Questions about Dyno Types . . .

[rcl4668]

I am a complete novice when it comes to dynoing cars so I had some questions. My plan is to have my dealer install Sidewinder rims, ACR Stoptech brake rotors, a rollbar and related safety equipment (harnesses etc) on my 2008 before picking up the car.

After break in at about 1,200-1,500 miles I will get a baseline on a local Mustang dyno. I will then have the dealer install the Mopar/Belanger headers, Belanger sidepipe exhaust with high flow cats and (if available by then) a Mopar or K&N cold air intake. I will then drive the car an additional 500-1,000 miles and run the car on the same dyno to see the impact of those mods.

What is the difference between a Mustang and other types of dynos such as the Dynojet? I did a search on this and other sites but did not get a clear answer other than there may be some differences in the hp/tq figures produced by the two. For example, the Mustang dyno I will be using is recommended by my Viper tech. When I asked him about the differences he said essentially that if one was interested in "bragging rights" -- which I intepret to mean higher hp and tq figures -- we should use a Dynojet. I told him I was not and just wanted an accurate way to measure the delta or change in performance of the intake and exhaust parts.

Any dyno gurus out there care to educate me? Thanks!

/Rich

 

[britospeed]

A load bearing dyno is going to give much more accurate numbers. Inertia dynos(dynojet and a few others) are not as accurate.

 

[mjorgensen Woodhouse]

By load bearing he means the dyno can be loaded to simulate the car driving down the road and the load on the engine can be duplicated to see the real gains under "real" conditions.

 

[Nine Ball]

Keep in mind that the net gains (or losses) from doing a modification and testing the car on the same dyno are what is important. Comparing dyno numbers between different dynos, or different shops across the country, is highly inaccurate and is what we refer to as "dyno racing".

A Dynojet or Mustang (load based) dyno both work fine for seeing before/after results. The Mustang dyno will typically show lower numbers than a Dynojet, but the net gains/losses will be nearly identical between brands.

 

[rcl4668]

Thanks for the informative responses. So just to be clear: A Mustang dyno is load bearing whereas a Dynojet is not?

/Rich

 

[Nine Ball]

you are correct.

 

[rcl4668]

This board rocks. Thanks for the helpful replies.

/Rich

 

[black mamba1]

If I get 528 rwhp on a Mustang dyno, what does that convert to on a Dyno Jet?

 

[V10SpeedLuvr]

If I get 528 rwhp on a Mustang dyno, what does that convert to on a Dyno Jet?

I saw online where DynoJet's typically read 10% higher than Mustang dynos. I dynoed on a Dynojet and then a couple months later on a Mustang dyno. The Mustang #'s were about 10% lower than my prior #'s, so the 10% spread seems to be accurate. In your case, I'd say you'd get ~580RWHP on a Dynojet

 

[black mamba1]

Geezuz!!

 

[adamlotus]

what kind of dyno does dan uses at dc performance, my 08 stock with 1500 mils and it did 515 rwhp

 

[plumcrazy]

keith, i thought your numbers came from ROMAR's dyno which is a dynojet dyno ?

 

[black mamba1]

Yeah, I dynod 528 rwhp back in January of this year on the dynojet. The new motor had about 3,000 miles on it. But it has been feeling really strong the last few months and now I have 10,000 miles on the new motor. I dynod at 512 rwhp on a Mustang dyno about a month ago and 557 rwtq. Now according to what I read in here about the Mustang dyno to Dyno Jet comparison, the Mustang dyno yields numbers 10% lower than dyno jet. I see that Woodhouse dynod a new 08 at 481 rwhp on a Mustang dyno.

I may be at 512/.9 = 569 rwhp on a dyno jet, right? That seems more consistent for the type of mods I have, but I am just not sure. If you take 481/.9 to get the dyno jet number for the 08, then divide by .87 for tranny loss, you are at 614 flywheel hp. Close to what the 08's are advertising. Now, if you take 569/.87 that yields 654 fly wheel hp for my car. But I am seeing numbers all over the place from different guys on different dynos.

