When to shift

[lee07]

Taking it down the 1/4 this Sunday, 1st time

 

What rpm is best to launch and when is it best to shift into 2nd?

 

Was thinking 3500 for launch and around 4500 to shift into 2nd

 

2nd to 3rd and 3rd to 4th maybe 5500?

 

When does the time start? When the light turns green or when your tires move?

 

05, 5spd

[JermTheElf]

Stock turbo?

[iNVAR]

Never been to the strip, but I'm fairly certain 3500 for a launch is not high enough for a fast launch. Try more like 4500-5000. If you value your drivetrain, you shouldn't be dumping the clutch either. You should slip it.

 

And you're not supposed to be revving it up to a constant speed either. If you hold your engine speed at say... 4500, you are building absolutely no boost. However, if you're blipping the throttle instead and get it on the "upstroke" of the engine rev, you are giving the engine load and it will develop boost much quicker.

 

If you have launch control, that's a different story....

 

As for the other question about when the time starts, maybe you should Google the drag process and what the lights on the Christmas tree actually mean.

 

As far as when to shift, I believe you should be shifting at about 5500-6000 because the turbo will lose VERY rapidly after 6K. But 4500 I think is a bit too early.

 

Disclaimer: the above is just my 2 cents. Lots more experienced people will hopefully chime in. I defer to their experience. I'm also assuming you're on the stock turbo.

[lee07]

vf52, lwfw

[iNVAR]

lwfw? yeah, 3500 would most likely not be enough for a nice hard launch. also, vf52 you should be able to bring it up to 6K and shift around there. again, my opinion from what i know.

[JermTheElf]

You should get the launch control patch. But I've read first gear you usually want to shift around 5000, then second and third closer to 6000

[underground000]

right when the last yellow light lights up you go, it takes time to get everything going thats why....

 

when you do launch, rev it but dont hold it there cause youre just gonna heat soak the tmic, and when you do let go of the clutch. let go in a hurry do not release it all at once

 

do you have a boost gauge? if yes look where the boost starts tapering and shift when it begins to taper to stay in the power band

 

everything you'll get a hang of after a few passes

[NSFW]

When does the time start? When the light turns green or when your tires move?

 

The timer starts when you leave, so don't worry too much about reaction time. It only matters for competitive racing.

 

Run 1st and 2nd all the way to redline. Run 3rd until you feel the power drop off - until just before you feel the power drop off, really. It will take some practice but it'll probably be around 6000 RPM. You'll run out of track before you need to shift out of 4th.

 

For launching, the key thing is not to bog - not to let the RPM drop too low. You do that by holding RPM high (3500, maybe 4000 RPM) and using clutch slip to get the car moving without pulling the RPM down too low. Or if you have a rear-biased diff, you can use wheelspin instead of clutch slip, but the stock LGT center diffs are all 50/50 split if I remember right.

 

When you shift, get back on the throttle before you release the clutch, so that the engine RPM comes up, and the engine is pulling you forward when the clutch grabs.

 

The main thing is to drive it like you stole it. You won't get a decent time if you launch and shift like you do on the street. It's kind of painful at first.

[GTTuner]

The timer starts when you leave, so don't worry too much about reaction time. It only matters for competitive racing.

 

Run 1st and 2nd all the way to redline. Run 3rd until you feel the power drop off - until just before you feel the power drop off, really. It will take some practice but it'll probably be around 6000 RPM. You'll run out of track before you need to shift out of 4th.

 

For launching, the key thing is not to bog - not to let the RPM drop too low. You do that by holding RPM high (3500, maybe 4000 RPM) and using clutch slip to get the car moving without pulling the RPM down too low. Or if you have a rear-biased diff, you can use wheelspin instead of clutch slip, but the stock LGT center diffs are all 50/50 split if I remember right.

 

When you shift, get back on the throttle before you release the clutch, so that the engine RPM comes up, and the engine is pulling you forward when the clutch grabs.

 

The main thing is to drive it like you stole it. You won't get a decent time if you launch and shift like you do on the street. It's kind of painful at first.

 

^^^^^^ This. I go to 7000 in first and 6500 in second, the 6 k every gear after. But I also have a bigger turbo that doesn't fall off until 6500 or so. First and second rev so fast I take advantage of the raised rev limiter.

