Dynojet owners/operators 224 248x inside please

[Frost]

Hey guys have a question or so for ya...

I tune on a local dynojet 224x. The dyno I use does not have the eddy current brake option, so i usually do VE tuning on the street (MOST of my tuning is actually done on the street) and just finish the cars up on the rollers. For NA cars and SC'd cars this works great. HOWEVER... I cannot tune WOT for turbo charged cars ont his dyno at all. As a matter of fact, it doesn't even load up the cars enough to get any type of realistic spooling. I will use my own car as an example... I have a 76mm (P76GTS) front mounted turbo and make 16-17psi on the street FAST in fourth gear (3K-3500 RPMs I'd say) but on this dyno, I cannot make more than about 10psi Obviously I don't want to tune my car on it, but I can't even get numbers out of it. I hav seen an STS car that I didn't tune do the same on it.

Now... obviously the eddy current add-on would be nice, but that isn't going to happen at the place I use. Recently though, another local shop is looking at putting in a dyno and is talking with me about doing their GM work and asked me what I thought about the 248x. I have had my car on a 248 in the past and it had no trouble getting my car spooled and up into boost. I am still concerned about the accuracy of the loading though, which brings me to the central question of this post. For those of you tuning on 248s, when yout tune your WOT for TURBOCHARGED cars on the dyno, does the same final AFR carry over to the street?

Thanks for your time guys.

[EC_Tune]

We have had both 248 and 224x (ours is a 224xLC) and for inertia runs I'm estimating that the 248 with more inertia will load the car more heavily in inertia only mode. We were planning on upgrading the 248X to eddy current but ours was too old to upgrade. Just missed the cut....

[Frost]

this brings up another point.... DJ's website says that the eddy current addon is UNAVAILABLE for the 248x

What about proportional braking?

[VYSSLS1]

look at the dyno dynamics range, will do everything you ever wanted and more

[Frost]

look at the dyno dynamics range, will do everything you ever wanted and more

As a tuner I am sure, but for the DJ has quickly become an "american standard" for numbers. As long as I can get the tuning done on it that I need to, I don't care what brand it is, but the DJ brand is one that people (car owners) all know and relate to already.

[BLOWNZO6]

I am glad I came across this thread.

I have tuned several TT Vettes on a local 248 and have never had any issues with the inertia runs creating boost or duplicating the AFR's that I run on the street or the track.

I am in discussion with DJ now on a 224 and will point my sales person to this thread and see if he has any comment.

This is the first time I have heard of anyone having this type of issue.

[RWTD]

I would highly suggest the 224xLC. I was one of the first customers of Dynojet for this model, and it was definitely the smartest decision I ever made. It is extremely easy to use, and will still give you the famous industry standard Dynojet numbers. I'm also a fan of the fact that you can't screw with Dynojet's software in order to fudge the numbers, like so many Mustang Dyne owners do.

[BLOWNZO6]

I would highly suggest the 224xLC. I was one of the first customers of Dynojet for this model, and it was definitely the smartest decision I ever made. It is extremely easy to use, and will still give you the famous industry standard Dynojet numbers. I'm also a fan of the fact that you can't screw with Dynojet's software in order to fudge the numbers, like so many Mustang Dyne owners do.

You probably know they don't have the 248 any more. I would like to get the LC option, just don't know how useful it would be from a payback standpoint. It would be nice to be able to do the load based part throttle stuff in a safe environment though.

You can add the LC option to the 224 at anytime, so I was thinking of getting the dyno and once the balance of it was covered adding the load brake to it.

I like the last thing you pointed out as well..

[VYSSLS1]

As a tuner I am sure, but for the DJ has quickly become an "american standard" for numbers. As long as I can get the tuning done on it that I need to, I don't care what brand it is, but the DJ brand is one that people (car owners) all know and relate to already.

the "american standard 15-20% higher than every where else in the world"

if you want a dyno to load properly and able to hold a 1500hp car with out raising a sweat you need to look at the DD's

[Frost]

I like the idea of the 224xLC and am good and familiar with the 224x as it is, but the shop owner wants a 248x. I'm not sure about the above comment of not being able to get one, but I know he has been on the phone with DJ quite a bit so I think they wouldn't have him nearly setup with something that they don't have/make. I would hope...

