veilsideTT Posted June 19, 2006 Share Posted June 19, 2006 Ok, so ive installed a manual rear diff onto my UK Auto. Problem is im concerned what speed I'm doing. Am i going faster than what the speedo reads or slower? Im assuming im going faster than the reading. So, say for instance im doing 90mph.......Roughly how fast would i really be going? Scott Link to comment Share on other sites More sharing options...
ivan Posted June 19, 2006 Share Posted June 19, 2006 Has anyone near you got a satnav or GPS speed detector you could borrow? Link to comment Share on other sites More sharing options...
Whitesupraboy2 Posted June 19, 2006 Share Posted June 19, 2006 might be worth investing in one to be honest they arent too exspensive and least you always know your true speed Link to comment Share on other sites More sharing options...
veilsideTT Posted June 19, 2006 Author Share Posted June 19, 2006 my old man has a Tom Tom (one of the old first ones) ive always felt that the speed reading was a little on the slow side to refresh. Are they more accurate and faster to update now? Link to comment Share on other sites More sharing options...
Pig Posted June 19, 2006 Share Posted June 19, 2006 i find my new tom tom VERY useful. with a normal setup at 80 speedo im doing 70 gps. Link to comment Share on other sites More sharing options...
Jake Posted June 19, 2006 Share Posted June 19, 2006 my old man has a Tom Tom (one of the old first ones) ive always felt that the speed reading was a little on the slow side to refresh. Are they more accurate and faster to update now?No they aren't any faster to update now. But they are very accurate if you're cruising along at a constant speed. Try going along at a steady 70mph and compare the speedo with the GPS. The GPS will be correct if the car isn't changing speed at the time. This is how I calibrated my speedo anyway. Also, I'm betting your speedo is more accurate now that you have a higher geared diff in the car. With the stock setup the speedo usually over-reads by nearly 10% Link to comment Share on other sites More sharing options...
MrRalphMan Posted June 19, 2006 Share Posted June 19, 2006 Jake, How did you calibrate your speedo? Link to comment Share on other sites More sharing options...
Jake Posted June 19, 2006 Share Posted June 19, 2006 I drove at 80mph according to my TomTom and got my Mrs to stick the needle on at the 80mph postion. Which was still slightly out 'cos it's bloody difficult to stick a needle on in the right postion while the car is going along. Then did the fine adjustment by rotating the dial inside the Thor DSC. Wallah! Spot-on speedo! Link to comment Share on other sites More sharing options...
Ian C Posted June 20, 2006 Share Posted June 20, 2006 "Wallah"? Please tell me that's not supposed to be "Voila"? -Ian Link to comment Share on other sites More sharing options...
Jake Posted June 20, 2006 Share Posted June 20, 2006 Link to comment Share on other sites More sharing options...
Alex Posted June 20, 2006 Share Posted June 20, 2006 Is your Diff J-spec or UK spec?? Gearbox:- 2JZ-GTE AUTO 4-spd w/UK MANUAL DIFF Tyre:- Michelin all patterns 235/45 x 17 Top Gear gives 33.079 MPH/1000 RPM and a top speed of 231.551 MPH at 7000 RPM Engine speeds in top gear:- 30 MPH = 907 RPM 40 MPH = 1209 RPM 50 MPH = 1512 RPM 60 MPH = 1814 RPM 70 MPH = 2116 RPM 80 MPH = 2418 RPM 90 MPH = 2721 RPM 100 MPH = 3023 RPM Top Speed in 1 gear = 58.218 MPH And changes into 2 gear at 3822 RPM dropping 3178 RPM Top Speed in 2 gear = 106.625 MPH And changes into 3 gear at 4572 RPM dropping 2428 RPM Top Speed in 3 gear = 163.244 MPH And changes into 4 gear at 4935 RPM dropping 2065 RPM Top Speed in 4 gear = 231.551 MPH Gearbox:- 2JZ-GTE AUTO 4-spd w/JAP MANUAL DIFF Tyre:- Michelin all patterns 235/45 x 17 Top Gear gives 31.732 MPH/1000 RPM and a top speed of 222.122 MPH at 7000 RPM Engine speeds in top gear:- 30 MPH = 945 RPM 40 MPH = 1261 RPM 50 MPH = 1576 RPM 60 MPH = 1891 RPM 70 MPH = 2206 RPM 80 MPH = 2521 RPM 90 MPH = 2836 RPM 100 MPH = 3151 RPM Top Speed in 1 gear = 55.847 MPH And changes into 2 gear at 3822 RPM dropping 3178 RPM Top Speed in 2 gear = 102.283 MPH And changes into 3 gear at 4572 RPM dropping 2428 RPM Top Speed in 3 gear = 156.596 MPH And changes into 4 gear at 4935 RPM dropping 2065 RPM Top Speed in 4 gear = 222.122 MPH Link to comment Share on other sites More sharing options...
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