waynet

327red67,
My tune was as follows: The CAGS were removed(one of the most annoying stock features)Air Fuel flow corrected, TM removed from 2nd gear and red line changed to 7200RPM's. Do you still own a red 67? I have owned eight 67's in my life. The last one was a marina blue 427 390HP with air, P/S, P/B P/W and shoulder harness. The car scored 98.7 at the NCRS Nationals with a Duntov award in 1992. I should have never sold it!
Wayne

327Red67

Thanks for the information Wayne, very helpful

Don't mean to hijack the thread too much, but yes I still have my 67. Going on 30+ years now. I bet your car is worth some bucks now with a score like that! Did it have side exhaust? I also have a 390hp 67 w/ side pipes... that car is sometimes more fun to drive than the Z! Just can't beat the sound

robz

Cool, that would be helpful.

MONTVALEGOLF

Congrats Wayne...Great job and consistancy!

Halltech

I agree with your eval. The thing that controls trap speeds, is power and wind direction. On a day with a tailwind, you could probably see 1 or 2 mph better traps than a day with a side wind.

On a day with a headwind, maybe 3 mph down.

Ranger probably has a formula for this as well.

Wayne actually had a run that was close to 132 a few weeks ago.

To be honest, our program update was designed primarily to dial in the air fuel ratio for E10, rather than E0. We did not realize that MD was an E10 state.

On the dyno, there is about 5 HP difference between E10 fuel and E0. Part of that difference is due to the cooling effect of ethanol, and the added benefit of better timing without knock.

We are able to run E10 at 13.7:1 air fuel ratio in open loop, which is nearly stoich (14:1 stoichimetric for E10) without knock.

Imagine what could be done with E85, which is 100 Octane out of the tank.

If the new LS9 comes out as a flex fuel vehicle, running E85 could likely add 15 HP over gasoline.

Typically E10 fuel does not increase hp on the dyno all by itself, since the program from GM has the stoich set at 14.68:1, which is incorrect for E10 (14:1) Reprogramming for the proper stoich through injector pulsewidth and timing changes, does allow slightly better power at all throttle positions.

Jim Hall

dgussin1

I got the weather information from wunderground using mechanicsville, md and used the modular depot DA calculator.

dgdoc

Wind speed and direction definitely make a difference in trap speed. However, there was no noticeable wind yesterday. The only thing noticeable was that it was very cold. Because of this, most of the racers were surprised that their trap speed was down.

Regarding air density, the trap speed also depends on how much HP is made at colder temps. Not sure one can make a blanket statement that says that you will always make enough additional HP to overcome the impact of denser air - regardless of the speed of the car, the temp, or the Cd and frontal area. These are complex equations that go beyond my abilities.

Jim - Maybe you could help defer all these messy calculations by developing a tune optimized for cold climate drag racing.

Ranger

Thanks for the clarification and the effort involved in cranking out the numbers.

The TAG Wx station I carry as part of my track kit produces a reasonable measurement from the scene, once it reaches equilibrium and is kept out of the direct sun.

Ranger

waynet

Ranger and DGDOC
You guys are right again! The most plain and simple explanation of this comes from a friend of mine, who is a very successful drag racer. He said "You can't force wet air through an engine the way you can dry air"

Halltech

The issue of humidity is that the water in the air displaces oxygen, which is only about 21% of the air we breath anyway (sea level)--78% Nitrogen, 21% Oxygen, and 1%
Argon, Helium, Carbon Dioxide, and other gases. Here in WI at 900 ft. altitude, our Wideband O2 sensor baseline is 20.8. Moisture is held in the air (water vapor), which is why wet-bulb humidistats are used to add or subtract value to correction factors on the dynos.

The water vapor actually helps cool the intake charge slightly, off-setting some spark knock, but the amount of water vapor in the air also effects the density. Water vapor is a lightweight gas when compared to Oxygen. When water vapor increases, the amount of Oxygen and Nitrogen decreases. Air density decreases because mass is decreasing.

The scientists out there understand this better than I do, but in its simple explanation, you make more power on a day that has less water vapor in the air.

bernrex

Nice #'s ....

As far as I'm concerned .... you have a STOCK 10 second car.

All you did was give it the tune it deserved (from GM) ... and let some more fresh air get to intake.

Oh yeah .... and better rubber than the runflats offer.

Halltech

I think what is truely interesting is that Wayne experimented with taking the stock PowerCore filter out of his AIS and ran slower than with our F1P30Z RACE Filter. Same speed, which indicates that the 8 to 10 HP gain from the F1 is the same as running without the filter, only much safer.

We have 1" of foam in the F1P30Z, which if oiled, will hold dust and dirt, but not as well as a stock filter. The biggest disadvantage is, if it is oiled, the dirt and dust buildup will require you to clean the filter and reoil it with each engine oil and filter change.

The Halltech PowerCore LS900 replacement "High Flow Street Filter" is the best overall street alternative for long distance and maintainence free driving. Our F1P45Z, has better filtration than any of the filters, when oiled, but has no more power than the stock filter, until very high rpm, where it shines over stock.

Jim

waynet

Bernrex,
Thanks and I agree. It is not too much different than "Pure Stock "(Before brackets were invented) The rules were simple. NO mods to the engine. You were allowed any street tires, as long as they were no bigger than what the factory provided. A tune consisted of: jetting the carb, putting an advance kit in the distrbutor and setting the timming for total advance! Most guys used re-capped bias ply tires with 4 grooves of tread. I owned a new 1969 Dodge Dart GT-Sport 340 with a 4 speed that ran 13.70's in G/PS. Only to be 17 again!

robz

It's also too complicated for me. I do know that colder days produce better trap speeds and that temperature is the biggest factor. Occasionally when the temp is very cold but the barometer is not very high I see a lower mph than normal. Humidity likely plays a similar role in engine power but I think plays a bigger role in et than mph from my limited experience. (track moisture= wheelspin). My point originally is that we're not just measuring engine power but mph which is influenced by so many factors that it's hard to just pin it down to one thing. All of these things have influenced my mph on the strip:
temp
DA
shift points
speed of shifts
type of shifts
60'
tires used
speed of wind
direction of wind
ride height
weight
engine knock
sore back(lol)
etc...
It's interesting to try and figure these things out like, why my mph was down 2mph, for a given day. This knowledge and insight is what makes things evolve faster, bigger, and better.
It's good to learn something new everday.

GaryZ06

I will be calling Jim in a couple of weeks or so for his tune.I a have the Air-Charger....his F1 race filter,AR headers with Hi-flow cats,160 T-stat and hopefully soon to be here GHL exhaust.I am sure Jim's tune will give me very nice numbers

12oh

what size rear slicks? do you have a pic with this combo on the car?

VY427

Jim,

Have you ever tried running the F1P45Z without oil. Maybe this would be a nice compromise. The dry 2 Stage element would likely filter better than a dry Race F1 and make more power than the stock filter everywhere in the rev range.

What do you think? TIA

waynet

Hi 12OH,
The tires are not slicks, but Mickey Thompson Drag Radials size 275/40R17 and mounted on 17 inch ZR-1 wheels. They fit perfect and are smaller than the stock run flats, but they hook MUCH better!

Norm_427

Because the 275/40/17s are a bit shorter (25.66") they give an equivalent rear end gear ratio of 3.56 with the stock Goodyear tires (26.68"). So effectively going from the stock 3.42 to 3.56 is a slight advantage.

Norm

waynet

Norm,
That theory only works on silver cars.
You are exactly right the shorter tire creates a slight bit of an advantage!

Wayne