VYSSLS1: I don't know what to say; it is what it is

[BLOWNZO6]

I like the idea of the 224xLC and am good and familiar with the 224x as it is, but the shop owner wants a 248x. I'm not sure about the above comment of not being able to get one, but I know he has been on the phone with DJ quite a bit so I think they wouldn't have him nearly setup with something that they don't have/make. I would hope...

You could be 100% right.. I thought they said they were no longer available. I know for sure that they recommended the 224 to me.

[Frost]

I had some good responses to this thread on ls1tech, so I will link it here in case any are intrested: http://www.ls1tech.com/forums/showthread.php?t=823042

[Dyno Dan]

I won't get into the dynamics of turbo system design and operation, or how those effect "spooling" on a chassis dyno, but I will shed some light on our models and make a few comments.

The early Model 248 (around 1994-1995) was coined "248c", because the "c" was in the part number. Later on, somewhere around 1998, the 248H came on the scene as was indeed physically different. The "H" stood for high inertia, and it had 25% more mass and a higher speed rating (200 mph compared to 160 mph for the original 248c). The latest 248 is called the 248x, and it's easily identified because the drums are painted black. This version of the 248 has additional machining performed on the drums to allow for 2000+ HP testing, and the bearings are also upgraded on this model.

There are also two other variants of the 248 dyno, the 248HW and the 248HS. These versions use drums that are 25% heavier than the 248H and 248X, and the designed for specific markets. The 248HW has a wider frame to accommodate for light trucks (read> diesel tuner trucks and dualies), while the 248HS uses a special bearing system to allow for testing up to 250 MPH. They're are very few of these models in the field, I would say 10-15 units, whereas the rest of the 248's (the one that started it all!) are the "c" or "H" variants.

Where does the 224x fit in? The 224x dyno has about the same mass as the early 248's (248c), and of course, the 224xLC can provide a "frictionless loading environment" to absorb power / increase physical load for any type cycle or load test that you want to perform, similar to a traditional Mustang Dyno or Dyno Dyamics unit.

Personally, with the thousands of runs I made, and hundreds of turbo cars I've tuned, I have never had an issue "getting a turbo car against the gate" and keeping it there on ANY of our inertia loading dynos. Although a car may start moving more #/min or g/cyl of air sooner in the rev range while under increased physical load, it shouldn't have an issue with building enough energy / boost to open the WG.....and stay there for sustained power sweep tests. For what it's worth, if the car is calibrated properly, the AFR on the dyno will match what you see on the street / track.

Dan Hourigan
Vice President, Dynojet Research, Inc.

[BLOWNZO6]

I won't get into the dynamics of turbo system design and operation, or how those effect "spooling" on a chassis dyno, but I will shed some light on our models and make a few comments.

The early Model 248 (around 1994-1995) was coined "248c", because the "c" was in the part number. Later on, somewhere around 1998, the 248H came on the scene as was indeed physically different. The "H" stood for high inertia, and it had 25% more mass and a higher speed rating (200 mph compared to 160 mph for the original 248c). The latest 248 is called the 248x, and it's easily identified because the drums are painted black. This version of the 248 has additional machining performed on the drums to allow for 2000+ HP testing, and the bearings are also upgraded on this model.

There are also two other variants of the 248 dyno, the 248HW and the 248HS. These versions use drums that are 25% heavier than the 248H and 248X, and the designed for specific markets. The 248HW has a wider frame to accommodate for light trucks (read> diesel tuner trucks and dualies), while the 248HS uses a special bearing system to allow for testing up to 250 MPH. They're are very few of these models in the field, I would say 10-15 units, whereas the rest of the 248's (the one that started it all!) are the "c" or "H" variants.

Where does the 224x fit in? The 224x dyno has about the same mass as the early 248's (248c), and of course, the 224xLC can provide a "frictionless loading environment" to absorb power / increase physical load for any type cycle or load test that you want to perform, similar to a traditional Mustang Dyno or Dyno Dyamics unit.

Personally, with the thousands of runs I made, and hundreds of turbo cars I've tuned, I have never had an issue "getting a turbo car against the gate" and keeping it there on ANY of our inertia loading dynos. Although a car may start moving more #/min or g/cyl of air sooner in the rev range while under increased physical load, it shouldn't have an issue with building enough energy / boost to open the WG.....and stay there for sustained power sweep tests. For what it's worth, if the car is calibrated properly, the AFR on the dyno will match what you see on the street / track.

Dan Hourigan
Vice President, Dynojet Research, Inc.

