Dear Marjorie... should I take my TVIS out ??

[jondee86]

Here is some interesting stuff from a guy who went to the trouble
of actually testing performance with TVIS connected and disconnected.
Worth a read... http://websworld.org/marcel/tech/tvis/tvis.html

Cheers... jondee86

[mr30%jr]

theres plenty of tests. that prove no real loss in hp but response. and as allways argued thats exactly what its there for.

so if you got a stock car. dont bother.

if you run thinks like cams give it the boot

[rollaholic]

doesnt your car have a smallport jondee

[Leon]

Here is some interesting stuff from a guy who went to the trouble
of actually testing performance with TVIS connected and disconnected

I accidentally tested that, when I got my first MR2 back from the workshop after they did the head gasket. They left something unplugged, such that the tvis wasn't working.

Absolutely no power down low.

They plugged the line back in, and the car went normally again.

[jondee86]

doesnt your car have a smallport jondee

Yup I just posted that link up for the benefit of those people who
get fed a bunch of BS opinions on the pros and cons of TVIS.

Cheers... jondee86

[mr30%jr]

i kinda even question that link because he using street dyno

[cat007]

quoting myself:

OK so I hooked it up - set it to be on below 4200rpm and did some before and after trial runs. Here's the results.

The ECU logs 10 times every second - so the "readings" are every time the ECU logs data (i.e. 10 times a second)

Without TVIS
Reading: 205 = 2003rpm @ 0.43PSI
Reading: 479 = 4225rpm @ 7.46PSI

With TVIS
Reading: 161 = 2098rpm @ 0.43PSI
Reading: 381 = 4234rpm @ 7.83PSI

So - I managed to gain 0.4PSI from just having TVIS on.

It may not sound like much - but bare in mind, both tests were done with the car at the same temp and on the same stretch of road (up a hill of course). And if you work out, the difference without TVIS took 274 readings (27.4 seconds) to get from basically 2000rpm to 4200rpm but with TVIS it only took 220 readings (22 seconds).

Thought someone on here might find all this interesting

[jondee86]

And if you work out, the difference without TVIS took 274 readings (27.4
seconds) to get from basically 2000rpm to 4200rpm but with TVIS it only
took 220 readings (22 seconds).

Which brings us to another interesting point. It might be true that some
methods of measuring performance do not match the figures obtained on
a chassis dyno. But for measuring improvement in performance any
device that can can provide good repeatability, will do the job.

I am in the process of hooking up an Apexi RSM on my car, and I hope
that this will tell me if my mods are working

Cheers... jondee86

[JRS]

he didn't do a test with the butterflies and shaft removed so the whole exercise was pointless.

[sergei]

Most of the times the vacuum actuator is bust on these, so it will not pull the butterflies closed. I had that happen to my 3SGTE (gen1), the replacement part was way too expensive, so I took out the butterflies and shafts, then ported and matched the sandwich plate and filled in the holes. Then I have added different turbo among other things, so I cannot tell if there was a gain.

[pc]

You will theoretically get a tiny gain at the top end if you remove the plate and shaft/butterflys. But at the expense of all bottom end torque... would be good to see some dyno plots illustrating this though.