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Edelbrock Mustang Dyno heartbreak

3124 Views 18 Replies 12 Participants Last post by  t-ray
I know that the Mustang dyno is supposed to read low, but I wanted to cry when my Edelbrock SC only gave me 390 RWHP. Edelbrock has superior customer service, so I know they will data log with the shop to verify. Edelbrock advertises 559 at the flywheel and I've seen graphs online showing 473 RWHP. I am at 3200 ft above sea level, but it is supposedly altitude corrected. Anyone else have any similar issues with Edelbrock or Mustang dyno?
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Something definitely not right there. Did you log that run? First thing I would check is the timing you actually pulled on the run and then talk with whoever the tune is from. Car could be pulling a lot of timing out from bad gas or the tune. It's really hard to help out when you don't have a graph from the run or any more info on the logs.
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Ya, that's not much more than stock rwhp.
Find another dyno....that is the stock hp or whoever is tuning has no clue what they are doing...
my car bone stock on a mustang dyno put out 353 and with a tune and boss intake 382
From what I read about the Mustang Dyno they can read 10-12% lower than a Dyno jet, and you should be around 420 RWHP on a Mustang Dyno.
Something sounds fishy there, i'm not sure what dyno's Brenspeed and JPC use, but the lowest I saw my e-force using stock air, stock pulley, and stock edelbrock tune was 471rwhp. Now with the CAI, and 3.5 pulley and custom tune, it is making in the mid 500's.

What kind of boost pressure were you logging during the run, it sounds like you weren't even going into boost?

Were you going into detonation? It sounds like either you have an install problem or an issue with the tune. It is possible for the tune to hold back power if things are not functioning properly.
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I'm making 5 lbs. of boost. I haven't let anyone but Edelbrock mess with the tune. The car was not running lean. There was no detonation. I was getting some voltage spikes at idle, but those disappeared above 1400 RPMs.
I'm making 5 lbs. of boost. I haven't let anyone but Edelbrock mess with the tune. The car was not running lean. There was no detonation. I was getting some voltage spikes at idle, but those disappeared above 1400 RPMs.

Well assuming you motor is within spec, the e-force is making 5psi of boost, you have adequate gas flow, and the tune is functioning properly and not pulling timing for detonation etc, then the most probable explanation is a problem with the dyno. How does the car feel when you drive it as compared to before the e-force install? What were your intake air temps doing during the pulls?
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This sounds like a case where the butt dyno is more important than the chassis dyno. It should feel TONS faster than stock.
It does feel faster than stock, but not what I was expecting. I've had it on since May. I'm now at higher altitude and I can feel it start to fade at higher RPMs. Dyno was supposed to be adjusted for altitude. If all I'm getting is an extra 40 or 50 HP, Edelbrock will be getting their unit back. I'm giving them one more chance to fix the tune. The original installer did not do a pull after install. I should have demanded it. Something is fishy.
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Couple things nobody has asked...

1. What gear did they pull in?
2. Do you know your IAT and ECT temps during the pulls? Your SCT programmer could have logged that real time.
3. What RPM did they run it to?

If the answer to 1 is anything but 5th gear then that is your issue.
If the answer to 2 is not known, then that could easily be your issue as well if they were high enough to pull spark.
If the answer to 3 is under say 6600 that could be your issue.

It is my impression that you are running the base tune that comes with the E-Force kit. I do see those make over 420 on dyno jets, but again you are not on a dyno jet and the answers to 1 and 2 play a huge role in final numbers.

So I guess there could be no issue at all depending on your answers to 1,2, and 3. Hope you get it figured out! Let us know if we can assist!
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This is what my Mustang Dyno sheet looks like to compare with yours. My mods are in my sig.

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Sorry, there is just no help for me trying to post pics. Good luck getting it fiqured out.
You haven't provided any information about the dyno. I'm guessing the dyno is inaccurate, rather than problems with the supercharger.

Find somebody with a dynojet, somewhere close to sealevel, and see what your numbers are then.
Was there a baseline run done prior to the install to compare before/after? If not, then your single data point is useless as there are a number of variables that could produce a low number.

If it were me, I'd find a reputable tuner in your area to tune the car as it's likely a canned tune from Edlebrock is going to be down on power at your altitude. That, and/or stick the car on another dyno. IIRC, boosted cars at higher altitudes like more timing, which is something a canned tune won't likely provide for you personally.

Mustang dynos are great for tuning as they do a better job of loading up the powertrain (as if it were on the street). If the dyno isn't calibrated correctly or the operator enters the wrong vehicle information, the numbers produced during the pull are going to be off.
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Unfortunately, I have moved since having the SC installed. I was under 1000 ft pre install and am now up to 3200. It is a canned tune from Edelbrock. Since it is my daily driver and my first modded car, I am very nervous about altering the tune. I was running 93 octane with a 91 tune. Now all I get here is 91. They ran my car up to 7000 RPM on the dyno. I will reinstall the tune and have it run again. My tech support from Edelbrock is very responsive and helpful. Hopefully this will be cleared up early next week.
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My point is that you may not need any tech support at all. One sheet from a dyno, particularly one you don't have any info about, is no cause for concern.

Even if it's a haul, you need to find a *dynojet* (most repeatable numbers), at low altitude. Correction factors on forced induction cars will produce wonky numbers.
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