Dyno Tune Results

[Lazzman]

They set it so it would be at 12.0-13.0 on their meter.

Thanks for the info.

 

[aldive]

At WOT you should be running rich. The 02s cut out and you go back into open loop which will cause longer pulse widths. I would try to find a spec on what the a/f ratio should be at WOT. 15:1 is ok, but you may want to double check

-Drew

15:1 A/F ratio is not good at WOT. Thats way lean, not rich.

Please explain your comments.

Thanks.

 

[ExplorerDMB]

woops - I defilently mixed that up. Noticed it was written at 1 am -- yes you are running lean. For some reason I was thinking fuel to air. Anyhow, but yes at WOT you should be rich - with that a/f ratio at WOT there is a problem there and that is why your performance is :thumbdwn:

-Drew

 

[aldive]

woops - I defilently mixed that up. Noticed it was written at 1 am -- yes you are running lean. For some reason I was thinking fuel to air. Anyhow, but yes at WOT you should be rich - with that a/f ratio at WOT there is a problem there and that is why your performance is :thumbdwn:

-Drew

Kool, I thought it was a slip up. Thanks for correcting.

 

[JDraper]

That's one of the funkiest looking dyno charts I've seen in a while.....something ain't right.....

 

[aldive]

That's one of the funkiest looking dyno charts I've seen in a while.....something ain't right.....

Agreed, it ain't pretty.

I think they measured during shifting. Doug taught me to dyno in 2nd gear and no shifts.

 

[Lazzman]

Boy this really sucks. I sank $1200 in mods into this truck and have yet to see any results as I have a problem no doubt with the Fuel pressure line.

Some symptoms:

1. Very week idle hovering between 400-600rpm.

2. Initial fuel pressure reading of 12psi when key is in the on position. Goes to 30psi when the engine is started, then drops 10 psi within 5 minutes.

3. 12hp difference from 3200rpm to 5500rpm

I think it may be the fuel pump for a number of reasons. First off I can't hear it cycle on when I turn the key to the on position. Secondly the pressure is not at spec when the key is in the on position. Thirdly it is evident that not enough fuel is getting to the engine. Fourthly my truck has 137k mi on it and I routinely run the tank to almost empty- have since I owned the truck I am alwlays broke.

 

[aldive]

We have been telling you that your FP is too low; you just don't want to listen.

 

[spindlecone]

Agreed, it ain't pretty.

I think they measured during shifting. Doug taught me to dyno in 2nd gear and no shifts.

You Dynoed in 2nd gear? sorry Al but thats wrong, your final numbers should come in 4th gear with the 5R55 tranny, 1 to one ratio

 

[Lazzman]

Yup, Mine was dynoed in fourth gear.

 

[JDraper]

A dyno run should be performed in whichever gear gives you a 1:1 final drive ratio. On most 5 speed overdrive transmissions (manual or auto), that is 4th gear.

Al, if you did the run in 2nd, did Doug apply a correction factor to the results?

 

[spindlecone]

Agreed, it ain't pretty.

I think they measured during shifting. Doug taught me to dyno in 2nd gear and no shifts.

Al
Am bumping this thread to find out about dynoing in second gear, no dissing intended, as draper said, is there a converstion factor for doing so.
I don't think it can be done, but if so how?

 

[Doug904]

Hey guys,

The reason I use 2nd or actually 3rd on 5-speed auto's, is due to a few reasons....

If you dyno your car in 4th gear then you'll find on a stock tune the speed limter setting at 92mph as it will hit it.

With the auto if you punch it 4th, or 3rd on a 4-speed, it can downshift or even worse upshift into overdrive if it reaches a preset limit. This will screw up the HP and TQ readings because it will free up the rear wheels for a split second and cause a huge jump on the dyno sheet.

Now you can get by the above by starting the dyno pull at around 3500 rpm's but when you are only going upto around 5200 that's just too high in my opinion.

I used to think the same way you guys do until I seen it done a few times. The dyno I use, www.Walkerdynotune.com , has been in service since early 03' and has done it this way on stock to even mildly modified vehicles for along time now. The guy to talk to there is Blake and he can explain it in even further detail if anyone wants to talk to him about it. His email doesn't work anymore so If you have questions just call him from the number on the website.

