112 LSA guy here. Efficiency at idle was not a consideration when I selected my cam.

And my car idles fairly smoothly at 850 RPM. I've seen a couple of "cold start" videos from smaller cams that sound a lot more lopey/choppy, which is kind of funny.

 

A good tune is a HUGE part of how well a cam idles, which is why many with a "smaller" cam lope like a 3-flippered walrus. Sounds like yours is tuned right. A seriously loping engine is NO fun to drive unless masochism is a vital part of ones life.

 

No......this is just a case of people trying to pull the old sock in the pants. They just want to make it sound faster/bigger/meaner then it really is. There is nothing wrong with wanting to do what IMO but most people don't under stand what they are going to sacrifice to get the sound they want....or how much that sound is going to cost them to make drive worth a damn.

To this day the most memorable cam I've every owned was on 106 LSA(Non-LS) with a Pete Jackson gear drive with 240 duration@.050. The car wasn't built to be fast(it wasn't) it was built to sound good and turn heads.....and it did that very well.

I got far more enjoyment from the "sound" of that cam in parking lots and gas stations then I've ever get with the thrill of breaking the back tires loose in third gear at 7K RPM.

So.....I'm gonna have to disagree with you on this one. The "sound" of the cam can be just as important has how well it performs to some people. It's not about being macho, it's about what your REALLY looking for. Some people may want that extra 7hp at 7700 RPM......others may want that really choppy idle even if they loose 25hp up top.

 

I do believe cars are meant to bring people enjoyment. If a choppy idle is what you want, nothing wrong with that. I pushed my idle down even more recently just for this purpose lol. My cam needs are different than most on my 98 though, as it is rocking a 427 LS3 (in reality its a 431, and a 470 if you add in full swept volume from pistons and heads, etc).

My cam was spec'd out by the master himself, Pat G. Even at 114 LSA, I have 20 degrees of overlap. I run a SD tune so trims aren't an issue. It just likes SD better. It also makes good power. Nothing wrong with nasty sounding cams IMO. I also have cutouts to add to the effect. Boy that gets their attention. Kind of hard not too when you need earpro to rev it.

 

A tight LSA doesn't automatically mean it will drive like crap....the amount of overlap does. Plenty of 112 cams out there that idle and drive great, but they also don't have 15 degrees of overlap on a DD.

 

Short story. Ive always ran wide lobe seps. And my stuff has always seemed to run better than average. I knew better on my gto but the first cam I listened to someone else’s recommendation. I should have listened to what I know already. I was not happy with the first cam. Second cam, wider lobe sep and less duration, i like much much more.

 

a-men!

 

I know, I know...
Yeah, I'm 99% sure there's not a vacuum leak.

 

Thanks for that. Sounds like good info.
FWIW though, it had the same issues with the (Speed Pro or whatever) TB it came with. The Nick Williams didn't "fix" the issue.

 

something I learned. If you have a loose fit on the tps to shaft, you’ll have problems. Your previous throttle body can “stretch” out the D shaped hole in the tps causing a loose fit on the already smaller nw shaft. Measure the shafts of the throttle bodies you have. Slide the tps on half way and see if you have slack.

 

[QUOTE=RonSSNova;20151700]

Obviously, this is news to me. At 6 or 8 hundred bucks a pop, I would've hoped this is not news to the tuners I've paid to fix my drivability issues.

The second tuner I went to (Tommy Wong - Wong's Performance - Vancouver) told me that, among several other things completely derelict about the first tune, it was "still running a truck tune".

Yes, the car is running Hooker Blackheart Long Tube headers and Hooker Blackheart true dual exhaust.

I'm not trying to cut anybody's throat, I'm just telling what my experience has been so that the issue can be best understood.

So, is it beyond reliable streetability?

Tuner blaming??? I'm simply explaining to everyone how I came to basically lose faith in the idea of taking it to one tuner after another (at 6 or 8 hundred bucks a pop), all of whom say that they can tune anything.

