Keshav

I guess you mean down-shifting two gears at a time? I think the hand placement would be the same, you just need to get it into neutral quickly, first. From 5th to 3rd, for example, tug the stick out of gear with your fingers. It should center itself as you move your hand to the aft position and push the **** forward with your palm. One thing to consider is that it does not hurt the transmission in any way to pull it out of gear before engaging the clutch. Maybe this will help?

jonalan

If you were cruising at 50 mph, you should have been in 5th gear, not 6th. Therefore, to accelerate, you would need to down shift to 4th, or even better, 3rd gear.

Rule of thumb for cruising speed gear selection - gear times 10. For example, 4th gear for cruising at 40-49 mph, 5th gear for 50-59 mph, 6th gear for 60+ mph. Then, you can usually drop down two gears safely (6 to 4, 5 to 3, etc.).

8_wannabe

Actually, I meant upshifting, but its true both ways. If you think of 1-3-5 as the "top" and 2-4-6 as the "bottom", I find it easy to go from a top gear to a bottom gear in one smooth, fluid motion like you described. But when I really want to jackrabbit, I might run hi revs in 2nd then shift to 4th, meaning a bottom-to-bottom shift. Or 3rd to 5th (top-to-top.) I can do it, but it's not one smooth, fluid motion. I use the spring action to center the stick as needed, but it still feels like two motions: Pull it back, let the spring do it's thing, push it forward. Several times I've misjudged, and don't get right into gear so instead of that quick acceleration, I'm out of gear a couple of seconds hence the embarrassment of not taking off as planned. It just comes with practice and I'm getting better at it.

mzrx

8_wannabe try placing your palm on the shifter in the position that Keshav describe earlier on shifting using the wrist and a bit fore arm motion, that might help you with the 1-3-5 and 2-4-6 shifting.

Gord96BRG

I hope I'm misunderstanding - are you saying that when you want to accelerate as quickly as possible, you shift 1-3-5 or 2-4-6 rather than 1-2-3-4??? If so - I hate to say it, but you're seriously short-changing yourself. I short-shift (rev higher in the lower gear, then skip a gear on the upshift) when I'm lazy and not in a hurry or have reached cruising speed, but for quickest acceleration you have to hit every gear. Skipping a gear will always be slower.

Regards,
Gordon

Speed-ER doc

Especially in this car where you have to keep the RPM's high to get the torque you need. Your 1-3-5 might work better in the Cobra.

But you're missing out on half the fun, too. :D

8_wannabe

Nope, you're not misunderstanding. That's exactly what I"m doing, a technique I learned on this very forum from someone -- judging from your comments -- who was just blowing smoke out his butt. He had some argument that this was how to accelerate quickest, so dumb me believed it. It really jacks me around where people throughout this forum post opinion as fact, and those of us who don't know any better just suck it up. So my bad for being so ignorant and I'll go back to driving as I was.

jdwk

Glad to see you are human 8_wannabe.

To figure out your fastest shift points, you have to have a dyno plot. From that you want to shift when your torque equals the torque available in the next gear. That is torque at the wheels, which is engine/crank torque multiplied by your gear ratio and final drive, minus frictional losses.

Engineers usually select gear ratios that corresponds to the peak power of the engine for fastest acceleration, which is usally well before redline. In most cars, like my MX-6, it is pointless to hit redline in anything but first gear.

The rotary is a different breed of engine, and on the 247hp version, fastest acceleration is acheived by hitting redline and then some every time.

In the 238 hp version, however, you might need to shift a little earlier.

I suggest everyone read this write-up on HP vs Torque. I thought I had a pretty good understanding until I read this and it was then that I saw the light.

http://www.rs-productions.com/RSP_Mo.../hptq/hptq.htm

OK, since I am sick and actually enjoy doing this, here you go. I found a dyno of a stock RX-8, and I have the gear ratios.

Redline it in first.
Redline it in second as well.
Redline it in 3rd too.
Ah ha. Due to the big torque drop aroud 7400, you want to shift into 5th at about 8500. (don't take it to redline)
Same deal with sixth, shift at 8500.

This is going to be different slightly for every car, and you are going to need to dyno it to know for sure.

If I had the dyno in digital format like an excel spreadsheet, I could write some code to calculate 1/4 times and such shifting at different RPMs. I actually did this for my car by just using a ruler and figuring out the torque at every 100 rpms. Did I mention I was sick?

Also, from the dyno I saw, it is not worth it to take it past redline except in first gear where burrying the needle will help a tad, but I personally don't think it's worth the stress on the engine, or the embarassment of hitting the rev limiter.