Now, there are ways around this with tuning. What I like to do these days is to lock the vehicle in 4th gear with the tuning and raise the overdrive shift point to like 155mph. That way I know it is in 4th and I also know that it won't go into 5th if it reaches the set parameters. ALSO, I fully lock the converter from 1mph out and this way you dont get the funny spike at around 4800 rpm's on most automatic cars. This is from the converter quickly locking and unlocking, I have no idea why it does this but on the dyno you dont want it.

I've also attached a dyno sheet of two of my own personal car runs, I have an 05' Roush Automatic GT with the 5R55S transmission. It has 5 gears as well. The first run of the day was just a drive on and pull run and then I finished my tuning for the day and to ensure a proper comparison I always do an final stock dynopull to make sure nothing has went wrong while I was doing something to the vehicle. You can see the major MPH difference at the bottom of the screen, if I put it where it read RPM across the bottom of the screen it would put the runs over the top of each other and you would never know it was in two different gears.

Now I wouldn't go and try to make a pull in first gear but from my tuning experiences with over 100 cars/trucks/SUV's on the dyno now I've learned quite a bit and this is definatly one that helps.

Just thinking about it, I just did a Diesel 05' 6.0 auto on the dyno. This was at a dyno in North Carolina, not my local guy. The dyno operator would try to run it up in 4th and being that a diesel only goes to around 3000 rpm's total it would upshift on him everytime and the rear tires would go crazy on the rollers. Yes, it was even strapped down with 4" straps. I told him to try it in second and we made a full power pull without any problems from the tranny. Made 408rwhp and 580 rwtq with just the street tune .

Thanks, Doug.

 

[spindlecone]

And if you do not have a speed limiter?

 

[Doug904]

Hey Lazzman,

Sounds like you may have a FP issue but do this, check the fuel pressure while idleing and then while driving. Your Fuel pressure should be 28-32psi at idle and around 38-42 psi at WOT. If you find that your FP drops quickly while driving, like it just spikes downward for a second or two that could definatly be the sign of a bad fuel pump. Actually though when was the last time you had your Fuel filter changed?

Your Graphs dont look that odd to me, the reason the HP isn't really in a curve is that they started the runs at a high RPM so you are really seeing how the cams or really head flow kinda play out up top on these engines. Now for your Tq to be so high is weird though, HP on a dyno is actually a calculated number from the measured TQ. What type of dyno was it? Dynojet or Mustang dyno?

Just trying to give you some ideas, but dont forget the basics. Good Spark plugs, Fuel Filter, Air filter, and clean MAF sensor.

Thanks, Doug.

 

[Doug904]

And if you do not have a speed limiter?

On a stock pull, you do. If you dont then it can be done in 4th but there again it would have to be started at around 3500 rpm's to ensure it doesn't downshift into 3rd. I prefer the 2nd gear if I dont just lock it in gear.

Thanks, Doug.

 

[spindlecone]

On a stock pull, you do. If you dont then it can be done in 4th but there again it would have to be started at around 3500 rpm's to ensure it doesn't downshift into 3rd. I prefer the 2nd gear if I dont just lock it in gear.

Thanks, Doug.

Not talking stock, I have no limiters, if you lock out the OD, the final Dyno numbers are in 4th gear, Correct? 1to 1 ratio for the tranny

 

[Doug904]

Yup, if I lock out OD and lock the tranny into 4th gear.....

 

[Lazzman]

Doug, my run was done on a dynojet. I recently had another run with a brand new 190lph Walbro fuel pump, Napa fuel pump assembly and fuel pump relay.

Turned a bit more HP on another guys Dynojet and a bit less tourq, but he could not get good readings, because he did not know how to test my automatic. Started in 4th with the o/d off. See new Dyno Chart

Car still bogs down and idle's weak with strong misfire causing stall out at times, heavy throttle causes bog. Maf is clean, no fuel issues, TB clean.

Next up:

New 8mm Magnecor wires
Motorcraft AGSF22FMF6 or Denso Iridium plugs
New Motorcraft Coil Pack

Re-tune of my Diablosport chip if all goes well.

 

[Lazzman]

Notice the funky spike right around 4800rpm, wonder if this is what Doug was talking about.

While I was getting it dynoed the guy kept it for a few days and went through the entire fuel system. He replaced the Crank sensor with no effect.

He did say that his diagnostic machine showed bad gap in my spark plugs??