Well, I got a dyno today to check out the latest Predator tune I got after putting on the KB. It was about 82-86 degrees outside today in sunny San Ramon, CA.

The results are as follows:
1. 416.9/492.9 w/ 3.5 upper pulley and 6lb lower (14-14.5 psi)
2. 405.2/477.1 w/ 3.5 upper pulley and 6lb lower (14-14.5 psi)
3. 409.8/503.3 w/ 3.25 upper pulley and 6lb lower (16 psi)
4. 276.8/440.7 w/ 3.25 upper pulley and 6lb lower (16 psi)

As you'll see on the dyno sheets I'm posting, I was extremely pig rich as the A/F went off the charts in past the 10:1 zone. Large puffs of black smoke came out the tail as the engine raced to 5300-5800 rpm. Hence we tried a smaller upper pulley to see if it would respond to more boost and make the A/F leaner.

On the 4th and final run, something happened. The engine started missing. The idle now is very choppy and is popping at idle. At mid-throttle, the engine seriously misses and bucks as I put my foot in on it.

I'm thinking I fried the plugs.
I'm hoping I just fried the plugs.
What do you think?


(Here's the short list of my mods:
JLP CAI box
Accufab Throttle Body
Extrude Honed upper intake
KB with a 3.5 and 3.25 pulley
JLP 6lb lower pulley
Denso Iridium IT-22 plugs gapped at .35 or .36
Bassani Catback Exhaust )

I was thinking of running the NGK BR7 plugs instead.
Sal's flying out to the Bay Area in three weeks to tune the truck for a dyno day.

Without further delay, here are the pics:

 

Sure looks like a dead plug to me. You can see it's missing badly on the last run, because of how much leaner the A/F gets. I'd check them all and see how they look.

 

Thanks for the quick reply Sal...
Placing an order right now for new plugs.

 

Why not pull a few out and check before you order?

 

Well, if I'm going to pull plugs, I'm going to put new ones in just because I won't go through the trouble for nothing... also for $20 its not like I won't need them eventually... plus, its my daily driver, so I'd rather have them on hand in the event I have to swap something out.

 

Thats good enough for me!

 

I agree with the others. Doesn't look like anything is seriously "hurt", and probably a bad plug or two.

Also looks like the MAF voltage is pegging in the upper rpms.

Once Sal gets his hands on it, I predict over 450rwhp with that mod list, especially if you stay at 16psi. It's obviously in a poor state of tune now with it running so darn rich.

Good luck.

 

Whats Up?

I have a KB on mine. Ay my first dyno after the swap, I was putting down 383rwhp. I swapped a Diablo "red" for a "black" and Sam tuned it giving me 436rwhp. Big difference, but my tune was really jacked up before hand. Its all in the tune, and probably the plug issue also. I have a 3.25 upper on mine.

Phil

 

Yep, the mass air was pegging out at 5 volts at somewhere around 4000 rpm.

I was hopeful that with the 3.5 pulley I'd be pulling somewhere around 430 esp. since I'm using 91 octane gas in CA.

So when I got 416 and saw the A/F was rich, I thought adding the smaller pulley and adding 2 more lbs of boost ought to lean it out some and I could tweak the predator from there.

Does anyone know how to datalog with the Predator to figure out which cylinder is misfiring?

 

As everybody said PULL THE PLUGS don't worry about data logging it and don't drive it if it's that bad.

Since you are in California PEP BOYS should have your plugs.