[chormelvin]

hy i have had 175mph out of my r33gtst on track only mod is uprated wheels and cat back,can a standard gtst do this or does this give me reason to believe my car is delimited or unrestricted modified in anyway i am not aware of?

 

[Endorx]

Yes it has been derestricted mate....... Probably as soon as it entered the country.

 

[DVDA 1980]

Be careful when you post speed even if it is on your own private test track . Could be reading speed in Km as you would need a very long track. IIRC the max on the gtst is supposed to be 160 delimited. If your speedo were in miles then it could be out due to a larger rolling radius (caused by fitting bigger wheels). best way is to GPS verify using sat nav or similar

 

[chormelvin]

thats what the gps said thankyou,and it could easily do more but i need to shell out on some bigger alloys
and some 265s,thanks for your replys mr.T an dvda,just wandering what you got from yours?

 

[b16 nyk]

"175mph and could easily do more" I'd suggest your car has much, much more than a cat back,so the answer is no,a standard gts-t can't reach anything like that speed

 

[DVDA 1980]

My thoughts exactly andy -final drive should mean top end is near 160 as chormelvin has an auto. Chormelvin as to what mine tops out at - i wouldnt post it on here (public forum) thats for sure, learned that lesson from others. Hint` look up the story on the bloke with the VX220 who was bragging about going fast and got prosecuted.

Besides if we factored in aerodynamics and your cars projected power output (a healthy 260hp??) i think 175 could be pushing it. You need serious power to push over 150. Your mods indicate otherwise. Volkswagen engineers reckon you need around 250hp to punch 150mph. You are saying on a car over 12 years old with near stock modification is pulling 175mph. Sounds unlikely as even with larger radius wheels your speed may only be out by 3- 4%. I saw a video of a 500hp R34 GTR on the Autobahn and it was topping out at around 180mph. What ever you did to halve your drag co efficient tell us all!!

On serious side not denying you may have seen 175mph on GPS but you have to look at things with an analytical viewpoint. Im not into a whose car is faster, whose dick is bigger contest etc.... I own a skyline I have nothing to prove.

 

[buffy]

we have 18's fitted 265's on the rear 235's on the front, gtr wing etc, and it wouldn't get near 175 mph perhaps with another 1500 revs and another 150-200 bhp with a very long stretch of track like the ring straight maybe
ours is around the 310-340 bhp mark atm,

 

[cong]

agread...you would have trouble getting to that speed on a modded gtr let alone a gts, maybe on a gts with 350 - 400 bhp but standard.....

 

[jedi-masta]

i got 420ath and have got it to 170 (mates got a plane and let me borrow his runway ) at about 6250 rpm.....and it still wanted to go more! But I bottled it

Skyline running standard I'd say it'd go 160 max as these cars are like 15 years old now!

 

[Japtastic]

I've never found power to be a problem on the skyline, the gearbox tops out at 165mph so anything above you need your rev limiter removed and be in to the red or have larger wheels, that's the way I see it.

How much can bigger wheels effect it? Any one with some proper knowledge?

Transmission 5 speed manual
Gear Ratios Maximum Speed in Gears
1 3.214 62 km/h (38 mph)
2 1.925 104 km/h (65 mph)
3 1.302 154 km/h (96 mph)
4 1.000 200 km/h (124 mph)
5 0.752 266 km/h (165 mph)
Reverse 3.369 59 km/h (37 mph)
Final 4.363

I did an indicated 169mph once on the autobahn but that shows you the problem with the standard clocks.

 

[cossiedave]

have you been smoking the peace pipe....

 

[iansr33]

can i have some of what he's got, maybe then my dads micra will do two hundred million miles per hour

 

[DVDA 1980]

Been thinking about tyres size and rolling road radii at work and remembered the car bible. Just used the tyre size calculator to work out possible speed differences at 70mph.

http://www.carbibles.com/tyre_bible_pg2.html

put in the figues for a stockish 16 inch set up (225 55 R16) and put up the specs for an 18 inch wheel (265 35 R18). Figures indicate at 70 mph the difference is approximately 1.8%. So at 70mph a car with 18's would be reading 71.25mph. My 3-4 % was a little optimistic!

Also on the site it mentions speedometer calibrations and your speedo can be more innacurate as the car ages. Also worth pointing out is that some of the best calibrated speedometers are made by porsche. They are calibrated for 300km/h. Thinking back to skylines when using my sat nav unit (also does GPS speed) I found that my speedometer varied by +or - 1mph. So the stock unit is pretty good at motorway speed (legal ones ). The question is since the car is JDM did Nissan actually bother to calibrate the factory speedometer for higher speeds since the car is factory limited to 120????

So to reitterate, I think he can and did hit 160 but due to spec (lack of) I would think it is unlikely that he hit an indicated 175. He simply doesnt have enough power.

 

[gtrcraigo]

I think some of the speed converter chips are to blame for over reading speeds, the one fitted to mine is absolute pap and over reads by about 8-9mph at higher speeds! I must get some 320kph clocks instead! :drool:

 

[Japtastic]

So you may be able to get 170ish on 18's hitting the limiter?

 

[thescotsman]

the X/Y axis 'motor' that moves the speedo needle is fine.
The I.C. that 'drives' it is fine.
The error most people see is for 2 reasons...
1. the speedo is not calibrated, it can be.
2. This use of the X/Y axis 'motor' (in this application) requires the use of a 'watch' spring to zero it, this spring is NOT linear, it's force on the needle varies with needle position.
IMHO.
Andy.

Good call Andy.

 

[DVDA 1980]

Speedometer would show maybe 170 it but if you used GPS car would be around 160mph. It is all down to what speed the factory speedometer is calibrated to (anyody know??????). Your final drive ratio in the gear box would prevent it going much faster unless you have a raised redline. Even then it wont be by much.

Using calculated values the 1.8 % difference with 18's would at 160 indicate on the speedometer 162mph. Allowing for slight increase in size in wheel maybe 163 / 164. 175 is not going to happen. We also havent looked at aerodynamics yet and lets face it the skyline has a significant cross frontal area (not as slippery a shape as say a MK4 Supra) which would also afect this.

 

[DVDA 1980]

Andy you say the speedometer is not calibrated - it must be surely to meet any type approval for various sales markets. The spring used must be able to provide at a given amount of force a set speed is delivered. E.g 0.5N force = 15mph (example figues). They couldnt fit an unknown quantity as it would put buyers at peril??

Also from reading your thread on how to delimit the speedometer the speedometer is calibrated to its input using a series of soldered pads (ADJ pads 1-9). By doing your mod you are resetting the speedometer calibration???

 

[DVDA 1980]

Not out for an argument just want to get my head around what you said andy

 

[cossiedave]

when i had my 33 auto i was driving down motorway when i spotted 3 camaras on a motor way bridge, **** i thought 3 points as the speedo read about 88 mph , i then got the wife to chech the gps speed on my tomtom against my speedo and guess what 88 mph was 74 mph gps speed and no ticket ever came through post so i guess speedo would be miles out at 160