Time for a cam swap, opinions welcome

[frankwjr]

look at the dyno graph overlays...identical curves...

[zz430camaro]

Was the first lower graph tuned by the same guy? Like after you had headers installed or something?

I don't know that it is peaking early, I think it is falling off early.

So the fuel looked good, what about the timing?

Seeing how similar the two curves are leads me to think that it is not a problem with the internal engine work that was just done. It would be interesting to see the data log of the throttle position, A/F ratio and timing during a pull.

[go_go_gadget88]

No, the first graph is the factory tune with the longtubes and the CAI. It was just a dyno pull, no tuning involved.

I believe timing is fine too. After fuel was lined up he started adding timing in. Before that the peak number was like 411. So timing brought it up quite a bit, but after that is when we we quit gaining anything.

I would concur maybe it's not peaking early so much as falling off. That's the only reason I think I'm being mechanically limited. Dyno makes it look like it's choking out on the big end.

I have known my tuner since we were all in highschool, and have seen what he has done with many other rides. I have faith that he gave me his best effort from that side of things. And like I said, while low on power number wise, the car is driving fantastic! Just not as stout as i' d have guessed.


We joked about pulling exhaust while he was tuning on dyno. Maybe we should have

[go_go_gadget88]

I spoke with him about tuning though when it was just headers. He was pretty sure we could pull 20rwhp from it as it was. So, in theory, if He could have gotten it to 405rwhp with LTs, cai, and tune..then the actual cam/heads swap only gained like 48hp...that doesn't seem right to me

[frankwjr]

drop the exhaust yet my man?

[go_go_gadget88]

No? I don't own a dyno so that isn't gonna tell me anything right now lol.

It's seemingly running fine so I'm not in a dire need. They are doing a dyno night for the local cruise night the first weekend of may. I'll get some better exhaust on there before then and we'll see if that helps it any.

I will also note, his weather station isn't working right so he had the correction just set to 1.00 that was about right for that point in the day. But I feel like it had crept up some as the day wore on, so that may be adding to the low number problem if it needed a different correction factor. Wouldn't be a huge amount, but it is a factor to note

[zz430camaro]

That drop off in torque at 5500 has nothing to do with weather correction. You might want to post this dyno chart and build in the tuning section to see if anyone there has come across readings like this.

[zz430camaro]

Could this be a dyno issue? Have you looked at any other graphs off of this dyno from a 5th gen camaro? Just a thought.

[frankwjr]

'yo another thing..what plug and plug wires are you runnin? I have been doin sum research and an issue that came up was plug wires...

the fact that the dyno graphs are so freakin close AFTER all this work means the problem existed before the upgrades...which items did you happen to reuse?

with your combo the hp should be climbin all the way to at least 6750..more likely 7k...with a gradual but not to abrupt drop after that..

when the heads where done, did they incl the spec sheet showing the spring installed heights and what the spec is? I am goin to give you a really wacky posit...one of the consistent variables are the heads themselves..correct? So, even with all the CNC work and the .005 flat whack, nothin else was done to the heads, so far so good? So what if the valve spring pockets on these heads for some weird reason were just a wee bit too deep? why dos this matter? by now we all SHOULD know that valve springs are designed to operate at a specific height based on the cam lobe lift.

So if the above is possibly true, then even when you had the stock setup the spring height was wrong. There for at the higher rpm your car is goin in to premature float( better than the other premature..heh?). So now even with the new springs if the installed height is off, you end up with the same prob but as the dyno proves the newer springs keep it going a tad bit higher.

So like I said...wacky...but I can only remember thinkin when I first saw the original dyno run how it looked like valve float.

So here you are my man...2 items to consider and the second would of course require poppin a valve cover and measurin.

Now to cover my a$$ I will say that this is all HYPOTHETICAL and am not suggesting TSP didn't due their due diligence...but at this time of year they are SLAMMED...and I bet if you ask and because it would such a rare occurrence that they prob don't check unless something looks way off...I mean we are talkin very small measurements and the mark one eyeball sometimes isn't enough..

whew..that is gonna be my last cup of joe for the morin....good luck!

[sixty9fordkiller]

did you use your old lifters or did you use new ones?

[13SSCamaro]

I agree with the others when they mentioned it matches the before dyno so the problem appears to be there before the install. If it were me, first thing I would do is send all the info and dyno to TSP, they are awesome and extremely smart with their LS stuff, they will most likely guide you in the right direction. Then I would see what difference is made with an upgraded cat back exhaust. If it is still there, then look into an issue with the valvetrain. Look at my dyno vs yours, your power is dropping like crazy. After 5,500 is where the real fun begins with the TSP stage 3 cam.

[go_go_gadget88]

I put new stock lifters/buckets in it. Plug wires are one of the reused items. Put new ngk plugs in it

Yeah I will shoot TSP an email tomorrow and gather their thoughts. My gut says I didn't do something right. Just dunno what yet.

Someone mentioned it earlier, about is cam off a tooth. Would it even run like that? Let alone very well.

It's certainly something to think about and could account for the curve being nothing like expected. Go figure, I dug thru pics of the build and never took one of me lining up the dots on crank and cam gear. So, I don't have a photo to ease my mind there.

[zz430camaro]

I have to give you credit for keeping so cool.

[Bretts]

good luck with this just read it fully and is full of good info, and now wonder why my upgrade kit for trunnions on a btr3 cam going in are not the bushing style hmm