View Full Version : Dyno Numbers Question
Dan12GT
10-07-2012, 01:06 PM
I learned a bit more about dynos yesterday; there are a few different types. I didn't realize there were even different types of Dynojets (STD/SAE). Anyway one thing I didn't expect to see was the same horse power number as I had in the past. Here is some history: My wife bought me a dyno session with HPP back in February (pretty sure it was colder then). The car was bone stock, still had temp tags :) It put down 382/359. Pretty reasonable. This was on a STD dyno. So yesterday I dyno with an added Air Raid intake and full Borla S-Type Catback. I dynoed 382/387 yesterday. I picked up a significant amount of torque but I thought it was odd my horsepower remained exactly the same. Now I know several other things factor into this like altitude, air temp, etc and it was on a different dyno. I just thought it was odd the HP didn't move at all, up or down. I expected a little bit more considering what I have done so far. I know I hardly have anything done for performance but this just kinda threw me.
PLASMAN
10-07-2012, 01:13 PM
The factory air box flows well, and if you havent tuned for a CAI and used a bigger MAF then you will not see a gain in power. The exhaust will benefit the low end torque and your running the same program as your initial dyno run
There are also always differences between dyno's. i picked up 10HP/15TQ from my dyno at HPP. It was also not 103* like my first session and the DA was better yesterday.
Had a guy with a GT500 that dyno'd at gearheads 2 weeks ago with full TVS setup and did 575/575, yesterday he did 640/640 which is where it should be
As mentioned that Cai will do nothing for you without removing the restrictor in the maf and getting a tune to take full advantage.
Dan12GT
10-07-2012, 03:34 PM
I guess the factory air box is built quite well then. I have heard this before too. I guess this proves it quite well for me. Now I guess I just need to decide if I want to bite the bullet and throw away the warranty for a tune.
downtime!
10-07-2012, 03:40 PM
Tuning hasn't ever voided a warranty on any car I've ever owned. It can cause grief if your service manager is a prick, but if you have a good one that understands what a tune actually does, you shouldn't have any issues.
Taxman
10-07-2012, 06:00 PM
Tuning hasn't ever voided a warranty on any car I've ever owned. It can cause grief if your service manager is a prick, but if you have a good one that understands what a tune actually does, you shouldn't have any issues.
Actually I've heard Ford has put out a TSB that tuning WILL now void your warranty.
Midnight11
10-07-2012, 06:09 PM
Tuning hasn't ever voided a warranty on any car I've ever owned. It can cause grief if your service manager is a prick, but if you have a good one that understands what a tune actually does, you shouldn't have any issues.
yes tuning will void warranties on 5.0s. technically you cant even put a kn air filter on it from what the tsb said
Dan12GT
10-07-2012, 07:15 PM
yes tuning will void warranties on 5.0s. technically you cant even put a kn air filter on it from what the tsb said
Well shoot I am already screwed then if that is the case. Might as well go tune! lol.
I have heard though that the cause of failure what ever it may be must be linked back to what modification was done to cause the failure. Obviously an engine tune won't cause something somewhere else like in the differential to fail spontaneously.
It seems like such a grey area... blah.... sooo tempted to tune...
PLASMAN
10-07-2012, 07:23 PM
Its the magnusson moss act, they basically have to prove that the modification caused the failure of said part to void the warranty. It can get to be a long ugly battle...
Also realize if you bought an extended warranty when you purchased your car that you can cancel it at anytime for any reason. They have to refund you a prorated balance of unused warranty by law. Did after i ported my shelby's blower after I had the car for 2 years and still got back $1500. Dealers hate this cause it comes out of their bottom line and gets charged back to the finance dept. if they void your warranty, then cancel it on them and get a portion of your money back.
Doug1227
10-07-2012, 07:26 PM
STD and SAE are correction factors available on all dynos, not actual different dynos. The most common 2 types of dynos are dynojet and mustang. Mustang typically reads lower than dynojet, but even dynojets will vary a little one from another. Not sure what all influences this but certain tuners are known for having higher or lower numbers than others.
DirtyD
10-07-2012, 08:23 PM
STD dyno numbers are what your car out down at that exact time, on that day, in those conditions. Basically incorrect end. Colder atmosphere yields higher STD numbers that a hotter atmosphere. SAE applies correction factors to the numbers to account for atmospheric conditions, locations, etc. So as long as the car is dynoed in the same configuration in both conditions, the SAE numbers should read pretty close to each other (within 5 HP I'd say...)
