Detonation
Thread Starter
Intermediate
Joined: Jul 2012
Posts: 25
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From: OAK GROVE MN
Detonation
My tuner sees some detonation while scanning/tuning my 2001 6 spd vert. This is nothing that you can hear by ear - something that shows up on the scanner. Engine internals are stock - have added Black Wing, ported TB, LT headers, Corsa x pipe and mufflers Baseline dyno was 308 rwhp on a Mustang, then just 325 after the mods on the same Mustang. Using 92 octane and adding a can of Sea Foam to the last two fills. I have not tried spraying Sea Foam in the intake yet - that's supposed to be helpful in getting rid of carbon build up. Something I haven't tried spraying something like starting fluid around the intake - But, I don't know what type of spray would work and yet be safe - looking for suggestions re spray and other potential detonation sources. My goal is to steam some of those ricers we see now and again, so hopefully a supercharger in the spring
Thanks
dave
Thanks
dave
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
Not all detonation or knock is REAL kncok--Especially with LT headers---The wall thickness of the tubes are so much thinner than the stock manifolds that the knock sensors will pick up some new strange noises which they interpret as knock--Vey very common--Fix is to
De-senitize the knck sensor sofware in your tune---make sure you use your data logger to identify exactly where in your run the knock is coming from and only adjust it there--don't just do it globally--also simply adding timing to your hi oct table won't do it as the sensors will just take that extra timing out too---Best table to de sensitize is the "cylinder mode B" 100 KPA is WOT--If you are getting false knock say at 4000 to 5000--then add 2-3 points at both 95 and 100 KPA in that area---Log again and see if the knock goes away---Real knock can usually be heard by a pinging sound--If you hear pinging after the table change--back off on the table change back some---Best to roll up the windows and listen for pinging as you make a run
De-senitize the knck sensor sofware in your tune---make sure you use your data logger to identify exactly where in your run the knock is coming from and only adjust it there--don't just do it globally--also simply adding timing to your hi oct table won't do it as the sensors will just take that extra timing out too---Best table to de sensitize is the "cylinder mode B" 100 KPA is WOT--If you are getting false knock say at 4000 to 5000--then add 2-3 points at both 95 and 100 KPA in that area---Log again and see if the knock goes away---Real knock can usually be heard by a pinging sound--If you hear pinging after the table change--back off on the table change back some---Best to roll up the windows and listen for pinging as you make a run
Thread Starter
Intermediate
Joined: Jul 2012
Posts: 25
Likes: 0
From: OAK GROVE MN
detonation
Tb - 92
Thank you for your responses - I was unsure whether to check for vac leaks with starting fluid or brake fluid - hate to blow something up... Re your info on the detonation, I will send that over to my tuner - I understand nothing.
Dave
Thank you for your responses - I was unsure whether to check for vac leaks with starting fluid or brake fluid - hate to blow something up... Re your info on the detonation, I will send that over to my tuner - I understand nothing.
Dave
Le Mans Master
Joined: Nov 2003
Posts: 8,004
Likes: 250
From: Tampa Fl
St. Jude Donor '12-'13-'14
It coud be a couple things.
Detonation. If it is true knock, that's ok. I like taking out about 1/2 of the amount shown in an area about 1000 RPM BEFORE in apprears.
an example would be, if you getting 4-5 degrees of KR at 4800 RPMS
(which is common for stock) and your fueling is at the AFR target range, I like to remove about 2 degrees of main timing at about 3800 to 4800 with the theory of getting 2-3 additional degrees of spark. So on my first attempt, I dont like removed the whole 4-5 degrees.
False knock. If you take out a couple degrees several times from the same area, and you still have KR, you may have something rattling underneth you cant hear, but the sensors pick it up because its the same frequence.
The sucky one is if oil consumption is and issue. To much oil pooling in the valley with cause knock.
Detonation. If it is true knock, that's ok. I like taking out about 1/2 of the amount shown in an area about 1000 RPM BEFORE in apprears.
an example would be, if you getting 4-5 degrees of KR at 4800 RPMS
(which is common for stock) and your fueling is at the AFR target range, I like to remove about 2 degrees of main timing at about 3800 to 4800 with the theory of getting 2-3 additional degrees of spark. So on my first attempt, I dont like removed the whole 4-5 degrees.
False knock. If you take out a couple degrees several times from the same area, and you still have KR, you may have something rattling underneth you cant hear, but the sensors pick it up because its the same frequence.
The sucky one is if oil consumption is and issue. To much oil pooling in the valley with cause knock.
