1g 660's + SAFc = Too much timing for 91 pump?

[sunflashx]

This all pertains to 91 octane pump gas, not race gas. I am also located at 4600' Altitude.

There aren't any local 1g's in town running bigger than 550's, so I have no one to refer to.

My base pressure is set to 38 psi to lower the timing a bit from the previous 43 psi I had it set at. My car feels the strongest (by far) and has the best feeling power curve when I get a bunch of timing retard from a 10-15 knock count or so. That knocks my timing down to the 17-19 range, I think a no knock run will land my about 24 max degrees of timing. I am also running about 19-20 psi in hopes of the higher airflow lowering my timing, I'm not sure that it made a significant difference in the amount of timing I was getting over running 16 psi.

Full list of modifications can be found here:
http://utah.dsm.org/members/sunflashx.htm

 

[NOSLO2PT0]

Remember, timing = power. I'm running 660's with a small 16G right now. The more timing you get, the better. If you want to make the most power, tune the car for about 6 counts of knock. Once you hit 7 counts, it puts you in a lower timing map, and you get some timing pulled. Hell, with the 660's, i was seeing 12 counts of knock and still getting 24 degrees of timing.

You don't want 10-15 counts of knock. That is enough to do some damage if you stay in it too long. Check your EGT's as well. You very well may be getting rich knock. Let us know where your AFC settings are for hi on pump gas.

Mike

 

[Turboniam]

What is your base timing set at?

I've read that some people have seen great gains by lower their base from what was 7 degrees, to 5 degrees or even lower.... some have even had better results by putting their base timing down to 3 degrees.

I told a friend of mine about this with a WRX and I think he is going to try it (lower his timing) as he explained something to me that other WRX guys were trying similar to this.

 

[NOSLO2PT0]

My base timing is stock, 5 degrees.

 

[ILOSE]

Originally posted by NOSLO2PT0
You don't want 10-15 counts of knock. That is enough to do some damage if you stay in it too long. Check your EGT's as well. You very well may be getting rich knock. Let us know where your AFC settings are for hi on pump gas.

Mike

Too much knock does not casue damage! And by no means is 10 -15 bad. It may not be optimum, but it is not terribly bad. I have ran at 43 counts at the track the whole run without andy problems besides having 7 degrees timing. Definetly not good for performance.

 

[Turboniam]

Originally posted by ILOSE


Too much knock does not casue damage! And by no means is 10 -15 bad. It may not be optimum, but it is not terribly bad. I have ran at 43 counts at the track the whole run without andy problems besides having 7 degrees timing. Definetly not good for performance.

ROTF ... whatever you say there smart guy. :laugh:

Ask anyone that tunes their car alot, they will tell you they can feel when their car starts knocking without even looking at the datalogger...

Knock is bad, and even worse is running it with 43 knock counts... but I guess your sig explains everything...

I'm slow

 

[90tsi]

Originally posted by ILOSE


Too much knock does not casue damage! And by no means is 10 -15 bad. It may not be optimum, but it is not terribly bad. I have ran at 43 counts at the track the whole run without andy problems besides having 7 degrees timing. Definetly not good for performance.

Bwahaha!

I'm running 660's with base fpr set @ 37psi, knock within reason 1-5 counts, get about 19-22 degrees of timing advance on 93 octane.
Car still feels slow

 

[2-0turbo]

Originally posted by NOSLO2PT0
Remember, timing = power. I'm running 660's with a small 16G right now. The more timing you get, the better. If you want to make the most power, tune the car for about 6 counts of knock. Once you hit 7 counts, it puts you in a lower timing map, and you get some timing pulled. Hell, with the 660's, i was seeing 12 counts of knock and still getting 24 degrees of timing.

You don't want 10-15 counts of knock. That is enough to do some damage if you stay in it too long. Check your EGT's as well. You very well may be getting rich knock. Let us know where your AFC settings are for hi on pump gas.

