind is that pump gas never seems to work the same from one pump to the next or one gas station to the next. I always suggest tuning for maximum power on pump gas on the dyno. Then pull 2-3 degrees of timing and add 2 gallons of 109 unleaded to every full tank of gas just to be safe. I don't know how many people actually listen to me but I say it just to be safe and thats what I do with my personal car. An extra $15-$20 per tank isn't that much money and its a good insurance policy.

 

[QUOTE=all_motorsi;38897589]





tried to run 20 degrees of timing@20PSI and got a tiny, tiny bit of knock at about 5800-6200RPM (right after turbo spooling peak) so I backed off peak timing to 19deg@20.2PSI and let it drop to 17deg@redline. obviously I used a progressive declining curve for the timing; peak timing at peak torque. Timing curve was altered to cam/manifold setup

QUOTE]

i thought you want to pull some timing at peak torque(Peak Fuel consumption) and increase timing as the RPMs increase?

 

Time to take the gas can to hales to get a $13.00 a gallon insurance plan

 

How do you know you were knocking? If you can hear your detonation on the street (assuming) at 20psi, that is bad. You can NOT street tune high boost pump gas cars, there is too much you decide and measure on a dyno to do this properly on the street.

If you can do this on the street, why stop at 20 psi, just pull your timing and go for 40 psi. If you cant hear detonation, its good right?

Why is it obvious to use a "progressive declining curve for the timing"? What is that doing to cylinder pressure?

 

I used det-cans made from copper pipe, pvc tubing and rifle-range earmuffs. They work awesome, you can hear the minute little ticks and scratches that a knock sensor would be oblivious of, the motor was NOT audibly knocking outside of what I heard as PRE-DET in the cans.


because there is a "base ignition timing added all the time on top of the timing tables" that supposedly adds ignition timing as RPM increases, so i pull a hair out of the tables as rpm increases after peak table timing to basically make it _______________________