Alright,

I just got back from the dyno. Needless to say, I'm a little SUPRISED and a little confused. Two weeks ago, I dynoed my truck. I got 401rwhp/496rwtq with a .99 correction factor (405rwhp actually put down) and race gas. That was with the JDM J7 program that was mistakenly burned on a single program chip. Since then Jim sent me a loaner chip so that I would have a chip while waiting for the reburn of my original chip. It's the J49. Been on vacation and haven't had the chance to send the original back. Well,a club I'm part of was having a dyno day so I held off for a week to do sometrue testing.

Mods:
JDM chip (duh!)
JL 3lb lower pulley
K&N open element with a homade AirRaid
NGK TR6's

First pull with what Jim@JDM states is his most conservative 3lb pulley chip:
347.3rwhp 423.3rwtq after a .95 correction factor (SAE) (I'de say it's conservative.)
Here's the confusing part: Using one of the tailpipe probes, the A/F got to a minimun of 13.2. At 4000rpm it SKYROCKETED to 18.0! The dyno operator stated that if water comes in contact with the probe it will give a false reading. The truck was very cool and there was condensation. To be on the safe side, I swapped in the J7 program and added 4 gallons of 100 octane to ~1/8th of a tank. This covers the little bit of detonation I was getting in cold air with the J7.

First pull with the J7:
390.4rwhp 477.6rwtq with a .95 C.F. (SAE) the A/F was minimum of 14.2 and then it shot up at ~4700rpm to 18.

I let the truck cool for ~ 5 minutes and made a second pull.
387.0rwhp 475.9rwtq with a .95 C.F. and the A/F was a tick better 14.0. It shot up at ~4400rpm.

I was watching the exhaust on EVERY RUN. There was VERY LITTLE IF ANY SMOKE from the exhaust. The power NEVER FELL OFF in the upper rpms. Stayed just as flat as the 401/496 run. I know that the A/F is way high for these engines.

To make it more interesting: There was a second Lightning that was running a JL chip, more boost, power cooler, TB, etc. etc.

He made a tad bit less power but was blowing ALOT, and I do mean ALOTof smoke out of the exhaust. His A/F was mid 11's on one run, low 12's on the second but his A/F SHOT up to 18.0 as well at just about the same spot.

We both had some condensation but after THREE FULL PULLS you would think that the exhaust would be dry. WTF was going on? We were both confused about this. The dyno operator couldn't explain it and I couldn't rationalize it.

Are the tailpipe probes just crap or what? BTW, I ran a 12.91 with the J49 chip with a 1.97 60' last weekend under VERY similar conditions to my best with the J7. This was three tenths slower with a 60' a tenth slower than my BEST with the J7. You would think that 43rwhp/54rwtq would make MORE of a difference than that?

Are you confused as I am? LOL
Needless to say, I will be giving Jim a call Monday to talk with him. I really wish I could have a wideband reading now...

 

Paul, it's not the chips. It's the A/F meter. It's junk. The tailpipe sensors are VERY sensative. Get water on them, junk. Knock them on thier side, junk. I've had the same thing happen to me at many dyno shops using the tailpipe sensor. That's why I always use my wide band on top of that. I wouldn't worry about your a/f being that high . However, if they charged extra for the use of the A/F meter as some shops do, I'd ask for a refund.

 

Paul
What is almost surely happening is that the pulse wave at that rpm point is strong enough to pull air back into the tailpipe, This is why it only happens at 4700 rpm..
It is common when I'm running a Motorcycle, that I'll have the probe for my four gas in the pipe and at high rpm I'll see the co% stay relatively stable but the o2 will shoot up.By locating the probe deeper into the pipe you'll clear the problem

Paul
this was taken from Factory pro's website..just so you know I have some experience with dyno's

Razor's Edge FL Margate, FL (954) 815-0360 Paul Riccio - Paul is Factory Pro's racetrack dyno operator - and one of the most experienced operators in the States

 

Phew! Thanks Sal. I had a gut feeling they were pretty much crap. Especially after seeing TWO L's do the same thing. Funny this was, all the N/A cars weren't doing that. Then again they all had the cars idling waiting on their turn.

It was a club event and I got three pulls for $40. Wasn't gonna complain too much. LOL

Thanks again.

