Need help with dyno results

[STAMPEDE3]

Last 2 times at the track my car was .5 slower and 3-4 mph lower in the traps. Put it on dyno today and found strange results. on three pulls, at different rpm's it just dropped power and torque? on the first pull it spiked back up twice. the air/fuel was consistent on the second and third,and not really bad on the first, just not as rich so I don't think it is fuel related. Seems almost like the computer is pulling timing or something. Any help would be appriciated.. Barry

 

[STAMPEDE3]

2nd sheet

 

[STAMPEDE3]

Come on guy's no one has seen this before or has any ideas?

 

[Booyah]

How old are your plugs and plug wires?

 

[Chris95SVT]

That is one messed up Dyno graph..

I don't even know where to start.

 

[SNK BITN]

Could be something wrong in the ignition. That happened to me when I had a dead coil pack that I didnt know about. I replaced it and now my graphs are smooth. Check the plugs, wires and coil packs.

 

[STAMPEDE3]

New plugs and Wires. Coil packs are one thing someone else said who was there. I just hate to start changing parts for nothing..I'll try the packs first I guess. Thanks guy's

 

[SNK BITN]

My buddy tested them for me and told me the passenger coil pack was dead, not sure how its done but have someone do that for you.

 

[Neurotoxin]

I'd like to add a couple of questions to your thread if you don't mind

What coil packs are available from the aftermarket?

Can you check plug wires with a multimeter? For impedance?

Thanks

 

[Booyah]

Originally posted by Neurotoxin
I'd like to add a couple of questions to your thread if you don't mind

What coil packs are available from the aftermarket?

Can you check plug wires with a multimeter? For impedance?

Thanks

Taylor and Screaming Demon make a set of aftermarket coil packs.

And yes you can use a "fluke" to check your plugwires.

 

[Neurotoxin]

Cool...thanks. What reading should I be looking for when checking the impedance?

 

[STAMPEDE3]

Originally posted by Neurotoxin
Cool...thanks. What reading should I be looking for when checking the impedance?

Ditto, and also, what kind of plugs are ya'll using, I went back to the OEM motorcraft double platinums, The previous owner went to autolite copper and I found it ran better with those.

 

[chknhwk]

Cool, good tech.
How do the Taylor and Screaming Demon coils compare performance wise to eachother and stock?

 

[Neurotoxin]

Originally posted by STAMPEDE3
Ditto, and also, what kind of plugs are ya'll using, I went back to the OEM motorcraft double platinums, The previous owner went to autolite copper and I found it ran better with those.

I'm using Autolite Copper.

 

[SNK BITN]

The differences in SD, Taylor and MSD coils are minimal. Performance Distributors claim you can open the gap on the plugs to accomodate the inccreased spark. I think mine are gapped to .065. I do feel it when I reach teh upper rpms though.

 

[Neurotoxin]

Originally posted by SNK BITN
The differences in SD, Taylor and MSD coils are minimal. Performance Distributors claim you can open the gap on the plugs to accomodate the inccreased spark. I think mine are gapped to .065. I do feel it when I reach teh upper rpms though.

I'm looking at those Screamin' Demon Coil Packs from Performance Ditributors and I'm wondering if you absolutely require their Livewires. I guess what I'm really asking is will stock wires hook up to the coil packs?

 

[chknhwk]

Thanks SNK BITN.
Another good question Mr. 'toxin. I may have to do this.