jo_ker

i guess the flaps have their base only for homologation issues.
somehow like: 3rd gear 50kp/h - valves closed - noise test ok.

back in my R&D time - we programmed even throttle bodies on motobikes to close (nearly to zero) exactly after 0,5sec holding at 50kp/h in 3rd gear...

inactiveuser7616

We only saw a loss of 8hp with the valves closed.

As for heat, I can't comment.

I find I don't use the closed option that much. Maybe 15% of the time.

I will say, I am thrilled with this ability to keep open / closed all the time. One of my favorite mods!

There was also an option for a unit that also added to integrate with the PSE and have a third option as 'OEM' / function as from the factory. But that required tapping into the computer. I didn't want to get into that.

Charles@dundonmotorsports

Closed all the time up to 5500rpm and part throttle part load is ok as the stock DME program still keeps them closed here.

Closed all the time and visit Laguna is not a good idea. Yes there is a huge power loss up in the RPMs but down low say below 5000 it's maybe 10whp which is nothing if you just want them closed all the time.

John@Fabspeed

In stock and ready to ship. Kits typically come with the Valvetronic systems we offer for cars that don't have PSE. We sell them separately for $295. Power, ground, and vacuum and you are good to go

inactiveuser7616

We didn't see any more than 8hp loss across the entire RPM range.

But...I'm no expert and have come to accept that I don't care what the dyno says. So far the system has been fantastic. Granted I haven't ran a track day with them closed. What do you believe I'd experience / see if I did?

Charles@dundonmotorsports

If you dyno the car with the flaps stuck and forced closed it will go into limp mode, or reduced engine performance in red, take to workshop. With them stuck closed it is about a 80whp loss around 6500rpm before the car shuts down. Also the car will not let you drive it hard until the faults are cleared. Just turning the car off and cycling the key does not work.

meaker

Last fall at the smokies (track day) a few of us had our flaps wired closed to keep below sound db limits. Nobody's car went into limp mode also power didn't feel much down at all( butt dyno). Now I will say, I was concerned with doing this cause of excessive heat and if any other ill effects. Also will avoid doing it again.

allans

Never happened to my car when run on track or street. I would limit this to short durations due to uncertainty of heat issues. Best, Allan

Charles@dundonmotorsports

This was on the dyno after a few hours of runs and testing, so the engine was already well heat soaked. Compare this VS street or track while moving.

my experience was also with our exhaust not a stock exhaust setup. I could see the design of the stock mufflers reducing turbulence where the flow actually bottle necks into the small 50mm piping.

Power loss is relative. If the power loss is everywhere and gradually loosing power , not a huge dip that can be felt as easy, then i could see it being less noticeable.

Next time we have one on the dyno I will try to remember to record the run, and maybe even post up the dyno and conditions the ECU says. I do remember coolant temp going from 200* to 230 before the end of the pull

GT3 KSA

If you did end up going to the dyno, please share the results!

meaker

17 hp gain from just no mufflers. I wonder how bad it drones?

CDinSing

Is this just the center muffler delete exhaust? If so, that is better than they claim. Nice! I have it, didn't dyno it, but the sound at highway speeds is quite acceptable. Even the wife likes it!

meaker

I believe it's side and center muffler delete. Basically straight pipes after header/cat.