I'm interested to see what type of trap speeds we will be seeing from stock GTs

 

Topnotch
Nice...

Is that the new Steeda package
One sticker

 

I see alot of people are getting a car education out of this thread, is good to see people willing to teach others, without making them feel like dunces.

 

Yeah, the more I read I feel the less I know, if that makes sense.

 

Been lurking since this time last year and have finally decided to join.

Anyway, I think Topnotch is trying to confirm the guys post. If you go to corral.net and look at the orignal poster's profile, he is a Mustang technician in Pompano Beach, FL, which is where Steeda (Topnotch is employed here) is headquartered. A Screaming Yellow was dynoed supposedly.

Also, the guy at corral.net posted a dyno sheet of an '03 Cobra in August of '02. Wasn't that before they were available?

 

Just when you thought you knew something....

 

Topnotch loves giving hints and clues and letting you draw a conclusion. I have to admit, its pretty fun.

Good to know the dyno numbers are correct.

 

103mph w/ a sorry driver and 105mph w/ an experienced one would kick major tail!

 

Personally, I'm a cruiser, not a racer. [/b][/quote]
Yeah?...so are ricers! :P

 

Yeah?...so are ricers! :P [/b][/quote]
This is a great opportunity to bring in a new generation of gear heads. A $25K 300HP Mustang may bring over some of the "displacement impaired" (or judgement impaired) import enthusiast.

I also think it's great that people are interested in RWHP, gears, and other "gearhead" topics. We shouldn't belittle the new gearheads, we should welcome them!

The gear ratio of the rear end multiplied by the gear ratio of the transmission gear is the effective gear ratio of the drivetrain. We're just going to talk about rear end gearing, so we'll assume the transmission is always in 4th gear. 4th gear is usually a 1.00 ratio (1 to 1), so it just drops out. The gear ratio is the speed reduction ratio and the torque multiplication ratio. The higher the gear ratio number (ie 4.10 vs 3.55) the more the torque produced by the engine will be mechanically multiplied (going to the wheels). Numerically high gears are usually referred to as "low" gears, because they multiply the torque, but increase the speed the engine RPM must be for a given wheel speed.

Why wouldn't you put a really high numeric ratio gear in your car? Firstly, your engine can only go so fast. An extremely high ratio would produce massive torque, but if the engine speed is limited to 6250 RPM, then you might only be able to go 5 MPH.

Ideally for Drag racing you want as high of a numeric gear in the rear end that your engine can tolerate. This usually means that you want a gear ratio that would allow you to be a the redline in 4th gear at your quarter mile trap speed. If your car traps 120 MPH, then figure out the ratio that will make you be at your redline at 120 MPH.

This usually produces a high numeric gear ratio that is undesirable for highway driving speeds. You don't want to have the engine at 4500 RPM going 55 MPH down the highway. I'm out of time, but I hope I helped. Theres a technical gear discussion below, plus an ideal gearing calculator.


How Gear Ratios Work:
http://www.howstuffworks.com/gear-ratio2.htm

Ideal 1/4 Mile Gear Ratio Calculator:
http://www.richmondgear.com/112901.html

 

The '03 SVT Cobras went on sale in June of 2002.

 

With the 2005 GT engine's knock sensors and advanced engine controls, it should run faster if you put 91, 92 or 93 octane in it.

November 2001 C&D had an article about using regular or premium gas. Their conclusion was that for most cars designed to run on 87 octane, you are wasting you money on 91 or higher premim gas.

As part of the article they tested a 2000 Mustang GT. They measured ONLY 2 more HP (rear wheels) when they used 01 Octane in place of 87. However they were somewhat surprised that with the 91 Octane they were able to run 0.3 seconds faster in the 1/4 mile. I'm skeptical of that big an improvement in the 1/4, though. Since they did the 91 octance test 2nd, my guess is they got that big an improvement because they had learned to driver the Mustang better.

 

If you get your car dynoed please realalize that different dyno's will give you diff numbers especially diff types of dynoes A Dyno Jet dyno will be diff from other Dyno Jets but a diff type Like a Mustang Dyno will have a bigger diff.

