4.1 l h/a

M

MikeStarner

Broke Guy
Joined
Sep 11, 2010
Anybody actually running a 4.1 H/A and doing great things or if anyone else is having the tuning issues like myself I'd love to know.
 
I actually have a correctly tuned car thanks to the help of an expert. I learned alot and will share any and all information. Why don't you post up some logs? Tuning is a slow process which took off and on three months to find and resolve all issues. Some of my problems were false knock, bad chip, boost control, bad MAP signal, real knock, vacuum leaks, etc. The only way to tune your car is to use your powerlogger as you already know. Brad
 
Before I post logs I want to let you guys know I pulled the heads off due to popped gaskets and I found a lot of carbon on the pistons for only having 3000 miles. I also want to install the map sensor before it goes back together and before I post logs. One last question is what did you use for boost control brad? I'm going to be running 91 octane and alky when it goes back together. Sadly I'm deep into this project with money and am 2 sec from throwing the towel in and going I/C just to get rid of knock, but I won't let it beat me lol.
 
And to help brad, the only things you have I don't are the ls1 maf and I haven't connected my oil cooler yet, will the oil cooler lower engine temps enough to help with knock?
 
I can help you here without throwing any more money at it. Boost Control- The wastegate solinoid was disconnted at the y by the turbo. Cap off vacuum line to the solinoid. The original dual hose actuator was connected directly up to the turbo and boost reduced to 10. As the tuning progress went forward the boost would flutter. The boost gauge and MAP sensor cannot be connected to the front of the intake manifold but rather in the rear as designed. Replaced the dual hose wastegate actuator with a newer single hose actuator. Better. When boost got to 20lbs it would fall off. The solution was to remove the turbo and have the waste gate hole enlarged to inch and a quarter-just smaller than the puck. I run 20 lbs boost, alky, zero knock, no wastegate solinoid. This is the max boost I am ever going without race gas or E85.

The oil cooler will not help your problem. It is in the tune. Carbon means running rich. You really need to turn the boost down to 10 lbs and start your tune completely over. I also found out that a TT5.6 or 5.7 is a hell of alot easier to tune than a 6.0 or SD. Fewer variables the better. Also, only use the wideband for reading the A/F ratio. One less thing to fail and damage your engine. Brad
 
MikeStarner said:
Before I post logs I want to let you guys know I pulled the heads off due to popped gaskets and I found a lot of carbon on the pistons for only having 3000 miles. I also want to install the map sensor before it goes back together and before I post logs. One last question is what did you use for boost control brad? I'm going to be running 91 octane and alky when it goes back together. Sadly I'm deep into this project with money and am 2 sec from throwing the towel in and going I/C just to get rid of knock, but I won't let it beat me lol.
Click to expand...

I know you already motioned this, but please refresh my memory on each of the questions;

Are you sure it is real KR?
At what boost do you see KR?
Have you verified timing yet?
Fuel pressure keeping up?
Injectors verified to be clean?
What CR?
Alky pump working ok?
Good battery voltage?
Good plug wires/ignition system?
Engine using oil? (PCV hooked up?)
Rich KR? (Pre-ignition)
 
I am tuned in on this,because I am having the same rich condition.My car knocks after 14lbs but moves good.
 
MikeStarner said:
Before I post logs I want to let you guys know I pulled the heads off due to popped gaskets and I found a lot of carbon on the pistons for only having 3000 miles. I also want to install the map sensor before it goes back together and before I post logs. One last question is what did you use for boost control brad? I'm going to be running 91 octane and alky when it goes back together. Sadly I'm deep into this project with money and am 2 sec from throwing the towel in and going I/C just to get rid of knock, but I won't let it beat me lol.
Click to expand...

I know you didn't just type that out loud........:eek::eek:
You just need to get it back together and let the Turbo Farm West get it's grubby little hands on it....;)
 
ok, its real knock, i can hear it. happens at 16 lb
timing is accurate with light, but seems way high to me, already talked to jerryl once, its not pulling timing under boost
fuel pressure is doing great, static of 43 and rises with boost correctly
injectors seem fine, they did great on my 3.8 before the 4.1 and got them cleaned when replaced engine
no clue on comp ratio, 4.1 .030 over stroker with diamond pistons
alky not connected yet
good batt voltage
new super conductor wires, new coils, new module
not burning oil, only have breathers but no residue around them since rings seated at about 1500 miles
knock retard only under boost and when i up the blms it goes away but nose dives and loads up
 
MikeStarner said:
ok, its real knock, i can hear it. happens at 16 lb
timing is accurate with light, but seems way high to me, already talked to jerryl once, its not pulling timing under boost
fuel pressure is doing great, static of 43 and rises with boost correctly
injectors seem fine, they did great on my 3.8 before the 4.1 and got them cleaned when replaced engine
no clue on comp ratio, 4.1 .030 over stroker with diamond pistons
alky not connected yet
good batt voltage
new super conductor wires, new coils, new module
not burning oil, only have breathers but no residue around them since rings seated at about 1500 miles
knock retard only under boost and when i up the blms it goes away but nose dives and loads up
Click to expand...

Mike,
16 PSI on a 4.1 w/o alky is not bad at all . . . . what octane was that again?
What timing and did you pull timing on top to see if the KR goes away?
 
i know i sound like a moron, but if you want a 450 hp NA dependable 350 chevy im your guy, these thing confuse the H**L outta me. this much power from a six? no wonder its a pain to dial in
 
MikeStarner said:
i know i sound like a moron, but if you want a 450 hp NA dependable 350 chevy im your guy, these thing confuse the H**L outta me. this much power from a six? no wonder its a pain to dial in
Click to expand...
Mike,
You are a pretty sharp guy and it really is easier than you think.
On a NA engine, you typically advance timing with rpm.
On a boosted engine, you retard timing with rpm/load/boost.

Remember this;
When looking at the PL file, you will NOT see the net effect of the timing.
If you run 30 deg timing, and see 4 deg KR (example), the log will still show timing at 30.
You just know the net timing is 26.

On these HA cars, I would start at about 20-22 timing with 100 octane.
Once the fueling is right for your boost target and there is no KR, you can play with timing.
What version TT chip?
Post the log . . . :tongue:

Edit:
I bet your MAT is around 280F ~ 300WHP
With alky, it would drop the meth to 170F ~ 350WHP, all else being equal
 
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