I had previously dynoed on a Mustang dyno and made 331hp on my old tune. Sent the chip back to Alvin for some touching up and the tune is now dead on. Since nobody seems to use Mustang dynos it makes it difficult to compare results, so I found a DynoJet this time. So when I went today to finally dyno on a DynoJet I was expecting 370ish. To my surprise the best I was able to get was 350. This is cam only territory, so I need to figure out where the power is hiding. It was breaking apart up top which I realize is not good, but it stayed together until 5600, so I don't think reving an additional 400rpms will yield 20+ horsepower. Any thoughts on whats holding me back? I'm thinking 1 5/8 mids and the stock cat is the problem. Any thoughts?

 

Did you say stock cat on 1 5/8 pacesetters?! Ya i'd say thats where the power is!

 

I think the 1-5/8 header and the cat ar contributing to your problem some, however somthing else must be going on too. Better be calling Lloyd cause those numbers are not impressive for the LE1 package.

Do you have a graph that shows RPM rather than MPH?
How do you know the tune is dead on? You cant get dead on without a real dyno tune, mail order wont do it.

 

Keep in mind these are LE2 heads also, which worries me more about seeing only 350hp.

I'm not entirely sure what all is entailed in a tune, but the A/F looks great and the timing is on the verge of detonation with the crappy 91 we have in CA, so 34 degrees is the most timing I can get away with. Not really sure what else could influence power in a tune.

 

I hope you figure it out soon, I sent my heads to Lloyd today to be ported to LE2 specs and to be used with the LE1 HL cam.

Why did you not get the LE1 HL cam with those LE2 heads? Lloyd claims higher torque of the regular cam while not raising the shift points.

I would definitely get better headers; at the least some AS&M mids or any LT's.

 

Not being uable to run up past 5600 rpm is hurting your HP number. I think the LE1 cam peaks higher than 5600 rpm with LE2 heads. It won't help your TQ any, but your HP should have looked a lot better.

I seriously doubt it's the headers, but the cat is holding you back for sure. Are running through a single cat?

Also, there is something else wrong if you are breaking up in the higher RPMs.

Your A/F is still pretty wacky too. When did you actually go WOT? It's hard to tell from the chart.

Dan

 

Its my understanding that the LE1 cam reaches peak HP at 6200 and should be shifted at 6300 RPM.

 

The cat might be more of a problem then ya'll are leading on. He said it was a stocker, It might be clogged? At the higher rpm's it could be choking out the motor?? Get some long tubes and a off road y pipe... Or duals with bullets, I bet you will see your 20+ hp.
Regardless you have a great H/C package and I wish you good luck on working out the bugs. Be patient, and it will pay off.
Steve

 

Seems to be a common issue with 50% of the heads/cam installs.
(Lloyd and otherwise) Whatever is causing the issue is there somewhere.
Hopefully Lloyd will have ideas for you. The good news is that since you
have an M6, it's not the stall causing the problem

 

The cat is the factory single cat and has 120k miles on it. I can put a pipe in place of the cat this week to test it out.

Its difficult to see on the scan I made, but the A/F on the first and last runs are pretty good. I think he wasn't floored at first on the second run which explains the A/F looking weird at first. Once its to the floor it stays at 13:1 or slightly above, which I'm told is ideal.

 

Lloyd or Bret, where does this cam peak?

 

Get rid of that cat!

 

Bret made it sound to me, like it should peak at right around 6,000 and should be shifted at around 6300ish. A LE1 HL can spin a little higher, but donest need to. It just helps keep it in a better powerband.

 

That's about right, my LE1HL peaked at 6300. (TQ peaked at 5000)

 

James,
Did you get the LE1 HL cam dyno numbers yet?