Potential Damage Caused By Restricted Exhaust

[Randon_I_Am]

Just wanting to know peoples thoughts about running a very restricted exhaust only at cruise and idle?

My car in question is an R34 gtt with 290rwkw, all the usual mods.

could it really do any damage running the exhaust closed basically only at idle and cruise?

[zebra]

nah, might run like a bucket of ass, just dont flog it

[R31Nismoid]

it only makes 290rwkw @ 6000rpm+ remember.

putting around, 2000-2500rpm, it'll be making less than stock most likely so it'll be fine.

use light throttle always. dont full plant it to 2500-3000 type thing otherwise you are forcing etc.

[GTScotT]

Agreed, at cruising speeds it will be more than fine.

Start flogging it and your asking for trouble, it will back up te system and transfer heat into the cylinders = detonation.

Personally I would pick my poison and stick with it (loud or quiet exhaust). I CBF for these halfway points that are neither as good as either. A crap restrictive version of a quiet exhaust and a dirty untuned sound of a loud one.

[The Dan]

I would disagree, if you close the exhaust as stated, then you will generate massive amounts of heat and pressure. Burn valves, lunch turbos etc.

If you are talking about having a 2 or 2.5 inch system on it then it will be fine at cruise and idle.

Maybe a little bit better description of the system that's on it?

[Randon_I_Am]

It's a full 3 inch turbo back with metal cat. With a varex muffler. This had a butterfly valve in it which re directs the exhaust flow through a series of baffles when closed.

[89CAL]

Yeah a Varex should be fine at cruise/low loads, but I know they do restrict a bit up top end.

[Crans]

These mufflers mixed with a ferrari type actuator setup would be awesome.

Basically as you hit boost an actuator opens up the muffler.

Could also work with an electronic setup based on revs and throttle position

[jet.26r]

it would agree it can do damage i once had a dc5 type r... and my loud exhaust got defected anyway i bolted up my standard exhaust went to the prick at granville it failed like 1db i wanted to give the guy a beat down for not passing me. Any way getting to the point now i put a hot dog resignator in my standard exhaust and it burnt out the o2 sensors and it was a straight through resignator.

so that defect i laughed at..... bent me over lol.

I would disagree, if you close the exhaust as stated, then you will generate massive amounts of heat and pressure. Burn valves, lunch turbos etc.

If you are talking about having a 2 or 2.5 inch system on it then it will be fine at cruise and idle.

Maybe a little bit better description of the system that's on it?

[Randon_I_Am]

I could do that. At the moment I've got it hooked up to my G force meter, with a touch of a button it switches off the meet and closes the exhaust. I was thinking about putting an override in connected to the revs, so it opens itself up at 4000 or so... Need a bit of tweaking to the electronics at the moment, so I might write that in.

[Trozzle]

Yeah Pat, you're a smart cookie. I'm sure you'll have no worries whatsoever wiring it into something like that. Maybe even get one of those things from Jaycar that people use to control VCT when using an RB20 ECU for their RB25 nistune?

[Randon_I_Am]

I'd rather hook the signal up to my own microprocessor and program it up. On that note, I've had no experience on hooking anything up to the ecu like a taco... does any one know what signal the ecu gives out to the taco? Is it pwm or voltage modulation?

[paulr33]

it wont cause damage

thing of the big powered v8s that come with tiny pee shooter exhausts factory