Contour Enthusiasts Group Archives Forums General Dyno and Drag Reburn coming up: tips and prep

I'm heading back to Street Flight in June for a reburn. I've been getting Rich CEL codes. Chris and I have discussed a few ideas, and I've probed many CEGers for ideas too. Thanks to all!

Here are the old plots:
Dyno plot

1) Is it normal for the A/F to fluctuate like it did? (Runs 24 & 27 did have slightly different tunings.)

Chris checked the O2s w/ an OBD-II scanner, and he said they seemed to be working properly.

2) Otherwise, do the A/F curves look about right for optimal power?

I'm prepping for a reburn, so I want everything to be in top working order. UIM/LIM gets cleaned tomorrow, along w/ (hopefully) some butterfly optimization.

With an optimized TB and optimized butterflies, I'm hoping to actually see 180+ . Wish me luck.

Have you picked a date yet? I'm looking forward to solving this.

That fluttering is unusual and could be from fluctuating fuel pressure maybe??

I would tune leaner than 12.5:1 for an N/A SVT, Try shooting for about 13:1 to 13.25:1 then richen up a little bit about 6500+ , say back down to about 12.75:1

You can gain several Ft-lbs of torque in the midrange, perhaps enough to throw you solidly into the 180's HP range.
Richening up above 6500 is based upon my personal experience with my car since I tuned mine to 13.5:1 . It would ping just a little if it was really hot right about 6500rpm. So I just added a tad fuel to bring it back down to about 13:1 right there.
It worked great and gave minimum 6HP gain on my 3L. That's probably worth 3-4 on a 2.5L.

Remember, this is just my experience and may or may not be accurate for you. I do know that SVT's that make good power safely run A/F in the low 13's. I've got probably 30 dyno scans supporting this.

Tom

Derk- I thought we would read your computer, being as you said it has 'a high altitude' package, check the base tables and aim for those. I think that the EEC really knows what it wants. We can check the LFT's to make sure we are kosher.

Tom - Thanks for the tips. You da man.

Chris - what do you think of Tom's ideas? Looks like I start loosing TQ right at 5500 where the A/F changes.

Originally posted by Keyser:

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Derk- I thought we would read your computer, being as you said it has 'a high altitude' package, check the base tables and aim for those. I think that the EEC really knows what it wants. We can check the LFT's to make sure we are kosher.

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What are LFTs? Otherwise, it sounds like a great idea. I'll bring my ProM spec sheet in, too. That should help. You da man, too, Chris.

Just wondering do you still have the stock rubber belows or a pipe?

I currently have the rubber tubing, but a heat reflecting coated intake pipe is on the way.

Hey I was wondering, whats a 179hp contour run in the quarter.

I've never been to the track (I fear the differential Gods).
But (I'm guessing here) w/ my launching skills I'd probably run a high 14 or a low 15. I don't practice that stuff too often. But, I bet a better launcher could pull a low 14.