Well its been discussed up and down in these forums, and I have read most of it and want to come to some solid conclusions. If you have a 4inch exhaust, from what I understand the only reason to not reroute is if you love the loud sound. I read alot about the re-entry angle, position in relation to the manifold, pipe size and how it affects back pressure but from what I understand with a 4inch or larger you can reroute with basically no drawbacks to performance, is this correct. Also just to confirm if I am running a gt42R and I set the boost for 18 psi, this would mean that in a perfect world, so long as I am boosting under 18, the wastegate is closed and thus not making any noise, its only at full boost with WOT that the gate would open and cause onlookers to require ear surgery, does that about sum it up.

I know its dangerous asking general questions like this because someone is gonna wanna micro anylize the 6 hp loss at 6317rpm, but in a nut shell is this all sound logic. Also for the guys running a little higher boost that do not have a reroute, is the volume that bad, or is it tolerable, again I know general question, for what its worth I like it a little loud.

 

It will attract Cops non rerouted, hehe.

 

Just an open wastegate with a dump tube is LOUD. Make no mistake about it.

Also, it'll open any time you let off the gas. Not just WOT at peak boost to bleed off pressure.

Pluses:

You know your wastegate is working


I've run wide open, and open with a muffler setup. I'd like to try some more muffler setups, but this year I'll be re-routing it because I haven't tried that (on this car) yet.

 

Thanks for the insight, looks like I will be re routing, anyone have any pics of their reroute, with an A SPEC manifold, v-band if possible, thanks.

 

You should be able to find pic of what you want on this thread.

https://www.rx7club.com/spec-tuning-154/new-stuff-09-a-814635/

I just got this setup from A-spec. Seeing how well the reroute was done, I can't see it hurting performance much if at all.

-Andy

 

Mine is open, i don't think the noise is that bad. And mine doesn't open when i let off the gas, only about 2 psi before my target boost does it open.

 

So why is it thtat everyone else says its crazy loud, just the 4 inch system itself or the dump to atmosphere is loud???

 

Yes

 

WG will always crack open before target boost level is reached. I've had cars here dump to atmosphere that weren't that noticeable. I've had others that were horrible sounding. I think a lot has to do with how it's dumped ie length of pipe, pipe diameter, exit etc.

As example I had one car here running our long runner with almost no dump at all and you couldn't even tell when the gate opened.

 

On my old setup I ran the FC HKS log manifold with a standard (40mm) gate. I had it bolted right to the manifold flange. There wasn't much room to route a dump pipe so I just had it open. That thing was earsplitting.

 

Mine doesn't have a dump tube just the gate open. It's loud under boost but not that bad. It doesn't hurt your ears or anything. I like how it sounds. Mostly quiet until i'm racing then the gate opens and i fly by.

 

Dumped to atmosphere video

http://videos.streetfire.net/video/P...n-a_188521.htm

 

My open wastegate makes my ears bleed. If I'm messing around with someone on the highway and they are on my passengers side with the windows down...they almost crash.

But yeah I'm getting mine re-routed into my exhaust. F-that noise.