Dyno correction factor

[From The Future]

Tuning wizards of the forum... educate me on correction factors used on typical dynos.

I finally found a semi-local shop with a Dynojet and I went down yesterday to do a few pulls and get some numbers. I chose Dynojet because I feel like I know what a stock LS3 makes on a Dynojet based on what I have seen on this forum (about 365-370). I wanted to see how much of an increase I had made.

I was a bit disappointed, my best WHP number was 384 and my best Torque number was also 384, but on different runs. I had hoped to hit 400 WHP with the mods I have.

The Dyno operator told me they didnt use a correction factor on theirs. Now that I look at all the dyno sheets posted on here, most seem to have SAE correction on them.

How does this affect the dyno numbers? Does it make them higher or lower? I dont really know exactly what the correction entails other than ambient air temperature and barometric pressure.

It was 94 degrees in the shop on my best run, I feel like that affected things a bit. I also feel like I need some more hot rod parts for my car!

Can anyone guesstimate what my 384/384 numbers would have been if the dyno operator had used SAE correction on my runs?

[SGOS252382]

Here's a good read from GMHT about dyno numbers. http://www.gmhightechperformance.com...wer/index.html

Basically SAE numbers are corrrected to 77 degrees
STD numbers are corrected to 60 degrees
And uncorrected numbers are just that uncorrected.

That's why STD numbers are traditionally higher than SAE numbers. Uncorrrected numbers can be high or low depending on the weather. altitude, etc.

So your numbers would be a little higher using SAE numbers and you'd most likely see a nice jump if using STD numbers in summer conditions.

My best guess is you'd be in the 39x rwhp range SAE and 40x rwhp range STD.

[From The Future]

hey SGOS252382, thanks for the info and a most informative link. That makes me feel better about the numbers since it was so hot in the shop at the time of the runs

There is another link within that GMHP article that will supposedly let me download the Dynojet Winpep software. I am about to go try that.

If I can get the software loaded, I will then call the dyno shop and get them to e-mail me the .drf file of my dyno runs. That will give me something to play around with. Maybe I can even get it to show me some corrected numbers.

Thanks again for the info and the link, now I guess I need to start looking around for camshafts...

[JANNETTYRACING]

Originally Posted by From The Future

hey SGOS252382, thanks for the info and a most informative link. That makes me feel better about the numbers since it was so hot in the shop at the time of the runs

There is another link within that GMHP article that will supposedly let me download the Dynojet Winpep software. I am about to go try that.

If I can get the software loaded, I will then call the dyno shop and get them to e-mail me the .drf file of my dyno runs. That will give me something to play around with. Maybe I can even get it to show me some corrected numbers.

Thanks again for the info and the link, now I guess I need to start looking around for camshafts...

The Corrected numbers are only as good as the Calibration of the Weather station connected to the dyno.

Basically on a Hot day, Anything above 60 Degrees, Dry air, 29.92 Baro, your Corrected Numbers would be Higher than actual.

We have seen Corrected numbers that don't add up from a couple Dyno jets where I believe that the Baro Sensor calibration is off by as much as 10%

[From The Future]

Ted, Thanks for the info and thanks for taking a look at my tune the other day as well.

I wish I could find a place around here that sold ethanol-free gas that was consistently good. I think my car pulled 5-6 degrees of timing at high rpm even with the octane booster I added to the "good" gas I thought I was buying.

I got the Dynojet software loaded, now if I could just get the shop to e-mail me the .drf file I could look at the corrected numbers. My best uncorrected numbers were 384 hp + 384 tq on a 94 degree day.

I still need to make some changes to get more power though. Does anyone know how much of a HP/TQ gain I would get from LT headers vs my current JBA shorties/JBA midpipes combo?

[Parag]

The shorties and midpipe added very little over stock. And ive heard people getting 70 hp with just headers and a good tune

[Rhino79]

LOL, 70 rwhp with headers and tune.....no. Hell no.

[Tampa Tuning]

Originally Posted by Parag

The shorties and midpipe added very little over stock. And ive heard people getting 70 hp with just headers and a good tune

More towards 50 RWHP with LT headers and the rest of the bolt ons and a tune with a real tune plugged in and with a wideband.

Dynos are great to see numbers and play a roll in tuning, but the numbers arent the best factor. Track times are the best tool.

I enjoy both dyno and street tuning, but street tuning give me reading through all the gears. Dynos are one gear. If you have a very good air intake like Vararam, on the steet while scanning, you'll see it leaning out some because if the extra air your pulling in at speed.

On a dyno, you can only allow for it.

the good side of dyno tuning it sure saves me time from a business sense.
www.TampaTuning.com
Phil

[JANNETTYRACING]

Originally Posted by From The Future

Ted, Thanks for the info and thanks for taking a look at my tune the other day as well.

