Virtual Dyno vs Dynojet at 700hp

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Originally Posted by CoopKill

Man, twice the torque @ 4k from td04 3.1L vs a T4? 2.3L.

That dyno is what JBuhrman is looking to replicate in his Evo. Let's hope the earlier torque will help me out!

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Unless you both race at 3k I don't see how tq helps you there in a race. An FP Black evo is a serious car and it's also a bolt on turbo. Kinda funny actually that a bolt on 3S and bolt on evo can make similar HP. Crazy that 700awhp is available on each in bolt on fashion. Great time to be a gear head.

I'm thinking about a bolt on 62mm for my DSM transplant that should be good for 750 on kill. 75lb/min bolt-on! Wtf! (A DSM black is ~60mm and 68lb/min. Not sure if Evo black is the same comp wheel as DSM)

ive yet to use VD myself since i have a dyno here. Id like to at some point for a comparo. all the the VD cars that have come in here read much lower on the real dyno though. Maybe they are underestimating the weight.. who knows

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Originally Posted by Ray Pampena

ive yet to use VD myself since i have a dyno here. Id like to at some point for a comparo. all the the VD cars that have come in here read much lower on the real dyno though. Maybe they are underestimating the weight.. who knows

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Not all;) My VD read 5hp less than your dyno. No changes, 3rd gear log straight off the trailer, but I have a good road and I feel an accurate weight of my car.

I also read many evoM threads so know what to look for when a graph is junk which has narrowed my road choice to two spots that are accurate and repeatable.

Edit: they may be overestimating their weight. That would make the hp read higher on VD.

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Originally Posted by Ray Pampena

ive yet to use VD myself since i have a dyno here. Id like to at some point for a comparo. all the the VD cars that have come in here read much lower on the real dyno though. Maybe they are underestimating the weight.. who knows

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It has a TON to do with the corrections. My car Virtual Dynoed 750HP before correcting on a good cool dry night at near 30psi (3bar MAP can't see past 29). Corrected it said 700. The temp and baro need to be inputed for consistent results.

Jeff

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Originally Posted by Toni

Nice! I've certainly looked around and found good examples of VDs matching up with Dynos. If you tune on the same road with the same conditions it's a great tuning tool for sure. My big problem with it is that it's so easy to get bad data out. Like you said, bad road, wheel slip, incorrect weights, incorrect ratios, etc. It's very easy for a user to make a mistake either by accident or on purpose. So instead of trusting the dyno/dyno operator, we have to trust the user.

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I very well may be reading into this way too much, but... trust the user? I really don't understand why other people should care what a dyno says. It is a tuning tool for the individual tuning the car. Lets say you are a stock vr4, and have a VD that reads 500hp. Sure it's wrong, but as long as you are consistent, and you get it up to 600hp (using same inputs)... you have made an improvement. It doesn't matter what the number is, all that matters is the comparison to the original/previous number.

Again, I am not really trying to single you out, I see a lot of people say the same kind of stuff. It is not worth getting hung up on the number... ESPECIALLY if the driver sucks at driving haha.

Well my first couple sentences say it's a great tuning tool :) Plain and simple people always want to compare power levels even though all dynos are supposed to be used as a tuning tool. Everyone should only post gain threads and not top power threads lol.

I am actually more reliant on a track slip, but I know thats tough for some! But I agree with you, like I said, I wasn't trying to call you out or anything :)

No worries at all. Track slips can be tough too because people don't practice enough. Couple that with broken cars lol etc, there are always excuses no matter what. The best thing is to provide the most data to average these setups power levels. That was a goal of taken on the new dyno chart site. I'll be accepting VD charts in the future I just need to get some time to make them more obvious.

thanks for posting this. It is like everything in computers, garbage in, garbage out.

If the numbers entered in to it are good, the math formulas are good (they have been shown to be), and the road is smooth there really is no way it can be wrong. A real dynojet is just measuring the drums' acceleration over time (which is a known weight), which is essentially the same as measuring the engine rpms acceleration (held back by the driveline, weight of the car, wide resistance, etc) when the variables are accounted for properly. The virtual dyno software is really no more or less accurate than the variance from dyno to dyno.

The power the car is making going down the road is more important than what it makes sitting still. The biggest issue of course is the danger in doing road tuning on the highway. I'd much rather tune on a dyno than worry about finding a good, safe stretch of road, and then still worrying about things.

An eddy brake dyno does have some advantages though.

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Originally Posted by kywhitelightning

It has a TON to do with the corrections. My car Virtual Dynoed 750HP before correcting on a good cool dry night at near 30psi (3bar MAP can't see past 29). Corrected it said 700. The temp and baro need to be inputed for consistent results.
Jeff

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Yea thats what I mean.. if you werent a savy guy and if you never were on a real dyno.. you wouldnt have known it was reading high. Its user programmed so its great for back to back runs but not great for comparing setups with other people. Mustang and dyno dynamics are like that too. I do so much tuning at other shops and those dynos are all over the place with numbers because the owners have their own user corrections in them. Thats why I favor dynojet. They read the same and theres no user adjustments.