hi i have a 120y with a12 engine and a 4 speed 56a gearbox. I have 12 inch tyres at the back and 14 upfront and at 100km/hr it sits on exactly 4000rpm and around 4500rpm at 110 km/h this seems excessive to me?

the car would be basicaly not drivable at 120km/h for long trips?

Thanks im quite sure it was quite less with my 13inch wheels it just one had ripped so i changed them

sorry i meant 13 inch up front

I drove Melb to Perth to Bris back to Melb in 9 days sitting on 3500rpm no problems at all

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My ute with a worked a12 (which is torquey) with a single sidedraft same box and 4.1 ute diff sits at around 3500 at 100km.
It does sound a little high, better off getting a word from one of the datto pros...

Also doesnt the 120y run like a 3.9??

I drove my A12 at 5000 RPM for hours on end last month (113 kph - speedo is not calibrated). No problems with the RPM. Very responsive.

thanks guys yer its 3.9 borgwarner 68 rear end i reckon it used to be around 3500 at 100km/h with the 13 inch tyres

dd seems that it wont cause much harm sittting that high rpm its just sound like the engines screaming of its head LOL.

with the 12 inch it spins the wheels every corner if you kick the clutch a bit which is fun and take of is abit better imo hehe.

Thanks seems the old a12 can take it :)

Shortly I will be aiming for 110 km/h at 3000 rpm or just under, with my new 3.5 H165 lsd and 5spd.

That sounds like a good setup Nickmitty, you planning on racing it or something? OR just better crusing?

sounds nice wandering if acceleration would be affected greatly?

also stock1200ute1 if you dont mind me asking what modifications did you make to the a12 to give it more torque (was thier head porting involved) did you change the camshaft? do you know which one it is?

i would love bit more torque from the a12

Thanks!

10 thou over, flat tops, bigger valves, ported and polished (only a little bit), shaved h89 head, Mild cam (wade 240) and a single 45dcoe weber.

Goes well and very responsive. Havent done a comp test as yet and could probably go with a good dyno tune but its pretty close atm, not going to bother as im going bigger a series with twins, then i will dyno that motor rather than spending the money on this one...

Keep in mind, doesnt seem like much but it sure is expensive! haha