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Discussion Starter #1
Well I hit the Superflow this morning because they swore they could lock up my converter. They lied! It did an even worse job than the 2WD Dynojet, but at least it didn't make wavy lines. Whoopee! They seemed to have other issues too. I believe their boost sensor line had a leak in it. Somewhere we lost over a pound of boost since my last log. Nothing's changed on my Jeep, and it doesn't feel down on power. Took a guy from work for a ride afterwards. He rode in it before the cam/converter too. Said wow, it didn't snap my head like that before.

Whatever their problems, it showed 122 hp less than the 2WD Dynojet I was on last. Not possible. ??? So looks like I'll have to wait for the track to open and calculate accurate numbers form my slips. Apparently I'm un-dyno-able now. :confused: I sure as hell won't spend another penny spinning rollers for fantasy numbers!

These were both 4th gear pulls. We did try 3rd on the last pull. It showed 478 hp. I don't believe a 38 hp gain from a different gear. Plus last time I was on this dyno (with no converter) 3rd to 4th didn't show that much difference. It was more like 5 hp.

Fantasy 1 - 2WD Dynojet


Fantasy 2 - AWD Superflow


I wonder if our crippled TCM could be playing a role here...

wink
 

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Yeah, i wouldn't spend anymore money on dyno's if i were you. let the track do the talking for your beast :D
 

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I Wouldn't be worried Wink , Track numbers is what counts , you could very well make more or less depending on the dyno you hit .
 

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Discussion Starter #4
Yeah, i wouldn't spend anymore money on dyno's if i were you. let the track do the talking for your beast :D
I Wouldn't be worried Wink , Track numbers is what counts , you could very well make more or less depending on the dyno you hit .
Yeah Michael said don't worry, you'll be where you wanted to be at the track. Just ranting because I wanted to see the numbers say I got what I paid for. Be different if the track was already open. I wouldn't have pissed away that money this morning...

wink
 

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Nice smooth Dyno run Wink! Like others have said hitting the track will also tell you if you really gained anything....
 

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Discussion Starter #7
Nice smooth Dyno run Wink! Like others have said hitting the track will also tell you if you really gained anything....
Yeah I know about the track bro, but it's been closed for 5 months, and still 2 more weeks to go. So since I can't go run I wanted the numbers to do my what ifs. They were quite accurate last season, and using the same dyno I was on today. I'm just frustrated more than anything else at this point. But I got a new toon tonight so that'll entertain me for a bit. ;)

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Wink, you know that the superflow and dyno dynamics dynos read lower numbers than the dynojets do. Dynojet reads the highest and are the least accurate. Then mustang dynos, then superflow and then dyno dynamics. Don't sweat it bro, the track opens in 2 weeks.
 

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Discussion Starter #9
Wink, you know that the superflow and dyno dynamics dynos read lower numbers than the dynojets do. Dynojet reads the highest and are the least accurate. Then mustang dynos, then superflow and then dyno dynamics. Don't sweat it bro, the track opens in 2 weeks.
Yeah I know bud, but not 122 hp lower. Even the Dynojet estimator on the SF says 465 on a DJ. That's only a 25 hp difference. That I could buy. It's the converter plain and simple...

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Mike i cant see why there having trouble with your jeep and convertor because theres a lot of guys out there with a convertor with no problems unless its just your convertor and there could be a problem with it. Like Paulie said its just for tuning as i have beat guys with 20 more hp than me at the track.
 

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Discussion Starter #13
he isnt. that was clear IN ALL HIS POSTS.

PLUS he did about 200 passes on his 2010 last season.
188, but who's counting. :rolleyes:


Mike i cant see why there having trouble with your jeep and convertor because theres a lot of guys out there with a convertor with no problems unless its just your convertor and there could be a problem with it. Like Paulie said its just for tuning as bi have beat guys with 20 more hp than me at the track.
It's definitely the converter, but also the particular dynos. Here's some info from Precision Industries...

The Truth About Dynamometer Readings and High Stall Torque Converters

There is a misconception and a lot of misinformation about the poor vehicle performance numbers that are generated by testing a car with a high stall torque converter on a dynamometer. Most people that are not familiar with how a torque converter operates will automatically think that the torque converter is inefficient. This is totally false and the following facts are why you should not believe the dynamometer numbers while using an unlocked high stall torque converter.

All late model dynamometers have a software program that commands the loading and speed of the vehicle over a certain period of time while making a test pull. The software used in these dynamometers is setup to be used with a locked 1:1 connection between the engine and the rear wheels, such as using a standard shift transmission in 3rd gear or when an automatic transmission has the torque converter clutch locked. When an unlocked high stall torque converter is used to make the pull and the dynamometer software has not been changed to allow for the fluid coupling differences the dynamometer readings will all be bogus.

For instance, the low rpm torque readings will be high due to the torque multiplication of the torque converter being run in partial stall. Likewise, the high rpm torque readings will be low due to the long period of time the dynamometer takes to allow the torque converter to transition from partial torque multiplication to a hydraulic locked condition. The only cure for this phenomenon is to rewrite the dynamometer software to prevent this from happening. Torque converters with a low STR or low stall are not as adversely affected by this phenomenon. The high rpm transition problems never occur when the vehicle is being driven or raced normally. Therefore, worrying about what the dynamometer numbers are is a total waste of time.

If your dynamometer operator refuses to alter the software to give correct readings then the only things you can do is (1.) lock the torque converter clutch and do the testing, (2.) use the readings you get with an unlocked torque converter as a baseline and continue to tune the car like normal until you get the best numbers remembering these are just numbers and not the actual horsepower and torque or (3.) use a dynamometer shop that gives you the service you deserve for your hard earned money. The only really true test of the performance of a vehicle is to take it to the track and see what ET and MPH the car will run.
So I expected this from other units. I'd already seen it in action on my tech's DJ, and he confirmed his software lacks the code to lock it up. What irritated me is I went by and talked to Carz before making an appointment, and was assured it wouldn't be a problem on theirs. I even rode in the Jeep for two pulls. He said it's locking I feel it. As the only person that's driven my vehicle for several months with the converter, that's BS, especially the way he was rolling on the throttle. Their boost sensor was defective as well.

But I realize the numbers aren't the end all be all, so give it a rest guys... But in lieu of an open track to make passes, it's all I've got to see where I am, and calc where I think I'll be this season. And as I stated before, this is the same dyno all my previous baselines were run on. Dynos are for more than tuning (and personally I think the worst place to tune except for a baseline, and then only really for exotic setups), they are also to see gains/losses from mods. And for those that are curious, from my last season slips I was making ~470 hp before the latest mods according to the calculator.

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The first one looks like a seismograph from Japan.
 
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