Just wanted to get an opinion on something I've noticed. I've spent a ton of time on this site READING about our cars; tuning, modifying, and so forth. However, I have very little experience actually doing any of it.
Recently, I took my 100% stock 2005 and had the following parts installed:
So, before any modifications, when my car was 100% stock, I would get up to 7 KR. I asked around and was assured this is normal for a stock setup using 91 California piss gas. I shrugged it off and was also assured it'd go down once I started modifying.
After my mods, I was getting quite a bit of hesitation so we checked my plug gaps and found that they were all at .55. Naturally, we lowered this, haha. We dropped it down to .35, put them back in, and took it out for another spin. The hesitation was still there, but much less severe.
Since we still had hesitation, I decided to replace the plugs with brand new Champions (stock) gapped at .33 and even new Mopar performance plug wires to be safe. STILL had hesitation, so I decided to reset the PCM. At that point, the hesitation went away and all was well.
I drove the car for two weeks and generally saw knock counts of around 4-5 at the most. Now, when I do a 2nd gear pull, it'll get up to around 2-3 at the most, but when I let off, it'll jump to 5 or 5.5 KR. I've done pulls in fourth gear that only produce around 1-2 KR, sometimes none at all.
Aside from this, this Monday I noticed my car is now...misfiring when idling, but only when it's first fired up in the morning. In the evenings, after work, it doesn't seem to.The misfiring goes away once it's warmed up, and doesn't occur at higher RPMs. Kind of odd. I'm going to be looking into the battery, coil and alternator just to be sure this weekend. Figured I'd add this in, just in case.
I have a scan gauge, so I'm wondering what else I should be looking at?
At WOT, my AFRs are pretty much 10 to 10.5...sometimes 11 to 11.3. So, I'm running piiig rich, which I honestly expected. I just figured I'd be getting a lot less knock.
I'm posting this in this forum to see if this is normal, and if not, what to check? Or...perhaps, to discuss some tuning options (DTEC, SAFC II, as an example).
Let me know if you need any additional information.
I know people always suggest to double check the knock sensor to see if it is torqued down correctly. However, i've never seen anyone say that it fixed their knock problems, but it's a pretty easy fix if that is the problem.
The only other thing I can think of is phantom knock, maybe a broken exhaust hanger, or the NDS DP hitting something?
EDIT: I thought I remember reading a thread where the poster said they got more knock count with the Needswings DP open, have you tried opening / closing it and seeing the difference? Here's the thread: Confused with my knock count.
I know people always suggest to double check the knock sensor to see if it is torqued down correctly. However, i've never seen anyone say that it fixed their knock problems, but it's a pretty easy fix if that is the problem.
Which is a good point...I guess I'm trying to identify if I'm having knock problems to begin with.
I would think KR should be 0.0 on a 100% stock car...as mine always read 0.0 even modded downpipe open or closed or whatever...only time I started reading something on the knock count was when I started hijacking the ECU via my MAP clamp....then some tuning later I got the counter back to zero.
From what I've "heard" (key word is HEARD) that up to 3.0 KR on pump and up to 5.0 KR on race gas is considered "acceptable"
I would think KR should be 0.0 on a 100% stock car...as mine always read 0.0 even modded downpipe open or closed or whatever...only time I started reading something on the knock count was when I started hijacking the ECU via my MAP clamp....then some tuning later I got the counter back to zero.
From what I've "heard" (key word is HEARD) that up to 3.0 KR on pump and up to 5.0 KR on race gas is considered "acceptable"
Take that for what it's worth
It's entirely possible it's my knock sensor...then again, I KNOW I heard knock when I was stock. Not so much now that I'm a little modded.
In general, I'm just confused. It seems like I get and read conflicting information on this. That's why I was hoping the tuning section would know for sure.
As far as KR is conserned i would blame it all on californa 91 octane, my car did the same and its slightly modified, nothing i changed could change it. I heard that the timeing curve is more agressive for the stage 1 computer, and also more picky when it detects knock, causing it to pull more timing then it would on stock or other stage computers. The only fix i have found is to run 100 octane, my car likes it and gives me all the timing it wants. I only run it at the track though, thats the only place where i really push the car anyway.
About the misfire, i know my car gives out a slight hesitation or hichup at idle usually after the car warms up. I have noticed this too on other staged cars expectually on stage 1 cars. Its kinda sounds like a big cam but comes and goes. I never get it in a higher rpm or under load. Its hard to discribe in a text. If its anything like that then I woundnt worry about it, its normal.
As far as KR is conserned i would blame it all on californa 91 octane, my car did the same and its slightly modified, nothing i changed could change it. I heard that the timeing curve is more agressive for the stage 1 computer, and also more picky when it detects knock, causing it to pull more timing then it would on stock or other stage computers. The only fix i have found is to run 100 octane, my car likes it and gives me all the timing it wants. I only run it at the track though, thats the only place where i really push the car anyway.
About the misfire, i know my car gives out a slight hesitation or hichup at idle usually after the car warms up. I have noticed this too on other staged cars expectually on stage 1 cars. Its kinda sounds like a big cam but comes and goes. I never get it in a higher rpm or under load. Its hard to discribe in a text. If its anything like that then I woundnt worry about it, its normal.
I'm just trying to make sure I'm not ignoring something that could potential damage my motor. Basically, something I COULD have done something about, but didn't.