8_wannabe

Great explanation, jd. I don't have time to study it and understand in depth right now but sometime I will. I am totally not into dyno, but I'm sure many '8 drivers are. I just want the ride to be fun, and work my technique a bit but I am never going to push the'8 to its limits. There are many different motivations for buying this car. I've never had anything like a sports car before. The '8 just grabbed me and here I am, but I'm not gonna race or squeeze out all the torque I can. Not to detract from your explanation because I appreciate it, but no way am I gonna put my car on a dyno. It just doesn't interest me. I expect and hope a lot of people will follow your instructions; I think they will get a lot more from their car if they do. hey, sorry you're sick. Hope it's not the flu.

jdwk

I think I posted somewhere how this isn't a 1/4 mile car, at least not stock. So most owners aren't going to dyno or drag race.

I have only dynoed once and drag raced once, but I rarely back down from a stop light or quick highway race. I did it for knowledge more than anything. My MX-6 is definitely not a drag car either.

The link to the HP vs torque is very good though, so if you get the time please read it. You may understand why a few us care so much about 25whp, when the car is so fun to drive anyway.

I think most of the owners that don't care about the gas mileage or HP are new to Mazda or new to the rotary. Most of the RX-7 owners seem to be complaining about it. While I haven't had a rotary yet, I have always owned Mazdas.

The Mazda fun factor is ingrained in me. So the RX-8, while superior to my MX-6 in almost every category, wasn't THAT much more fun.

My MX-6 actually has a little more torque, but a slightly bigger final drive. What makes the RX-8 so much fun (besides the handling) is gear ratios. They multiply the torque, and the 9000rpm redline is what allows the car to have such low/short/high numbered gears.

RX-8 MX-6 C5 Z06
1 3.76 3.31 2.66 2.97
2 2.27 1.83 1.78 2.07
3 1.65 1.31 1.30 1.43
4 1.19 1.03 1.00 1.00
5 1.00 0.80 0.74 0.84
6 0.84 0.50 0.56

FD 4.44 4.105 3.42 3.42

Tq 159 161 350 400

So in first gear, the RX-8 has an effective 2657 ft lbs, and the C5 has 3184 ft lbs (2924 in an auto). In first gear, you get pinned to the seat almost (5/6ths) as much as a vette. However, you will be nearing the end of second by the time the vette has to shift.

It took me a long time to understand this, so I don't expect everyone to understand it all. For some people, it is common sense.

This is why I was disappointed with the performance of the RX-8 on the highway. While most people don't drag race, everyone wants to get around a truck on the highway as quickly as possible. Or wants to speed up to get ahead of the Civic with the 120dB exhaust.

From 60-90, my car is at 3000 to 4500 in fifth. My torque is steadily increasing (from about 135 at the wheels to 145) and you can feel it, torque equals fun. I don't really ever need to downshift. But if I do drop gears, 60-90 is perfectly placed between 3750 and 5600 rpms with an added boost from the lower gear.

In the RX-8, I remember 60 being around 3500 rpms in sixth. It's around there. When I dropped to fifth, the torque curve is so flat that the 16% increase from the gear was not really fast enough. So I dropped to 4th, the 40% increase should have put me in the back seat.

But actually, your stock dynos have you at 131 peak. When you drop to fourth at 60-70 mph, you quickly hit the first drop off in torque, "yay" less torque. A drop all the way down to 120 completely negates the gearing advantage the RX-8 has. To top it all off, my car weighs 2650 lbs and has an equal coefficient of drag. So when I thought my car "felt" faster on the highway, I was probably right.

Now the smart RX-8 owners are going to jump and say, 60-90, put it in third gear. But look at your dynos, that's where you are really missing the HP. That is 6900-9000 rpms. It's a nice drop from about 125 to 100 ft lbs. Yes, this is the fastest way from 60-90, but a decrease in torque is the opposite of fun and winding up the engine that much for such a small gain is disappointing.

The RX-8 is amazing, but that 25whp is crucial to me as well as the 4mpg. I think Mazda will fix it, but who knows. Until then, I will wait.

canzoomer

When gently driving, such as around town, I usually go 1st, 3rd, 5th.
The ratios are close enough to comfortably allow this, and it keeps the revs below 3500 to conserve fuel.

Shifting back down is also not hard with these.

The one I find hardest is 6th to 4th.

Speed-ER doc

Nicely said jdwk. I am also disappointed with the freeway passing; it is doable but would sure be better with a little more kick. I hope that your add-on works as well as it sounds canzoomer, I need to get on your list. What is the estimated delivery time if I ordered now?

Speed-ER doc

Never mind, I just checked your main thread. Now, instead of zoom-zoom, it will be zoom-ZOOM!