Mike

10-15 counts of knock is not enough to do damage. Don't fool yourself. The number reported by the pocketlogger and TMO logger are "knock sums", a calculated value by the ECU/Logger. If you notice when you get a spike of knock, it never just goes back to zero, but sort of stair-steps back down to zero. This is because it averages the reading. Even though the "knock event" disappears, it takes the new reading, the old reading, sums them and divides by some window to develop this moving average.

Our ECU's are SO conservative. Do you hear knocking with a knock count of 10? No, or course not. I have never heard knock with a knock count of 43 and you are not going to do damage until you get well beyond that. I will agree with you, though, that you should tune for the lowest knock. That is just the nature of the DSM ECU. Our ECU aggressively pulls timing when it sees knock. Tune for lowest knock and get great timing. Great timing equals great power.

Bottom line: 43 counts of knock is not going to hurt your engine. There are plenty of safeguards built into the stock ECU. Your car will be slow with 43 counts of knock and feel like a turd.

 

[ILOSE]

Originally posted by Turboniam


ROTF ... whatever you say there smart guy. :laugh:

Ask anyone that tunes their car alot, they will tell you they can feel when their car starts knocking without even looking at the datalogger...

Knock is bad, and even worse is running it with 43 knock counts... but I guess your sig explains everything...

Wow please don't overwhelm us with your vast knowledge.

So, if you can feel the knock then why do you even need a logger?
Do you at all understand that the ecu retards timing when it detects knock to *prevent* damage. Knock in itself does not cause the damage.

And if you were anywhere near charlotte I could easily show you what my sig means. I love to holeshot on an AWD!

 

[2-0turbo]

Originally posted by ILOSE


Wow please don't overwhelm us with your vast knowledge.

So, if you can feel the knock then why do you even need a logger?
Do you at all understand that the ecu retards timing when it detects knock to *prevent* damage. Knock in itself does not cause the damage.

And if you were anywhere near charlotte I could easily show you what my sig means. I love to holeshot on an AWD!

Come on boys, put your penises away. No one is going to Charlotte and no one is going to hole shot anyone. (that actually sounds vulgar). Anyway....

You don't "feel" knock, you feel the results of it. You feel the ECU pulling timing. That is what you feel--the feeling of driving a big turd. And I too, can "feel" the timing going away. Because I know (and so do you) how our DSM ECU operates, you know you must be getting knock too. If you look carefully, next time you "feel" the timing being pulled, check your EGT's and they will start climbing too.

And yes, KNOCK does damage. Actually, if you really want to get technical, it is not the knock that does damage but the very high increase in peak cylinder pressure that puts too much stress on the tops of your pistons and rods. But we are arguing over 18 counts or 43 counts. I am talking real knock, which sounds like someone hitting your pistons with ballpeen hammers.

 

[NDgsx]

Originally posted by 2-0turbo


But we are arguing over 18 counts or 43 counts. I am talking real knock, which sounds like someone hitting your pistons with ballpeen hammers.

No you are talking about one kind of "knock". That is detination, which is caused by runnign too lean. Yes it does take a lot of detination to cause damage (typically melting a piston or valve).
Preignition is also picked up by the knock sensor also. You can not hear preignition. It also causes much greater damage, cracked ring lands, spinning rod bearings, bending rods.. You will only know that preignition is happening by logging.
If you think that a knock count of 43 does not damage your engine I have some dehydrated water to sell you; oh and 4 pistons with cracked ring lands after a run with a knock sum of 35 from a while back.

 

[2-0turbo]

Originally posted by NDgsx


No you are talking about one kind of "knock". That is detination, which is caused by runnign too lean. Yes it does take a lot of detination to cause damage (typically melting a piston or valve).
Preignition is also picked up by the knock sensor also. You can not hear preignition. It also causes much greater damage, cracked ring lands, spinning rod bearings, bending rods.. You will only know that preignition is happening by logging.
If you think that a knock count of 43 does not damage your engine I have some dehydrated water to sell you; oh and 4 pistons with cracked ring lands after a run with a knock sum of 35 from a while back.