STD dyno numbers are what your car out down at that exact time, on that day, in those conditions. Basically incorrect end. Colder atmosphere yields higher STD numbers that a hotter atmosphere. SAE applies correction factors to the numbers to account for atmospheric conditions, locations, etc. So as long as the car is dynoed in the same configuration in both conditions, the SAE numbers should read pretty close to each other (within 5 HP I'd say...)
Actually there are 3 common correction factors, STD, SAE, and Uncorrected. Uncorrected is how much hp the vehicle made that day at that time on that dyno. STD and SAE both take that uncorrected number and multiply it by a correction factor to give the best reading of what the vehicle would make in ideal conditions. Each give hp numbers by using load, rpm, etc and inputting them in a mathematical equation. Dyno numbers will vary dyno to dyno, day to day, engine temp to engine temp. There are so many variables that WILL cause numbers to be different its un real. You can almost literally make a dyno read any number you wish. We have set ours up to give the most accurate numbers possible and we maintain it to ensure its calibration is precise at all times. A lot of shops do not properly maintain their dynos thus causing variations.
DirtyD
10-07-2012, 10:16 PM
I always understood STD to be the uncorrected form. Thanks for clarifying that, Toby.
It still seems that SAE reads a more realistic number to me.
I always understood STD to be the uncorrected form. Thanks for clarifying that, Toby.
It still seems that SAE reads a more realistic number to me.
:High 5: No prob
Grandpa
10-07-2012, 10:22 PM
Actually there are 3 common correction factors, STD, SAE, and Uncorrected. Uncorrected is how much hp the vehicle made that day at that time on that dyno. STD and SAE both take that uncorrected number and multiply it by a correction factor to give the best reading of what the vehicle would make in ideal conditions. Each give hp numbers by using load, rpm, etc and inputting them in a mathematical equation. Dyno numbers will vary dyno to dyno, day to day, engine temp to engine temp. There are so many variables that WILL cause numbers to be different its un real. You can almost literally make a dyno read any number you wish. We have set ours up to give the most accurate numbers possible and we maintain it to ensure its calibration is precise at all times. A lot of shops do not properly maintain their dynos thus causing variations.
Very nice explaination Toby.
In the current state of the hobby, there is way too much emphasis put on dyno numbers. It's just a tool to tune a car, but more often than not it's used as a way to equate how fast a car is going to be which isn't true at all. The only true way to do that is race.
DirtyD
10-07-2012, 10:29 PM
Very nice explaination Toby.
In the current state of the hobby, there is way too much emphasis put on dyno numbers. It's just a tool to tune a car, but more often than not it's used as a way to equate how fast a car is going to be which isn't true at all. The only true way to do that is race.
I see it as a comparison tool. You can use it to measure gains from mods, that you can then couple with track times to back to those power gains.
I see it as a comparison tool. You can use it to measure gains from mods, that you can then couple with track times to back to those power gains.
I think what steve is trying to say is what a car puts down at the tires has nothing to do with what i might run at the track. For example with an auto trans, if the converter is not locked during a pull, it can affect the numbers by as much as 20-30 hp, now let me emphasis on the CAN part. Also things like the stall speed of an aftermarket converter will affect the dyno numbers. Dynos were invented as a useful tool to assist in tuning a car, diagnosis a problem, properly calibrating a speedometer, etc. They are used for much much more then just finding a number.
DirtyD
10-08-2012, 09:53 AM
I think what steve is trying to say is what a car puts down at the tires has nothing to do with what i might run at the track. For example with an auto trans, if the converter is not locked during a pull, it can affect the numbers by as much as 20-30 hp, now let me emphasis on the CAN part. Also things like the stall speed of an aftermarket converter will affect the dyno numbers. Dynos were invented as a useful tool to assist in tuning a car, diagnosis a problem, properly calibrating a speedometer, etc. They are used for much much more then just finding a number.
Gotcha. In that sense, I agree.
Dan12GT
10-08-2012, 10:41 AM
There are so many variables that WILL cause numbers to be different its un real. You can almost literally make a dyno read any number you wish.
This is why I felt it was so strange I made exactly the same HP number. Anyways, thanks for the lesson on dynos Toby!
This is why I felt it was so strange I made exactly the same HP number. Anyways, thanks for the lesson on dynos Toby!
Anytime! :High 5:
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