And as for your misfire description, it's somewhat like that. Basically, only during the FIRST startup in the morning when I'm letting it warm up for 3min or so before I take off (and still drive it easy until it's fully warmed up) it'll sound kinda like this: brrrrrrrrrrrblop...brrrrrrrrrrrrrrrrrrrrrrrrrrrrrr rrrrrblop...brrrrrrrr
And so forth. The intervals at which it seems to shake and cut out are very random. I don't notice any difference in AFr, no difference in PSI (vac in this case)....no real difference in anything but spark adjust. Even the RPMs don't really dip or anything. My car generally idles at 800-900; just under the 1000RPM mark.
Once it's warmed up, that all goes away...no more slightly funky idle. I thought maybe it could be related to a vacuum leak, but I've leak tested this car up to 40psi and everything held perfectly. Maybe I'll test it again this weekend.
I dealt with hesitation like you have... even with race gas.
I got knock, even with race gas.
Turned out my fuel pump was shot because of crap in the gas from the gas station I was buying from.
Replaced it w/ a walbro and no more hesitation.
You might also look into Meth/Water injection... without it.. I get 7-9* of KR.. running 91. With it.. I get .5-1* of KR in the heat of AZ... at 17psi.
edit: I see you're running rich on the top... I was the opposite. Running way lean on the topend.. 12-12.3:1
I dealt with hesitation like you have... even with race gas.
I got knock, even with race gas.
Turned out my fuel pump was shot because of crap in the gas from the gas station I was buying from.
Replaced it w/ a walbro and no more hesitation.
You might also look into Meth/Water injection... without it.. I get 7-9* of KR.. running 91. With it.. I get .5-1* of KR in the heat of AZ... at 17psi.
I did do the fuel pump rewire mod. Hmmm.
And, I was thinking about getting meth. I guess I just wanted a baseline first; basically, to know if my KR was on par with other SRT-4's, or at least similar. Or...if it was crazy off and something was wrong. =/
And, I was thinking about getting meth. I guess I just wanted a baseline first; basically, to know if my KR was on par with other SRT-4's, or at least similar. Or...if it was crazy off and something was wrong. =/
I think Meth was the best mod I did to my car.. in all honesty.
I don't see a catch can mentioned.
It doesn't take very much oil to contaminate the input charge and reduce octane.
Also, try running Union 76 Unleaded Premium - it alsways showed a lower KR (about -1 or -2) on my car than other brands (-5 or -6) ...when I could afford premium
ps try that before spending a ton of money on WI, Meth, fuel pump and rewire mods etc - what I said above was without any of those.
Last edited by Simon.Starkie : 06-06-2008 at 02:13 PM.
I don't see a catch can mentioned.
It doesn't take very much oil to contaminate the input charge and reduce octane.
Also, try running Union 76 Unleaded Premium - it alsways showed a lower KR (about -1 or -2) on my car than other brands (-5 or -6) ...when I could afford premium
ps try that before spending a ton of money on WI, Meth, fuel pump and rewire mods etc - what I said above was without any of those.
I've always used Chevron of Shell in my car...and always 91. I have no idea what the former owner used/did, but hopefully the same.
I have no issues investing in a meth kit and all, but before I do, I just want to know where my car stands. A meth kit will help, no doubt, but it might only mask another problem I can/should take care of first.
Edit: No Union 76 stations near me, by the way. As far as I'm concerned, any of the 'major' stations should have more than adequate gas. There might be slight differences in additives and such, but I can't imagine only one gas being better.
I've always used Chevron of Shell in my car...and always 91. I have no idea what the former owner used/did, but hopefully the same.
I have no issues investing in a meth kit and all, but before I do, I just want to know where my car stands. A meth kit will help, no doubt, but it might only mask another problem I can/should take care of first.
I used to use Chevron 91 in my car all the time also.
Until I got an Aeroforce ScanPro and noticed the KR difference compared to Union 76.
Try it for a couple of tankfulls and see if it helps.
And the catch can? Again, it doesn't take much oil in the intake charge to reduce octane which will increase detonation and increase KR.
The only issue I have with a meth kit is cost. One can buy alot of race gase for $599, even now! And none of the kits are completely foolproof - for example, if a line pops off at WOT/redline.
I used to use Chevron 91 in my car all the time also.
Until I got an Aeroforce ScanPro and noticed the KR difference compared to Union 76.
Try it for a couple of tankfulls and see if it helps.
And the catch can? Again, it doesn't take much oil in the intake charge to reduce octane which will increase detonation and increase KR.
The only issue I have with a meth kit is cost. One can buy alot of race gase for $599, even now! And none of the kits are completely foolproof - for example, if a line pops off at WOT/redline.
Yeah, I have an Aeroforce Scangauge as well. That's when I noticed I was getting up to 7 KR on a stock engine. I about had a heart attack.
If I kinda find a 76 station, I will try...but I do not know of any near my house.
As for the meth kit, if I did install one, I wouldn't use it to turn up the boost...I'd keep the same levels and run it safer. That way, if something did happen during WOT, it would simply pull timing and knock more.
As for catch can, I'll look into getting one. I get a lot of mixed reviews/feelings on running them.
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Stock KR vs. Modified KR
282HP, 312TQ
Running way lean on the topend.. 12-12.3:1 
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