Time for a cam swap, opinions welcome

[go_go_gadget88]

Well, weather looks like it's going to hold out for me!

Touched base with my tuner this morning. We are shooting for starting around 9am tomorrow. Going to take it on a short run this afternoon, just put it through a couple easy paces before we hammer it on the dyno tomorrow. I will be posting up results once I have them.

I feel like a kid on christmas eve! It's been months since I've driven this thing. Ready to see what all this work has netted me! Probably gonna have trouble sleeping tonight.

[sixty9fordkiller]

excellent!

[zz430camaro]

Cool!

[Hixson]

Good luck Gadget. Been following the thread since I commented early on - nice to see the exciting part finally happening!

Quick update on my situation. I order the rest of the GPI cam kit this weekend to go along with the other storage until full of parts I have amased over the winter. Build weekend should take place in the back half of March. Very Very exciting stuff right before spring - yay for everyone that was bitten by the mod bug

[zz430camaro]

Originally Posted by go_go_gadget88

Well, weather looks like it's going to hold out for me!

Touched base with my tuner this morning. We are shooting for starting around 9am tomorrow. Going to take it on a short run this afternoon, just put it through a couple easy paces before we hammer it on the dyno tomorrow. I will be posting up results once I have them.

I feel like a kid on christmas eve! It's been months since I've driven this thing. Ready to see what all this work has netted me! Probably gonna have trouble sleeping tonight.

Is that thing on the rollers yet?

[go_go_gadget88]

Well, the results are in!

Not remotely close to what I was expecting, so that's kind of a letdown. But, seat of the pants says this thing runs great! Torque was actually higher than I'd have guessed. Driveability isn't bad. Some low rpm bucking but it's more mild than expected. Mostly just need to get used to taking off with more throttle.

What's weird is that the curve is so similar to the previous run. I was expecting a loss down low from heads/cam. And the fact it peaks at like 5600. It's like it has a smaller cam than it's supposed to be. Either that or something else is bottlenecking?

Only thing I can think of is that I am still running a stock cutback. I thought they were good to 500rwhp. Maybe it was just to 500fwhp? He said fueling looked good and injectors were at 66% max on duty cycle

Smoothing knocked it down a couple but best printed run is 453hp/455tq

[zz430camaro]

Something is seriously wrong, that torque curve is really screwed up. What, I dont know, I would contact Pat Guerra and get a remote tune from him and let him look at that tune file and dyno graph or Ted Jenettey Racing. Go straight to the masters!

Those rapid swings in torque and the fall off at 5500 is not normal.

[13SSCamaro]

something isnt right, you might have too short of pushrods and not getting full effect of cam, or something. There is something wrong somewhere

[go_go_gadget88]

Originally Posted by zz430camaro

Something is seriously wrong, that torque curve is really screwed up. What, I dont know, I would contact Pat Guerra and get a remote tune from him and let him look at that tune file and dyno graph or Ted Jenettey Racing. Go straight to the masters!

Those rapid swings in torque and the fall off at 5500 is not normal.

It's weird though that the stock tune did the same thing though. He put a lot of time into trying to dial it in just perfect, and was also surprised at the numbers. I really don't think there's an issue with the tune.

Originally Posted by 13SSCamaro

something isnt right, you might have too short of pushrods and not getting full effect of cam, or something. There is something wrong somewhere

It really seems like it, but I promise I spent way more time than was probably necessary measuring for these pushrods. I was really feeling like I was between 2 sizes on them, so I erred on the longer side. I agree something isnt right somewhere, but I don't think that's it.

I can say, now that I look, I can't really find much if any dynos of cars running heads and a sizeable cam that are still running the stock catback. Has anyone ever really tried? Or for sure know what the limits of it?

I just feel like something is choking it out. It'd have to be intake or exhaust I would think. And plenty of people make better power with the stock intake manifold.

[13SSCamaro]

cheap easy test, simply unhook the catback and run it on the dyno, i cant imagine the stock catback killing your top end that bad though but it is something to look into

[zz430camaro]

How is the low speed drivability? Is it bucking and surging really bad? Is it really low on torque down low? Did the tuner think that torque curve looked funny?

[go_go_gadget88]

Found this interesting post in an old thread while searching about the catback:

Originally Posted by Joe@CPR.com

We actually found this out on a members car infernometallicss. He has long tubes, cold air, our cam (big) milled heads, circle d stall and at the time of test that was it. He has the no weeds cutouts w/ stock cat-back including the middle resonator. So we dyno'd it cutouts open and closed and it made roughly 30 more rwhp with them open! Now on a bolt on only car i don't think it's going to be that much at all, but start really moving some air and it does become a restriction for sure!

So there may be something there? That's a good rwhp gain on an auto. Unsure if LS3 exhaust is that restrictive.


Low speed there is some bucking but it's a pretty narrow range. He's got it dialed in pretty damn good I think. We ran it on the street after the dyno so he could make sure it looked good there too. I don't think he thought the torque curve was funny because it did that before. But like me, he is surprised that the curves are so similar too. These should have drastically different power curves, yet it's not showing that. It's like the same curve shifted up some the entire powerband.

And how early it peaks. TSP has this cam peaking at like 6500. Mine is peaking at like 5600. Hearing it run on the dyno it sounds like it literally doesn't want to rev any further. And since he can look and see that the fuel side of things looks good, my only guess is that is got an air restriction. This is admittedly a long shot guess though.

[frankwjr]

Originally Posted by frankwjr

tks fer da kudos! as I have stated before I like to help(or at least point ya in the right direction) and a prob resolved is enough...

as for #'s..that is a new area on these motors..I have seen so many different results and the variables are astonishing....add to the fact that I believe the mustang dyno's show lower numbers(right?) than another dyno....

but...445/470 mustang....460/465...diff dyno...prob seriously off base and don't be pissed at my #'s...and lookin at your previous dyno run I think your valve springs where shot and she went in float at such a low rpm...that curve just doesn't look right...

good luck and no worries...it'll hold together just fine! peace.

Originally Posted by go_go_gadget88

Well, the results are in!

Not remotely close to what I was expecting, so that's kind of a letdown. But, seat of the pants says this thing runs great! Torque was actually higher than I'd have guessed. Driveability isn't bad. Some low rpm bucking but it's more mild than expected. Mostly just need to get used to taking off with more throttle.

What's weird is that the curve is so similar to the previous run. I was expecting a loss down low from heads/cam. And the fact it peaks at like 5600. It's like it has a smaller cam than it's supposed to be. Either that or something else is bottlenecking?

Only thing I can think of is that I am still running a stock cutback. I thought they were good to 500rwhp. Maybe it was just to 500fwhp? He said fueling looked good and injectors were at 66% max on duty cycle

Smoothing knocked it down a couple but best printed run is 453hp/455tq

damn my man I wish I hadn't called it so close...and no...I am no the amazing Kreskin either(GOT TO GET TO VEGAS!)..but I had based it upon the first dyno results..

so what do we know? first the same prob exits so what ever was done to the motor has nothin to do with it..2nd you have an CAI(filter clean..lulz) so air in has got to be good...3rd headers and cat deletes can't be any restriction...so the above suggestion about disconnecting the rest of the exhaust would be a quick(and loud) way to see if that's the prob...

if the clutch was slippin you would smell it...so get out in the morning and drop that exhaust soldier! peace...

[WHAMMO]

Something mechanical is wrong. Its peaking 1000rpm too early. Its not the catback, sorry. Its like 5hp stock muffler compared to NPP.

Install went wrong...like way off timing marks and wrong pushrods. Id go over it again, right after getting my tune checked by someone else.