G5x4 dyno #'s

**z28misfit** · 01-11-2007, 01:43 PM

I have a 99 z28 and had the car dynoed back in June. The car dynoed at 412hp and 368tq. Now this was on a humid 90 degree day. I believe on nice weather it should be closer to 420hp. I don't know if anyone thinks the same, but any input is appreciated. THANKS

Current mods are in signiture.

**z28misfit** · 01-12-2007, 11:59 AM

I'm pretty sure I'm going to be adding an electric water pump and 160degree stat. That should help out just a tad bit.

**T's99BlackLs1** · 01-12-2007, 12:28 PM

uuuummmmmm......500RWP???? I wish!!!! just hope I can crack 400 w/ the same setup - the 90/90. we will find out in mid to late march.

**z28misfit** · 01-12-2007, 12:42 PM

Are you using your stock intake or are you getting the FAST 90 setup?

**whiteghoztt** · 01-12-2007, 01:31 PM

Originally Posted by z28misfit

I have a 99 z28 and had the car dynoed back in June. The car dynoed at 412hp and 368tq. Now this was on a humid 90 degree day. I believe on nice weather it should be closer to 420hp. I don't know if anyone thinks the same, but any input is appreciated. THANKS

Current mods are in signiture.

Good hp, but why is the torque so low? Seems odd.

**BLKCLOUD** · 01-12-2007, 02:59 PM

Originally Posted by z28misfit

I have a 99 z28 and had the car dynoed back in June. The car dynoed at 412hp and 368tq. Now this was on a humid 90 degree day. I believe on nice weather it should be closer to 420hp. I don't know if anyone thinks the same, but any input is appreciated. THANKS

Current mods are in signiture.

So long as your dyno numbers were corrected (and the vast majority are - especially in the summer), then you shouldn't see any appreciable difference with the same mods on the same dyno.

To find out if they are corrected numbers, look at your dyno sheet. The max HP and/or TQ numbers should be preceded by "SAE" or "STD".

I'm pretty sure I'm going to be adding an electric water pump and 160degree stat. That should help out just a tad bit.

The 160 Tstat probably won't show anything. The electric water pump might be worth a few RWHP.

Originally Posted by whiteghoztt

Good hp, but why is the torque so low? Seems odd.

Big cam, which provides a relatively low tq number, but at a higher rpm, providing for the higher HP (given that HP = Tq * rpm).

**whiteghoztt** · 01-12-2007, 03:30 PM

Originally Posted by BLKCLOUD

Big cam, which provides a relatively low tq number, but at a higher rpm, providing for the higher HP (given that HP = Tq * rpm).

Ahh, thanks for shedding some light.

**z28misfit** · 01-14-2007, 07:34 AM

I want the 160 t-stat because first I think running at 210degrees is high for performance and second, when the car was on the dyno the guy said he was running into knock retard. So I assume with the stock t-stat and the 90degree day caused that and would like to prevent that if at all possible.

**T's99BlackLs1** · 01-16-2007, 11:31 AM

The whole reason this question is being asked is b/c a friend of ours dynoed his SS on a real hot day and had 411rwhp. They he did it on a cooler day @ the same dyno w/ out changing anything and was @ 426rwhp. Now this car is s/c if that makes a difference.

**z28misfit** · 01-16-2007, 11:37 AM

That's the thing some say n/a is more affected my hot and cold and some say forced induction cars are more affected. I think on a good day my Z should be at least around 420rwhp. Just want other opinions, hopefully I'm not just dreaming.LOL!

**z28misfit** · 01-18-2007, 01:29 PM

I'm pretty sure the dyno #'s were corrected have to look though. I still don't think that should matter. It's the fact that can the heat affect your results by 10-20hp? Like my buddy T's99blackls1 said, our friend has a P1-sc SS and dynoed at 411hp, then had it redynoed at the same place on better conditions and made 426hp! I'm hoping it's the same in my case as his. The only difference is I'm naturally aspirated.

**BLKCLOUD** · 01-18-2007, 05:56 PM

Temperature (deg F or deg C), water vapor content (% humidity), and air pressure (usually in/hg) will have a direct affect on power, and thus dyno numbers. A dyno records the power you are making in the current conditions. Those numbers are then typically corrected to a certain standard, usually SAE (77F, 0%, 29.23 in/hg).

Theoretically then, and so long as you don't change anything on the car, your corrected dyno number should read the same in 90F weather as it would in 40F weather, even though you will actually make more power in the colder weather.

That's why you correct dyno readings in the first place. If you didn't, they'd be virtually useless, as any differences in power could easily be just the weather and not something you added, tuned, changed, etc.

In the end, its just a number, and fairly useless by itself.

**z28misfit** · 01-19-2007, 12:53 PM

ok, thanks, I guess I'll have to check my dyno sheet. I wasn't sure on the whole SAE corrected # thing.

**z28misfit** · 01-21-2007, 11:53 AM

I looked at my sheet and it has "STD" on written on it. So I guess that means it's corrected according to BLKCLOUD. Hoping for heads in the next month or two, so if I do get some, I'll have to post up the new results!

**BLKCLOUD** · 01-21-2007, 04:25 PM

"STD" is the abbreviation for "Standard" correction. That's a bit different from SAE. For the STD correction, HP & Torque are corrected to a meteorological "standard atmosphere", which is 59F, 0%, and 29.92 in/hg. The end result is that STD corrections show ~3% more power than an SAE correction. For example, if STD reads 310 RWHP, SAE for the same run would read ~300 RWHP.

It really makes no difference which you use, so long as you use the same correction type each time. Of course, STD gives slightly bigger numbers for those that wish to brag about such things.

**z28misfit** · 01-22-2007, 10:29 AM

Thanks for the info. I wish I could have bragging rights about my dyno results,but I don't feel they are worth bragging about. Expected more out of my setup!

**z28misfit** · 01-26-2007, 04:44 PM

This is my dyno sheet( hopefully it shows up,never put a picture on here before)

**z28misfit** · 01-26-2007, 04:46 PM

Ok, cool it worked!

**BLKCLOUD** · 01-27-2007, 05:13 AM

Nice numbers. Notice how high your HP peak is. For optimum ET, you'll want to shift several hundred rpm above that point. However, I assume you have a stock shortblock, so I don't know how well it would like spinning to 7k rpm (which is where it would need to go). That's one of the problems with a big cam like you have - it makes big HP numbers, but at an elevated rpm, so it is hard to take advantage of.

Also....remember that gearing discussion we were having? Throw it out the window. For optimum ET, you'll need more gear.

Finally, that is indeed a STD correction. Notice the "STD: 1.03". That means that your raw numbers were multiplied by 1.03 to correct to STD. Converted back to uncorrected, you made ~400 RWHP.

Again - nice numbers.