| Author | Message | ||
     James Feller Frequent User Username: james_feller Post Number: 79 Registered: 5-2008 |
Guys, I am wondering where I find data relating to what the Rpm should be per klm per hour. ie what should 1000 rpm cruising mean speed wise? what should 2500 rpm mean speed wise etc etc does anyone have this performance data Cheers j | ||
| Stefan Morley Frequent User Username: myupctoys Post Number: 85 Registered: 7-2009 |
James, From the 1988 RR manual for the Turbo R, Top Gear per 1000rpm without cat converter 35.6mph (57.3kph) and with a cat converter 30.1mph (48.4kph). Assume those figures are when the torque converter is 1:1. Guess for other gears you would use the gear ratios to figure it out. The difference in speed between the pre cat and post cat are the overall ratios are different between the two models. Stefan | ||
| Stefan Morley Frequent User Username: myupctoys Post Number: 86 Registered: 7-2009 |
James, What I dont know is how does one know if the torque converter is 1:1. There is a good 1000 rpm takeup in the converter so when do you know its really 1:1, no idea. BTW Turbo R and Turbo RL seems to be the same. Only difference is pre/post cat. Stefan | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1965 Registered: 4-2003 |
First, what is your axle ratio ? Mine is 2.28:1, the home market version as often retrofitted to all by enthusiasts. Most are 2.68. Some are even 3.08 like Silver Spirits and Silver Shadows. Almost all 4L80E-equipped cars have 2.69, so the oberdrive puts them near the 2.28 3-speed at around 62. This subject has been here on the Forum before - do a search. It is also in the Technical Library. If the number you need is not visible; do the arithmetic. 2.28 axle, 4500rpm, 278 km/h. 62 km/h per 1000 rpm for the privileged with a 2.28. Multiply by 2.28/2.69 for a regular 2.69 final drive or 2.28/3.08 for a Silver Spirit/Spur, a T-Series or a Silver Shadow. RHT. ps I have seen 4500RPM with the 2.28 on the Autobahn too many times to remember. Pity we crawl around at 110 here. This chart also shows what happens when you play around with tyres.  | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1967 Registered: 4-2003 |
Turbo R - short wheelbase like a Silver Spirit. Turbo RL: long wheelbase like a Silver Spur; L for Long wheelbase. It has nothing to do with engines or catalytic converters whatsoever. The Turbo R handles much better than an RL, as does a Silver Spirit vs Silver Spur, but the longies are nice for the kids in the back seats. You reach almost 1:1 by 2800rpm. At 4500rpm it is still about 0.985:1 on full power, but when you back off the revs will drop by 500rpm or so. RHT. | ||
| James Feller Frequent User Username: james_feller Post Number: 80 Registered: 5-2008 |
Ta Guys, RT, have no idea the axle ratio on my RL. It is an aust car with all the cats etc etc. Essencially what I wanted to understand is what should my rpms be doing a sustained 120klms on a freeway. Oh BTW, if you rememeber my speedo issue, i forgot to tell you that after all the fussing around with tyres and speedo drive gear ( I have 41 teeth on my drive gear and its yellow what is should be for my car) it was found that my speedo was out. VDO fixed up the calibration for me. ill have a look when it comes back re my fuse thing... looks like the dimmer thing is a bit cactus. J | ||
| James Feller Frequent User Username: james_feller Post Number: 81 Registered: 5-2008 |
RT, you mention axle ratio and clearly this makes a huge difference re your chart in top speed peformance. How do I determine if mine is 2.2, 2.6 or 3.1? I cannot see thins mentioned anywhere in the handbooks for the car. All I can see in the VIN chart in my handbooks is the engine number: 6836L410IT/I and the VIN: SCBZPO3AXKCH27595 Is there something I look for on the car that you are aware of? PS, I drove both an R & RL before buying and could not tell the difference, I admit none at 270klms mind you so could be different at that speed. Truthfully the only time the car feels big, or bigger than the Spirit, to me is negotiating carparks... Cheers J | ||
| Stefan Morley Frequent User Username: myupctoys Post Number: 87 Registered: 7-2009 |
James, Richard is right the cat converter has nothing to do with it, except that presumably the final drive is different between the models with and without cat converters.  Assume this would be with the 255/65/15's for the Turbo R/RL's Stefan | ||
| James Feller Frequent User Username: james_feller Post Number: 82 Registered: 5-2008 |
