nuzee

iTrader: (2)

I like to post hard numbers (track times) to back up my statements. In this case, I haven't had enough time to test out the 206 cam to generate any numbers. I just installed it 4 days ago!

BUT, I can't let your statement go unchallenged. Actually, alot of you guys, although you may mean well, will recommend a cam based on your own situation/desires without considering what the other guys intent or setup is. A Hotcam may be the perfect cam for you, but it may not possess the qualities that I want. Same for the LS6 cam, TR224, etc..... Perfect for some, not for others.

Anyway, excuse my digress, the 206 cam should boost the low-low end, give a good midrange, and make top-side power close to the LS6 cam. The entire power range should get a boost. The tradeoffs are likely to be the choppier idle and the rpm range will not be extended much over stock. So far, I can confirm that the low-low end is improved. The jury is still out on the mid range ... The first mid range acceleration test showed very quick & strong pull ... However the second test felt flat, like timing is being pulled ... so I have since taken off the HPP3 tune and have yet to test it. I plan on going to the track next weekend. I should then have some numbers to indicate how much the cam puts out on the mid & top-side.

If the cam delivers as expected, what would be so wrong with those characteristics? I think alot of guys might find this style of cam appealing ... well at least marc_w, lol!

MyLS1Hauls

iTrader: (2)

Marc-You're just over-reacting. That cam was a great choice for your truck, if you wanted a good street performer. Sure the valvetrain is noisier...ever listened to a LS6? They are noticeable louder than an LS1 due to the cam. As for your loss in low rpm torque? I'm not sure what thats about since my buddy has the same cam in his 5.3L truck and lost none. With you having a bigger motor and more compression, that cam shouldnt cause a loss...the loss you are feeling must be due to the KR. What thats about I'm not sure. As for the 206/212 cam...the older stock LS1 cam was a 200/210, so thats not much of a jump, and if you run that cam advanced much you'll have no top end.

soliari

How does that look for low end torque?? If you like it, PM me.

marc_w

Lowend in my case is under 2,000-2,500.

You're probably right Brad... on all acounts. I was really miffed yesterday because any tuning change I made, just made the driveabily just as bad in different areas. I'm back to square one right now, basically just running a boost in idle RPM, and the cam IS running pretty strong, especially from the midrange up.

To be honest - I actually felt it pull STRONGER than stock down as low as 1,500rpm this morning. Reported gas mileage (via the dashboard computer) is actually better than stock in that range, so something must be going right.

Still, under 1,500 I feel the power drop off rather quickly. I pretty much expected this though.

I'm blind as a bat when it comes to tuning this thing. I took a lot of advice I've seen given on here, but all I got were driveability problems. It seems to run the best on a stock tune.

I'm dissapointed that I don't actually feel the cam come alive at all - it's a very mundane powerband. I figured I'd feel a little bump in torque with the 112 LSA, but it just pulls harder the more you rev it out. That's one reason why I'm interested in the Comp 206/212 cam... I don't particularily like to rev to make a good power.

Nuzee - I'm in the same boat with you on that midrange thing. Sometimes the engine pulls awesome, other times it's revving like hell and not much is going on.

So about the cylinder pressure thing - how would I combat that? It almost sounds like I need to bump the VE up in that area? I can only absorb so much of the "VE table cracked" thread each day. It skips over the basics and goes right to the theory of relativity. I see a lot of conflicting info on the VE table in older threads too, so that just adds to my confusion.

marc_w

Brad - I'm mainly nervous about the valvetrain because I think that's were my KR is coming from.

My KR *was* all down low, at "tip in" throttle positions, but for some reason today it's all up high. I get a consistant 8 or 9.1 degrees at peak - so I kind of feel that it's false. I don't THINK real knock would be that consistant.(?)

soliari

same cam vs stock :

marc_w

Looking good!

I'd imagine your 218/218 in the 5.7 is similar to what the 220/220 is to my 6.0...

marc_w

Nuzee, Hows the cam working out for you?

I go back and forth on mine. I think I get something nailed down with tuning, but it turns out that I'm just running in circles. I get these little "teasers" where the motor runs STRONG off of part throttle, but then at the next stop it's doggy. Fuel trims and timing never change, so I can't pinpoint anything. I don't think I can get much more out of the cam with backyard tuning. I'm basically disappointed the cam doesn't match my driving style better. I still really... REALLY desire big fat lowend power more than anything. I would never miss revving over 5,500rpm, if I could gain 50ft/lbs down low.

I've got to pull a 5,000lb camper on vacation next Tuesday. I'm frustrated enough to overnight a 206/212 to me right now. Honestly, I'm considering going right back to stock if it's not here in time... how bad is that?

lsx24

iTrader: (45)

Stock Heads? Unreal

Another_User

I think you overreacted. People ask for input...I give them input. If people agreed with me, then the guy would probably listen. If not I would get ignored. As usual...unless somebody wants to disagree with me....hmmm...I sense a pattern forming...

nuzee

iTrader: (2)

marc_w
I am planning on going to the track this weekend to get a better idea of how the cam affects performance. During daily driving, I can only get up to 35 mph in very limited areas. Most of my driving is done at or below 25 mph in traffic. So I can only give you a report on how the off-idle to 1500 rpm feel is. There is definately an improvement in torque during light acceleration. This is strictly SOTP. It is not a 50 ftlb improvement though. But it is enough to be felt. Remember that I also retarded the cam 2 degrees, so the cam might give even better lowend if installed straight-up (110 ICL).