I wish I could find a place around here that sold ethanol-free gas that was consistently good. I think my car pulled 5-6 degrees of timing at high rpm even with the octane booster I added to the "good" gas I thought I was buying.

I got the Dynojet software loaded, now if I could just get the shop to e-mail me the .drf file I could look at the corrected numbers. My best uncorrected numbers were 384 hp + 384 tq on a 94 degree day.

I still need to make some changes to get more power though. Does anyone know how much of a HP/TQ gain I would get from LT headers vs my current JBA shorties/JBA midpipes combo?

You can expect about 28 RWHP from adding headers to your set up.

LS3s make on average 415 RWHP with CAI LT headers and Tune on 93 octane.

[SGOS252382]

Originally Posted by Parag

The shorties and midpipe added very little over stock. And ive heard people getting 70 hp with just headers and a good tune

70 hp from headers and a tune is as likely as seeing Bigfoot on your way home from work. Jannetty's numbers are more realistic.

[EliteCZM523]

I made 445/444 with LT's, Vararam, UD Pulley, Tune. Never got a baseline done, so mine might have been stronger from factory

[JANNETTYRACING]

Originally Posted by EliteCZM523

I made 445/444 with LT's, Vararam, UD Pulley, Tune. Never got a baseline done, so mine might have been stronger from factory

Severely inflated Numbers, Dyno is out of calibration Unless you have a Cam you are not telling us about.

The Highest LS3 with your mods ever Recorded on an Accurate Dyno was like 421 and we are skeptical at that.

[SGOS252382]

Originally Posted by EliteCZM523

I made 445/444 with LT's, Vararam, UD Pulley, Tune. Never got a baseline done, so mine might have been stronger from factory

And track times?
With 445 rwhp your traps speeds would be really fast.

[EliteCZM523]

Let me dig up the dyno sheet. No cam when the dyno was done...has one in it now though!
Just with VR and UD pulley + Tune I was trapping 109-110....havent gotten back to the track since though. IIRC, a E-Forced Corvette A6 with Gears and Converter made around 540 ish on same dyno, same night....could be off a little bit on the Vette's #'s though!

[From The Future]

Well, it sounds like I need to move on over from shorties/hi-flow midpipes to the LT Headers alright. The Stainless Power LT's that JRE has on their website look like a good option for me, especially since Ted will also provide an updated tune to go along with them.

Does anyone know if the Stainless Power headers come with extensions for the oxygen sensor wires?

Or maybe they dont require any because the stock wires are already long enough to reach to the new O2 bung?

Some of the LT header kits I have seen photos of appear to come with wiring extensions. My JBA midpipes have the O2 bung in the same place as the stock midpipes so it wasn't an issue.

[JANNETTYRACING]

Originally Posted by From The Future

Well, it sounds like I need to move on over from shorties/hi-flow midpipes to the LT Headers alright. The Stainless Power LT's that JRE has on their website look like a good option for me, especially since Ted will also provide an updated tune to go along with them.

Does anyone know if the Stainless Power headers come with extensions for the oxygen sensor wires?

Or maybe they dont require any because the stock wires are already long enough to reach to the new O2 bung?

Some of the LT header kits I have seen photos of appear to come with wiring extensions. My JBA midpipes have the O2 bung in the same place as the stock midpipes so it wasn't an issue.

Yes they come with O2 harness extensions but we recommend ordering the optional GM Gaskets as they do not come with any, just a tube of RTV

[From The Future]

Well, I took the plunge and ordered some 1 7/8" LT headers from JRE this morning. They already sent me my invoice and my shipping information too. I should have the goods on Thursday. How's that for some awesome service?

If I really do pick up 28 horsepower from these headers and the new tune I will be completely stoked. If it was 5 HP it wouldn't be worth it but I think 25+ HP will be quite noticeable.

I wonder how much louder these will be? I guess I will find out soon enough. Thanks go out to JRE for great service.

[JANNETTYRACING]

Originally Posted by From The Future

Well, I took the plunge and ordered some 1 7/8" LT headers from JRE this morning. They already sent me my invoice and my shipping information too. I should have the goods on Thursday. How's that for some awesome service?

If I really do pick up 28 horsepower from these headers and the new tune I will be completely stoked. If it was 5 HP it wouldn't be worth it but I think 25+ HP will be quite noticeable.

I wonder how much louder these will be? I guess I will find out soon enough. Thanks go out to JRE for great service.

Thank you for Choosing JRE.

Ted.

[dkg11]

If you go to Mustangdyne.com then go to performance dyno's there is a link on the bottom left that has a dyno locator and you can find a dyno closest to you