 

With the 2005 GT engine's knock sensors and advanced engine controls, it should run faster if you put 91, 92 or 93 octane in it.

November 2001 C&D had an article about using regular or premium gas. Their conclusion was that for most cars designed to run on 87 octane, you are wasting you money on 91 or higher premim gas.

As part of the article they tested a 2000 Mustang GT. They measured ONLY 2 more HP (rear wheels) when they used 01 Octane in place of 87. However they were somewhat surprised that with the 91 Octane they were able to run 0.3 seconds faster in the 1/4 mile. I'm skeptical of that big an improvement in the 1/4, though. Since they did the 91 octance test 2nd, my guess is they got that big an improvement because they had learned to driver the Mustang better. [/b][/quote]
hmm dont u get better gas mileage too when ur on higher grade gas?

 

Not ness. The engines ECU is calibrated for different loop modes. Basically open loop (WOT) is calibrated to make the most power period. Closed loop is your driveability, where fuel maps and adaptive fuel curves come into play. Your car is tuned for a specific fuel burn rate (octane level) which means, if you change the octane without the ECU being tuned for it, your not really going to get much effect. The car isnt going to sense a slower burning fuel (higher the octane, the slower the fuel burns) and add more timing. Its going to add its global base timing that is programmed into the computer and not go past that point.

But say you adjust hte ECU, and add more timing. You will also need to raise the knock sensor level along with run a higher octane fuel to take advantage of it (and keep teh car from detonating). What happens when you mistakenly run 87 in the car when its tuned for 93.. well for one I hope you dont redline it... 2 the car is going to detonate due to increased timing and the knock sensor will kick in and pull xx amount of timing out till it doesnt sense knock anymore.

This all make sense?

 

The purpose of the knock sensor is to automatically allow the PCM to advance the timing as far as possible now matter what octane you are using. I don't know if the EEC-IV on the 99-04 Mustang works this way, but Ford's latest Black Oak PCM system as used in the Lincoln LS, T-Bird and now the 2005 Mustang, it automatically adjusts the timing as far as possible. With Black Oak there are no adjustements to be made if you change the octane you are using.

The LS & T-Bird are designed to run on 91 octane gas. If you put in 87 octane you will not harm the engine, but the engine timing will be retarded so much that both gas mileage and power will suffer.

The results on the 2005 Mustang may be different since it is designed to run on 87. But I would suspect that if you put in 91 or higher octane I would expect the PCM will let the timing advance more which normally would increase power and improve gas mileage.

 

Thats true to a point, but a mustang drivetrain absorbs about 35 to 40 hp max when lightly stressed. Higher HP applications may cause the drivetrain to absorb more (torque capacity of components being exceeded causing the parts to shift around and bind) but that would put it around 300 hp.

 

FWIW, I got a reply from the guy who originally posted the dyno numbers. The email came from steeda.com

He clarified that the numbers are thus:

292 ft-lbs @ 4300 rpm and 275 HP @ 5300 rpm.

Here is his email (I had also asked him about tuning software, so that is what the last part of the email is about):

"I do work at a very reputable mustang shop and thats why we have one so early....dont be fooled there are other cars out there as well. as for the dyno sheet Im not at liberty to release that yet...it will all be shown soon...just take my honest word. the SCT software can be purchased directly from them if you want to be a dealer but i warn you its expensive!!! i recommend you waiting for the hand held tuner coming out in late october."

Shea back here...in regards to tuning, personally, I think it is dumb to have to buy a hand held tuner. I already have a computer, all I need is an adapter and software to hook up to the car. A hand held tuner is just a small computer with the right software and hookups. I'll scour the net for some freeware to mod this car. I'm sure some gearhead geek will code it up. Gotta love the digital age!!!

All that being said, this guy was quite helpful, so my hat is off to him for giving us some cool info.

Going by the proper 15% drivetrain loss rule (I see some people were using 20%, which is not correct), that would give our Stang 324hp and 344 ft-lbs.

 

Those are awesome #s.