I just looked uo the hand book and it states cars conforming to Australian, Austrian, Canadian, Japanese, Norwegian, Swedish, Swiss and USA Spec have finl drive ratio's of 2.69:1. It goes onto to say top gear speed per 1000rpm with 2.69 is 48.4 klms per hour. Thanks Stef and RT your assistance and my pulling out the handbooks has answered my question. Cheers | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1970 Registered: 4-2003 |
As I imply, the pundits scramble for a 2.28. My Swiss Turbo R included. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 427 Registered: 6-2006 |
James , just wondering what you're trying to do/work out. I'd guess the diff you want depends on whether you prefer better acceleration or a higher top speed  | ||
| James Feller Frequent User Username: james_feller Post Number: 83 Registered: 5-2008 |
Hi Guys Paul, just trying to guage Speedo accuracy really. While a higher top speed is nice and desirable in some countries, frankly its irrelevant here in Aus as legally anything more than 110 is a potential fine... The fact is that an occasional blast to 200 is nice while on a deserted back road or some such place but just not sustainable given our speed restrictions for our motorways. Now that I know that 1000 rpm equates to 48klms for my car I can guage the speedo accuracy. Better accelleration is probably more advantageous for me anyway. Cheers J | ||
| Stefan Morley Frequent User Username: myupctoys Post Number: 88 Registered: 7-2009 |
James, Dont know where you live but on the "Hume Hwy" years ago (ie 20 years ago) there used to be lines in a couple of spots set 5kms apart to allow you to calculate your speedo. IE if your odo says five kms your spot on. There also used to be a speed warning radar on the freeway above woolongong with a sign over the road telling you what you where doing. Again a long time ago. Either that or overdo it and let a friendly cop inform you of your error :-( Stefan | ||
| Stefan Morley Frequent User Username: myupctoys Post Number: 89 Registered: 7-2009 |
James, Another way which I've used on one of my old bangers is use an electronic push bike speedo. Only goes to 99km/hr but plenty enough to guage accuracy plus you can dial in wheel circumferance. Just needs a magnet on the wheel and a suitable point to temporarily mount the sensor. Stefan | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 428 Registered: 6-2006 |
James, I'd probably agree with you re top speed and acceleration. I assume you have SAT NAV's out there, My TOMTOM has Aus maps on it! That is probably the easiest and most accurate way of checking, if you know somebody with one. Easy peasey James, Correct odeometer is no indication really, the needle can fit on at any possition. It is surprising how Many R-R's and B's are way off the mark. 20 MPH at 70 is about the worst I've come across. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1972 Registered: 4-2003 |
Ok. Acceleration goes in bands. Whilst the 2.69s may seem chirpier off the mark, the 2.28 is actually no slower. The 2.28 takes over as the speed rises in first gear and positively blast away by 80 and hammers the others while the 2.69s are upshifting at around 90-100. Not that the 2.28s are slow off the mark. With that fat torque converter, to break the tyres out into smoke at anytime in first gear is always a danger. With well over 120km/h available in first gear, the unwanted early upchanges of the 2.69 variety are no problem. I do find the 2.28 has many advantages. The engine relaxes more with lower RPM, the intermediate gears have longer legs, the torque converter is better exploited. Silver Shadows and Silver Spirits with the 3.08 have been renowned for decades as overspeeding the motors above just 180km/h, and the 2.69 is a nice upgrade there. A Turbo R with a 2.69 suffers the same way in Germany at 240, but of course with Oz walking-pace speed limits that is all irrelevant. Not that it matters, fuel economy is at least 10% better with a loafy 2.28 if you can find one. Check the speedo against your satnav. That's the easiest way, as the in-car computer will be driven by the car's drivetrain like the speedo. My speedo reads 100km/h while the satnav reads 101. If you don'y have a satnav, borrow one for an hour to check your speedo. The KM speedo test posts, 5 largish signs over 5km, are still on the Hume Highway and allover. There is a set on the Tuggeranong Parkway by Black Mountain in Canberra too. RHT. |
