jfairladyz

Only problem I see with what you said is that you said the gearing would give the camaro the advantage. 2.73:1 is not an advantage. That's really holding the car back as far as acceleration goes. Sure it helps with the mathmatical top speed of the car, but thats about it. The ZXT is 3.545 which is quite a bit above the rear end you mentioned. And the non turbo ZX's usually had the 3.9 out back so acceleration was even further improved. Of course that numerically low gear ratio will help the camaro grab traction better then if it had a higher gear ratio.

thxone

I agree with you that the gear would not help off the line but I was talking about top end speed and I was just disproving the 135mph comment as the camaro will easily go over that and has as I was in the car when it did it, but yes off the line and most of the way to 100mph the 280 would probably win...stock "305" for stock turbo L28ET but then the "numerically lower gear" would take the camaro into the lead with no problem after 100mph. Now I know people dont think this car is not aerodynamic!!!! Just look at this pic!

Attachment 4659

NismoPick

ick! All 70's & 80's Camaros should be burned.

jfairladyz

But as you mentioned that particular camaro was not at the stock power level. Sure the parts you mentioned aren't good for massive power. But those parts combined with a non emissions compliant tune would add some numbers. And any car that gets squirrly at 110 is either A)aerodynamically challenged, or B) suspensionally handicapped . My Z has hit well over 100mph )around 120) and I never felt uneasy about it's ability to stay on the road. And this wasn't on some super smooth racetrack. This was on some country backroad in Nebraska. And there's also weight to consider. The Z also has a weight advantage over the camaro.

I will admit error though: When I made the comment about the camaro hitting the brick wall of air, I wasn't thinking of the correct camaro. The one you pictured is definitely not what I was thinking of. I was thinking of something older than that.

thxone

Nismo, shame shame, come on, you know deep down inside you like the camaro...come on, lets hear it lol. I know not everyone likes them, personally being on the poor side of money I try to find the good in whatever car I might get or have owned...I will say the fastest car I have had was my 72 Firebird and the car I have had the most fun driving was my Shelby Charger "Turbos Rock!!" But now that I have me a ZX, let someone convince me it is not a good car, ain't gonna happen. So on that note I will stop talking about the Camaro after all this is a Z forum. Oh yeah I read on here my gear is a 3.54..and in this thread it says 3.90??? which is it (1982 NA 280zx Coupe Auto)

jfairladyz

Automatic non turbo and all turbo's had the 3.545. non turbo 5 speeds had the 3.9 (after 79). I kept the 3.9 rear in my NA when I swapped the turbo motor over.

PooFlinginMonke

I guess I'll put one of the 50 or 60 280zx turbo ecus I have in the warehouse on the tester and find out where and what type of limiter it has since I rebuild ecus for a living.

In the mean time, I was wondering about that wire that goes from the speed sensor to the ecu.

RodMoyes

I don't know exactly what the top speed is, but I can tell you that now that I have a '79 5 speed tranny and my '80 rear end... Mine is about 90MPH

I'm sure it's actually not that bad, but my RPM's are WAY up at highway speeds now.

Acceleration is good though!

Rod.

NismoPick

I have the wiring schematics if you would like to look at them

The speed sensor on the 280zx goes to the Cruise Control.

Oh... and I like this thread: http://www.zcar.com/forums/read.php?...5#reply_629487

jfairladyz

On the turbo cars the speed sensor IS used by the ECU. I don't know if has anything to do with a govenor though (doubtful).

PooFlinginMonke

The cruise control is independant to the ecu in it's operation.

So what does that wire that goes straight from the sensor to the ecu do?

NismoPick

I never said it's not.... but how does the cruise control obtain the current speed?

Well, it's not a speed limiter, nor a rev limiter. With countless peoples testimonies (including my own) of getting up to 130+ mph & rev'ing well past redline.... do tell me what the limiter is set at.

PooFlinginMonke

When you put in 3.90s in a car with the auto tranny in place of the 3.54, you can most definately feel the car hit a brick wall at a much lower speed than it did with the 3.54s.

And I did both tests only hours apart.

When I have time, I will chuck one on the tester and start offsetting the speed the ecu sees and see where and if it limits.

NismoPick

yep... the power issue was discussed already.... OBVIOUSLY there are power limits on all cars.

Good good... I would like to see the results.

lifegrddude

In my ZXT, I ran outta gear before I ran outta speed. I have an a/t with the 3.545 rear end and I have redlined 3rd (4th for you lucky 5 speed drivers), and I didn't touch a limiter. Transmission calculator said my speed was 140mph at ~6500rpm. I backed out right before 6500 since I have valve float at those engine speeds. I'm pretty sure with a 5 speed I could go as high as I wanted until I hit the aerodynamic wall, or limits of my tires' speed rating.

