Here is my dyno sheet of my truck from saturday. The numbers may seem low, but I am working on that. The A/F meter wasn't hooked up so I didn't get that reading. I am trying to figure out what happened at around 5300rpms where I get a bad drop in power. Any ideas? I will be hooking up a fuel guage this weekend and taking it out to see what happens. I figured I would post the pic to get some feedback from you guys on here.

 

no offense but that is WAY low for you set up

 

Did you have a recordable scan tool recording during the pulls?
I bet either you got some knock at 5300 and it pulled some timing then put it back in at 5500, or the opti started to miss...but that would not recover I would not think like that. Fuel I bet is ok as that would not recover at all with higher rpms past 5300.

Take a look at your timing tables and see if the timing goes up some in the table at 5200-5500 at 95-100KPA MAP readings.

 

your missing like 80-100hp lol make sure you have it tuned and fireing properly on all cylinders.

 

I agree with 2QUIK on that route to verify things,

People put too much into Dyno Numbers, not all dynos are setup the same, also there are plenty of addable variables to dynos to adjust for drivetrain loss etc. your looking in the right direction on trying to find the reason for the blip in your graph,

 

The 9.2 comp is not helping any?

 

before you get too worried about the #s, try to figure out whats happening at 5300, then if you figure that out get it to a trck and see what trap speed you put down. any possibility of the clutch slipping? have you verified with your eyes that the throttle blade is opening 100% with the pedal inside the car?

 

Interesting...Your numbers are definetly low for an M6 with those mods. Check the MAP readings thought the dyno run. I had a dyno graph that looks eerily similar(albiet 20+ more rwhp through stalled auto). It had a bad dip right at around 5300 rpm which killed my peak numbers, and it only made like 334 to the wheels. It wasnt pulling timing and everything looked fine, but with the Tech2 my tuner noticed that the MAP value dropped from 4.0 waaay down to like .9 right when the dip started, and went back up right when the dip started to rise again. The dip was right where my peak should have been, which really killed my numbers. The MAP was the only sensor that changed in the same spot the dip started. One ~40 dollar MAP sensor later and it was fine. A retune got me another ~15 to the wheels over the bad MAP dyno tune! May not be as big a gain for you, since my LT1 is speeddensity accurate MAP readings are very important!

Sensors are not always "work or dont work", they can have inacurate values or wierd quirks.

I have my screwy 5.3k dip dyno if you would like to compare. Mine dips at almost exactly the same spot, bumps for a second in the middle, then comes starts to back up around 5500 or so IIRC.

**EDIT** Whoaaa, just noticed from the post above that your compression ratio is only 9.2!!! You want it much higher for N/A power! That is a big reason why your numbers N/A are low. Throw that D-1SC on that thing!

 

yeah 9.2 is really low. GREAT though for the D1sc which Im sure is why you did it. it'll be fine for now to drive it around like that, just not ideal as youve found out. but it wouldnt make 100HP difference. forgot what the rule of thumb is, but its not THAT much at all.

chris

 

Perhaps start pointing fingers at ignition or valvetrain. Probably would be a real good idea to find out what your A/F is doing.

 

Thanks for the quick input everyone. I have a lot of work to do. I lowered compression just because I had to bore it, and I knew it would be supercharged as soon as my budget permitted. I have the twin intercooled D-1SC kit ready and willing, I just have to finish making a bracket to mount the head unit up higher since the f-body bracket puts the head unit into my frame and steering box. Then all I need is injectors and upgraded fuel pump, but I want all of the problems fixed first. That is why I posted here. Thanks again everyone.

I am trying to get the guys at the dyno to get me on again in a couple of weeks, and only if we can get the A/F ratio meter hooked up. Talking to you guys, and Bryan at PCMForless and I am getting some good input. I will look into the MAP sensor as I have another one on a motor here in the shop to use if needed. I don't really have any hook up with any good scan tools, but I am working on that.

Next I am going to rebuild the Opti as I do believe it has never been changed in its life of about 100,000 miles now. And if I can get on a scan tool I will try and see what the timing is doing and go from there.

I am not too worried about the numbers, though they are a little disappointing, but the dying off a 5300 is what I was looking to work on. And I really wanted to get a graph with the A/F ratio to get to Bryan so he could look at it, but that will hopefully come soon as well. If I get all the problems fixed, maybe the numbers will increase quite a bit as well. Thanks again everyone, and keep the good advice coming.

 

Yes it does look low for your mods. Here is my dyno sheet with Hot Cam Le1 Heads and Lt's.

http://img.photobucket.com/albums/v6...no04-07011.jpg