Hate to have to be "the guy" to post:
But I recently dyno'd the following hp/tq:
336/402
341/399
330/397
This is on the SAME day as 6 other Lightning owners, on the SAME dyno, in obviously the SAME weather conditions, of the SAME year... :( Our odometers read anywhere from 700miles to 5000 miles. I have 2,800 miles.

The WideBand O2 sensor shows my air fuel mixture levelling out in the HIGH 13's, low 14's, whereas EVERYONE else is in the mid to low 12's, OR running so rich, it is off the bottom of the chart.

Stock 01's that day are averaging 345/406 - so..I should at least be near average. The third run must've detected knock and pulled timing....hence the uncharacteristically LOW 330 hp . I only use 93 octane.

So, I am running EXTREMELY lean. I'm 100% bone stock - 100% is 100%. I cannot fathom why I run lean....

ANYONE have ANY ideas? And/or what to go check out under the hood ?

I know that a wideband o2 sensor after the cat ain't the best setup, but IF other trucks are using the same dyno with the same wideband o2 sensor (on the same day) and are in the low 12's for an air/fuel mixture..then I should also be in the low 12's for an air/fuel mixture.

Help!
Dean!
01 Lightning, dud?

 

Well Dean, your HP is not really off for an 01. I've dynoed many 01s and the lowest stock I've seen is 330, the highest is 347, so you're about average. Your torque does seem low for an 01 though, most are over 400 at the wheels. The knock sensor is not enabled so you wouldn't have had any timing pulled from ping. As for your A/F, those tailpipe sensors (we call them fishpumps, hehe) are not the best thing to use. They are super sensitive, and if you knock the box sideways once, the sensor is junk. If your truck truely is running that lean, you've got a problem. You should bring it back to the dealer and have it checked. You might have a vaccum leak somewhere. The dealer can check the fuel trims and if it's running lean, they'll know. Good luck, if you need any help feel free to ask!

 

Sal

Other than fish pump how can A/F be sensed on a dyno ?

Doug

 

Doug, dynos can also have the in pipe sensor, however most dyno shops don't care to go through all the trouble. I personally use my own seperate wide band, the only nice thing about the Dynojet one is you can display the readings with the graph.

 

sal
how can we remove the o2 sensor with out the computer
tripin on us. do they make dummy sensors for the plugs
cause i made a cross over pipe the truck wont run right
with the o2 disconnected or should i say 4 o2 sensors.

 

How exactly does one tune on a dynojet dyno? We are dealing with a truck that weighs in excess of 4k pounds being " tuned on an inertia dyno ( actually an accelerometer) with an inertia value of 1700 lbs..Without the ability to load the vehicle ie:and eddy current brake, you cannot achieve 100% manifold pressure nor can you reach the same combustion chamber temps as you do during real world conditions..using thermocouplers on the plugs you'll find the temps are 300-400 degrees colder on an inertia dyne...I also realize that tuning to a given 02 number is the norm however it is highly flawed, it is a left over theory from 9th grade chemistry relating to its ratio to unburned hc, residual oxygen ( lean 02 readings) can simply be attributed to a pump gas with a higher oxygen content, some range as much as 2.5 %..or to be more complex the condition of or the efficiency of the combustion area ex: how well the valves seal..The correct way to tune is to first look at CO however this could get long winded so unless you all want to know more I'll stop for now

Paul

 

Sal: I've sent an email to tech@powersurgeperformance.net last week, but never got a response. I'm interested in a 4way chip. Is it best to call ?? If so, who do I ask to speak with ?

Paul: Yes, I don't mind a discussion being long winded, so, please continue. As long as we are all learning here... That's me....

 

Dean:
there are a couple not so technical tips concerning you HP numbers..Because the Dynojet is really an accelerometer the numbers are greatly influenced by things such as tire pressure, if for example you had 25psi and made a run then raised the tire pressure to 50psi you'd see a significant increase in the Hp number..Did your truck make more power? of course not but by raising pressure you decresed the rolling resistance giving it the ability to accelerate faster thereby " tricking the dyne" I have done this test , put a set of 15 by 7 rear wheels with a tire that has 60psi and you'll see upwards of 25hp gain..this is not the way to tune nor is an inertia dyne the tool to be tuning with..
you didn't mention what your tire psi was compared to others..Other things, an e-brake slightly on the tight side will cause a low number as would a new vehicle whose drivetrain is not broken in..
Back to the Dyne, as I said earlier the inertia value is 1700lbs where as our trucks are 4k+, the amount of work the motor creates to spin the dyno drum or in reverse the amount of load applied to the wheels is far less then in real world conditions therefore the fuel needs are far less making it impossible to tune properly..another test, run a gph meter ( gallon per hour) on the vehicle in real world or on an eddy current dyne and you'll see usage is almost identical then make the run on an inertia dyne and usage is far less..out of post space

 

If I'm not 'tuning' but want an indication(hopefully real-world) of my L's hp/torque output, is a Dynojet useful for this?