The cruise works via a magnet (Hall sensor or something like that) that's located on the back of the speedometer. The rotation of the speedo creates a field on the magnet. It's the same thing that drives the system for the talking lady. I think the speed sensor wire to the ecu is for the digital dash and was wired regardless if the vehicle was analog or digital. That speed sensor wire is the one that gets tapped into for the z31 maf swap to keep the hotwire clean.

PooFlinginMonke

Power issue?

I lowered the point at which the car comes to a brick wall by a shitload and I doubt the density altitude changed much in the two hours I used to switch from 3.54 to 3.90 or 4.10.

nismo619

if u were to lower your dissy and lower your timing on your timing chain i do belive u could be able to hit 150 or higher..this is on both 280zx n/a/ and 280zxt i have hit 140 mph in my 1982 280zxt on a 28 mile freeway i was racing a honda b-16 i took him all the way until i got to yellowish redline " i didint know if my motor would blow if i was to hit all the way to red line" does any body know about that ? i know 5,900 rpm is yellow lineing it.. then 7,000 is dead redline.. but i have also heard that no matter how hard u push them to 7,000 rpm u cant or can blow a rod threw the roof ?

NismoPick

The concern (with our engines) @ high RPMs is valve float.... Like Lifegrddude was saying. Without high performance valve springs & retainers, the valves are going up & down so fast @ 7k RPMs that they just kinda "float." That's why there isn't any reason to go much over the peak hp rpm. If you just keep going, eventually the weakest part will let loose. Depending on the condition, age, & make of the engine, it could be different parts.

Heat Rave R

While we're on the subject, can someone tell me what #/color wire into the ZXT's ECU wiring that speed sensor signal wire is?

jfairladyz

YL and YW for the speed sensor. It uses two wires. The YW is the wire that actually goes to the ECU though.

lww

There is no rev limiter on any of the factory 280ZX ECU's.

Whatever you were hitting wasn't the result of a signal from the ECU. It was either a fuel, air or spark related problem.

Nismo, you weren't going 160 mph in a stock 280ZXT and it's better to BE the Police than cook for them. I'm sorry, your friends are pulling your leg. Unless you have a GPS or some other data acquisition system, whatever speed your speedo was reporting was WAY off reality. Aside from the fact that no factory (edit: 280ZX) speedo goes to 160 mph and even the cops won't do that in a freakin' boat aka a Police cruiser.

For people that don't understand how spring loaded speedo's work, they are calibrated to be accurate within a specific range. Typically 40 mph to 80 mph based on a calibration of 1000 'speedometer shaft' revolutions at 60 mph.

You'll notice that this is approximately 20 mph below 60 and 20 mph above 60. As the speedometer moves outside it's accuracy 'range' the reliability of the reported speed becomes inaccurate on a logarithmic scale.

Anyone that knows how to calculate a logarithmic curve will understand at the 'distance' the speedo is away from it's calibrated 'correctness' for a 160 mph reading will be WAY off. So, if your speedo reads a little high (like 2%) at 80 mph, it'll be off by 20% at 160 mph which is nearly 32 mph. So, a 165 mph reading could be anywhere between 133 mph and 198 mph depending on whether your speedo is 2% high or 2% low at the 80 mph upper limit of it's calibration point.

These cars can realistically do 140 mph with a stock turbo. When anyone claims any more than that, I want to see it reported from a modern data acquisition system.

I'm not saying it can't be done, but I am saying it's highly unlikely. My 200+ wheel horsepower NA 280ZX ST2 race car was clocked by a timing tower at 142 mph and it only had a little bit left in it due to gearing and aerodynamics. This was with a full race ground effects and suspension package.

The hp/tq required to continue to accelerate past 120 mph does not increase linearly with speed, it's logarithmic as a result of wind resistance and aerodynamics.

SHADY280

^ exactly, its good to have a scientist around, now i want to know is what redline can and unbalanced bottom end take, and what extra little thing are you doing to get 200+hp from an na, im close, but i need the little stuff.

jfairladyz

^ He's got those "Powered By Honda" Stickers

lww

^^ Each one is worth at LEAST 20HP!

3.0L, Sunbelt Racing custom ground cam, custom forged dome top pistons, fully ported and polished N42 head, custom built header, re-worked and ported intake manifold with the runners bored out to 1.32" (factory casting is 1.25"), 60mm Weber Big Throat TB, 2.5" mandrel exhaust (no cat), race muffler with only 3 baffels (later switched to a SuperTrap), 300 cc injectors w/a lower minimum pulse width than stock and a Bosch high flow fuel pump (I can't remember the model off the top of my head, but the flow rate was about 20% greater).

lww

A friend of mine is getting 273 hp from his 3.2L Rebello motor with triple Mikuni's.

Here's his website: http://www.bbgraphics1.com/73z/index.html