dyno question

**sscrazy** · 09-06-2005, 02:24 PM

Does a mustang dyno really give out a lower hp rating than what is actual. I was told that it could be up to 40 hp off. anyway I dynoed my car today and it came out 390 rwhp. this is with the stock intake. the tuner said that I need a 90mm fast intake and throttle body and It will increase about 50 at the tires. anyway if I dynoed at 390 on a mustang dyno does that mean that my actual is somewhere around 420-430 rwhp? I figured my hp would be alot more than 390 with my $10,000 motor!!!!

**sscrazy** · 09-06-2005, 02:25 PM

also the tuner said that MY intake was pulling vacuum around 4000 rpm. wich tells him that the intake is way too small.

**Sarge** · 09-06-2005, 04:33 PM

Basic explanation.....The Mustang Dyno provides resistance to the wheels based on the cars weight. This in effect will provide a more real world tune capability. A Dynojet is a "free spinning" mechanism with no resistance to the wheels....so bottom line is a Mustang Dyno will "dyno" lower RWHP numbers based on the resistance....my experience is around 15% +/-......now do not lose sight of the fact there are other variables which have an effect on the numbers...mainly temp/humidity....

**nhraformula** · 09-07-2005, 05:59 PM

mustang dyno gives more real world numbers.
on a mustang dyno my car pulled 366 rwhp.

**Liquifire** · 09-10-2005, 01:59 AM

also I would be shocked to see you gain fifty rwhp if you put on the 90mm fast intake and tb. More likely to see twenty to thirty rwhp from this. If you have more cubes than stock it will be better than the above by a little so probably 30 to 35. Also, is your car an auto or a M6? This might make a big difference.......Do you have a twelve bolt I assume, because that uses a little more power than the ten bolt, etc......Even so......with 10K invested you should be able to get north of 450rwhp maybe even 500 imho.

**LS1-450** · 09-10-2005, 04:50 AM

Originally Posted by sscrazy

Does a mustang dyno really give out a lower hp rating than what is actual. I was told that it could be up to 40 hp off. anyway I dynoed my car today and it came out 390 rwhp. this is with the stock intake. the tuner said that I need a 90mm fast intake and throttle body and It will increase about 50 at the tires. anyway if I dynoed at 390 on a mustang dyno does that mean that my actual is somewhere around 420-430 rwhp? I figured my hp would be alot more than 390 with my $10,000 motor!!!!

On my two cars, one recorded 19% less rwhp on a Mustang compared to a Dynojet & the other 18% less so 15% to 20% is likely a good estimation dependion on ambient conditions & how the Dyno is calibrated @ a given elevation.

390rwhp is not a bad start & is more like 440 ish on that Mustang. Unrestricting an intake is always a good idea. This will help to increase the engines VE & should add HP. Make sure that if you go w/ the 90mm TB, intake, ported MAF that your filter is sized accordingly.