Well, this has turned into a pretty good discussion. How fortuitous that one of my favorite magazines this month covered this topic in great detail. It was written by a guy with more experience than probably you and me. I'll scan it tonight and post to my website for your review--it is quite interesting and directly addresses the topic at hand.

 

[Turboniam]

Originally posted by ILOSE


Wow please don't overwhelm us with your vast knowledge.

No problem, you continue on your "fast" times with the knock that does no damage! :laugh:

So, if you can feel the knock then why do you even need a logger?

I'll let your sig answer your own question as to why you would even ask that!

Do you at all understand that the ecu retards timing when it detects knock to *prevent* damage. Knock in itself does not cause the damage.

Ok, whatever you say!

And if you were anywhere near charlotte I could easily show you what my sig means. I love to holeshot on an AWD!

I would really like to see that... keyboard comandos are always my favorite when predicting outcomes of races!

The bottom line was I didn't want others to be misled by your "opinion." Sorry that you got offended. You are right and you know everything. I don't need to personally insult you... I'll just let your sig do all the talking!

 

[2-0turbo]

From the October 2002 issue of Kitplanes magazine, an article titled Abnormal Combustion, by "Turbo Tom" Wyatt. Used without permisson, presented in it's entirety:

Page 1
Page 2
Page 3

It covers much of what we have been talking about and has some great information.

Regards,

 

[ILOSE]

Originally posted by Turboniam
I would really like to see that... keyboard comandos are always my favorite when predicting outcomes of races!

The bottom line was I didn't want others to be misled by your "opinion." Sorry that you got offended. You are right and you know everything. I don't need to personally insult you... I'll just let your sig do all the talking!

So let me get this stright, what I say is an opinion, but we should believe all of what ou say? OK!

I was and am not offended, at all. Juat tell me why we should take into consideration your opinion, when in your profile your best time is a 15.9? I just ask, because to me, I would rather take the advice of someone that actually runs somewhat fast, than someone running slow as slow as you do.

Why is my opinionm totally diregarded by you. I am giving you facts and experiences, not hype. "keyboard" commando Huh? ! You have the commando part correct though. I'll give you that.

 

[Turboniam]

Originally posted by ILOSE
So let me get this stright, what I say is an opinion, but we should believe all of what ou say? OK!

That is the point, get both points of view, then talk to someone YOU know, knows their crap... I just didn't want anyone reading your "opinion" and then trashing their car because "you" said running 43 knock counts is "fine!" I totally disagree with you. Now whoever reads this thread will have the FOX news "fair and balanced" information.

I was and am not offended, at all. Juat tell me why we should take into consideration your opinion, when in your profile your best time is a 15.9?

Good question. Answer=I don't post what I run because the street racers in my town have big mouths and will blab to everyone/amoungst eachother what I run. Whatever I run is what I run. You'll have to run me to find out. My car, my preference... bugs the hell out of the locals

But if you don't mind telling us what you run, since you think you'll out launch an AWD... I'm interested to hear. Also, include your trap.

 

[ILOSE]

Originally posted by Turboniam


That is the point, get both points of view, then talk to someone YOU know, knows their crap... I just didn't want anyone reading your "opinion" and then trashing their car because "you" said running 43 knock counts is "fine!"

I never said it is fine to run that high of knock, because sustained detonation in small amounts will cause damage. Pits on the pistons and such. What I did say was that " I have run 43 counts with no damage"


You are corrct though, I should have been more clear in my thoughts for others to have clarity.


But if you don't mind telling us what you run, since you think you'll out launch an AWD... I'm interested to hear. Also, include your trap.

I run low 12's currently, with traps in the 118 range and I still run street tires. As for my 60's let's just say that most awd guys don't launch as hard as I do!g

 

[Turboniam]

Originally posted by ILOSE



I run low 12's currently, with traps in the 118 range and I still run street tires. As for my 60's let's just say that most awd guys don't launch as hard as I do!g

So then what is your 60ft that most AWD guys can't hang with????

BPU and a good driver, an AWD can cut 1.8 60fts all day. So a greater modified AWD will cut even lower 60fts.

(BPU = exhaust, intake, boost controller)