Top speed in 3rd with an auto and the 1/4mile

[Stav]

At 101 mph crossing the line in a pefect run we could see a 13.469 1/4 mile. What revs do you estimate at 101 mph ? If you can answer that it would be a massive help.

[Casper]

about 5750, rpm cutout

[Ruger]

Stav what size tyre you running mate?

245/45/17 5750rpm with a 3.7 gearset in the bum, math tells me its good for 120mph @5750rpm 4.33:1 = 103mph @saidrpm

[Stav]

Thats awesome.That is such a big help mate..Top stuff!!! : . A slightly raised rev limit will see our cars across the line with limiter not kicking in.

[Stav]

Originally Posted by Ruger

Stav what size tyre you running mate?

17 inch on the front and 15 on the back.

[Casper]

Originally Posted by Stav

Thats awesome.That is such a big help mate..Top stuff!!! : . A slightly raised rev limit will see our cars across the line with limiter not kicking in.

unless you are looking to run 101mph with 4.11 diff gears the limiter in 3rd is not going to even be close to an issue. I'm not even close to touching it and cant see it being a problem for NA I6 AU's.

[Ruger]

also check for diff gear availability - i asked about gearsets for the BA and they dont make anything past 4.11 i was after 4.5's but they dont exist for my diff. im not sure what they make for yours.

[Ruger]

heres some data - said tyre size and said rpm limit in third gear (1.0 ratio)
4.50 - 99mph
4.33 - 103mph
4.11 - 108mph
3.9 - 114mph
3.7 - 120mph
3.45 - 129mph

[Stav]

Originally Posted by Ruger

also check for diff gear availability - i asked about gearsets for the BA and they dont make anything past 4.11 i was after 4.5's but they dont exist for my diff. im not sure what they make for yours.

They do for 9 inch diffs champ.
Casper ..a realistic mph range I am looking at is 94 mph to 100mph .Its anyones guess what my nuts n bolts approach will get me. Maybe I will go slower!!lol. I am mostly a diy guy without a clue.

[Stav]

Originally Posted by Ruger

heres some data - said tyre size and said rpm limit in third gear (1.0 ratio)
4.50 - 99mph
4.33 - 103mph
4.11 - 108mph
3.9 - 114mph
3.7 - 120mph
3.45 - 129mph

So with 4.11 ratio we can pull 108 mph ..right?

[Ruger]

Yep thats it at 5750rpm and 26" tall tyre. If you have your exact tyre dimension i can give you an exact mph
You going for a 9"? if i was in your position i would consider a hilux diff before hand for effenciency, alot of mild rotary blokes run that when a 9" would be overkill (less drivetrain power loss is the key) dealing around the 108mph zone i would be considering the hilux diff, one of the only times ive seen a built 9" break is behind a 400chev, top loader, sidestepping the clutch at 6500 with a slick on the bum.
Food for thought mate thats all.

And after that you can squeeze more rpm out of it by going a smaller tyre and really really really fine tune it to your mph. Did any of you blokes at the drag day see BigAl's black BA ute with the 22" slick? looks odd dont it but it works.

[Stav]

I better get a tailshaft loop ..it may be a good idea.

[ratter]

A nine inch would slow the car down due to the weight and the loss of power to turn it.


Are you guys factoring convertor slip with your equations?

[CMYAU3]

i ve got an au forte 3, in 3rd gear i hit the 180 kmh limit, now ive got 3.55 lsd and hit the limiter at 160 kmh and in drive my car shifts at 5000 rpm each gear. ive completed the 1/4 mile at 88 mph and when the car is held at full throttle the econemy button changes nothing for the shift points

[damon90]

i no its not au but got my auntys work car BA MK2 XT wagon 190 in third and run out of road(it was still gaining speed)