Percentage diff between a Chassis Dyno and an Engine Dyno

[art leong]

Can anyone give me a ball park figure?

[Ed Wright]

Average stick car is 15%. Automatic cars with stock torque converters are close to 20%. Those numbers were in the literature that came with my dyno, and usually proved to be close by shops I tune for that had both kinds of dyno.
Hope this helps.

[art leong]

Almost 2 HP per cubic inch. And we might have valve float, or lifter pump up over 7000 rpms

[Jeff Lee]

I think he's asking how they compare in test data to one another; after the drive train loss calculations I assume.

[Ed Wright]

Originally Posted by Jeff Lee

I think he's asking how they compare in test data to one another; after the drive train loss calculations I assume.

Jeff, I thought he was. May have mis-read it. Thought that was what I answered.

[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.

[art leong]

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]

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]

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

[art leong]

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.