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Discussion Starter #1
High temps and high humidity are not good combos for drag racing.

I was able to clock off a couple 13.1's which I'm very happy with. It was in the mid to upper 80's with the humidity equaling the temps. The air pressure wasn't great but wasn't bad either. Da was between 2200 and 2500 feet.

I saw a G8 GXP run. It was an auto and the driver did a pretty good job with it. I couldn't find him, but I think it was stock. He ran a couple 13.2's and a couple 13.3's.

There were several SRT8 cars there. Again there must not be any drivers of SRT8's in the Orlando area that can get their cars in the super special mode. They ran between 13.4 and 14.0's. The guy that ran the 13.4 had a Challenger SRT8 6M with a catback and what looked like a K&N intake, or some other intake with a K&N filter and stickers. A guy with a Magnum SRT8 that was all stock struggled with 14.0's till the he all of a sudden hit a 13.7.

A guy in a GT500 ran a 12.6. He had a pulley DR's and an intake and that was all. That suprised me a bunch.

I ran a stock LS2 C6 and beat him to the line due to a better reactin time. He ran a 12.96 at 111 to my 13.11 at 108.

With the high humidity the tires didin't stick very well. Tack prep was poor too and the best 60' I could get was 1.97 on DR's. The Vette got a 2.18 60'.

Guy in a Focus with a 5.0 V8 and rear wheel drive was running mid 11's. It wasn't too loud and if you didn't know what you were looking at you might make a mistake and pull the trigger against this cute powder blue beast.

Well that's about it. There was a bunch of Mustangs. They were anywhere from high 10's to high 14's. A stock S197 Vert with a 5spd auto and a hot chick driving was running 14.4 most of the night. Her boyfriend was riding a 9 second Busa.
 

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Thanks, I have a reputation at Orlando, first two runs were good but as the track got slick I started doing 360's at about the 60 ft mark. They do have nice concrete walls there.............
 

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Good stuff. I assume the LS2 C6 was NOT an A4 and possibly a Z-51?

I would be curious to know the 60fts and trap speeds of the GXP and SRT-8s for what it's worth. How about the GT500 trap speed?

The ETs were so bad due to traction, the trap speeds may be more telling?
 

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Discussion Starter #6
Good stuff. I assume the LS2 C6 was NOT an A4 and possibly a Z-51?

I would be curious to know the 60fts and trap speeds of the GXP and SRT-8s for what it's worth. How about the GT500 trap speed?

The ETs were so bad due to traction, the trap speeds may be more telling?
C6 was an A6. It was not a Z51. The Z51 doesn't make a difference at the strip.

The SRT's were in the 104-107 range.

The GT500 was real high. I think he was at 115-116. He had traction problems it looked like, maybe some driver error too.

Couldn't tell you what the 60's were.
 

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Thanks, I have a reputation at Orlando, first two runs were good but as the track got slick I started doing 360's at about the 60 ft mark. They do have nice concrete walls there.............
I had an event at Speedworld too.

An A4 2004 GTO that was running a 150 shot went down the track ahead of me. It was nighttime so we couldn't see that he lost his transmission at just past the 1000 ft mark. He turned off the track and didn't hit his flahers or anything else to let someone know there was a problem.

I was in my 05 GTO and the 1000' mark was where I shifted to 4th. I made my shift, not a powershift but a real strong shift. The car immediately swung the rear to the right and the wall filled my windshield. I over corrected and saw the eye's of the Cobra driver that I was in the process of beating. They got real big when he realized the nose of my car was aimed at him.

I corrected and wagged the tail a couple of times. I put my foot on the brakes and was instantly in full ABS. I kept my foot planted and when I got past where this GTO had turned off I got some traction.

I put my flashers on and sat at the far end of the track.

Somehow I managed to keep from losing that new car smell, but I'm not sure how.

I still got a sub 14 second time slip from that run. :rofl:
 

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C6 was an A6. It was not a Z51. The Z51 doesn't make a difference at the strip.

The SRT's were in the 104-107 range.

The GT500 was real high. I think he was at 115-116. He had traction problems it looked like, maybe some driver error too.

Couldn't tell you what the 60's were.
So the Z51 has different gear ratios - not enough to effect ETs?

The SRT trap speeds sound spot-on based on conditions and what you shared with me about the track. So get this - my race-gas tune was improperly tweaked so my 2-3 shift sucks. (the 91 daily-driver tune is fine).
BUT...with 1.9x 60fts at Sears Poin I ran a 12.981 @ 106.71mph and 12.949 @ 107.61mph a couple weeks ago. Well off from my canned-tune best of 12.82 @ 109mph and 12.71 @ 111mph with race gas. Similar conditions too.

