Todays Dyno Results - Not impressive

[Super XR7]

Today I ran my car on a Mustang Dyno, with Jerry Wrobelski doing the dyno tune. I was not very happy with my car based on all the work that I have done to it.
Can someone review this dyno sheet and my mods to find out where my weaknesses are. The heads, the 2.25" downtubes, cam?
Another thing is that I drove 70 miles to get to the dyno the day of the dyno run.

Mike Tuck

Noted that one of the other papers stated 13.5 hp at 50 MPH

[wezar]

What kind of torque did it make? I have a lot of the same mods (same cam, headers, 2.25 exhaust) and with a stock intercooler (Look out its gotta fan) and running real rich I made a hair under 253 HP and 332 torque late Nov last year.. Was it really hot? I would have expected you to be around 300HP.

[XR7 Dave]

Are you sure that is your last/tuned chart? I know that he didn't command a 13.25 AF ratio so something doesn't seem right. Maybe they gave you a pre-tune printout?

I won't comment without some more info...

[supercatxr7]

Yea Dave, I'd be surprised if a/f was set where it is at. Somewhat lean for my tastes. Also, the Mustang Dyno will have lower hp than a DynoJet due to it more closely simulating real conditions.

[BT Motorsports]

Mike, little off topic, but dyno sheet aside, how does the car feel compared to before the tune?

Paul

[Super XR7]

Here is the last run which also had the lowest horsepower, due to heating up?
If I didn't have the interior work to do, I would tear out the motor tommorrow and fix what needs to be done. This does not take away from the car being a blast to drive, just very disappointed with the dyno results, which I will do something about. I am looking for 350 hp at the rear wheels, period.

I consider you guys the experts and am requesting your advice. Anymore info I have is yours, just let me know.

Paul, I can not say that the car feels any different, I am just a little more relaxed knowing that I am not running lean.

[Super XR7]

This goes with the first run.

[Super XR7]

and the last run. Hey want to thank you guys in advance for the help.

[XR7 Dave]

Originally Posted by Super XR7

and the last run. Hey want to thank you guys in advance for the help.

Now I see why people don't like Mustang dyno's. Nevermind the power levels, those graphs are azz.

Anyway, back to the car. Did Jerry tell you anything about the car, did he make any comments or offer any suggestions? Were other people happy/dissapointed with their results that day?

How many pulls did you make? I don't think heat was the problem. With a MP IC you should have been fine all day. If it really makes those power levels, the car wouldn't be all that fun to drive. 300rwhp says you are going fast in a hurry, 240rwhp is fun in first and even 2nd for awhile but it makes you wonder when you are going to get there in 3rd. As Paul said, how does it feel?

I am bothered that your power falls off by 4800-4900 but that may be a function of the cam. However, my cam has only slightly more duration on the exhaust (same lift more or less) and it peaks at 5200-5400 depending on the day. How much boost are you running? I do think you are way overdriven. With that cam and blower combo a 5% should be good for about 14psi which is plenty for 300rwhp. I ran my best with a 5% pulley on my Smodel. Moving up to 10% added 10rwhp but I didn't run any faster at the track so I think it was saturating things down track.

You need to get to a dynojet and try again if you want comperable numbers to what everyone else has.

[XR7 Dave]

And for the record, a lean pull on the dyno which results in a higher HP reading will not result in a quicker time at the track. I have gone faster (12.48) with 330rwhp and 12.0:1 than I did (12.68) with 345rwhp and 13.5:1.

[David Neibert]

Dave,

Your's is the only car I've seen make big power on such a small cam (freak). I don't think Mike needs to reduce the amount of overdrive so much as he needs a bigger cam. IMO, 350 rwhp isn't going to happen without heads similar to Stegs. and much more cam.

David

[Super XR7]

Made three pulls, the dyno owner invited me back for a free pull when things were cooler. The guy that followed me was a 89 cobra mustang with a 5.0 rebuild which included a cam, long tube headers, port and polished heads. I didn't get the specifics but when I left he was at 232 hp / 265 ft-lbs and I am sure he wasn't very happy either. Like the owner told me when I arrived "that dyno is a heart breaker", I wasn't sure what he meant by that at first but now I know.
Driving the car it moves very well and I am sure that I am making more HP than 247 but not 350. It sounds like I need better heads and a bigger cam (any suggestions). I will get the interior done and then start back on the motor.

Mike Tuck

[FastSC]

mustang dynos are usually lower, so it's really not that bad.

[fastsc92]

those aren't that bad of numbers from what i can see. I think you're tip in is a little off in the last pull. It seems to dip way down then come up to a good ratio of 12.3ish. Much better than the first run. Work with the tuner some more and i think you can hit around 270 at the wheels no problem.

He's a pic of my dyno run, notice the scary a/f ratio. This was before a long awaited tune. Its just about squared away now, and i think i can unleash a lot more ponies at the wheels. However, take a lot at my torque curve, it peaks at 422ftlb, but the hp was only 280. Kinda strange. Anyways, I think you'll have no problem getting to your goal. There are always going to be road blocks. Good luck man!

[Super XR7]

Well guys just got this email and this makes me feel a little better.

The last pull Saturday was done by Bill Phillips to allow me to provide you guys with a correction factor. This correction factor will allow you to get a very accurate number for what your vehicle would pull on a Dynojet dyno. The Dynojet is more of the industry standard as far as rear wheel HP numbers. The mustang Dyno we used this weekend had load absorption which loads the cars up and makes the pulls much longer and builds up allot of heat. In my opinion loading up a car like we did this weekend allows the tuner to give you a much safer tune, but that is my opinion only.
Bill Phillips had his car on the Dynojet in Atlanta on Thursday and pulled 621 RWHP. On saturday he pulled 528 RWHP. 528/621= .85 This tells me that the Mustang Dyno was reading 15% lower than the DynoJet
I have often been told and read that a Mustang Dyno will read about 15% lower than a DynoJet. So I would say it would be very safe to say of you guys take the HP you made on the Dyno Saturday and divided it by .85 and that would be a conservative pull for your car on a DynoJet.
So if you made 220HP saturday, that would be 220/.85= 258RWHP on a DynoJet.

So that would make me at ~290 hp and ~350 ft-lbs. Not at my goal but closer.

Mike Tuck