? = timing being pulled - SRT Forums

a7594217 · 04-27-2006, 12:44 AM

What makes the car pull timing an how much is normal. I have a 50trim. Just because you are getting timing pulled doesnt mean your running lean right? So i guess my big ? is if your not running lean then why is timing being pulled. My stock/modified setup never went leaner ther 11.5 and i was still getting 6 degrees pulled. My 50trim isnt even boosting 8(on purpose) and im pulling 3 degrees. Im using my techgauge. Vector, aaron, nivo, anybody drop some knowledge

reed32 · 04-27-2006, 12:51 AM

timming might be pulled because of the stock injectors. also do you have the pcm clamped with your detec? that could be the problem.

a7594217 · 04-27-2006, 01:34 AM

yeah possibly the injectors but its weird because my af's were never lean so i didnt need bigger injectors. And my dtec is just dead weight right now since i dont have my 750's yet. Dont get me started on that, there "in the mail"

fade · 04-27-2006, 09:45 AM

I'm having the same prob on stock turbo. Can't seem to get my KR any lower than 2.5 or so. That's even with W/I.

TJ1376 · 04-27-2006, 10:04 AM

Have you guys checked to make sure the knock sensor is properly tq'd to the engine?

I would imagine those solid motor mounts you all install help contribute to the sensor believing a bump in the road is a sign of detonation.

Other than that, Ive got nothing.

TJ

fade · 04-27-2006, 10:19 AM

I'll check that this evening.

wannasupra · 04-27-2006, 10:21 AM

and where is the knock sensor? looking at my dyno, i'd say my timing is being pulled like mad.

fade · 04-27-2006, 11:12 AM

By the dip stick I believe

acancelledczech · 04-27-2006, 11:12 AM

the knock sensor should be on the front of the motor, just underneth the intake manifold, i think it's right behind the dipstick, but don't hold me to that.

Timing gets pulled if you experience knock. Knock is experienced if the fuel burns without the use of spark (uncontrolled ignition). This "pre-ignition" is caused by something that has caused the fuel-air mixture to be heated past it's autoignition point. Several things can cause knock:
-Carbon build-up on spark plugs will be heated by the spark and if they don't lose the heat, pre ignition can be the result on the next compression stroke.
-Exhaust valves can get quite hot, and if they are over heated and not properly cooled, they too can cause pre-ignition.
-Carbon deposits on cylinder walls will stay hot and can cause pre-ignition.
-Low grade octane fuel because of the compression ratio, will lead to knock.

If you want to reduce knock, you need more octane and better cooling, ie big intercooler or water injection. W/I using water and methi is best to reduce knock as it has cooling properties and will increase the octane levels.

a7594217 · 04-27-2006, 11:41 AM

Quote: Originally Posted by acancelledczech

the knock sensor should be on the front of the motor, just underneth the intake manifold, i think it's right behind the dipstick, but don't hold me to that.

Timing gets pulled if you experience knock. Knock is experienced if the fuel burns without the use of spark (uncontrolled ignition). This "pre-ignition" is caused by something that has caused the fuel-air mixture to be heated past it's autoignition point. Several things can cause knock:
-Carbon build-up on spark plugs will be heated by the spark and if they don't lose the heat, pre ignition can be the result on the next compression stroke.
-Exhaust valves can get quite hot, and if they are over heated and not properly cooled, they too can cause pre-ignition.
-Carbon deposits on cylinder walls will stay hot and can cause pre-ignition.
-Low grade octane fuel because of the compression ratio, will lead to knock.

If you want to reduce knock, you need more octane and better cooling, ie big intercooler or water injection. W/I using water and methi is best to reduce knock as it has cooling properties and will increase the octane levels.

x2......I only have like 5000 miles there aint no way i have carbon build up that takes a few miles know what i mean. Im wondering if its time to switch to a cooler plug.

aaronneon@RealTune · 04-27-2006, 12:01 PM

Oh man I dont have time to discuss this all today. Real simple, 5-6KR is nothing to worry about on pump gas. Granted the ideal thing is to have zero. Thats a pretty hard thing to do with this car.

I dont care what anyone says, but the stiff mounts and external dumps will set off the KS. Its not a bad thing. Remember the KS will advance timing untill it ''sees'' knock and it will back it down a bit. The timing is so high in these cars when we start using piggybacks and big injectors that I welcome some KR. Now you need to determine if its a problematic KR or a saftey KR. Thats where the tuning comes into play.

I am actually working on a device that will set the KS off and it will have a small window of adjustability to it. That will allow us to run a bit more boost and lower timing with the piggybacks.

Sorry guys I know that doesnt help much. I have alot of running around today. Im sure someone will chime in and help out. Ill check back tomorow.

fade · 04-27-2006, 12:03 PM

Ok..not worried about my 2.5 KR now.

a7594217 · 04-27-2006, 12:03 PM

Cool thanks it helps some. I dont know anybody with a srt-4 local and i wasnt sure if 5-6 knock was normal. And yeah i notice our cars run lots of advance.

aaronneon@RealTune · 04-27-2006, 12:16 PM

Quote: Originally Posted by fade

Ok..not worried about my 2.5 KR now.

Thats not bad at all on the stock turbo

a7594217 · 04-27-2006, 12:36 PM

Im going to keep checking this thread so if you have time to share some more whenever that will be sweet.