What do you guys think?

 

[Bobpantax]

I think that either the car is fast enough to get your juices flowing or it is not. Numbers are always going to vary even among dynos of the same type. In addition to machine calibration variations, Dyno numbers are easily affected by the operator's technique or lack thereof either inentionally or inadvertantly. Going from 528 RWHP on a Dynojet to 512 RWHP on a Mustang dyno is basically going from 528 Dynojet RWHP to 563 Dynojet RWHP. The difference is 35 RWHP. Whether that increase is possible based on mod component breakin I'll leave to GR8 ASP's expertise. At 563 RWHP, you would be making 640 flywheel HP assuming a 12% driveline loss.

 

[black mamba1]

I think that either the car is fast enough to get your juices flowing or it is not. Numbers are always going to vary even among dynos of the same type. In addition to machine calibration variations, Dyno numbers are easily affected by the operator's technique or lack thereof either inentionally or inadvertantly. Going from 528 RWHP on a Dynojet to 512 RWHP on a Mustang dyno is basically going from 528 Dynojet RWHP to 563 Dynojet RWHP. The difference is 35 RWHP. Whether that increase is possible based on mod component breakin I'll leave to GR8 ASP's expertise. At 563 RWHP, you would be making 640 flywheel HP assuming a 12% driveline loss.

Bob, what do you think the real flywheel hp is based on what I have told you. As far as the car being fast enough, honestly I cannot imagine going much faster. This car is sick-fast to me. But again, I drive in the crowded New England environ, and have not been beaten in a road war yet. I am sure the first car I come across that smokes me I will be forcefully inducting air into my engine! But, if I am making 563 rwhp in actuality, that seems pretty respectable to me.

 

[mjorgensen Woodhouse]

We built a heads and cam car in 05' using a custom Comp Cams cam, Jessel roller rockers, a Unichip tuner, and a polished set of big valve heads from JM. The car had Belangers and Corsa exhaust with one set of high flow cats. Aluminum flywheel and 3:73 gears.

Although the car was a complete BEAST on the street it only made 477 RWHP on our regular Mustang dyno which ends up just short of 600 crank hp.

FWIW

 

[plumcrazy]

and then you also have the whole power under the curve thing too......

 

[black mamba1]

We built a heads and cam car in 05' using a custom Comp Cams cam, Jessel roller rockers, a Unichip tuner, and a polished set of big valve heads from JM. The car had Belangers and Corsa exhaust with one set of high flow cats. Aluminum flywheel and 3:73 gears.

Although the car was a complete BEAST on the street it only made 477 RWHP on our regular Mustang dyno which ends up just short of 600 crank hp.

FWIW

Do you remember what the rwtq numbers were for this car?

 

[Bobpantax]

Bob, what do you think the real flywheel hp is based on what I have told you. As far as the car being fast enough, honestly I cannot imagine going much faster. This car is sick-fast to me. But again, I drive in the crowded New England environ, and have not been beaten in a road war yet. I am sure the first car I come across that smokes me I will be forcefully inducting air into my engine! But, if I am making 563 rwhp in actuality, that seems pretty respectable to me.

Assuming a 12% driveline loss, 600 FHP if the 528 RWHP is correct and 640 FHP if the 563 RWHP is correct. If you have them, post both dyno runs. It would be interesting to see same.

 

[mjorgensen Woodhouse]

Do you remember what the rwtq numbers were for this car?

Sorry I do not I just had the hp number in my head file because we did not do more than a couple and they were all about the same.

 

[black mamba1]

Assuming a 12% driveline loss, 600 FHP if the 528 RWHP is correct and 640 FHP if the 563 RWHP is correct. If you have them, post both dyno runs. It would be interesting to see same.

I have both, but dont know how to post them. I will ask Viper Tony to assist me.