You NEVER dyno in anything but a 1:1 or closest as you can get to it (some transmissions do not have a true 1:1 such as BMWs, etc.).

Now, although Dynojet claims they can "correct" these #'s, it's still just that, a correction. You can't get a true reading in 2nd. I noticed a 15 rwhp difference between 2nd and 3rd (1:1) in my Corvette, and about the same for my Cobra.

Your #'s are high because your dyno operators aren't keen on how to properly get true #'s, whether this was a Dynojet dyno, or not.

BfB

 

Don't care what anyone says... those numbers are impressive... Way to go Snake!

 

Sure, I'm not trying to make his pride be hurt by my remarks, and not speaking for Wes , but I know he is not either. The truth is, anyone can have overinflated #'s, regardless if they are impressive or not.

BfB

 

me and my big mouth.
guess I'll keep my track times to myself.

 

People from Everwet are kinda like that.

------------------
Red 99

 

Hey snake, nice numbers.

A chip/filter combo can pull up another 50hp or so pretty easily these days. I remember Sal's earlier chips (when SHM was also "the rage") added an easy 46hp, and that was a year ago.

Daniel

 

Don't be like that. You come on here and post some nice #'s and then you admit you were tested in 2nd and not direct drive. What are you expecting? We're not trying to hurt your pride, not at all.

I would be more interested in the fact that I have learned some information here on proper dynos of vehicles, the fact that the dyno that tested me doesn't know how to properly dyno a vehicle and would request a redo for FREE or a reduced fee, than I would be in trying to take up for my #'s.

Whether or not your #'s change is cool. I'm not doubting that you have a strong truck, but I would like to see you know that you have "real" #'s so you can really tell if your mods worked as well as others and future mods as well, using the #'s as baselines.

Once again by no means am I saying your #'s are actually fudged, just "?'tionable" that's all. Fudged #'s have also given wannabe-tuners increased sales from scamming people in the past and it continually goes on today.

BfB

 

I completely agree with BfB. You learn something new everyday, and at least you'll have an explanation for your lower #'s when you have the truck properly dynoed.
People need to take dyno #'s with a grain of salt! This does NOT tell you how well the vehicle can perform. It's simply a tuning tool. I'm going to put my Chevy II on a dyno in the next month or so just so I can do some finetuning with the wideband O2 sensor. I think people will be VERY shocked to see the car pull ~450 RWHP. It has 4.88:1 gears, fat slicks, a fat stall, etc., and all of these things will contribute to lower dyno #'s. The dyno doesn't show the complete drag suspension, the consistent 1.4 60' times that it pulls, etc. 95% of the people out there are shocked at how little power it takes to make a car run 10's when you have an excellent suspension setup for your purpose. Take it to the track, and see what it does. Like I said before, your MPH will be the true indicator of what kind of power you're making. It can't be fudged.

 

This post is so funny!

Yep snake has a 392 RWHP truck with ONLY a chip, I must have a lemon, oh well!

As he states, 'I'll let the track times speak for it's self'. That a pretty fair statement.

I wonder if we'll ever seen that 1/4 mile post?

I've only raced 1 other 01 with a chip and he was blah, 350 - 360 RWHP just like me? I must have a tuner with a dyno that posts really low HP.

 

Guys, I'm still not clear why the dyno pull should NEVER be done a non 1:1 gear.

The Dynojet already compensates for rear gearing... and everyone is happy comparing 3:55, 3:73, 4:10 geared L's. Shouldn't be any different for 2nd gear vs. 3rd gear.

I have tested past cars and have always made more a few more HP in the higher gears... so I consider the higher gear results "fudged".

Anyway, the big BENEFIT in doing the pull in 2nd is that the tranny wont shift to 1st... so we could see some nice long 1.5K to 5.5K graphs and really see what mods are doing down low and up high. Instead of just 3.5K+ to 5.5K...

Just my $0.02 worth...

 

The Dynojet isn't a pro at calculations and the software they use isn't foolproof. Rear gears WILL cause lower #'s as well from reduced rwhp. This has been gone over many a times in the past and proven to be true. Rear gears can cause rwhp losses! Dynojet will tell you to dyno in 1:1 and that any reason not to dyno in it is if you can't.

This is true and is very beneficial for this purpose, but there is NOTHING wrong w/ having your car shift gears on the dyno at WOT. My dyno operator does this route just in case we can't keep it in 3rd at a lower rpm. My Vette does 95 in 2nd and runs 175+ in 3rd. They can fix the "spikes" w/ the software and show you the gear you choose.

Overall, if you want truer #'s do a 1:1 run.

BfB

 

I never said I was tested in 2nd.
I was tested in drive with the OD off from 50 mph to 100 mph.

 

That right there says that the run was done in 2nd...unless you're running a set of 5.38's or shorter.
As for dynoing in any other gear other than 1:1, the gear multiplication is producing "multiplied" numbers as well. As BfB stated, do your dyno runs in another gear other than 1:1 if you're forced to. For instance, the '99+ Chevy trucks have a speed limiter at 98 MPH, so you can't do 3rd gear dynos.
As for steeper rear gears, they will net a lower HP # every time, but it will show up as more torque. I saw it when I went from 3.42's to 3.73's in my T/A, and I've witnessed it many other times on other cars.
Like I said, dynos are tuning tools. If you're looking to "bench race" your dyno sheets, it's not hard to get higher peak #'s. Lighter wheels, skinnier tires, lighter driveshaft, etc. will all contribute to better dyno #'s.

 

NM I see what you are saying now. 2nd insteady of D.

Mike

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2001 Lightning
(Recv. Date 05/18/2001)



[This message has been edited by twiztid (edited 06-03-2001).]

 

For the tranny, lower gears will show lower dynojet numbers, higher gears will show higher numbers. I've done this test many times and have seen other peoples results.

Here's the theory.

Here's a sample a found via google - scroll down to the actual dyno plot. I'll try to post some of my dyno plots if anyone cares.

I totally agree with the statements that for the MOST ACCURATE results, run in a 1:1 gear. But running in a lower gear, does not artificically inflate your dynojet numbers (the opposite actually).

[This message has been edited by DreaminAboutL (edited 06-03-2001).]