Look...the engine was built by NRE - Nutter Racing Engines - Vancouver. They did the engine tune, and the first tune with it in the car (This involved me towing the car from the Upper Olympic Peninsula, a four hour drive each way). It seemed like they did just enough to keep the car from stalling.

The second tune was done by TJ Wong - Wong's Performance. This, again, involved towing the car from my home down to Vancouver. He does all his tuning on the dyno. Frankly, he is hard to get a hold of by phone, and seemed less than enthusiastic about further tuning on my car.

Tired of having to drive four hours to Vancouver, I found Turbo Technologies in Tacoma (only a two hour drive). My first experience there was being told my car was ready and tuned perfectly. I was told that the previous tune (Wong's) was all outta whack. Upon picking up my car, it stalled in their parking lot...twice.

[Incidentally, I took Matt, their tuner, for a test drive to illustrate the types of conditions (other than parking lot driving) where the car would stall, during which the transmission blew up under hard acceleration (3-4 drum). This was due to the fact that the transmission builder, whom, to his credit, admitted to me, that when I brought him the donor 4L60E and said it was going behind a 550 HP engine, he assumed, I, like many in his experience, was having delusions of grandeur or had fallen victim to wishful thinking - and so pretty much did a stockish rebuild on the trans.]

Moving on, the trans was fixed, and the car was driven back to Turbo Technologies. Other than the fact that with their first tune, Matt/Turbo Technologies successfully tuned out the tendency to idle at high speed, there was no discernible change with their second tune, i.e. the car still has some low speed stalling tendencies. Matt told me that he didn't want to put any more time into the car unless it involved putting in a "smaller cam".

Honestly, I don't know why. I came to NRE based on good reputation and positive reviews, and asked them to do a performance build on a donor LS1. They informed me that that's not what they do, but that they could sell me one of several performance LS engines, with the donor LS1 as a $1400 core. And we were off and running. I was interested in a stroker LS1, and was sold on the better reliability and drivability of a non-stroker, brand new LS3. I went for the 550 HP engine package - essentially a stock LS3 with a cam kit. And, yes, it was billed as being highly streetable.

Personally, I would prefer a smoother idle, and would've always preferred a smoother idle, and of course, mellow street manors. I really couldn't have known what the characteristics were going to be until the engine was in the car and tuned.


I hope this helps. I definitely appreciate your feedback, Ron.

Dave.

 

For context, your cam has 10 degrees of overlap at 050, mine has 9, but your engine is also slightly larger (6.2L vs my 5.7L) which probably offsets the extra overlap.

I added some throttle follower to my tune and went for a drive tonight. Also tweaked the 0 RPM and 400 RPM columns of the idle timing tables based on ChopperDoc's example - I already had something kinda like that (increased increased to fight stall) but with ~38 degrees for both 0 and 400 RPM at low load. That might have been excessive.

After about 30 minutes of stoplight to stoplight plus randomly putting in the clutch at various RPM, idle was great, and I thought that follower change must have fixed the return-to-idle problem... The cam itself is definitely not the problem. Every single time I put the clutch in, RPM would drop to about 1200 (because throttle cracker?) and then settle to 850 when the car comes to a stop. I'm fine with that...

But on the way back home, I put the clutch in to coast down a hill, and the car almost died. I kept driving around for another half-hour up and down hills, but couldn't figure out how to reproduce that problem reliably. It did come back a couple times though. I have a (very weakly held) theory that putting the clutch in while in DFCO might be contributing to the problem, but when I tried to deliberately induce the problem that way, the problem usually wouldn't come back.

It almost always returns to idle just fine. But once in a while, RPM drops right past 1000, and every time that happens it's a sure sign that it's going to drop all the way to about 300-400 at which point the anti-stall stuff kicks in and tries to save it (and actually does save it about half the time). The only other repeatable aspect of this problem is that when it occurs, the engine continues to refuses to idle for a while, even after repeatedly stabbing the throttle to stop it from dying, or after holding it at 1500ish RPM for a couple seconds. When I release the gas pedal, RPM plummets again. I have to cruise around in gear for at least ten seconds before the car will idle properly again.