 

CornerCarver,
After reviewing your dyno runs from 2 weeks ago and your present ones you did over the weekend i agree do not put to much worry about your air-fuel tables this past weekend something obviously was not right.However on your dyno runs it sounds like your J49 program is set for stock settings with improved shifting most likely for people that live in cold weather is why your numbers were low with that chip! The numbers you put up this weekend actually are more in line with your mods you have on your truck and i see they were done in SAE correction.I would bet your first dyno done 2 weeks ago at another dyno were done in STD correction which inflated the numbers higher.There is a big difference in HP and Torque between the 2 as much as 10-14HP! I have over 60 dyno runs not counting tommorrow's huge day at the dyno since fall at 2 different dynojets and my truck is always within 2-3HP at both places on SAE correction! Word of advice to all that plan on making dyno runs in the future please make sure your dyno operator has it set on SAE correction factor or your numbers are meaningless when comparing your numbers against someone elses.CornerCarver thanks for the input on your dyno session!

Matt

 

Matt,

I'm 99% sure that the dyno number before were SAE as well since Ed (dyno owner) has always provided me with SAE numbers before. I've gotten ~40-50 pulls (on a couple of vehicles there as well) The differece was amount of race gas. This second time I mixed 4 gallons in with a little more than 1/8th of a tank. Last time I ran the truck until the fuel light came on and then put the race gas in. Obvisously the first time I was running a much higher octane (more suited for the race program) than I was yesterday. How much? Can't be much 10 points (96 octane vs. 97 octane) would make a difference when talking about detnation.

The one thing I found funny was this:

The dyno operator was showing me some of his files on a 2000 Lightning. He was proud of the fact that it dynoed at 283rwhp...STOCK! Myself and JC both told him something was WAY OFF on that one. He then showed where they put a 100 shot on it and it made 360rwhp and 500rwtq. I've heard guys complaining about low numbers from there before but I pretty much dismissed it since I was really interested in the A/F ratios... which didn't even come out right. I guess I'll stick to the one I've always used before. His corresponds to FIVE other dynos around the Southeast (well within 1% of the others). Too bad it's 2.5 hours away. I'll get a bung welded in and then I can get some wideband readings. LOL Helps to know other dyno junkies out there.

 

CornerCarver,
Is it possible that he is using a mustang dyno instead of dynojet dyno because a mustang dyno will show alot lower numbers than a dynojet will show.

 

Nope, both dynojets.

 

You should be able to get you files (the .001, .002, .003, etc.) that each run creates and view them in the Dynojet Runviewer that is available free on their website. This will also youto view the runs with no correction, SAE, STD and some various other Euro correction factors. I dynoed my truck this weekend with Jim's J49 and J69 programs on a flip chip. I didn't dyno the J49 side since I always run race gas in my truck and rarely if ever flip to that side. My truck made 399.7 rwhp and 504.4 rwtq with an A/F that started at 14.5 at 3300 rpm and dropped to low to mid-11s from 3700 rpm on up to 5600 rpm (down from a previous high of 404/504 done when my A/F was hovering in the 13.2-13.5 range on Jim's J7 program). I usually shoot for 12.5 on my A/F readings and I figure that's what I'll see when I dyno with the smaller upper pulley. I would say your A/F readings (especially based on the numbers you pulled) were way off. My mods are listed in my signature (with the exception of the K&N panel filter that wasn't in and the interchangeable upper pulley - I was running the stock size).

Dan

 

I'm the owner of the second L at the DYNO event ... I too, I'm puzzled by the results. To clarify a bit, here are my power making mods:

JL Chip
4 lb pulley
Filter Kit with no ram air
Breather Filter
TR6 Plugs
Power Cooler (With just water - no ice)
NO aftermarket TB !!!

My numbers:

385 RWHP SAE Corrected (0.95 CF)
471 RWTQ

404 Actual RWHP
494 Actual RWTQ

My truck was wayyyyyy rich if you looked at the black smoke out of the pipes, so I don't buy the A/F readings from that probe either.

Here is my run on video:

JC Dyno Run

Here is CC's run:

Corner Carver's Dyno Run

Look at the pipes...

What do you all think???

 

Stuck,

Is the J69 Jim's new race program? Does it require you to run race gas? I drove around everyday for awile on the J7 program and wasn't getting any detonation until we had cold air. There's a BIG difference between the J7 and J49.

 

CornerCarver,

The J69 program is Jim's newest race program. The main difference, at least as I understand it, is Jim has changed the default tables for when the MAF reaches 5.00V. The program made similar power to my previous J7 program (within 3 hp of one another) with more torque and an A/F of almost three points lower (13.5 versus 11.5-11.0). I assume the gas needs are the same as the J7 program...I only run race gas because I have the upper which I will be running and we can only get 91 octane in AZ. The J7 and J69 programs feel almost identical to one another when driving (shift firmness, etc.). All in all, I'm extremely pleased with the new program.

Dan

 

Thanks Dan. The race gas makes sense now because of the 91 octane. Luckly we got 93.