What is your shift indicator light set at? and Why?

I currently leave mine at 7000 because I find the light very annoying. Usually, I shift around 3000-4000 so I do not see the light. Granted there are times I do catch the light out of the corner of my eye to let me know I need to shift

~~nisslow02~~

 

4000, but I'll be upping it in another couple hundred miles to 6700 ish

 

4K during the first 5000 miles, then went up to 4500, recently moved up to 5500.

5500 agrees with my driving.

 

4 grand until break in is done.

 

5500 b/c it's a good general RPM that's near where the HP and torque curves are peaking.

WayneTN

 

6200 so I don't have to ever worry about it blinking. If I do get into some spirited driving, the light will remind me and I'll never have to set it every time I feel like stepping on it!!

 

Redline baby!

 

Redline. It's nice to have it set there when I race. Sure don't want to bounce that rev limiter.

 

6400, to give me a split second of solid red before I bounce off the limiter.

 

OK. Why would anyone set the light at redline? If you're waiting until near redline to shift, your losing out. Max HP is at about 4,700 RPM and max torque is at about 6,100 RPM. That's why I say I set the light at 5,500 because it's a good blend of HP and torque.

Just asking........
WayneTN

 

The more often you shift, the more often you are out of gear and not making more speed. If you shift too soon, especially in first (IMO), you are losing time. Second and third might be OK to short shift a bit, but you need to run 1st up to near redline. If you are shifting at 5500 every time in the quarter, you'd be hurting, I suspect. You need to at least run into the low 6000s, even if short shifting, to get the most amount of time at the sweet spot.

 

Good point. If I ever go to the track, I'll set it up higher.

 

Uhh... you've got those figures reversed.. The basic theme is that to maximize acceleration you want to shift at the point where HP would be higher in the next gear or when you are forced to (i.e. redline). This is a little bit complicated to explain but I'll try, let me know if it makes no sense.

- What makes your car accelerate most is torque at the wheels. This is what you want to maximize at all times.
- Torque at the wheels is equal to engine torque x gear ratio x final drive ratio
- Let's say you are going 55mph, you can choose to be in 2nd gear at about 5500 rpm or in third at about 4500rpm (let's imagine).
- Which gear gives you greater torque at the wheels?
- Well, 3rd gear is puts you closer to the engine torque peak so you may have greater engine torque in third than in 2nd but let's look at wheel torque.
- However, the gear ratio advantage of being in 2nd over third is more like 20-30% and there is no way that you are generating 20-30% more torque at 4500 rpm than at 5500 rpm, therefore, due to the gearing advantage, you'll have more wheel torque in second than in third.

Why do I say that you only want to swap cogs when you could get more power in the next higher gear? Because HP is torque x engine speed. And if you run some quick math, you'll realise that the higher engine speed allows you to use a better gear for a given road speed. Therefore revs are your friend. Imagine having an engine that made 100 lb-ft of torque at 10,000 rpm. You could use extremely aggressive gearing and convert that relatively small amount of torque to the equivalent of 200 lb-ft at 5,000 rpm or 1000 lb-ft at 1000rpm. It's all about the gearing. The low redline of the 350z is the only part I don't like about my car.

Jason

 

Jason,

Thanks a lot for the detailed explanation!

Wayne

 

Redline, I dont need a little light telling me when to shift. You can hear the engine and know when it is ready. In racing in traffic you dont look down you look around. So you have to feel your car when and how it feels for your next shift. Be one with the car...

 

I have mine set at 6500 or so. It starts to blink at 6000 and then stays red right at the end. I found that I notice the blinking better than the solid, so it gives me a couple hundred RPM to make the shift.

I've found that I have a real hard time telling when to shift in the Z by feel or sound. To me, even at redline the car still sound very good, and it feels like it wants to keep on going. I've bounced off the rev limiter quite a few times when I've forgotten to shift. Especially when racing a new track or Autox course, where I'm focused on the line and not the RPM's.

I estimated the torque applied by the rear wheels before I got my car and found that in the Z you want to go as high in the RPM's as possible before shifting. There is no reason to short shift in our car (well, except for reliability and fuel efficiency).

-D'oh!

 

I like to keep mine set as low as possible. To me, the only thing better than giant wings and stickers, are crazy blinking lights on my dashboard. Its like a strobe light for my speedometer.


Actually I think its set on revline, I hardly ever see it unless I am in a really driving mood.