It's like there's some condition that's required for idle-control to kick in, and that condition is usually there, but not always. I have no idea what that condition could be, though.

In case it helps, my spark advance at 800 RPM is 19 degrees from 0 to 0.3 g/cyl, tapering to 3 degrees at .76 g/cyl and above. The underspeed/overspeed tables add or subtract 10 degrees for errors more than 100 RPM.

Base airflow is 16 g/s at 175F and above, ramping up as temperatures decrease. It's 26 g/s at 45F, which might be too high (I won't know for a couple months) and it's 60 g/s at -40F, which I'm pretty sure is way too high... If I remember right, I just scaled the entire stock table until the 175+ airflow was 16 g/s. I'll actually tune the colder cells when the weather allows me to.

Throttle cracker adds at most 0.5 g/s. For that table I just cut every value in the stock table that was over 0.5 down to 0.5. Except the 400 RPM column, which is 1.0 (to fight stall).

 

What is going on here? If they build you a motor AND tune it then it should've ran fine out the gate. Now other things will blow up like the trans and diff but we know that's not their problem. Why would you take it to someone else to tune? Now you just made them a loophole to jump right on through because now that someone else touched it, its not their problem. You should've made them make it right. Idk what this truck tune nonsense is, it sounds like you are being tossed around like a fool.

 

The P0121 code is very common with performance camshaft. Have your tuner set the P0121 Error Max table to 100 KPA, and the Min table set to 0 KPA. This will fix the P0121 code due to the higher Map KPA at low RPM with your cam.

Russ Kemp

 

Do like Russ K said. A lot of the Check Sums should have been disabled, with a setup like that.

I have also ran into issues like u state about the tps with the cheaper eBay tb's. Sometimes u can fix them, others its best to throw it in the trash and replace it with a better brand. In saying all this the Nick Williams is usually my go to tb. I prefer them over the fast tb, and the Holley tb is even better than both!

If u found a tuner tht knew what he was doing, im sure he can make tht cam work. Ive tuned some pretty aggressive cams without issues. It really all boils down to knowing what u are doing!

 

Take this for what its worth! I've seen big name shops do a worse job on tuning a car, than a local guy street tuning it! These shops usually only care about Dyno numbers at WOT.

Usually a big time shop with a dyno, want spend the time to dial in the cruising, idle areas etc.

By the way WOT tuning is way easier to tune than driveability etc.

 

i used to be stumped as to why people always had problems with tuners getting their **** to run right.

then I started tuning for money, and holy **** people like to throw some random **** together with a leaky hotside and all sorts of mismatched parts and then wonder why I cant do a full drivability tune for $300, on a sunday and they're calling on saturday night.

 

Lol no ****!

 

With respect Doug, That's not the situation here. Linson has paid good money all the way along, Bought the best parts, and followed what he believed to be the best advice.
If THREE different tuners cant get it right, You wonder what a guy is to do.
There's been a lot of noise in this thread, Perhaps we could move the meter back to more signal. I am in a position to assist the OP , and will, Then we will at least have a baseline of data to work with.

On a side note, I wonder why HP tuners (or others) hasn't come out with a full crack/hack of the stock ECU that gets rid of all the multiple tables BS, RAF , Adaptive, STIT, LTIT, LTFT , wacky IAT, G/cyl spark , Dynamic airflow, friction airflow, Airmass, Cracker, follower, huge injector data....etc etc......and replaced it with something simple like many aftermarket ecu's. Imagine all the junkyard ECU's that could become superman. Especially with repurposed I/O (emissions stuff become boost control) . The hardware is all there....the processor just needs a gender reassignment.

 

true, and I wasnt specifically referring to the OP I was just dogpiling and for that I apologize.

OP, wish you were closer