STX550 only does 180kph

G'day

I had to drive between Tenant Creek and Alice Springs this week. Some sections of the road have no posted speed limit. This gave me the opportunity to see what the truck had. The cruise control will go to 180Kph (GPS at 179). The engine sits on 3000RPM at that speed with engine temp 10 degrees hotter (96) then if I was doing 110. If I put the boot in to see what else it had the transmission kicked back at least 2 gears the engine would rev at 4000Rpm but no more speed. I'm guessing that it is speed limited to 180.

I have slightly larger tyres on that have corrected the speedo error, now the ecu is 5% slower than actual speed.

That is very fast to be going in a dual cab.

i wonder how steep the hill would have to be for a d22 2.5 to do that? i`m guessing a 2000 meter cliff maybe! (((-: lol, what`s the rush?

308bever said:

i wonder how steep the hill would have to be for a d22 2.5 to do that? i`m guessing a 2000 meter cliff maybe! (((-: lol, what`s the rush?

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don,t under estimate the D-22 when its in 5th gear and cruising at full pedal. sometimes when i have to overtake on certain highways before i know it i am doing 140k,s with ease , i don,t normally speed but should observe the speedo more. i do think the D-22 will hit the 180 mark on a flat road.

jonney said:

don,t under estimate the D-22 when its in 5th gear and cruising at full pedal. sometimes when i have to overtake on certain highways before i know it i am doing 140k,s with ease , i don,t normally speed but should observe the speedo more. i do think the D-22 will hit the 180 mark on a flat road.

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i doubt it will, the max i have done is 165km/h on Athens highway which is something similar to german high speed with max speed to 200, and it was at 4500rpms already. which is alot to run on a diesel. techically the yd25 has max revs at 4900, but i wouldnt never ever push it harder than 4500rpms.
BUT i would never do that again, running a navara at 160km/h is a death wish. if something happens in front of you it will NEVER stop, you can easy FLIP the truck with the slightest steering wheel movement and generally is a death wish.

Top speed seems to come up every 6 mths or so, there has been a few You Tube clips with over 200 shown for the YD25 D40, Perhaps Nissan has some sort of limiter at 180 for the V9X. It would be be a wise choice, only a clown would go beyond that but it would be capable given the torque and gearing.

180 speed limiter is pretty common in most Jap cars.

The 5 speed man's might have gearing issues getting that high, but the 6 speeds and auto would be more than capable *in theory.

Ive sat on around 140 in my 99 d22 and usually over 125 it starts to feel like you have a death wish - mainly the front suspension.
My old mans yd d40 will sit on 150 all day long if you wanted, but it feels way more like a normal car.

unkn0wn said:

180 speed limiter is pretty common in most Jap cars.

The 5 speed man's might have gearing issues getting that high, but the 6 speeds and auto would be more than capable *in theory.

Ive sat on around 140 in my 99 d22 and usually over 125 it starts to feel like you have a death wish - mainly the front suspension.
My old mans yd d40 will sit on 150 all day long if you wanted, but it feels way more like a normal car.

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they have no issues getting that high because 5th or 6th gear has nothing to do with max speed in fact a d22 5th gear (overdrive) is 0.760 while the 6th gear on a d40 is 0.827. the differance in the d22 and d40 gearbox is just 1st 2nd 3rd, the d40 gearbox has more options there. 5th gear on the d40 is same as 4th gear in a d22 (1 to 1) and 6th gear is the overdrive on a d40 like the 5th gear in a d22.
V9X is one of the best diesel engines on a truck so it should do 200km/h easy.

I'd say there is no limit and 180 is the true top speed. It's not the mass or weight of the truck that is limiting top speed so much but the frontal area and drag co-efficient. A Navara is about as slippery thru the air as a block of flats. Everything that creates turbulence increases drag. A bull-bar would have a dramatic effect. Large gaps between the tyres and wheel arches, a squared off rear end. Even things like mud flaps windscreen wipers, antennas, you name it all create turbulence which in turn increase the drag. 180 Kph in this type of vehicle is still not bad and you would certainly know your doing it.

ben85 said:

That is very fast to be going in a dual cab.

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Totally agree you would have to be an absolute fool to want to do that sort of speed in a 4wd, 120 would be more like it.

abouttogobush said:

Totally agree you would have to be an absolute fool to want to do that sort of speed in a 4wd, 120 would be more like it.

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Looking at your avatar you would corner like Noah's Ark. Top speed is probably limited by the Rangers ecu too.

happy john said:

Looking at your avatar you would corner like Noah's Ark. Top speed is probably limited by the Rangers ecu too.

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HAHA Bipolar John, Ranger could top 211kph easy.

Goodnight, best you play elsewhere please.

tyres would probably be rated for no more than 180.

c'mon guys! this IS the 3L V6 turbo charged STX550 we're talking about! If it was the drag, it would have had trouble reaching & maintaining top speed. There is no bulbar, it is not lifted, it has larger tyres so not as much gap around the wheel arch. the car was humming along quite nicely with no problems & had plenty of power & stability to spare! For anyone to suggest it couldn't go faster, you obviously haven't driven one & have NO idea!!!(Mrs O4-HUG)

04HUG said:

c'mon guys! this IS the 3L V6 turbo charged STX550 we're talking about! If it was the drag, it would have had trouble reaching & maintaining top speed. There is no bulbar, it is not lifted, it has larger tyres so not as much gap around the wheel arch. the car was humming along quite nicely with no problems & had plenty of power & stability to spare! For anyone to suggest it couldn't go faster, you obviously haven't driven one & have NO idea!!!(Mrs O4-HUG)

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none said it cant go faster, it can do at least 200km/h easy. what was said is that is idiotic to go that fast?

Looks like the ECU cuts the power as previously mentioned, obviously it would be capable of a higher speed given the touque and gearing.

happy john said:

Looks like the ECU cuts the power as previously mentioned, obviously it would be capable of a higher speed given the touque and gearing.

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One of my old man's warranty client's took me for a ride in an R35 GTR they had at the yard which had the same thing, except apparently the GTRs had a fancy program in linked to GPS which remove the speed restriction when on legitimate race tracks. Correct if wrong, it was what I was told.

Is it a Japanese or Nissan standard practice for high powered vehicles to restrict the speed to 180km/h anyone?

I'm certain it's for structural and personal safety they have a programmed top speed most high performance cars are the same. 120-130kph when overtaking is more than enough speed IMO. Such ludicrous high speeds from a robust hunk of steel so high off the ground with no aerodynamics woul equate to a Darwin Award. I say thank god it can't exceed 180kph, my TD2.7 is damn lucky to achieve 100kph down hill with a tail wind I couldn't imagine the fear of 180kph! I think more pick up down low and less high speed gearing is more desirable in a 4x4.

happy john said:

obviously it would be capable of a higher speed given the touque and gearing.

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Theoretically yes. However the power needed to push an object through the air increases with the cube of the velocity. Say a small car with small frontal area and good aerodynamics was cruising on a highway at 80 km/h it may only require only 7.5 kW to overcome air drag, but that same car at 160 km/h will require 60 kW. With a doubling of speed the drag force quadruples per the formula. Exerting four times the force over a fixed distance produces four times as much work. At twice the speed the work is done twice as fast. Since power is the rate of doing work, four times the work done in half the time would require eight times the power! Remember where talking a brick on four wheels here or maybe a slightly chiseled brick

It may be ECU limited but doubt it would go to much faster anyway.

It all gets a bit academic anyway, as stated the tyres are probably only good for 180 and on an un-dived road in this type of vehicle is risking it.