[BAC5.2]

For launching, I parked in the stage lights and held with the handbrake. Bring the revs up, and let out the clutch until the car starts to grip. Once the light flashes off the last yellow (unless it's a pro-500 tree, where'd you go a little earlier), lower the handbrake, let up the clutch, and drop the hammer. It's a fine balance between clutch and throttle to get off the line, and everyone is different. It's a lot trickier to launch the 5MT cars than it is the tunnel-case 6MT. You actually have to have some degree of mechanical sympathy if you want to be able to drive the car home.

 

As for shifting, just what NSFW said. Shift just before/as power is peaking. 1st is too short to consider short-shifting it, though. The rest of the gears, shift by feel. You'll get the hang of it after a few passes.

[JermTheElf]

There is a lot of great info here, thanks for the posts. I guess the logic is to beat on something that is meant to wear out (clutch) and don't put tons of strain on fixed components (axles, tranny, etc). With something like launch control what rpm do you usually set it at? You said 4000 but I've heard of 5000 which just seems too high

[NSFW]

LC RPM will vary. I agree that 5000 sounds high for the stock turbo but it might be low for a 35R. I've been experimenting with 4500 with my setup.

 

4000 sounds reasonable to me for the stock turbo. But, I didn't have LC yet when I was on the stock turbo, so that's just speculation.

 

Consider using launch control just as a simple rev limiter - don't go full throttle, just rev right up to it, so you don't build boost. Then go WOT as you release the clutch. You won't launch as hard as you would with boost, but you also won't be as likely to break stuff while you work on your clutch release. (LuckyBob gave me this idea.)

[LosAngelesLGT]

Been to the track more than a few times on a bunch of setups. Dont rev out 2nd gear. First gear rev out. NO other gears with oem turbo. Stay in boost.

Shift ~5600-5800rpms. Launch instructions given sound good.

 

Dont listen to people giving instructions for "bigger" turbos.

[leggyman17]

MAKE sure you check your oil...last time i dragged my stage 2 LGT i spun 2 bearings from overheating them... also do not reccommend 5w-30... try heavier oil

[Turkeylord]

Well I'll throw in my $.02

 

Your VF52 should be pretty similar to my 16g. I haven't really done enough passes to say this with any authority, but the one run I tried "short shifting" at 6k was significantly slower despite being a clean run. 6500 seemed slightly faster than 7k as expected.

 

I was launching at 4500 and had intentions to bump that up but abandoned them as I was already having traction problems.

[lee07]

Little disappointed just came back with a quickest time of 13.6 and a fastest trap at 101mph

 

Most were in the 13.7-13.9 range with a couple low 14s

 

1.8-2.0 reaction times

 

5k launch with a few 3k launch and shifting at 6k

 

Had a good 18 runs

 

First time so how can I get a 13flat?

 

850ft elevation

 

Vf52 287whp 5spd

[iNVAR]

what's your 60' time?

[lee07]

On the 13.6 run, a 2.0 but had a few 1.8 and 1.9s and a lot of 2.0+

[iNVAR]

what's the weather like? were you heatsoaked?

[lee07]

about 55-60 and yeah it was heat soaked, run after run with maybe three 5 min breaks and I was back in line running it, Which was why I had 20 passes. Tmic btw

 

13.6 came on mine 2nd run at 101.85mph and finished my last run with a 13.6 but at 98mph

 

Only had 7 100mph speed traps, the rest were 97-99.9mph

[BAC5.2]

 

First time so how can I get a 13flat?

 

Drive better.

[Brett]

your 1st to 2nd shift is the most important one and to me, the toughest. my best launch was a 1.888 with a 13.5 @100.6. no matter what i do, i cant launch perfect. but i redline every gear to 6500rpm. i always trap over 100

[lee07]

Yes after a few more runs I will drive better

 

Looks like I could of gotten at 13.4 or 5 since I had a 2.0 60' on the 13.6 run and then with better driving/shifting maybe a 13flat

 

Ran 14.8 on my first run so I improved 1 full sec, I'm sure I knock off another .5 sec

 

Next Spring maybe give it another run or 20

[Turkeylord]

13.6 came on mine 2nd run

This is pretty consistent with my runs as well - my best runs were always the first, second or third right away or after a LONG cool down.

 

The first time I was out last year, I shut down my 2nd run of the day early for some reason - only to later find out it had been my fastest through the 660'

 

The last time I was out I had been letting mine cool down for a good 45 minutes and was getting ready to run again when a DSM oiled down the track. About an hour of cleanup later I went back out and had my two best runs of the day.

[lee07]

Is it normal for the rpms to rise a bit when you are disengaging/shifting

 

Was shifting at 6-6.5 but the rpms rose to 7k+ on its own