I made two runs on a Dynojet back in July(South Georgia-Hot) and would like to do another two(on the same machine) this fall/winter. Am I wasting my time and $$? I've read earlier(may have been yours--don't remember) posts that told of the 'eddy-current' efficacy vs. the Dynojet's inertia accelerometer but I can't find an eddy-current machine down here. What is their trademark name ie: 'Dynojet'?

Dan

 

Hey Dan
Names to look for are- Mustang- Superflow-land & sea- Factory..As I stated earlier, You cannot duplicate real world conditions on an inertia dyno..Dynojet's software attempts to give you flywheel horsepower and NOT rearwheel horsepower " this is a fact" unfortuneately they use a blanket inertia value for all vehicles so even that value is flawed..example: our trucks make approximately 380hp at the flywheel subtract the 23-25 percent driveline loss and you should see true rear wheel hp numbers of 300 or slightly less...From a marketing standpoint the magazines etcc..know this is not what people want to see hence the reason for the the use of the percent added back in...And yes the driveline loses are 23-25% the tests to prove this are numerous,one such way (I'll keep this simple) is to accererate the truck on an eddy-current dyno to redline and then let off the throttle and allow the eddy current unit to decellerate the truck all the while the load sell is measuring frictional or negative losses, this can then be converted to actual driveline loss..To give you an example of the % added in I can offer this, a motorcycle that makes 100 true rear wheel horsepower on a Factory, superflow or land and sea eddy current dyne will show 115-118 on a dynojet ( they figure 15-18% driveline loss) people on the inside of the dyno industry also know that Dynojet admits upwards of a 6% error factor on a single dyne and sometimes greater from dyne to dyne .. I know this is getting winded so if anyone has questions feel free to ask I'll give you the most complete answer I can and if I don't have an answer I will get it for you..
Paul

 

Liquidlightning, when we tune on the dyno, we reset the computer between every pass to clear the adapative fuel tables. The PCM doesn't look at the HEGOs at WOT, and since that is mostly what you are doing on a dyno, there are no negative effects of putting the wideband in place of it for the tuning session. As for having no cats, we can shut the downstream HEGO test off for you, or you can get MIL Eliminators from Dallas Mustang, ask for CJ.

Paul, it's nice of you to add your "comments" about Dynojets, however your obvious intention to degrade Dynojet tuners is a feeble one. While your "text book" info is mostly correct, that fact that Dynojets are useless is not. The worlds best tuners use Dynojets. Maybe you've heard of some of them- Mike Wesley, UPR, Johnson Motorsports, RACE Systems, Powertrain Dynamics, Dallas Mustang, etc.. If you look at the fastest Mustangs, the ones still using the Ford EEC are all powered by Autologic chips, and tuned on Dynojets. UPRs record setting Wild Street car is Autologic equipped and Dynojet tuned. Dynojets are perfectly fine for tuning vehicles. It doesn't matter if the "actual" hp compared to a different dyno is off, you still see the results of your tuning. And since most of the world uses Dynojets, it's an even playing field for the average guy to get his truck dynoed and compare to his friends.

Just for the record, I use a Dynojet, however that is not the extent of my tuning. I also use the track for final tuning after the dyno. The combination of several tuning resorces is the best way to have overall performance. Just because large companies have the $$$ to buy eddy current dynos at three times the price, doesn't make them any better. Oh, and BTW Dynojet has an eddy current option now for thier Dynojets.

 

I need to expand on this post a little, first you all need to know that after reading Sal's post I personally called him to let him know that my intention was not to degrade any Tuners or Dynojet for that matter...the info was directed at any Inertia dyno..Second Sal backs up all his testing with real world street and track testing and also uses Data logging to gather pertinent info, it's very obvious he does a great job, just look at the times his trucks run and the comments his customers make concerning his work "top notch"..there is no need to call or e-mail him with queries concerning his abilities or test procedures..while I still contend you cannot solely tune on an inertia dyno you can do some a/b testing...
I get an awful lot of mail from people who have spent hard earned money tuning ..Scenario: I spent x$ at a shop, they had my truck all day and when they were done it was 40hp better but at the track the next day it was slower and no matter what I could not match the times..How come?...Or more recently after a day of inertia testing only a local L owner promply went out and burned a valve on the street..why? because the dyno operator leaned the truck out so far to make it accelerate the dyno roller faster that as soon as the motor was put under the load of the truck it burned a valve...As Sal pointed out I did say in another post " Beware of anything tuned on a dynojet dyno" and that is what I meant ..unlike many operators Sal knows the limitations of an inertia dyno and uses it properly..I can assure you he spends alot of time developing his products and services both on the dyno and backed up in the real world, you WILL Not be dissapointed with any product or service he has to offer..
Paul