Critique my dyno

[CHeRNoBYL]

Previously dyno'd 419/402 with Stingers + K&N Aircharger in December. Dyno'd yesterday with the following mods:

2.8 Pulley
Billetflow Stealth Idler
74" Gatorback
Denso IT20's @ .040
Borla Stingers
K&N Aircharger
Custom Tune from RWTD

I'm kinda bummed about the numbers. Texas heat I guess...It was only about 80 degrees outside though

 

[MyT-Mouse]

What was the temp outside. What boost were you seeing?

The upper RPM's look abit erratic..

 

[jream]

those numbers are low... your hp should be close to 450 and your torque close to 470 with those mods? could be the tune?

 

[CHeRNoBYL]

Of course I peg the stock boost guage but I guess I should be seeing 14.5 or so. I need to get one of Ray's boost overlays next. Outside temp was ~ 80 degrees. As you can see, my first 4 runs were almost back to back. After each run I was adjusting the fuel tables on the Predator. After the 4th run I called it quits while someone else dyno'd ... The 5th (last) run was made and my A/F was in the 11s which I was more comfortable with? Do you think the outside temp could have had such a big effect on my numbers? I dyno'd 419/402 with just the Stingers + CAI in December and it was about 60 degrees outside. FWIW, there was another 03 Cobra there with a 2.93 + exhaust and CAI with a tune from Strictly Performance ... He pulled 409/402 but had a dyno graph from Strictly when he got his mods done and that graph showed 442/474 so he was disappointed with his numbers as well.

 

[racerat]

You either have spark plug blow out or bad belt slip. Your torque drops off way too quick and your peak power levels out earlier than normal too.
Try regapping your plugs at .035 and look for evidence of belt slip.

Is this a custom tune? That's a weird spike in the A/F just before 3500rpms.

 

[CHeRNoBYL]

Originally posted by racerat
You either have spark plug blow out or bad belt slip. Your torque drops off way too quick and your peak power levels out earlier than normal too.
Try regapping your plugs at .035 and look for evidence of belt slip.

Is this a custom tune? That's a weird spike in the A/F just before 3500rpms.

Well I don't see any belt dust, so I'd be alright with a Gatorback + idler. My first thought was spark blowout when I saw the chopiness up top. My Denso's are at .040 now, do you think bringing the gap down to .035 will cause any driveability issues? The tune is from James @ RWTD (Dynorun 001) but I was adjusting on the fuel-tables after every run because it was so lean. I think the spike around 3500RPM is from the dyno operator not hitting the button quick enough ... this is one of those deals where you run your car and give him the signal to start the dyno. I think he was a little off Do you think them outside temp could have been a factor even though it was only 80 degrees yesterday? Everyone seemed to be dyno'ing very low.

 

[racerat]

Your low numbers are coming from the dips in torque and power at 4K and then again starting at 5k. Remember, these car should pull all the way to redline. From 5500 on you level off completely.

A lot of people, including me, run .035 gap on pullied cars.

Do you have the previous dyno graph of your car? Take a look at how long the car makes power and torque on that one.

 

[lwantSonicBlue]

Hey racerat where do you go to get work done on your car?

 

[CHeRNoBYL]

SONIC_SNAKE03,

I think racerat like's Murillo's shop up there in SA if I remember right If I go down to McAllen on the 24th of April do you want to bring your car and redyno? SouthTXSnake says he wants to meet and tear the dyno up

 

[racerat]

Originally posted by SONIC_SNAKE03
Hey racerat where do you go to get work done on your car?

98% of the work on my car has been done by my husband and friends, including pulling and replacing the motor.
Tuning has been handled by Don @ Modular Madness (he also built my new shortblock) and more recently, a dynotune by Mike @ Murillo Motorsports in SA.

 

[stvdman]

So these runs were on different dyno's or was it same dyno, just different weather conditions?

 

[soniccobra 03]

Yea, like tracy said,looks like you need some adjustments on your setup. I am sure the heat has some to do with the numbers being low but your numbers should be higher regardless.......enjoy.

 

[TXTERMIN8TOR]

Those numbers are definitely low for those mods. We have similar mods and the numbers are fairly different. I don't know about the heat making that much of a difference. I believe when I had my last dyno here in Dallas it was over 70 degrees, so I don't think 10 degrees would make that much of a difference.:shrug:

 

[CHeRNoBYL]

Originally posted by stvdman
So these runs were on different dyno's or was it same dyno, just different weather conditions?

All my runs have been on the same dyno. My first dyno was with CAI + exhaust only and that netted 419/402 in December. Outside temp was approx. 60 degrees. The dyno sheet above was from Saturday afternoon where the outside temps were around 80 degrees.

 

[CHeRNoBYL]

Originally posted by soniccobra 03
Yea, like tracy said,looks like you need some adjustments on your setup. I am sure the heat has some to do with the numbers being low but your numbers should be higher regardless.......enjoy.

I will double-check the gap on my plugs, in the meantime I am wondering about belt slip or perhaps the converse which is a belt that is too tight. I've heard that a tight belt can cause the tensioner to bounce under high RPM/heavy load situations ... although I think a 2.8 pulley, idler and 74" Gatorback is a proven combination so :shrug: I'm just thinking out loud. Tonight I am going to take a picture of where my tensioner is positioned after the idler install. I thought it would be more in the middle than it was, so maybe that is something to look at also...

 

[CHeRNoBYL]

Originally posted by TXTERMIN8TOR
Those numbers are definitely low for those mods. We have similar mods and the numbers are fairly different. I don't know about the heat making that much of a difference. I believe when I had my last dyno here in Dallas it was over 70 degrees, so I don't think 10 degrees would make that much of a difference.:shrug:

I don't see an idler listed in your sig. Are you getting any belt-slip with your 2.8? What belt do you run and are you running a non-slip pulley?

 

[TXTERMIN8TOR]

I don't have an idler pulley...yet. I have the Gatorback 73.5" belt and have seen no evidence of belt slippage. I have the Steeda 2.8" inch pulley, that came as part of a 03 Cobra Performance Kit at Dallas Mustang.

 

[drkchk03svt]

ouch!!!!!!!

 

[TXTERMIN8TOR]

Why do you say ouch??? Price?

 

[drkchk03svt]

Originally posted by TXTERMIN8TOR
Why do you say ouch??? Price?

His numbers and dyno tune is horrible. I was not referring to your setup.