Thread: Thoughts on the best way to combat KR on a stock-ish car

So, I have a little bit of KR showing up somewhere between 3 & 5k RPM. My car is mostly stock, and I am wondering what else, short of intercooling/ e85/ meth I could do to eliminate it before digging into a tune or (hopefully) adding any power to it. I feel like I've got a pretty good baseline, with no issues to speak of otherwise- no engine codes, fresh plugs, wires, fresh fuel filter, all sensors seem to read what they should. I can only assume the little bit of KR that I'm seeing is just part of the factory tune on my car, but I'd like to zero it out completely if possible to have an even better place to start from.
Parts sellers will have you believe that almost anything they sell will combat KR, but I've read there are basically 2 ways to really do it- cooling the charge air or adjusting fuel & spark advance. Is this correct? or could it actually be reduced with something like a plog?

How much knock are we talking here though?

i had 8º kr stock. set of yt 1.95 rockers killed off 5º. a u bend delete killed off the last 3.

Originally Posted by ThatOldCarSmell

ok, so the u bend delete WILL make at least a little difference? No doubt it would flow better, but I wasn't sure about KR. Thx for the input! Rockers are on the short list too, so good to know that will help as well.

truth be told. if i had it to do all over again, id have skipped the rockers and got a cam. but they did kill a lot of kr.

Originally Posted by Scottydoggs

truth be told. if i had it to do all over again, id have skipped the rockers and got a cam. but they did kill a lot of kr.

Only thing with this is, while I feel like I'm pretty well versed with shadetree mechanic work, there are a few things that still somewhat petrify me, and installing a cam on my DD is one of them (bearing issues and such). If I ever get a spare motor to work on at my leisure, then A cam is absolutely at the top of the list, but for now, nothing more invasive than rockers and springs for this guy.

the spring swap is kinda scary too lol cams dont blow the bearings either. rod knocks can happen to any one at any time stock or modded. odd but you see more na engines with rod knock then the supercharged engines.

Originally Posted by Scottydoggs

the spring swap is kinda scary too lol cams dont blow the bearings either. rod knocks can happen to any one at any time stock or modded. odd but you see more na engines with rod knock then the supercharged engines.

Yeah, I've thought about the prospect of dropping a valve when doing the springs. I was specifically concerned with scoring the cam bearings or knocking one slightly out of place, and creating huge issues later on. I understand it *can* be done in- car, which is inviting, and I sure like how the vids I've seen of the NIC cam sound, but if I'm not mistaken, that one calls for replacing the springs too. Realistically, though, I will probably do a downpipe, and hopefully exhaust, and then move towards tuning before I put any more go fast bits on it. Seems like a fairly wise sort of way to approach it. I still have a world of suspension garbage to deal with too. the shocks are for sh*t, and even with the "miracle" pogo washers, the thing still bounces like an f'n bobble head when I go over, well, anything.

we all had to start somewhere. rockers were just a intro to modding my regal for me, over the next 8 years it kept getting a little more and a little more.

if using compressed air to keep the valves up. tap the tops with a hammer to make sure they are seated 100%. especially if you hear a air leak.

I appreciate the head's up on the tapping the valves to make sure they're seated. I've heard mention of people tapping them with a hammer & socket or whatever, but didn't really know to what end. Sort of related, I got bored at work and window shopped that NIC cam, and there is a good bit of supporting crap to go with it to, it looks like (dbl chain and all the stuff to make that work, as well as the balance shaft delete, which as far as I know, shouldn't be done with the motor in- car). sounds like the remedy for me is going to have to be to source a spare motor to build. Wonder how amicable the wife would be for father's day

Originally Posted by dezldave961

For that, a tap with a rubber mallet is the safe route to not risk chipping anything (or small piece of wood as insulator for regular hammer). It only takes 10-20psi pumped into the spark plug hole with a compression tester hose (did the rope version... once... due to limited resources in college, and was sweating bullets when I almost got it knotted... never again).

NIC cam is a bit of a big jump for less overall gain than the XP or S1x, which also have nice idle sound with more power gain. The tuning is a little more difficult on the NIC due to the extra overlap meant to bleed off extra boost (basically a band-aid to satisfy people wanting to run a smaller pulley than they should). I may or may not try an NIC in a project for fun someday, but other cams have more benefit with less headache.

Also, deleting the balance shaft is unnecessary, and only introduces the chance to have an oil path leak after plugging. It's only a pound or two of static weight, centered right over your drive axles, and does nothing wrong sitting there if you run a double roller chain.

I forgot about the s1x, those seem to be a favorable option for a lot of folks too. I don't ever have any intentions of going sub-3.0 on the pulley, if even that low, so maybe the s1x is a better alternative. As far as the balance shaft delete, I have no interest in removing it if I don't absolutely have to for something else to work. I just recall reading somewhere (maybe the zzp site?) that it was required with the NIC cam. maybe not. I'll have to look more seriously at the s1x before time to act on any of it, but as of right now, a new xp cam appears to not be available.

I did my first cam (in car) install last fall. It's pretty straight forward. I went with the VS only because it's one of the cheapest options and I'm trying to keep my transmission alive. But now, of course, I wish I went bigger. Or do I? I dunno... Anyways, I think if your mechanically inclined just jump right in and do the cam. I would tell my younger self the same thing but I learned most of what I know on this car so for me it was a fun journey doing bolt one, like a top swap?...yeah....I should have just done the cam out the gate. ;(

So along similar lines, and still relative to my KR question, it seems like a wise idea to go ahead and free up the exhaust some. The only option I see currently for a 3" ZZP DP is through Ebay, not their site, and after shipping is around $239 to me, or I can order the SSautochrome headers for about $6.00 more. I know full headers are the favored way to go, but I guess my concern is fitment, which seems to be an issue with any headers to be had new these days. I'm assuming these are the same ones that I keep seeing referred to as SSAC headers, which a lot of folks have had positive things to say about them, but I have heard of bad runs and fitment issues too. What say ye on this? Any other factors to consider regarding one or the other here?

So I bit the bullet, and went with just the DP for now. Haven't logged it yet, But I'm expecting at least some reduction in the little bit of KR that I was seeing. Kinda glad I didn't go for the full headers yet, since it was an absolute PITA to get the DP installed (yeah, I know....only 4 bolts, etc.). The 2 nuts at the manifold came off no issue, and with some PB blaster, one of the exhaust side bolts came out fairly easy, but then.....the dreaded *tink* noise of a bolt breaking. I got the factory DP out, but it took some part of 3 more days to get the rest of that bolt out, between work and other obligations, plus not being able to make the kind of noise it took to get it out of there in the middle of the night for my neighbor's sake. So, a couple of days ago, I got everything back together. It took all of 15 mins to put everything back in. There is a minor audible difference, and I don't know that it really feels like it pulls any harder, but I've only driven it once or twice since. Progress.....slow, painful progress.....

you may not feel a whole lot. but if your kr is gone. 2 nd gear will now feel like its pulling harder wot. i had 8º, when that was all gone 2 nd gear came alive. it used to fall on its face hard and id get like 6º timing due to the kr pulling all my timing out.

If I've learned anything, is that the @ss dyno is rarely relevant, so I'll log numbers as I go out and drive around some this weekend. I'm curious to see what happens...

I ran a quick log when I went to lunch (drive link here) . Looking a lot better. there was a total of 2 seconds during which between 1-3* of KR showed up, so I would say that's progress. Curious on the pattern in the timing advance, though. I'm assuming that gets back to the stock GM tune, though...