Texas Speed Stage 3 VVT Camshaft C7 GS does not make power before 4600 rpm

Guys,

I need the help of the experienced tuners here...

What the car has :

- ARH long tube headers
-MSD Intake manifold
-Katech ported TB
- AFE Cold air intake
- VVT3 Camshaft / PRC dual springs/C5R timing chain/Phase lockout/Chromoly pushrods/Trunion upgrade kit etc

Dyno : Mustang dynamometer

Final numbers :

508 WHP at 6750 rpm
424 WFT/Lbs at 5200 rpm

So this is a Mustang dyno, we could fairly assume a dynojet would have read significantly higher (530-540WHP and at least 450-460 WLbs)

Power is not really the issue. Mid range is.

See the dyno results compared to FBO 455WHP/420 ZFt/Lbs on exactly the same dyno. Basically I loose a lot below 4600 rpm and only start to make more above 5200 rpm. Then the difference is big no question. But this is far from satisfying me.


Attachment 97133

This weakness down low concerns me. You can see the difference of torque already at 3300 rpm, but then the torque drops even lower at 3800 rpm !!

I see my cylinder airmass decreasing in this area FYI I'm at 0.72g at 3300 rpm and it drops at 0.69g at 3800 rpm (2700Ft elevation where the dyno is). This does not make sense as the with more rpm my airmass should increase (the MAF value increase) . Also no torque management intervention on the logs, no throttle blade closing...

I tried adding or removing timing... Adding timing does not change a lot past 25 deg. Removing 10 deg makes me lose a ton more.

I tried SOI 10 then 15 deg before no change. I tried 10 deg after no change. Always this damn weakness and this drop.

I'm lost. Dynos I see for this cam don't show that. I think all of the one I saw were on Dynojets, but even if they read higher, they don't show this drop and as much torque difference between min and max.

I really need your help, this afternoon cost me $490 in dyno rental :( and I did not make a lot of progress...

Here are my tune and log also

Attachment 97134

Attachment 97135

Thanks

Alex

So I compared our airmasses from a log I just took. I have a TSP 228/236 111-ICL 114-LSA .635/.635in with PRC ported heads, ported stock intake, ported stock TB, and Rotofab CAI.
So yes it looks like your airflow is down its about 45 F here and my Air Density Torque Multiplier was 1.0703 (I am not sure if this multiplier actually means anything useful but I am assuming it is a way to sum up how the ambient conditions, someone correct me if I am wrong):

Attachment 97155

But first thing I see you didn't log cam position, I know you probably have a zero degree limiter, but if not I think you need to check that to make sure the cam isnt moving first.

I'm at 2700 FT, this will play for the cylinder airmass...strange to see your cylinder airmass decreasing at you build rpm?

I have a 0deg lockout kit yes? Do you with yours ?

My camshaft is the 235/239 116LSA 112ICL

And yes I did not log my cam position because everything is disabled for the VCT in my program. Everything a 0.

Texas speed is saying it could be a fueling issue. Looking at the log the fueling looks good and comparable with stock.

Then they say my cam could have been installed retarted or advanced...I really doubt it because I checked and double checked my timing...Could I have messed up the cam phaser lockout ? I looked again online and I'm sure not..

I did not degree my cam, perhaps I should have, who tells me TSP sent me the right cam....I have the feeling this will be a long process...

Sorry, I've still only worked with my stock camaro so I'm not sure about the correct changes for a cam, but I'm wondering why you're running so rich? From everything I've seen, these motors are safe and make power up to .9 lambda, and you're targeting .833. I don't even think LT4 guys run that rich

It was a trial to see if the car was making more power. Ho My usual target is 0.87. 0.84 or 0.87 does not change power from what I saw

FYI I'm tearing the engine appart to see if I missed something. I'm gonna degree my cam also to see if it has the advertised specs

Mine has a lockout too, it is possible to put the block thing in backwards, I'm not sure if that will let it move more though.

Like I put in my other topic : I teared the engine appart and replaced the cam phaser just to be sure. still the same. I think my torque issue down low comes to the fact that I still have OEM heads. TSP advertises the whole package with heads. Need to buy the TSP 360 CFM ported heads. This is the only thing I see

You would certainly expect to lose torque at low rpm by removing VVT and installing a rather large cam. However, I would have thought it would have equal or better by 4K rpm or so. I would recommend checking the ICL and see where it is. I wouldn't be surprised to see it be retarded a few degrees.

The cam came with the card test from TSP. TSP degree all their cam before shipping them...

Where is the cam set for intake centerline?

Log tq management spark!! Does it show anything in the problem areas?

Quote:

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Originally Posted by Sachs

The cam came with the card test from TSP. TSP degree all their cam before shipping them...

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It doesn't work that way. They may have the dowel pin in the correct spot, but that doesn't mean that the timing set is correct or that the lower cam gear is perfectly dialed in. It also doesn't mean that the lockout kit puts the cam in the perfect spot. That's all incumbent upon the installer.

They is only one spot to put the 0 deg lockout. Timing of lower sprocket relative to cam phaser has been checked and rechecked 10x times. Moreover 1 tooth off makes a huge difference in alignment

Nothing....

Quote:

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Originally Posted by Ben Charles

Log tq management spark!! Does it show anything in the problem areas?

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Nope. Look at my log. Torque management spark at 0 ...

Quote:

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Originally Posted by Sachs

They is only one spot to put the 0 deg lockout. Timing of lower sprocket relative to cam phaser has been checked and rechecked 10x times. Moreover 1 tooth off makes a huge difference in alignment

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I understand that. The only way to know for sure where your Cam IC is located is to put a degree wheel on it. That is the only way. Yours may be retarded a few degrees.

Texas Speed designed that cam for VVT applications. They give you the option of either using a phaser limiter kit or a lockout kit. If you use their limiter kit, they supply a good base VVT table. You'll definitely make more low-end and mid-range torque with the VVT option.

O.P. you locked out a VVT spec cam? If so, I also suggest you take the lock out and use their phase limiter and use their vvt table specs.

Quote:

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Originally Posted by kevin87turbot

I understand that. The only way to know for sure where your Cam IC is located is to put a degree wheel on it. That is the only way. Yours may be retarded a few degrees.

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I agree with this. It's worth trying before spending the money on ported heads to try and resolve the issue. Even if it spec'd out correctly, you could try an offset cam sprocket to advance the cam a degree or two (assuming you have good piston to valve clearance) and see if that shifts the power more to your liking.

Good luck. I'm curious to see how this goes.

The first thing i notice in log, is the fuel you are commanding vs what you are achieving. I didnt look at the tune, but i am going to assume you have a ton of fuel in the pe table, to compensate for a lack of fueling in the airflow tables. It looks like your maf is way off, as well as vve. Honestly until that is corrected, its not going to be happy, and it will limit torque output, as it clearly is. The log clearly shows 3, 4, even 5 degrees being pulled