First Times for the car. Respectable?

Black_02_GT said:

4.10s hm? what does the difference come out to on the track compared to the 3.73, and this is my DD so i dont want anything that is just going to kill my gas mileage

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Good times the first time out. With 4.10s you can still get 20mpg around town and 24 hwy. That's what my old 03 gt got.

Yup, not bad at all for the first time! It takes a LOT of practice to nail good times at the track, it is completely different from driving on the street. Every .1 you can gain in the 60' will give you .2 in the quarter. I can't describe it, but the way street tires hook is way different at the track.

First time I had the 97GT at the track, I ran times pretty similar to yours. I made 6 passes and finally got it from low 15s to 14.67@94. That was the first time driving a manual at the track too, as my other car is an automatic. My new best time is at the bottom, but I know an off-road pipe doesn't gain .4s. lol

Here's an average run for me (for street tires): I drive around the water box, get it streight and I do a small dry hop (just enough to clean the garbage off the tires). Once I'm staged, I get the clutch close to the engagement point and rev her to around 3200. On the launch, I get hard into the gas while letting the clutch engage firmly. A good launch will give slight tire spin or clutch slip, but either way keeping the revs above 3000 without blowing off the tires. The jump from 1st to 2nd is a bit steep, so I run it to about 5200-5300, then from 2nd to 3rd at 5100-5200. Finally, I grab 4th at 5000rpm but the quarter is nearly done. I think it hurts my times that I can't run it out in 3rd. Fast power shifts can make a huge difference in your times, I'd guess at least .2-.3. You don't have to be violent with it, but give it a smooth and positive shift. This took my NPI with only an offroad H pipe to 9.18@77.17. Who needs gears anyway?!

COramprat said:

There is a lot to breaking good runs. Shift points, and launches are the two most important in a stock car. Shifting about 5 grand is the limit. Some people assume shifting at redline is optimal but the stock engine falls off at around 4700. Launches are a science depending on track and grip. I try to launch at 2500 on street tires but slip the hell out of the clutch. Bad for clutch but good for 2.0 sixties.

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A stock 99-04 mustang peaks at 5200 so you would never want to shift below that. As a general rule in racing you want to shift point to be 10% higher in RPM than your peak. Going fast down the track isn't about getting to your peak power it's about staying in your power band as long as possible while going down the track for maximum acceleration. If you shift at or below peak power all you do is allow the engine to drop down to far in RPM slowing you down. By shifting higher you keep the engine RPMs in the sweet spot longer. Just like having steeper gears gets you into that power band sooner. It's all about average power while going down the track.

Bill

Not very scientific, but that's the general idea.

More precisely, you can figure out shift points using a dyno sheet. Take a dyno sheet and plot the speed vs rear wheel torque for every gear (I use excel). Where the torque lines cross are ideal shift points.

I've done this using a dyno sheet from a stock NPI engine. The theoretical shift points are: 1-2 at 5600, 2-3 at 5400, 3-4 at 5000 and 4-5 at 5400. Notice the greater the change in gearing, the higher the ideal shift point. For example, the 1-2 is pretty steep, from a 3.37 in 1st to a 1.99 in 2nd. Same for the 4-5 shift, it is a bit steep, so it pays off to rev a bit higher before shifting.

My syncros have 145k miles on them, and don't like shifting that high, so I was shifting a bit sooner. I'd expect a PI engine to like even higher shift points than what's listed here, but the pattern will be the same: Run out 1st far as you can, it has a huge gearing advantage, run out 2nd nicely but not too far, short shift 3rd. Then, if you haven't won by the end of 4th, you probably not going to...

Mustang92 said:

A stock 99-04 mustang peaks at 5200 so you would never want to shift below that. As a general rule in racing you want to shift point to be 10% higher in RPM than your peak. Going fast down the track isn't about getting to your peak power it's about staying in your power band as long as possible while going down the track for maximum acceleration. If you shift at or below peak power all you do is allow the engine to drop down to far in RPM slowing you down. By shifting higher you keep the engine RPMs in the sweet spot longer. Just like having steeper gears gets you into that power band sooner. It's all about average power while going down the track.

Bill

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can't remember what my 1/8 mile time first time on the track but i ran a 14.2 at 99 with a 2.25 60' with just a catback and xpipe with some ****ty walmart tires (previous owner) i'm going back as soon as the weather is nice with my current mods and new bfg kdw 2's expect to run around 13.8 or so

Black_02_GT said:

4.10s hm? what does the difference come out to on the track compared to the 3.73, and this is my DD so i dont want anything that is just going to kill my gas mileage

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you dont want anything to kill gas mileage huh?? well nitrous is the cure for that drives like stock when you dont want power and hauls when you want it

bhuff30 said:

Not very scientific, but that's the general idea.

More precisely, you can figure out shift points using a dyno sheet. Take a dyno sheet and plot the speed vs rear wheel torque for every gear (I use excel). Where the torque lines cross are ideal shift points.

I've done this using a dyno sheet from a stock NPI engine. The theoretical shift points are: 1-2 at 5600, 2-3 at 5400, 3-4 at 5000 and 4-5 at 5400. Notice the greater the change in gearing, the higher the ideal shift point. For example, the 1-2 is pretty steep, from a 3.37 in 1st to a 1.99 in 2nd. Same for the 4-5 shift, it is a bit steep, so it pays off to rev a bit higher before shifting.

My syncros have 145k miles on them, and don't like shifting that high, so I was shifting a bit sooner. I'd expect a PI engine to like even higher shift points than what's listed here, but the pattern will be the same: Run out 1st far as you can, it has a huge gearing advantage, run out 2nd nicely but not too far, short shift 3rd. Then, if you haven't won by the end of 4th, you probably not going to...

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Right that's the ideal way but I was trying to keep it simple...thus why I say as a general rule. I'm not sure why anyone would shift into 5th going down the track but more power to you. I agree with the concept of shifting higher 1-2, and progressively lowering your shift points but ideally you want to cross the line in 4th.

Bill