Hi Guys,


just rebuilt my engine after the wiggle test, my car is a 2006 with around 70,000 kms on engine.


We dynod the car stock with a custom tune and a K&N Intake and the car made 469 WHP on a mustang dyno which was very happy with, peak power was also up high into the 6500k ish region.


we replaced the cam with a comp custom cam ( 279/297 Dur .050 227 / 243 632.627 lobe 116). Also put ARH headers, new valves, bronze guides , double spring kit lingenfelter and replaced most of the parts like push rods etc to ensure its a strong build with reliablilty.


we dynod the car and power has to increased 498 WHP - we now have 50 WHP more at 5500 RPM than before however it drops off here and goes down to around 460 ish which seems strange to me and I am looking for some advice if the cam isn't correct with the cars character I used to love those long gears up to the red line in stock form but now its pointless having that extra 1500 RPM.


any advice ??


cheers


Matt

 

You will lose some TQ with a cam with a slight more duration on the intake side and raise the TQ RPM band level up also. Have you put any thought of any intake mods.. or aftermarket replacements. Also you did state that you had head work done... Remember stock LS7 heads are great with a cam but have its limits. The cam looks OK by numbers but: Getting the Guru's such as The TOP 5 or a LS builder is Key when trying to get the maximum out of a cam SWAP. You do pick up 50 btw which seems to be on par. Porting the heads Should result in you being over 515rwhp and over 525 with intake. Does this sound Better.

Oh I see that you are saying that you are not able to extend RPM further with a larger cam.
Power sound right but wrong RPM. Sounds like A Cam GURU ? But sounds like the cam is out of sequence with the RPM it needs to be @. With a 116 lobe power would normally result in power coming on further and having good idle characteristics. Top of my head would be Cam TIMING events are in the wrong spot.....Cam needs a RE in Stall. That particular engine Needs to be AROUND 6600 to 6900 for peak Hp.
NOT 5500 rpms.

 

We just did the GT21 LPE cam on the spintron the other week. With PAC-1209X and stock pushrods we were stable to 8500 rpm.

 

thanks for the response guys


No head work done just stock heads , with a K&N intake.


my issue isn't so much the lack of power made, its more that it is dropping off at 5500 RPM and this doesn't in my opinion work well on the car, I loved the last factory set up where it pulls all the way up the rev to 7k.


Just been talking to BTR about a Stage 3 cam and springs which has a higher lift and lower lobe of 113


Maybe my cam spec isn't ideal for what I wanted achieve ??




I think the custom set up my guy ordered just doesn't suit what I want out of the car.

 

what kind of numbers did it put down and where was the peak power??

 

exactly - I have thought about a 102 intake and TB and if this solves the issue then I would buy it but I am not convinced it will to be honest.

 

Give a few CAM (My TOP 5) people a call as you really don't need a NEW cam just POWER @ a HIGHER RPM LEVEL...

 

Cam sounds Like it is not installed correctly as the HP is There JUST not @ the correct RPM.

 

From DanZ28 in 2006: Stock Zo6 cam

That cam was cam doctored at 210.5/231.1 .594/.588 and looks like the LSA is 120

Thats pretty dam close to the advertised specs of 211/230 .593/.588




Your cam specs are: You've moved the RPM up with a larger cam So: Somethings not right I'm willing to bet that U need a cam re-install.

Dur .050 227 / 243 632.627 lobe 116)





Also WHY in the F*%K did you get rid of the valves ....I could Re-size them and use them(aka My heads are still off waiting for springs to be put on 2 LAZY from working & 2 much work around the house it's *Spring time.)

Good Titanium valves gone done the drain BTW.

 

Not a dyno, so don't know numbers, this is just a tool to track valves to make sure they are under control on the lobe and closing. Was with stock LS7 Delwest valves too.

 

Ok so by the sounds of it the cam needs to be reinstalled then check it again on dyno to see how numbers match up.



I'll check with my builder guy




Thx a lot for your input

 

My guy said he wants to pull timing after 5500 see how it responds, does that sound right ? He said cam is defiantly installed 100 percent correctly

 

What springs exactly did you use? What are your pushrod specs?
Did you replace the Ti intake valves with solid stainless?

I bet you're experiencing valve train instability

 

Yuck. Just the thought of a stainless ls7 intake valve with ls7 lifters makes me cringe.

 

Well the valves are gone by now so...let's try to figure this out I maybe right I may be wrong. But here are the facts: he made more power around 50 giver or take. Now valve train instability issues usually happen @ a higher RPM(past 6000 grand). Now he's making power right around what we would guess 500rwhp is acceptable. Now lets say he has valve train problems from 5500 to a LS7 peak of 6900. The valves maybe too heavy but I would think it could hold up past 6000 rpms and not die after 5500.. Maybe not. Also correct springs, push-rods etc... all come into play.

I Have no experience on working LS computer timimg: I got FASTLANE right up the block. I do know how to work a OLD distrubutor and this is my best break down on engine timiming: An engine with timing too late (retarded) will have a low idle vacuum, have slow throttle response, feel like a turd at low RPMs and will run hotter than normal. An engine with the timing too soon (advanced) will have a high and erratic vacuum signal. It might have a snappy throttle response but it won't pull very well under a load, and it will have pre-ignition (detonation) problems, sometimes called "pinging". It will also idle rough, like it has a bigger cam than it actually does.

Also, that's a lot of pulling to go from 5500 to 6800. As stated get with the guy's like Tick Performance, Cam Motion or Pat G. They will lead you in the right direction.


Your close you just need the RPM band moved up. It's more than likely 1 or both of these areas that's the problem. The guys listed will be able to give you tips 2 help move the RPM band up to your desired 7000 rpm, possibly with out purchasing a new cam.

 

Don't feel bad I bought the wrong springs my self...Martin wanted 625 -650 open spring pressure. Luckily I don't drive the car too much and nothing was broken. Didn't go back & read thru my emails when I purchased them.

 

My springs are the lingenfelter lsx double valve spring kits.

http://www.lingenfelter.com/mm5/merc...gory_Code=C159

 

I'll also get the spec of the valves let's see if there incorrect we still have the old stuff So can put it back in if Required

 

I'm going to bed on this 1...To much smoking/drinking and eating(Lamb gyros with rice and Hammus with flat bread) 4 the Rockets.We did win!!!(Not a Muslim BTW..but Christian).


Try weighing the old valves VS the new ones...$$$$$$ spent in the wrong place.

As stated get with my buddy Mars @ Tick...He'll figure it out as the the only true problem is getting the RPM point up from 5500 to 6700- 7000. Google the number and call.

Tell him: Lil John aka / Andre/ Paco/ or LSX RACING- 2 the XBOX community 1# Drag Club *Scorpions* on Forza 4 ...Forza5 drag sucks on Xbox1

 

My thoughts exactly. A stock cam pulls to 6500rpm in a LS7.

An aftermarket cam even with "horrible" or "un-optimal" valve events will still pull to the same RPM.

It's either a lifter issue or a valve spring issue. Or a valve spring issue allowing a lifter issue to occur. Such as lifter pump up from valve train instability related to spring or push rods.