Can you RED LINE an N/A?

[steve b]

isnt it the TVIS or am i confusing that with something else?

Its ACIS this discussion has been going on on the american boards and mr2oc, n/a's have ACIS on the sw20 they never had TVIS, turbos had TVIS. TVIS involves 8 runners on the inlet manifold 4 of which are blocked uptill a certain rpm. ACIS has i chamber that opens no blockages or extra runners like TVIS.

[mr2 dan]

bit like a vetc .
there must be a way to make it stay open all the time .
mine kicks in at 5000 rpm and pulls lots harder it nice tho when it kicks in at 120mph in 5th lol

[MegatronUK]

If it was open all of the time you would lose a lot of low down torque - it's to do with the air flow (velocity), through the intake ports.

Having the ACIS or TVIS open increases the intake port size (on the TVIS, anyway.. ACIS is somewhat different, but similar principles apply) thus allowing a greater volume of air to flow.... the problem is that at low rpm's and speeds, having a big intake is not really great... the volume of air needed is lower thus it tends to enter slower through the larger intake.

Hence the TVIS is closed at low rpm, decreasing the intake size... the result is that the air velocity entering is increased, and you get more torque as a result.

(think about putting your thumb over the end of a garden hose - the amount of water coming out is the same as if you didn't have your thumb over, but it comes out at a much higher velocity when you do - of course if you want a lot more water to come out, you need to take your thumb away as it will eventually become the limiting factor)

[Mike 'MR2' McHugh]

Karl no wonder you lost. 5-5.5 k? LOL

take it to 6.8ish and you will feel the difference. These cars need to have the revs kept up to make the best of them!

He was up your rear end wasn't he?

you gotta love that pullin feelin you get when you take it that far, i know its nothing on a tubby but hey, were talkin na's here !!