Difference between dynojet and Mustang dyno

[BlairTruck]

What is the difference?
Does it matter which one i get my tune done on?
Any info would be great

[Ryan@RhynoTune]

I'd get my tune on a Mustang dyno. The real diff is they load the vehicle to the actual weight.

[2002BlacknBlue]

I agree. The mustang is a true on the street dyno. There is quite a diff on the numbers. I think it's about 15%. The regular dyno giving you bigger numbers just looks better.

[2002GreyHD150]

bragging rights are for whimpy little maouse people.. look for consistent #'s...

good thread... mid way through as a reference to Dyno variance, by yours truly

http://www.nhtoc.com/vbforum/showthr...rt+Compact+car

Rob W

[Tazz]

It really doens't matter which dyno you use IMO just that you use the same dyno for all your runs. This way you get a consistant reading of gains/losses. Most dyno places use Dynojet dynometers and hence if you want to compare someones elses with yours it's probably best to go Dynojet since they probably dynoed on a Dynojet.
A dyno is a tool to help you gauge what is working and not working for you. A dyno should not be used as a tool for bragging rights as to who has the most hp or tq since there can be a great difference even between two dynojets of the same model. Ive seen about a 3% difference between two dyojets in my area. Also you want to look at where the power is being made. Peak hp or tq really doens't really tell you much it's the area under the curve that really matters. The longer period of time that you have max tq and hp the quicker you should get from point A to B. All things being equal someone can actually have higher tq and hp numbers than you but be slower due to the fact that your curve is flatter and you sustain near your max tq and hp #'s for a longer time period.
As far as A/F readings with either dyno it's in your best interest to get the reading before the cats and get your tune based on those more accurate readings unless you are running no cats at all then it won't matter where you take the reading.
Tazz

[BlairTruck]

what if they only have the a/f tester that goes in the tailpipe>?

[Tazz]

The tail pipe sniffer may read a bit leaner than what your A/F'as really are. How much of a difference depends on alot of different factors. With my truck for example the tail pipe readings vs precat bung readings were off by more than a 1 point to 1 1/2 points difference. A 12.3 vs a 10.8 precat reading. Others have seen only about .3-.5 of a point difference.
Tazz

[2002GreyHD150]

A/f sampling point is irrelevant as long as the sample is take at the same place each time...

As my post in the link & Taz said... its about consistent measuring... you cannot go from Mustang, to Dynojet, to XYZ or PDQ dyno & expect to see any consistency...

ONE dyno in YOUR immediate area... so no traveling 200 miles for tuning & expecting perfection... ain't gonna happen

One dyno, one dyno operator, one tuner.. & in the real world the Dyno operator & tuner should be the same person,

Rob W

[BlairTruck]

well then only place that can do custom tunes on predator is 200 miles away
is it worth it, or should i just check my air/fuel at my local dyno first?
gonna be running 6lb lower and predator

[2002GreyHD150]

if the closest tuner for your program is 200 miles away, use whatcha got... be aware that the tune may not be at top performance

Rob W

[BlairTruck]

SO what im getting is go to the mustang dyno that is local and check my air/fuel. then do a little adjusting in the tuner to get the air/fuel to the best i can?

[harleytruck9144]

i would have to disagree on the location of a/f readings... tailpipe sniffers SUCK!!! the first place i took my truck totally screwed it up because they were using one, when they put the wideband on it turned out i was running 12.5-13.0 a/f when the sniffer read like 10.5-11.0, definately only use a wideband BEFORE the cats, there is no other way. as far as mustang or dynojet, it doesnt matter which one you use, the dyno is not the tuning instrument, the tuner is and you are only tuning fuel and spark, nothing else. the dyno is only to tell you how much power you are making and to keep your truck stationary while you tune it, nothing else. a mustang dyno may be slightly better for street tuning because it will put the amount of load on the wheels that your truck weighs and so the extra load you would have running on the streets from tuning on a dynojet will not be there and you are less likely to experience any detonation.... but the dynojet will show higher numbers.

[2002GreyHD150]

9144 if they were that far of there was a definite problem with their tail pipe probe...

There have been 100's of comparisons done & as long as the probe is at least 12-18" inside the tail pipe everything should be fine.

There have been lots of arguements about the pre-cat, post cat gig.... On my Mustang,(675 rwhp) in the header collector versus the final tailpipe measured within .05 either way & traded positions durning 20+ dyno runs.

The big issue for many is the cost/time of adding the bung (cutting, welding, wiring etc) is a concern for many as well.

Unless you are in the 450+hp bracket the minor variations are insignificant.

Rob W

[BlairTruck]

good information in here.

[Tazz]

All I know is that AEM and Innovative Motor Sports both of which make wideband units all say to get the most accurate reading possible to take it precat. Innovate has even run into the readings being richer aftercat than precat. My readings were a 1.5 off from the shops readings on my truck. Jwhites readings if Im correct were only off .5 and we use the same dyno shop.
Wouldn't you want to be absolutely sure of your readings?? I know I would but then again I should have never doubted that the tune tune I have was anything less than perfect.
I'm running Del W's Recal right now and I can say it's more aggressive than my recal in that the A/F's don't drop to 10.8 right when I drop the hammer. With his recal I drop to 11.4 and slowly drop to 10.8 as speed increases precat bung values.
Also Jwhite 02 comes in at somewhere at 422RWHP and 490RWTQ. Mods are ported blower,SB TB, 6# lower, custom Pred tune RWTD, Headers, C&L plenum, CAI, Aux idler and elect fan. Not sure if he has the FTVB
My mods on my 03 are ported blower, SB TB, CAI JLP, 2.93" upper L pulley, BOP Recal PCM, Aux idler and I run about 400RWHP and 475RWTQ and that with my original BOP recal and not Del's which should be better. Now we both use the same dyno shop so the numbers are as close to accurate as possible. Now some vehicle are stronger than other and act differently than others to the mods we do.
I'm still waiting to dyno with my C&L plenum and 2.76" upper hoping to see at least 410RWHP which I think is very possible. Just have to wait and see..
Tazz