Well put. :) :happydance:
I really like that smiley^^^

God I can be such a dumb **** sometimes. I meant "your" power levels, and I totally forgot that you were going to be adding boost at some point in the future. I was framing the gears question in terms of the car staying NA.

Sorry for the confusion.

So - going back to one of my earlier questions, NA, where does the car stop accelerating?

Updates??!?!?!?!?!??

Well the answer to that is "at the drag limit", and I don't think many people know that since the ECU speed limiter is below the drag limit. If I had to guess, I'd say with no wind it's probably around 170-180 mph with good bolt-ons in top gear, although it probably varies by transmission type. You'd probably loose all steering control and wreck the car before then though, at least without some aero upgrades and/or lowering to keep the nose planted harder.

A more useful answer: I don't think I would see myself using my 7AT's 6th or 7th gear to accelerate on any reasonable track. If the track had a long slow curve or straight where for whatever unrelated reasons I desired to maintain constant speed for a stretch, I might drop into 6 or 7 just to give the engine a rest, but useful acceleration at speeds the stock aerodynamics can handle all occur in gears 1-5 on the 7AT w/ stock diff ratio. 6MT may have a different answer, as the transmission and diff ratios are all different.

That is ultimately where I was going with the gears question - based on the assumption that the car remained NA. I was wondering a gearing-reduced top speed had any practical impacts on real-world tracks.

From the service manual, the 6MT's ratios are:

1st 3.794
2nd 2.324
3rd 1.624
4th 1.271
5th 1.000
6th 0.794

.. and the rear end is 3.692. From that you can derive that 5th (on stock Sports Package wheels and rubber) tops out at about 160mph @ 7500rpm. So technically you don't *need* 6th unless you're on a track where your car could exceed 160, which doesn't sound like the kind of track people run these cars at :). But still, it's not like you always have to be in the lowest possible gear all the time. 6th will still pull decently and be useful. If you went to a 3.9 rear end, it just makes 5th top out sooner, at about 152. If you also combined that with moving to say, 305/30/18 tires in the rear, the number drops to about 144.

It's all about the ratios of the gears in the trasmission, not in the rear end.

The 370z is geared for good acelleration off the line to get good 0-60 and quarter mile times and it is geared for progressive shift points to get you to its terminal velocity of ~185 mph. Those gears are meant for the street.

Most track cars and motorcycles are geared for shift points that roughly go 60, 80, 100, 120, 140, 160 mph, because until you get to the elite classes, 160 mph or so is all you will see on most tracks. For example, at Portland International Raceway, I could get my Aprilia RSV to trap 165mph at the end of the front straight.... and they run indy cars at that track.

The 370z is geared for 42, 69, 99, 126, 160, 188 mph. (I calculated 6th gear at 7,000 rpm, the rest at 7,500). If you give it, say 4.0 rear end gears, you'll get shifts points of 39, 64, 91, 116, 148 and 185 mph. in that scenario, you've made 1st gear useless and 6th gear still gives you the same top speed, just at 7,500 rpm instead of 7,000.

The real solution would be to rear gear the entire tranny.

Cage is in progress right now. :)

:drool:

Any updates? :happydance:

Here are some pics of the cage in progress. Only the main hoops have been welded into place at this point. We made an opening through the rear bracing, which will be boxed on when we are done. This is the most structurally intense cage we've done so far. Wait until you see the NASCAR door bars, seat mount, and pedal box. Should be wrapped up with all the cage related fabrication by Tues/Wed of next week. Then the fun really begins!

http://onfinite.com/libraries/1513986/333.jpg

http://onfinite.com/libraries/1513987/b84.jpg

:drool:

:iagree:

wow, good progress on the cage. you know we're going to want more pics than that?! :)

any plans to replace the stock lateral brace in the rear ? presumably the cage will be stiff enough, probably not getting anything from that brace at this point

double nascar style on driver door ? single on passenger ?

oh and when you say you are going to 'box in' the rear bracing... sheet metal or tubing ? what thickness and material ?

We are doing double bars on the both driver and passenger side to maintain balance, and symetry. Some teams go X on the passenger side, to save a little weight, but it's really a choice thing.

The rear brace will remain for now, but some additional bracing isn't a bad idea. I will look into it.

Looks sexy! In a cagey sort of way......

Subscribed. Nice work but it's got to sting a little ripping apart a brand new car like that. Can't wait to see the finished product.

great build Sharif! glad i finally found your thread. :)

You guys figure out what you will do with the pedals yet ? stock ? are you going to build a custom dead pedal ?

Whats a "dead petal"?

"Whats a "dead petal"? "
Its the foot rest on the left.

Any estimates on the overall weight savings when it's all done?

Thanks Knives

I am targeting 2750 to 2850lbs dry. I am setting a pretty high target, so we'll see where it lands.

Nice, s2000 territory.

You decide on rims?

I also assume you're replacing the glass to get to that 2750 target?

Time for more pics

:icon18:Stop whoring my gif and its kinda early to start asking for dyno numbers yet.

did u sell the passenger door panel yet?

LOL....way too early. :tup:

Still available. PM for pricing. THANKS!

HAHA. I think you are worthless for saying something so stupid....

:gtfo2:

heres a dyno.

so is that the torque curve or the horsepower curve on the neck of that dyno? :roflpuke2:

can't take a joke can you ?.... http://smiliesftw.com/x/emot-downsbravo.gif

Nope..:roflpuke2: I am going to end this argument, i dont want to ruin this thread.

Lol. You guys are funny!

Just a curiosity: if i want to move to a 3.9 final gear ratio on a 370Z 7AT, can I use the after-market ring-pinion couple offered for 350Z?

Central 20 for example?

Thanks!

I know that the 370Z 6MT differential is identical to the 350Z 6MT differential. so 3.9 gears for the 350Z will work on the 370Z.

However, I do not know for certain, if the 7AT 370Z uses the same differential, so I can't tell you with certainty.