I logged a couple of drives that had brief acceleration bursts to see if I was getting any knock retard. I did not have any KR. However the timing goes to sub 20 degrees (17-19) when aggressively opening the throttle. I think that this low timing may be hiding some of the power that this cam should be making. The pull feels similar to the stock cam. I'm going to try a few things to increase the timing. This whole scenario is what I had concerns with from the very beginning. I was afraid that the cam would build too much cylinder pressure in the lower rpms that the computer would pull more timing to compensate for predetonation. Leaving the net effect of no gain in the lower rpms. I'll see what happens while logging runs at the track.

Other than aggressive acceleration concerns, when light throttling it, it pulls noticeably stronger. It still has a very little chop at 550 rpm idle. No SES lights or any tuning related issues that came up yet. I'm hoping that over time the computer will find the best operating limits for the cam without me needing to get a tune. Wishful thinking.

Another User
Sorry for overreacting.

Another_User

No prob! If you are in the teens at WOT you are riding the low octane table for sure. You are losing a ton of power with that much timing retard. Reset you computer and see how much KR you are getting.

nuzee

iTrader: (2)

Excellent idea!! That lower octane table thing never occurred to me. Thanks!

marc_w

Sounds good, thanks for the update. I appreciate it.

Most of my driving is done below 45mph, and also at very light throttle. There's hardly a straight piece of road around here - it's all hills - so that ligh throttle lowend torque is what I spend most of my time in. It's where I experience most of my frustrations with the 220 cam.

The thing pulls HARD above 4K. It's like a little nitrous shot goes off. Basically, the rest of the powerband feels stock-ish, until you get under 2K, where power is noticeabley less.

That upper RPM gain is fun, but that not an every-day useable kind of thing. I'm not really a big track junkie...

I just threw another tune at the truck tonight, nothing fancy, and it's like it knew what I was thinking about doing. The thing was loping harder than ever at idle... it sounds beautiful. Driving around, it was pulling quite healthy from 1,300rpm up. It was like taking out a girlfriend to dump her, only to see that for some reason she looks hotter than ever. ...It's just too bad the cam doesn't always run like this.

I'm confused as to why you'd only be seeing 17-19* of timing when getting into it a bit. In my truck, I get a good amount of KR and my knock learn factor only dips down to about 0.89 at the WORST. (1.00 is full HO timing, 0.00 is full LO timing) It's always back up to 1.00 within five minutes or so. I would think your computer would be trying to get you some more timing back, and you'd be seeing SOME KR.

If you only see the 17-19* right when you jump on the throttle - that might be Bust Knock kicking in. It's not really knock, but a reduction in timing to quell any possible knock during an agressive tip-in of the throttle. You should see full timing very shortly after jumping on the throttle though. It might be possible you were getting in and out too quickly...

marc_w

OH... one thing that has been getting under my skin - the truck is lacking torque at highway speeds. I don't travel the highway all that much, but enough I suppose.

Normally, I could be all locked up in 4th at 65... I'd step on the throttle about 1/4 of the way, and rather easily pull up past 75 in a moment or two.

Now, I have to put it down more (up to halfway - "kickdown/unlock" area) for there to be any drastic change in speed, and it's not as quick to pick it up.

If I'm above 72-75, the responce is better, but it seems more on par with the stock cam. MAYBE slightly better.

What throws me for a bit of a loop, is that I get better highway mileage than I did with the stocker.

Anyway.

My plan right now is to get the 206/212 - at least "get it out of my system" and see if I can really just slide in a stump-puller.

I want the usual bolt-ons installed by late spring. Heads, headers, this dang converter, etc. I think I'll tuck away the 220 until I can better match it up with those parts.

Another_User

My 98 would regularly put itself in the low octane table. Until I copied the high octane table over top of it. No matter how much timing I pulled, it just kept pulling. Harmonics or something I guess. I still have not found anything banging, and it wasn't random. Always when I revved it up, even before all my mods.

nuzee

iTrader: (2)

Haahaa!!! You crack me up! Your style of describing stuff is truly unique.

I hope the best for your situation. I appreciate the info that you have been posting. I'm learning a lot from it and from the responses. Good luck with whatever you decide to do! My 2 cents to you, give that cam a fair amount of use before you decide to take it out.

marc_w

Thanks... and no problem.

For what it's worth, I've got about 800 miles, and an estimated 20+ tunes on the cam. I easily do two tunes a day, and I drive way too much!

marc_w

One more question!

What size pushrods are you using, Nuzee?

FASTONE

Hey Marc,have you thought about an underdrive pulley?I put a March u.d.pulley on my 95 z71 and it made a ton of difference from a dead stop to say 25mph,plus you'll pick a little mpg.Just my 2 cents