Manual boys - fook off now :xxx: lol

 

Right, when I was last at Santa Pod I toyed with using overdrive on/off for a 1/4 mile run, including changing it on/off when reaching 3rd gear. If there was a difference, it was less than 0.1 seconds overall, but I didnt log how I did each run (crap experiment then lol)

 

However what should the effect be, and in theory - what setting should you use, and would you go quicker by clicking it on (or off) part way up the strip? Eg on hitting 3rd gear?

 

My thinking would be to have overdrive OFF until 3rd gear was reached, then click ON again. Or just leave it off?

 

Any techies confirm the best way, bearing in mind how overdrive works?

 

Cheers

 

Pete

Pete leave it OFF when you are doing 1/4 milers;)

Thats what I've usually always done but would there be any advantage in clicking it back on to allow for higher speeds? Or wouldnt it make a difference until 130/140+ lol?

It will take off again when you get to 130 then click it on.

Cool cheers Mac ;)

 

Any idea of the ratios/ tech theory behind this anyone? Ie at what speed will the car pull harder with overdrive ON again?

 

Cheers

 

Pete

I would answer, but im officially fooked off :tongue:

LOL Ok Paul...manual boys are welcomed with open arms :hyper: :hyper:

LOL Ok Paul...manual boys are welcomed with open arms :hyper: :hyper:

 

ok - fit a manual!!! :xxx:

Right manual boys can fook off again :xxx: :D:D ;)

Cool cheers Mac ;)

 

Any idea of the ratios/ tech theory behind this anyone? Ie at what speed will the car pull harder with overdrive ON again?

 

Cheers

 

Pete

 

Ratios here;)

 

http://www.300zx.org.uk/gear_ratios.htm

 

Ie at what speed will the car pull harder with overdrive ON again? 120+

Ive experemented with this too and found that in my car , foot to the floorboard, wait till about 95mph ( do it too soon and nothing happens) then click overdrive ON and the revs jump up by about 250 and very noticably accelerates even quicker. apparently its not too good for the box tho!

Ive posted about this before but no one else seems to have tried it?

Its very good if u have a scooby nipping at your heels.

I'm confused. I've seen my speedo at over 160 mph in 3rd at ~7300 rpm. Are the ratios different on UK box's? Or the diff ratio? Or is the speedo absolutely *miles* out?! I know it's gonna read higher than the actual road speed, but those figures seem wildly different.

Sureley you have to keep it as close to 3,600 rpm as thats peak power isnt it?

 

If i was trying to gun it, id leave O/D off untill a 1'ner.

51X - and u werent in overdrive? i think your speedo is prob way out, mine was when i got the car, reading about 15% slow. Cost me 200quid to get it set up accurate at Protech.

B19rks - it might be max torque @ 3600rpm i dont know, but if u mean change gear at those revs (?) u would be left standing.

Yeah, not in overdrive. It /felt/ f*ckin quick - definitely quicker than 130-140 mph. Maybe I've got a US mph speedo?! ;)

I'm confused. I've seen my speedo at over 160 mph in 3rd at ~7300 rpm. Are the ratios different on UK box's? Or the diff ratio? Or is the speedo absolutely *miles* out?! I know it's gonna read higher than the actual road speed, but those figures seem wildly different.

 

Hate to say this, but your speedo is miles out!

 

Pete, I wouldn't think it would make any difference until well over a ton?

 

When does lockup kick in... 4k or so?

 

b19rks - that's peak torque@flywheel - torque@wheels depends on gear. Lower gear = more torque. At high revs there's a bit less torque but the advantage of being in a lower gear more than compensates.

This is what I don't get (about my speedo). But then, look at the jump between the theoretical 201 mph in 4th at 7200 rpm, and 139 mph in 3rd at the same revs - a 62 mph jump?! I need to do some more testing! I'm sure mine's something like 90 mph at 3000 rpm, so that'd make it 180 at 6K :confused: I'd better go book Rockingham again, FFS!

Mine is 80mph at 3000rpm o/d and lock up.

Try followin some lorries on the motorway next time,

most go exactly 60 so yours may read nearer 70.

Probably easier to borrow a GPS speedo. I feel like I'm in the twilight zone or somink at the moment :confused:

Right... this just proves what a tit I can be at times. As I get older, I'm obviously getting more confused :confused: Where's me slippers?!

 

I did a /quick/ check earlier, and it's around 60mph at 3K, OD off (in mine). I dunno where I got 90 from. I've definitely seen >160 mph on the clock - maybe it was in 4th!? I wasn't driving at the time, you see... I was busy trying to hold down the contents of the car which seemed to be going weightless with every tiny bump we hit.

 

When I've knocked up a basic autobox gear selector widgit, this stuff'd be /so/ much simpler.