Dnyojet vs. Dyno Dynamics same car, same day

[foghat]

Hey all,

A while back I had my car dyno'd on a dyno dynamics dyno. Pulled 352.3hp/440.1tq. Wasn't sure how I stacked up seeing as how most everyone dynos on a dynojet around here.

So decided to get a pull done on each dyno on the same day.

Compared to my first dyno dynamics pull about a month ago, this time the number increased by a whole 1.2hp and lost almost 9tq. Ended up at 353.5hp/431.6tq. Different days and warmer the second time, so going to call that a wash.

Next up the dynojet (actually went to dynojet first). Well, I was quite surprised. Was hoping to pull about 380ish. Ended up pulling a whopping 404hp/461tq!

I've read the dyno dynamics is a heart breaker dyno, even more so than a mustang dyno. Can't say I disagree. Still, I am surprised there was such a big difference.

Needless to say, I am now fairly confident I am right in the pack for my mods.

Std correction on dynojet. ATMC1 on dyno dynamics. 4th gear pulls on both.


2008 BMW135i PTF v5_new by Pheare, on Flickr


135i_dyno by Pheare, on Flickr

[631twentyeighteye]

Pretty crazy how different some dyno's read. It's just another example that a dyno isn't used to gain bragging rights, it's a way to measure gained horsepower on your car. I've used the same dyno for before and after my mods and i will always continue to.

[foghat]

Originally Posted by 631twentyeighteye

Pretty crazy how different some dyno's read. It's just another example that a dyno isn't used to gain bragging rights, it's a way to measure gained horsepower on your car. I've used the same dyno for before and after my mods and i will always continue to.

Yep. But seeing as how most here post dynojet numbers, I wanted to at least somewhat be able to compare apples to apples.

These were done back in April when it was much cooler out. No before numbers for the dynojet.

the stock run (except for dci) is actually cobb map 0, which I suspect puts out a little more than stock


2008 BMW135i 6MT stcok stg1 F23864 by Pheare, on Flickr


This was my run from a month ago. Comparing cobb stage2+fmic to ptf tune.


2008 135i PTF F23864 by Pheare, on Flickr

[wjk_glynn]

It's an old article, but Turbo magazine took a 350Z around to a few different dynos on the same day with significantly varying results:

http://www.turbomagazine.com/tech/03...ine_dyno_dash/

Karl.

[CrustyNoodle]

Apart from the 25 ft.lb. difference in torque (tq is not a unit of measure) the DD torque appears to peak earlier and start to drop off earlier than the Dynojet. By rights they should both peak and start to drop at the same engine speed. Looks like there is an error between the two not just in peak torque but also in measured engine speed - both errors are in favour of the Dynojet.

Very interesting!

[Andrewcoja]

Haven't you seen Top Gear? He has 404 horsepowers and 461 torques.

[foghat]

Originally Posted by CrustyNoodle

Apart from the 25 ft.lb. difference in torque (tq is not a unit of measure) the DD torque appears to peak earlier and start to drop off earlier than the Dynojet. By rights they should both peak and start to drop at the same engine speed. Looks like there is an error between the two not just in peak torque but also in measured engine speed - both errors are in favour of the Dynojet.

Very interesting!

Yes the peak happens at different rpms (~3900dd vs. ~4300dj), but the dd is pretty flat from where it peaks to where the dj peaks. So I dunno. While I don't have the graphs from my other pulls on that day, I suspect even between runs on same dyno there could be slight variance in where things peak (and how much that peak is)

To me it looks like in both cases tq is starting to drop at about 4300-4400rpm.

Keep in mind you need to be looking at the graphs in the first post. While I didn't mention it, the 352.3 DD graph had a slightly different version of the ptf tune. Plus it was taken on a completely different day and in cooler conditions.

[JZWBMW]

They definitely load the car different, you will see different peak rpm on the two dyno types. Dynojet is more like running it down hill, the dyno dynamics will load it much more. The Dynojet is what you want for bigger numbers. Compare stock to tuned for real gains.

You can change the CF on the Dyno Dynamics and make it read like a dynojet or read lower, the dynojet is usually run off a weather station, its not supposed to allow changes in CF.

Mustang dyno, Dyno Dynamics, heart breakers.

Dyno Jet, my car is bad ass, Ego Booster :-)

Here is my 135i with my stg 1 custom tune on it, Dyno Dynamics and Dynojet.

320whp on Dyno Dynamics and 353whp on the dynojet.

JZW

[RimasRS]

damn 50 whp I would pay money for them

[e36addict]

Yep I've spent a lot of time and done lots of pulls on a Dyno Dynamics.. My buddies old LS1 GTO put down 389whp on a mustang dyno, and a few days later put down 334whp on a DD.. Pretty depressing for most of the number-chasing type of clients.

[foghat]

Originally Posted by JZWBMW

They definitely load the car different, you will see different peak rpm on the two dyno types. Dynojet is more like running it down hill, the dyno dynamics will load it much more. The Dynojet is what you want for bigger numbers. Compare stock to tuned for real gains.

You can change the CF on the Dyno Dynamics and make it read like a dynojet or read lower, the dynojet is usually run off a weather station, its not supposed to allow changes in CF.

Mustang dyno, Dyno Dynamics, heart breakers.

Dyno Jet, my car is bad ass, Ego Booster :-)

Here is my 135i with my stg 1 custom tune on it, Dyno Dynamics and Dynojet.

320whp on Dyno Dynamics and 353whp on the dynojet.

JZW

Pretty sure the dyno dynamics was using a weather station as well, either way, with both dynos you can change the correction factors using the software afterwards.

That reminds me, I need to back in touch with my DD guy, he was supposed to send me the uncorrected numbers as well. I know that will be depressing.

[GeeRam]

Originally Posted by JZWBMW

Dyno Jet, my car is bad ass, Ego Booster :-)

That's why there's so few DynoJet's here in the UK, as their comedy reputation for unrealistically inflated figures mean no-one wants to use a DJ here.

Most dynos over here are Dyno Dynamics, Dastek, Rototest or old school types such as TAT.