7age use TVIS ?

[sun_moon]

ok if i were to put a bigport head on a 7afe block with smallport pistons and bigport cams, the compression would be nice and high due to an increase in combustion chamber volume as well as the smallport pistons in there. good good.

now my question is, due to almost 200cc extra capacity and also such high comp... should you run TVIS, as it would still help with port velocity ?? or is it not needed, as in could it be a restriction ??

would like more info on this, especially from SAMQ

[yoshimitsu9]

4ages them self run better over all with it still working properly

so for overall driving quality id say keep it

[rthy]

alot of doods in america still run the tvis
best way is to go to a dyno and test with it and with out

[sun_moon]

so it seems that despite the extra capacity and compression, the port velocity still isnt good enough to warrant the removal of TVIS ??

[Golberg]

Well the best solution is to go for a small port head, but I'd keep the TVIS on there if you're running everything on standard management.

[sun_moon]

hey goldberg, yep i definetly will be using a smallport head.

was just interested to learn about the bigport head tho as physics things like this interest me a bit ^_^

[Sam-Q]

beats me! I know less than you think

although I would expect it to help still. This is because the TVIS works up to 4000RPM or so and thats a pretty large range. So even with the extra volume it has a lot to make up for.