So anyway, I'm wondering does DA effects ET at all (vs. mph) and I'm thinking these guys do really suck at launching the car?
 

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So the Z51 has different gear ratios - not enough to effect ETs?

The SRT trap speeds sound spot-on based on conditions and what you shared with me about the track. So get this - my race-gas tune was improperly tweaked so my 2-3 shift sucks. (the 91 daily-driver tune is fine).
BUT...with 1.9x 60fts at Sears Poin I ran a 12.981 @ 106.71mph and 12.949 @ 107.61mph a couple weeks ago. Well off from my canned-tune best of 12.82 @ 109mph and 12.71 @ 111mph with race gas. Similar conditions too.

So anyway, I'm wondering does DA effects ET at all (vs. mph) and I'm thinking these guys do really suck at launching the car?
There isn't an easy answer to the Z-51 question. This will show you the gear ratios.

-GEAR------Mode--or--Option
------------Z06---Std 6-spd----Z51 6-spd--6-spd Auto---4-spd Auto
--1st-------2.66----2.66----------2.97-------4.03---------3.06
--2nd-------1.78----1.78----------2.07-------2.36---------1.63
--3rd-------1.30----1.30----------1.43-------1.53---------1.00
--4th-------1.00----1.00----------1.00-------1.15---------0.70
--5th-------0.74----0.74----------0.71-------0.85
--6th-------0.50----0.50----------0.57-------0.67
Rev---------2.90----2.90----------3.28-------3.06---------2.29

Axle Ratio--3.42----3.42----------3.42----2.56(or 2.73)--2.73(or 3.15)


Gear Ratio times Rear Axle Ratio
--GEAR------Mode--or--Option
------------Z06---Std 6-spd---Z51 6-spd----6-spd Auto-------4-spd Auto
--1st-------9.10----9.10-------10.16-----10.32 or 11.00----8.35 or 9.64
--2nd-------6.09----6.09--------7.08------6.04 or 6.44-----4.45 or 5.13
--3rd-------4.45----4.45--------4.89------3.92 or 4.18-----2.73 or 3.15
--4th-------3.42----3.42--------3.42------2.94 or 3.14-----1.91 or 2.21
--5th-------2.53----2.53--------2.43------2.18 or 2.32
--6th-------1.71----1.71--------1.95------1.72 or 1.83
Rev---------9.92----9.92-------11.22------7.83 or 8.35-----6.25 or 7.21

In 2006 the Z51 option on the automatic didn't have a different ratio so there was no advantage in the 1/4 mile. The Z51 weighed a bit more and it's larger rotors caused there to be more inertial mass so it might have been slower.

They added the 2.73 gears to the Z-51 A6 option and that has an advantage. But you can get the 2.73 ratio without the Z-51.

On the 6M there is different ratios and they do have an advantage over the non Z-51 cars.

The Z06 transmission is perfectly matched to the LS2. At redline when you shift, the rpms fall to the torque peak or slightly higher everytime. The A6 with it's wide spread between 1st and 2nd falls off the powerband. Even still with the quick shifts the A6 makes and the gear ratio advantage in 1st, the A6 is the faster drag racing transmission either with or without the 2.73 gears.
 

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Discussion Starter #11
On the other issue, you lose power with heat and humidity or a reduction in air density which is what heat and humidity are doing and altitude also does.

Here are some basic formulas to use for power.

For every 10 degrees above 77 degrees you lose 3% of your hp. For every 10 degrees in temperature drop you gain 3% down to 32 degrees. After 32 degrees you only gain 1%. in power for every 10 degrees.

So in a 400 hp car at 107 degrees you would lose 12% of your power or in effect have 352hp.

Humidity kills 1% for every 10 points above 0%. So at 50% humidty you lose 5%.

For altitude you lose 3% for each 1000'. So at 10,000 feet in the middle of summer on a mountain pass where the humidity is 50% and the temperature is 77 degrees, the LS2 makes 35% less power. That translates into 260hp. The guy you are racing in a Mustang GT has 195 hp and the guy that is watching you driving his 3cyl Geo Metro has 35 hp.

Putting that in perspective, The GTO becomes a 1999-2004 Mustang GT and the S197 becomes a 1983 Mustang GT.

As far as drag racing goes, I lost about 1-1.5 mph running in 85 degree heat with a humidity in the 80's. The air pressure was a bit better than normal. This is versus 65 degrees and 40 percent humidity. My guess is the trap speed drops at a different ratio than the hp.

It seemed like the SRT cars lost about 1-1.5 mph too.
 
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