Hi, My Mods are straight pipes K&N cone filter, 2LBS PSP lower pulley and NGK TR6's, First run was made with a Superchips chip, i don't know much about A/F numbers but the Dyno guy said that it was running a little bit lean, what do you guys think?

Here the other run that was done with a PSP chip, now on this one the dyno guy said that the A/F numbers were right one but for some reason the power just stars droping drops at 4700rpms! you guys have any ideas of why is it doing that?


Should I sent my chip for a reburn or what should i do? thanks a lot for any help.

 

does the truck shift at 5000 rpm? it should there is no reason to run it higher than that. I would probably get a reburn. Did you dyno the truck without a chip? Those are mild mods and you may make more power without it.

 

yeah that superchip is on the high end of the A/F.

who's truck shifts at 5000 rpms with a chip??? not mine, most shift at 5300 to 5500 with a chip. 5000 is to low for a perfomance chip. if you have a easy driving program, sure then.

 

well you might as well stomp the brake right before it shifts then because dropping from 345HP to 308HP in 100 rpms is the same thing. it would be just like hitting the rev limiter, to each his own I guess.

 

The truck shifts at around 5400- 5500 with both of the chips thats why I thought that it was wierd that the power dropped so fast after the 4900rpm mark.

 

Well, the Superchip is definitely way too lean for pump gas. That's where the extra power is coming from. But on pump gas, that'll burn a valve or plug in a hurry. That chip would work well with some race gas though.

The a/f numbers on my chip are exactly where I shoot for, 11.7ish, for pump gas. Looking at the numbers, and how they drop suddenly, it looks to me like the dyno guy forgot to shut the overdrive off for that pull, and it shifted into 4th.

Hope this helps.

 

Where did you dyno at? FLP? Street stuff?

 

the FLP guys know their stuff....they're a quality dyno place.

as for your truck shifting..yep 5400 sounds right...definitely not 5000...

your A/F on the first one is a bit lean...i'd get it richened up a tad...the PSP one is pretty safe and i'd run that in the winter...

also...the straight pipes might lessen your torque down load a bit...but i dont have exact #s for ya....loss of backpressure tho

 

Thanks for the help, and about the dyno guy forgeting to shut off the overdrive, he shut it off, actually i did because I didn't want him to forget that, both of the pulls on both chips were done the same way with the overdirve off on 3rd gear and staring at about 3300rpms and about 15 minutes betweeen each pull .

 

The dyno was done at Dyno Pro Performance in Wauconda IL, they are great guys, its a new place that just opened this year.

 

Hmm ok. Well something funky is going on. I've never seen a truck drop like that without it being something mechanical. The truck dropped 40hp and 50ftlbs all in one shot within 100 rpms and the a/f didn't change at that point, so it doesn't really look chip related. Do you feel that drastic drop on the street? It REALLY looks like the truck shifted into 4th. Do you have the graphs?

 

Yes Sal, I feel a drastic drop on power on the street after 4900 -5000, but it doesn't do that on the superchips chip, but why?, it almost feels like some one pulled 2 spark pulgs wires at 5000rpms, but the wierd part its that it only does this with the PSP chip, here is a copy of the graph, it has 2 runs on it and you can see how in both of the runs the power just drops at 4900

 

Wow, that is just weird as heck. The A/F looks great, the power curves look great, and then that drop at 5k. Well, pull the chip, and let me know what the file names are off it (on the white label on the front) and I'll check the programs. Could be a limiter or something that was missed, or some kind of a glitch. I doubt it, but I'd still like to double check it.

 

Here are the number that i found on the chip:


1.CUX2 2 C2SE355
PCM:CUX2

Thanks for the help Sal.

 

You didn't accidentally get out of the throttle a little too early did you?