Thanks for your comments Dan

[Bluecat]

I've got a 224 inertia only and never have any trouble loading turbo cars. Usually gearing is proportinal to power. So if they want to make it through the quarter with out running out of gear, big power = little gear. So cars that make close to 1000hp, usually are long legged enough to put them in enough of a bind. Making a pull from 80 to 170 usaully gives enough time and load to make the turbo act normal and get a decent reading. I know its not optimal but I make it work.

Now diesels are another story. Everytime I dyno a big "oil burner", I wish I had a way to load the dyno and slow the pull. On a motor with 800ft/lb and that can only rev to 2500... its over before its starts. The only success I've had is dynoing them in overdrive (if thats an option). Which usually gives them time enough to spool up and slows the pull enough to get a reading.

On another note, I've got a Dynojet that dosen't make "the famous industry standard Dynojet numbers". Mine reads horribly low compared to ones that other shops in my general area have. Ive had several cars from where I used to dyno before I got mine installed, a Superflow in Lexington, KY that constitanly reads 10% more than mine. I had a guy who dynoed 395 make 440 (11% more) on a land and sea in Charleston, WV. Then I had a Cobra that only make 414, dyno 474 (14% more) on the dyno at MD in Cincinnati, OH. From experiance I know it takes 400hp on my dyno to make a full weight f-body trap 120mph. I see people all over the internet make mid 400's and still in the teen's. So I'm pretty sure my numbers arn't typical. Either that or everyone is fudging thier numbers to make them bigger.

[Dyno Dan]

I've got a 224 inertia only and never have any trouble loading turbo cars. Usually gearing is proportinal to power. So if they want to make it through the quarter with out running out of gear, big power = little gear. So cars that make close to 1000hp, usually are long legged enough to put them in enough of a bind. Making a pull from 80 to 170 usaully gives enough time and load to make the turbo act normal and get a decent reading. I know its not optimal but I make it work.

Now diesels are another story. Everytime I dyno a big "oil burner", I wish I had a way to load the dyno and slow the pull. On a motor with 800ft/lb and that can only rev to 2500... its over before its starts. The only success I've had is dynoing them in overdrive (if thats an option). Which usually gives them time enough to spool up and slows the pull enough to get a reading.

On another note, I've got a Dynojet that dosen't make "the famous industry standard Dynojet numbers". Mine reads horribly low compared to ones that other shops in my general area have. Ive had several cars from where I used to dyno before I got mine installed, a Superflow in Lexington, KY that constitanly reads 10% more than mine. I had a guy who dynoed 395 make 440 (11% more) on a land and sea in Charleston, WV. Then I had a Cobra that only make 414, dyno 474 (14% more) on the dyno at MD in Cincinnati, OH. From experiance I know it takes 400hp on my dyno to make a full weight f-body trap 120mph. I see people all over the internet make mid 400's and still in the teen's. So I'm pretty sure my numbers arn't typical. Either that or everyone is fudging thier numbers to make them bigger.

Email me your data7.cfg and I'll check it against our database. There is a chance that your data7.cfg isn't representing your mass, bearing drags, etc etc, properly. The mass number is stamped on the side of the drum (on the rim), and that number should match what's listed under "Drum Information" in WinPEP 7.

[email protected]

Off to the PRI Show

[Bluecat]

Already did that. Worked with support right after I discovered the "non dynojet" readings. Dyno drum spins free. Stamped drum mass number matches my software and your database. Only think I can figure is it was weighed incorrectly.

Dosen't really matter much to me anymore. In the beginning it was a downer because no body wanted to dyno with me. Its different when they can say I only dynoed xxx because it was a Mustang dyno. But when people want to brag about thier numbers and can't because the low number came from a dynojet, it just dosen't work. But my areas pretty small, everyone knows everyone elses. Its finally excepted knowleged that my dyno really does read low because enough people have got redundant results from other places. Now nobody mentions the word Dynojet, then just say I made xxx on Bluecats dyno and its excepted. I would still be worried if it ever changed, but I've make over 900 pulls on it since June, and its never read any different, so I'm sure theres nothing wrong with it.

It would be nice if you could give me a different correction factor to select so I could print out numbers for people that compete with my compeditors. What sucks is the Superflow has "dynojet" corrected numbers that they give thier customers that are 20% higher then what I make. Talk about a kick in the sack as far as people looking for internet numbers to post!