Whazzup with the HP? (dyno sheet pic)

[DrumrBoy]

Interested in any ideas out there for rectifying this ugly ugly HP profile. I know I know, the TQ ain't nothin' to write home about 'neither but the HP flattens out so completely at about 3800 its amazing....never saw anything like it.

Have fussed with it for a while with modest improvement but no resolution.

The cam is supposed to be a 3/09-3119HR112 Comp Cam ......hydraulic roller with 112 degrees of lobe separation, 275/280 advertised duration, (220/224 @ 50) with 547/563 lift.

The valvesprings are Manley Comp 925's but I didn't install them so I can't vouch for their integrity.

Had lifters checked and replaced any suspect ones. Changed PCM's twice, curently running a stock DC unit. Added a VEC 1 to try and moderate the wacky A/F. Seems like it helps a little but I can still actually feel the thing stop pulling hard at 3800.

Pretty frustrated with it, ready to try ****** or C4 but figured I'd query y'all before doing anything rash....

Any ideas welcome. First time pic poster so if it doesn't show up I'll try to fix.

 

[DrumrBoy]

Re: Whazzup with the HP?

Vipermad, I checked your instructional message before I put this one together and seemed like I got it right. The image is uploaded (successfully) in the gallery. I can open it there just fine but when I copy and paste the URL, what happens (above) is not accessible. Can you tell me what I did wrong?

 

[KenH]

Re: Whazzup with the HP?

Here ya go.

 

[DrumrBoy]

Re: Whazzup with the HP?

Thanks Ken.

 

[KenH]

Re: Whazzup with the HP?

To post the pic, click on the 'image' UBB code below where you are entering your post and paste the link into the box that opens. That should do it for you.

Torque does go south pretty drastically on the upper end, big dip in HP and you have a heck of an A/F slope as well. What seems strange is that your power is going away just about the time that the A/F starts to get to a reasonable range.

 

[DrumrBoy]

Re: Whazzup with the HP?

Thanks again. Finally figured out how to get the pic in there.

I think the motor is possessed or under some kinda bad voodoo spell. Everything's normal when its way lean....

 

[GR8_ASP]

Re: Whazzup with the HP?

Kind of looks airflow related. Was the cam degreed, both in position versus the crank and intake to exhaust? Another thought would be a severe intake or exhaust restriction.

The f/a ratio is indicating the air flow is higher than expected at lower rpms and lower than expected at high rpms. That is why my first thought is can timing (******** or decreased overlap).

Not sure what other mods you have (especially those done at the same time).

 

[Russ M]

Re: Whazzup with the HP?

You brought a knife to a gun fight.

How can you do all those mods to that car and use a vec 1 to tune? Your problem is fuel/ignition control, get a vec 2 or better yet an AEM unit and watch those numbers sky rocket.

PLEASE dot it or your motor is going to go BOOM>

 

[Eric H]

Re: Whazzup with the HP?

your A/F is totally whacked, you start out REALLY lean, and then progressivly get rich, the highest point on the graph is where the A/F is where it should be @ 13-13.5 then it goes pig rich down to the 11's

This comb

 

[Eric H]

Re: Whazzup with the HP?

your A/F is totally whacked, you start out REALLY lean, and then progressivly get rich, the highest point on the graph is where the A/F is where it should be @ 13-13.5 then it goes pig rich down to the 11's

This combined with your lack of ******** timing is probably losing TONS of HP and you're going to wind up with a hole in a piston or 10

 

[J DAWG]

Re: Whazzup with the HP?

what are all your mods? I see you replaced the cam, but what else?

 

[Jack B]

Re: Whazzup with the HP?

Without knowing it looks like you have oem cats and no headers. Secondly, you are not that rich, 12.5 to 13.0 is where you want to end up at, so 12.0 is not going to kill you. A bit leaner at higher rpms is going to give you max hp. The lean mixture in the 3800 rpm area is killing the torque and maybe your engine. You are close to detonation at max torque.I would look at the plugs and see if you have any signs of detonation.

The VEC1 is not going to help you, you need the VEC2. The torque wouldn't drop off as badly if you could richen the mixture between 3000 and 4000.

 

[Schulmann]

Re: Whazzup with the HP?

DrumrBoy,

JackB is right. You need a VEC2 to fix these issues that you are having. You have a fuel and likely an ignition issue. You modified your engin but your didn't upgrade your fuel and ignition map. With a VEC2 you can fix them in a couple of minutes. In addition with the new Vec2 Logging feature you no longer need a dyno to test your car.

In the upper rpm I don't know what is going on but JackB's suggestion regarding your Cats seems to be a reasonable explanation.

 

[DrumrBoy]

Re: Whazzup with the HP?

Thanks to all for the analysis and suggestions. I'll start with a confirmation of cam degreeing and add a VEC 2.

The last time the heads were off there were no signs of detonation, lotsa carbon from being rich but no observed issues. I heed y'all's advise nonetheless!

Any opinions on VEC 2 vs. AEM would be appreciated.

The car has mildly ported heads, 1.7 rockers, John H's headers and airbox/tubes, no cats, no resonators, no mufflers. On the A/F, I think it may be lack of fuel down low rather than lack of air up high that's making it lean down low but will find out.

 

[Fast Freddy]

Interested in any ideas out there for rectifying this ugly ugly HP profile. I know I know, the TQ ain't nothin' to write home about 'neither but the HP flattens out so completely at about 3800 its amazing....never saw anything like it.

Have fussed with it for a while with modest improvement but no resolution.

The cam is supposed to be a 3/09-3119HR112 Comp Cam ......hydraulic roller with 112 degrees of lobe separation, 275/280 advertised duration, (220/224 @ 50) with 547/563 lift.

The valvesprings are Manley Comp 925's but I didn't install them so I can't vouch for their integrity.

Had lifters checked and replaced any suspect ones. Changed PCM's twice, curently running a stock DC unit. Added a VEC 1 to try and moderate the wacky A/F. Seems like it helps a little but I can still actually feel the thing stop pulling hard at 3800.

Pretty frustrated with it, ready to try ****** or C4 but figured I'd query y'all before doing anything rash....

Any ideas welcome. First time pic poster so if it doesn't show up I'll try to fix.

the problem here is with the camshaft. this camshaft has less duration than a stock camshaft. as a result your engine will not make peak hp in the upper rpm's of the rev range of the motor. the lift is virtually identical to stock as well, so there is nothing to be gained there. the only power enhancing quality that this cam has going for it is its 112 LSA. but this is the least important of the 3 components when it comes to making power. in fact with modern cam technology a 112 LSA is not even necessary to make power on the street. all it does is just make it harder to pass emissions. whoever designed this cam needs to be ***** slapped.

 

[PhilC]

Knowing the piece of sh*t that did the work on the motor, you can not assume anything was done correctly (hell they only put half the lifters in the right way and they only got that many because they had a 50/50 shot at getting it right)

I think you are on the correct path in following the advise posted here (VEC2 and/or cam) but just to throw another idea out there, could something as simple as valve springs cause this behavior? I certainly dont know enough to suggest that is in fact the problem, but maybe some of the experts here could chime in. I would bet that when that jag did the work on the heads, he didn't bother changing the springs which I'm guessing would do some weird things if they were "tired" enough.