how would I tell...
11-12-2003, 01:32 PM
#1
Guest
Posts: n/a
how would I tell...
Hey, guys, I've got another question while I am on my quest to learn all I can about my 240Z. I was talking to one of the members of our forum, about my top speed on the freeway. I was racing an eclipse one day, and the speed that was shown on my speedometer was 140 mph. He said that there was no way that a stock Z could do 140 down the freeway. He said that without a front air dam, and a rebuilt block, that there was no way that the Z could perform that well. I know my block has been rebuilt, but I don't know if it has been bored and stroked. I also don't have an airdam on the car, and I have an e88 head. Hopefully this helps. To sum it up, could my stock Z do 140 on the freeway without a front air dam, with a stock nissan engine and an electronic points condenser kit? And how would I know if the engine has been bored and stroked? Thanks!
11-12-2003, 03:44 PM
#2
the Dude
Join Date: Mar 2002
Location: Bay Area, California
Posts: 381
boring/stroking a 2.4 liter block is kind of pointless, when one can pick up an L28 and do the same thing, and with rebello's kit get a 3.1L stroker making gobs of power. The only way you can tell is to pull the head off, take measurements of the bore sizes to compare with stock, and compare piston sizes/model number with stock. E88 head is also not the optimal head to use with a bore/stroke kit
As far as top speed goes, just as I told you before, the Z in stock form makes about 100 lbs of lift in the front at 80mph. At 100mph, the Z with stock aerodynamics has a drag coefficient of 0.465, or, that of a brick wall or a jeep. For reference, my daily driver neon is .29, and the lower the number, the better. The 240z in stock form makes about 115-120hp to the wheels. The 150hp rating it had was gross, not net. Gross rating means power was rated at the crank without any of the accessories attached to slow down the motor (waterpump, alternator, smog pump, restrictive exhaust, etc). In reality, it made around 135 to the crank. You would top out around 120-125 max due to lack of power and aerodynamics.
As far as top speed goes, just as I told you before, the Z in stock form makes about 100 lbs of lift in the front at 80mph. At 100mph, the Z with stock aerodynamics has a drag coefficient of 0.465, or, that of a brick wall or a jeep. For reference, my daily driver neon is .29, and the lower the number, the better. The 240z in stock form makes about 115-120hp to the wheels. The 150hp rating it had was gross, not net. Gross rating means power was rated at the crank without any of the accessories attached to slow down the motor (waterpump, alternator, smog pump, restrictive exhaust, etc). In reality, it made around 135 to the crank. You would top out around 120-125 max due to lack of power and aerodynamics.
11-13-2003, 08:49 AM
#3
The Evil Twin
Join Date: Mar 2001
Location: Seattle, WA
Posts: 9,294
That's the same as what I've heard. clear up to the 280ZX the top speed has always been about 125-130 max. The 280zx has better aerodynamics and a bit more power from the fuel injection but still doesn't make a whole lot of difference for top speed.
With just the right gearing you could help peak that speed. Maybe you changed your rearend gear ratio and left the speedometer cog the same?
Or the old 240Z gauges just aren't accurate. I know that the tachometer reads too high in the higher rpms... right?
With just the right gearing you could help peak that speed. Maybe you changed your rearend gear ratio and left the speedometer cog the same?
Or the old 240Z gauges just aren't accurate. I know that the tachometer reads too high in the higher rpms... right?
11-13-2003, 09:24 PM
#5
the Dude
Join Date: Mar 2002
Location: Bay Area, California
Posts: 381
i've already told you twice, obviously you don't listen. The Z is NOT ****ING SAFE at that speed. PERIOD. If you feel like becoming a darwin award, by all means, go out on the freeway, but at least do it at 4am so when you lose control and crash, you won't hit anyone on the road.
My suggestion? Sell the car and get a civic. You're just going to become a statistic
My suggestion? Sell the car and get a civic. You're just going to become a statistic
11-14-2003, 09:33 AM
#6
The Evil Twin
Join Date: Mar 2001
Location: Seattle, WA
Posts: 9,294
I don't see how a 2.0 DOHC 4-banger can do 140 either! That thing has the same hp and a lot less torque than your car and its much heavier. Have his speedometer checked out too. Get a 350Z. You'll be much safer in a crash. 
Or maybe go out every night running your top speed for as long as you can. When you get pulled over, ask the cop how fast you were going!
Or maybe go out every night running your top speed for as long as you can. When you get pulled over, ask the cop how fast you were going!
11-14-2003, 12:41 PM
#7
the Dude
Join Date: Mar 2002
Location: Bay Area, California
Posts: 381
Fastest I've ever gone in my daily driver (neon r/t, rated at 150hp) was 133 calculated, I was doing 6100rpm in 5th at the time. Past that it would not pull anymore. The car also wasn't stock, it had mopar 4-2-1 header, cold air intake, mopar ecu, and a lightened crank pulley. Using ricemath, I'd say my car was making about 165-175 at the crank. Drag coefficient of my neon is also .29
11-15-2003, 12:07 PM
#9
Guest
Posts: n/a
Speedos are not all the accurate in any car... They are driven usually by gears...in which case, the mfg makes sure the gearing is as close as possible for normal driving.. ie highway speed. the faster you go, the more inaccurate it becomes.
Some of the older speedos in 240s read 160mph, and I have heard of guys burying the needle...it doesn't mean they can hit 160mph.
I had a pretty mean engine in my 280 with lots of aero mods. I hit 148 mph at 7200rpm in 5th....hp in the very high 200's...280-290 (flywheel).
No stockish 240 can hit 7000rpm in 5th gear (if equiped)
Stocko 240 hits a wall about in the low 120's... Its been well documented...
Most new cars still have inacurate speedos for the same reasons... my sis said she had her stock honda to 220kph with 108hp....not a chance..indicated ok..but no way a stock honda can do that.. (hers is an automatic as well)...
Some of the older speedos in 240s read 160mph, and I have heard of guys burying the needle...it doesn't mean they can hit 160mph.
I had a pretty mean engine in my 280 with lots of aero mods. I hit 148 mph at 7200rpm in 5th....hp in the very high 200's...280-290 (flywheel).
No stockish 240 can hit 7000rpm in 5th gear (if equiped)
Stocko 240 hits a wall about in the low 120's... Its been well documented...
Most new cars still have inacurate speedos for the same reasons... my sis said she had her stock honda to 220kph with 108hp....not a chance..indicated ok..but no way a stock honda can do that.. (hers is an automatic as well)...
11-20-2003, 08:46 AM
#10
Registered User
Join Date: Oct 2002
Location: Fremont, CA
Posts: 146
:-)
Hi. My 76 280 did do 140. The engine was new, only had 30,000 miles on it, but it did it smooth too, and stock. Why don't ya'll think the z can do it? Sure it can and why elce would the speedometer say it?
11-20-2003, 10:03 AM
#13
the Dude
Join Date: Mar 2002
Location: Bay Area, California
Posts: 381
Re: :-)
Originally posted by z_lis
Hi. My 76 280 did do 140. The engine was new, only had 30,000 miles on it, but it did it smooth too, and stock. Why don't ya'll think the z can do it? Sure it can and why elce would the speedometer say it?
Hi. My 76 280 did do 140. The engine was new, only had 30,000 miles on it, but it did it smooth too, and stock. Why don't ya'll think the z can do it? Sure it can and why elce would the speedometer say it?
by the way, you never got back to me about those rims.
