Sparky

Just curious, the guy I use now has a Mustang.

My stock dyno on a DynoJet with just a lid was 291RWHP. I had my new shop dyno about 3 months later (Mustang) and got 268?? Is this much differece normal.

Now, just dyno'd again last week (same Mustang) to see what my mods did. I dyno'd at 341rwhp. (Mods since last dyno: SLP LT's - B1 cam - LS6 Intake and ASP UD pulley). What would this have been on a DynoJet?

I asked the dyno operator that the Mustang is usually about 15HP lower but another operator told me it's closer to 10%! Any thoughts?

MarkT

Black Sunshine/ 00SS

iTrader: (1)

Well Mark T, On that same dyno (if it's the one I'm thinking of) I dynoed 300 HP/TQ, but at Camarofest on a Dynometer, I dynoed 320/353 HP-TQ. The only changes between the days was a ported TB, and the addition of the MAFT. My ET dropped quite a bit during that time, so I doubt I lost all that TQ, and any HP.. But hey, 11.49 aint bad for only 300 HP.
Truth is, there is a difference between dynos, it's just like different slips at different tracks, on the same day, with no other changes. I cant explain it.
By the way, send me your address, so I can send Dauna the $10 for those 2 pics. I wanna get those <img src="gr_stretch.gif" border="0"> Thanks.

ChrisB

It really depends on how your motor is setup - the main difference is the load applied - the mustang dyno will typically apply a greater load than the dynojet (~2800lb car). Add to this slightly different methods of operation (eddy current vs. inertial), correction factors, etc. and you do see a difference (as you noted).

But also realize that the value they are measuring *is* different. the HP output of the engine will differ based on the load placed on it. On a NA car it shouldn't be to great - on a 300rwhp car maybe 5-20rwhp - no more than that though (including all the above factors). On a turbo car you can actually dyno more on a mustang dyno many times since the turbo's work better with more load.

It's really difficult to compare between the two preciesely because they are measuring different points, but if you have more than 20rwhp discrepancy you may want to try loosing a little timing/richening your a/f mixture.


Chris

y2kz28

These dyno numbers confuse me also. I dynoed at the Superfest last year with the loudmouth and lid at 316/327. (Dynojet 248h). Last week on the Mustang dyno with all my mods, I got 355/350. The performance increase since the Superfest is awesome, certainly not from only a 39rwhp/23rwtq increase. I'll just wait for the next Superfest <img src="gr_stretch.gif" border="0">

BIGBOS

MotorTrends recent issue tested the Camaros RWHP and the cobras RWHP...the #'s were totally off...there were on a mustang dyno...the camaro made 268 rwhp and 270rwtq... <img src="images/icons/rolleyes.gif" border="0">

The cobra made 10 less... <img src="gr_stretch.gif" border="0">

Put them both on a dynojet and lets see who the king is... <img src="gr_stretch.gif" border="0">

BlackWS6LS1

iTrader: (5)

Well, the other day a group of us got together and had a dyno day. We show up to the place and the guy told us, "Now this isn't your typical dynamometer, this is a Mustang Dynamometer (Brand name not the Ford version), this dyno will read 15% less than any DynoJet you guys have been on. This is what GM, Ford, and Chrysler use at there facilities.

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Zman
98 Trans Am Ram Air
Black 6-speed w/ Ripper
DirectFlo Lid w/ K&N
MSD's for the TR55's
Spohn LCA's and Panhard
BMR SFB and IRS SFC's
Edelbrock Torque Arm
GMS MAF, MACs W/ ORP
ATR catback system
but not fast enough.