Percentage diff between a Chassis Dyno and an Engine Dyno

Jimi B · 04-04-2011, 02:14 PM

It also may vary depending on the type (load bearing edy etc) and brand of the dyno. The operator will also play a roll in it. You can make them read what ever you want. Mustang and Dynojet are the 2 most popular chassis dynos, and Mustangs tend to read a good deal lower. All though it may argued, one may not necessarily be better than the other. In the end most good tuners will tell you that chassis dynos are more of a tuning tool to help compare you percentage of change in power more so than actual power number. Not sayin that the numbers are not accurate. Its just a fiercely debated topic.

art leong · 04-04-2011, 02:20 PM

Quote:

Originally Posted by Jimi B

It also may vary depending on the type (load bearing edy etc) and brand of the dyno. The operator will also play a roll in it. You can make them read what ever you want. Mustang and Dynojet are the 2 most popular chassis dynos, and Mustangs tend to read a good deal lower. All though it may argued, one may not necessarily be better than the other. In the end most good tuners will tell you that chassis dynos are more of a tuning tool to help compare you percentage of change in power more so than actual power number. Not sayin that the numbers are not accurate. Its just a fiercely debated topic.

We first ran the car with the box (caravan) manifold. The switched to an ITB set up.
We saw a 10 HP increase through out the range, and an almost 10 foot pounds of torque with a broader flatter curve.
This was a Dyno Dynamics Dyno I don't know how to compare it with a Mustang or a Dynojet

Jimi B · 04-04-2011, 02:26 PM

Id say no matter what they read thats a good gain Art! Dyno dynamics read like a Dynojet from what Ive seen. Specifically the models that bolt to the hub instead or running on rollers.

Jimi B · 04-04-2011, 02:30 PM

Actually I just went to their website. Don think thats the brand I was thinking of.

art leong · 04-04-2011, 03:50 PM

Quote:

Originally Posted by Jimi B

Actually I just went to their website. Don think thats the brand I was thinking of.

It was on rollers, no bolting anything to it. that might be a hard to do with a fwd.

Ed Wright · 04-04-2011, 03:59 PM

As with any dyno, the numbers don't actually matter, it's the DIFFERENCE you see from the changes that matter. The shops I was refering to had Super Flow engine dynos and Dyno Jet chassis dynos. Mustang dynos don't alwaye read lower. Depends on the operator and the load factors they use. When the ATI Procharger people hauled their prototype cars from my shop (Dynojet), after tuning, to their place (Mustang dyno) they typically picked up around 5%.

Mike Taylor 3601 · 04-05-2011, 02:26 PM

Only thing I can tell you is my car lost 28% on chassis dyno.It was automatic then. Dynoed engine on superflow SF900AT It was calibrated as close as possible,air corrected to 29.9 baro 60 degrees. Then later we got a Dyno jet chassis so my car used to test it lost
28%.
As Ed said don't compare your # to others,just look at gains from where you started.
I don't know about others but dyno jet has setting where you let car coast after pull and it calculates driveline drag or % of loss I can't remember term they use.
I don't have much chassis dyno experience but in my opinion they probaly not as repeatable as good engine dyno.
Mike Taylor 3601

04-04-2011, 02:14 PM	#1
Jimi B Member Join Date: Nov 2005 Location: Cincinnati Posts: 226 Likes: 0 Liked 0 Times in 0 Posts	Re: Percentage diff between a Chassis Dyno and an Engine Dyn It also may vary depending on the type (load bearing edy etc) and brand of the dyno. The operator will also play a roll in it. You can make them read what ever you want. Mustang and Dynojet are the 2 most popular chassis dynos, and Mustangs tend to read a good deal lower. All though it may argued, one may not necessarily be better than the other. In the end most good tuners will tell you that chassis dynos are more of a tuning tool to help compare you percentage of change in power more so than actual power number. Not sayin that the numbers are not accurate. Its just a fiercely debated topic. __________________ Jimmy Bowling BF/S 3808 www.facebook.com/jimib1980

04-04-2011, 02:26 PM	#3
Jimi B Member Join Date: Nov 2005 Location: Cincinnati Posts: 226 Likes: 0 Liked 0 Times in 0 Posts	Re: Percentage diff between a Chassis Dyno and an Engine Dyn Id say no matter what they read thats a good gain Art! Dyno dynamics read like a Dynojet from what Ive seen. Specifically the models that bolt to the hub instead or running on rollers. __________________ Jimmy Bowling BF/S 3808 www.facebook.com/jimib1980

04-04-2011, 02:30 PM	#4
Jimi B Member Join Date: Nov 2005 Location: Cincinnati Posts: 226 Likes: 0 Liked 0 Times in 0 Posts	Re: Percentage diff between a Chassis Dyno and an Engine Dyn Actually I just went to their website. Don think thats the brand I was thinking of. __________________ Jimmy Bowling BF/S 3808 www.facebook.com/jimib1980

04-04-2011, 03:59 PM	#6
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Percentage diff between a Chassis Dyno and an Engine Dyn As with any dyno, the numbers don't actually matter, it's the DIFFERENCE you see from the changes that matter. The shops I was refering to had Super Flow engine dynos and Dyno Jet chassis dynos. Mustang dynos don't alwaye read lower. Depends on the operator and the load factors they use. When the ATI Procharger people hauled their prototype cars from my shop (Dynojet), after tuning, to their place (Mustang dyno) they typically picked up around 5%. __________________ Ed Wright 4156 SS/JA

04-05-2011, 02:26 PM	#7
Mike Taylor 3601 VIP Member Join Date: Oct 2008 Location: Somerset,Ky Posts: 1,370 Likes: 350 Liked 297 Times in 102 Posts	Re: Percentage diff between a Chassis Dyno and an Engine Dyn Only thing I can tell you is my car lost 28% on chassis dyno.It was automatic then. Dynoed engine on superflow SF900AT It was calibrated as close as possible,air corrected to 29.9 baro 60 degrees. Then later we got a Dyno jet chassis so my car used to test it lost 28%. As Ed said don't compare your # to others,just look at gains from where you started. I don't know about others but dyno jet has setting where you let car coast after pull and it calculates driveline drag or % of loss I can't remember term they use. I don't have much chassis dyno experience but in my opinion they probaly not as repeatable as good engine dyno. Mike Taylor 3601