DSM Link ..what do call acceptable knock

[Violater101]

Maybe this should be in advanced Tuning, I dunno, but anyhow

I've heard various things. That 3 degrees of knock retard is minimal and nothing to worry about. I personally don't like any knock if I can avoid it. I see that some 1g people get like 40 counts of knock...how much timing is the ECU pulling for that?

I wish i knew how accurate the a/f reading on it was. I'm guessing not to accurate, but merely smth to go by for an idea. I guess I might just breakdown and by a wideband.

Thx

 

[Violater101]

So I guess noone knows that's pretty amazing.

 

[Black95GSX]

if the check engine light flashes, too much knock

 

[Violater101]

That would be 5 degrees then.

 

[Black95GSX]

Correct -- if you want to change the check engine light "threashold" for knock... you can use the palm pilot version of the dsmlink software to do so. But hoenstly I have never found it necissary.

 

[Violater101]

So you don't worry about knock unless the CEL goes off is what you saying then? I get concerned when I get knock of 3 degrees and always get off it.

 

[candela]

If you mean 3 counts (not degrees) than thats really not anything to worry about at all. i would think that the best tuned car will show a little bit if not a lot of knock as, you are trying to get as much power from that certain fuel your using and sometimes it will just preignite. 0-7 counts will not retard timing and thats really nothing anyway. I usually have about 1-4 counts on a really good hard pulling run at the track. If I try to tune it out with a little more fuel, it just loses its edge and power. Your right about the timing thing, but I really just tune for seat of the pants. If I had a FWD I would have a much better idea cause I would have been on the dyno hella times already. Read Rich's (NJKGSX) post about this question hes wondering the same thing. i really dont know what is acceptable, and you really cant tell unless your on a dyno and you see what works... cause "everyones car is different"!

 

[Violater101]

I guess then Knock Raw would be the same as knock count for the dsmlink? I dyno'd over the weekend on pump gas and I think I got some bad gas cause I didn't make all that great of power for what I have. No matter what we did, the car kept pulling timing by like 4degrees. After I filled up and the knock seems to be gone...go figure...I would have bad gas when I go dyno. I didn't use race gas cause I wanted to tune for the street first. I was only getting around 14 degrees timing at best. Not that this is news to anyone, but the #'s the dsmlink uses to calculate HP is way off hehe.

 

[MaineDSM]

Candela, the DSMLink software reports knock in "degrees of retard" by default. You can also read the raw knock count, but it's not the default. I just wanted to point this out, as most 1G people report raw knock count, and most DSMLink users report timing retard. Which could lead to some confusion.

Check out this data from a DSMLink log of mine:

1 count raw knock = .4 deg of timing retard
3 count raw knock = 1.1 deg of timing retard
12 count raw knock = 4.2 deg of timing retard
18 count raw knock = 6.4 deg of timing retard

It seems that unlike the 1G ECU, the 2G ECU starts
pulling timing when it see *ANY* knock.

So maybe it's better for 2G people to tune for NO knock?


-Brent
'96 Talon TSi AWD

 

[MaineDSM]

Originally posted by Violater101
I guess then Knock Raw would be the same as knock count for the dsmlink?

Yep, see my above post.

I dyno'd over the weekend on pump gas and I think I got some bad gas cause I didn't make all that great of power for what I have. No matter what we did, the car kept pulling timing by like 4degrees. After I filled up and the knock seems to be gone...go figure...I would have bad gas when I go dyno. I didn't use race gas cause I wanted to tune for the street first. I was only getting around 14 degrees timing at best.

I think the MBTE they put in the gas here in Maine must really make it SUCK. I can barely run 14psi on 93 octane. I put in some VP C16 (117 octane) and I was running 20psi like it was a walk in the park. I'm also using the stock fuel pump on a FP T28, so lack of fuel may be my problem, in reality.
I guess the point is, good gas makes a big diff. that SUCKS that you got a bad batch for the dyno. Next time, don't screw around. Use some race gas.

 

[candela]

THanks very much Brent for clearing that up. i knew about the dsmlink just wants usre if hes was trying to say knock or what cause he was talking about degrees. You know Im not sure about the 2g ecu's, but I do know that every single obdII sucks a lot worse than previous models.... Maybe no knock is a good thing fo ryou guys. That does suck aout the gas thing... always a #@%#@%#@%#@%#@% when that happens

 

[larryd]

Originally posted by MaineDSM
Candela, the DSMLink software reports knock in "degrees of retard" by default. You can also read the raw knock count, but it's not the default. I just wanted to point this out, as most 1G people report raw knock count, and most DSMLink users report timing retard. Which could lead to some confusion.

Check out this data from a DSMLink log of mine:

1 count raw knock = .4 deg of timing retard
3 count raw knock = 1.1 deg of timing retard
12 count raw knock = 4.2 deg of timing retard
18 count raw knock = 6.4 deg of timing retard

It seems that unlike the 1G ECU, the 2G ECU starts
pulling timing when it see *ANY* knock.

So maybe it's better for 2G people to tune for NO knock?


-Brent
'96 Talon TSi AWD

aha.. finally i understand it.. so with a 2g the best options are to either tune for 0 knock or to go with a standalone so the ECU stops pulling timing. Thats not good news for us..