Top Speed Per Gear, Is This Right?

[jrm]

My tyres are 245/45/R17. According this this chart I should hit the speed I recall by redline.

A quick google suggests factory size for an R33 GTS-T is 225/50R16 or 205/55R36 - and your new rim/tyre combo doesn't have the same rolling diameter as factory - it's 3.3% out, and that obviously affects your speedo - it would read 100kph when you're actually doing 103.3kph - ie: reading low.

Still, doesn't sound quite right that it's this far out at 60, but I'm sure it's a contributing factor ...

[ShiftyTys]

I really don't know. Coming up the road earlier today, I was just sitting there watching my KM sit at about 58 and the revs increase.

I already understand the concept of how things work in relation to speed of engine to the wheels vs power is how quickly you get through the gear.

Ill take it out for a quick boot and check what shits what. Ill do it safely though, rather that watch the cluster Ill just use my hand controller to record the max data logged by the end of the gear, the clear it then try it to 6krpm, then clear it, 5krpm. ill get an indication of where this shits at.

You will reach the same speed in any given gear irrelivant of how fast you get there. So. Slowly build your speed to redline. this will illuminate clutch slip as you won't be boosting and bringing too much power through clutch causing it to slip.

That way if you are able to increase your speed whilst going to redline slowly, it may be a clutch slipping problem (as it only occurs on power). If your speed still stops at that rpm whilst your doing this method, something else may be afoot.

[JonnoHR31]

best way to diagnose a slipping clutch is to get on a highway or similar, chuck it in 5th and put your foot down, peak torque(3-4000rpm will do it) in 5th is the most strain you'll ever put on the clutch, if its rooted you'll see/hear the revs climibing quicker than they should be

[jjman]

i would say you have one of the gay R33 ecu's. I doubt that you would not be able to tell that your clutch is slipping. anyway its an easy test to find out if your clutch is shot, do it.

Otherwise, as i was saying, you have one of those conservative ecu's that go really rich above a certain airflow. Mine would rev to about4.5- 5000rpm n then it would not make any more power.

I cant remember what ecu thread this was covered in but i wouldnt waste your dyno time just to find out that the ecu has its thumb in its arse...

With all the stage 1 mods iv gone from about 150hp at the wheels to 300hpatw just from a tune. Stock ecu's are f*kd and god knows what they get up to when you throw on an exhaust, front mount n boost on the stock ecu. they seem very variable how they handle it. Some go alright, others just see the extra flow n throw a hissy. Good luck...

[89CAL]

Making no more power above certain rpm doesnt mean you won't increase speed.

And it's called rich and retard. All the 33 ecu's do it, just to different degrees. Ecu is seeing figures that it see's as being dangerous and adjusts to bring it to a safe level

[Birds]

You will reach the same speed in any given gear irrelivant of how fast you get there.

Except for 5th (top gear)

[SargeRX8]

I just tried it again. I think I'm trying too hard to compare a very stock car to a moderately modified car. 6500 rpm, power fc showed 55km/h. It just feels pretty sluggish after about 5000rpm.

[sleeper-r33]

I've got a series 2 and can only do about 50-55kph at 7k rpm as well?

wow, i get at least 62km/h out of mine