My 3B to RS2 project

[newsh]

http://s284.photobucket.com/user/new...ml?sort=3&o=10

[redz]

jesus thats loud

[Jonas_R]

Why both the DB killer and 3" silencer?

Does the DB killer go into the tail pipe?

Where do you mount the silencer?

My system is loud as hell as well, but I dont drive the car that much. But i think it would be nice to get the volume down a bit.

[newsh]

jesus thats loud

See what I Mean!

Seriously though, going to get a pull soon, any kind of car park I'm setting off alarms

[newsh]

Why both the DB killer and 3" silencer?

Does the DB killer go into the tail pipe?

Where do you mount the silencer?

My system is loud as hell as well, but I dont drive the car that much. But i think it would be nice to get the volume down a bit.

Was going to try and fit the extra silencer just in front of the subframe but I dont think it will work without major welding so will probably go a bit further forward in the straight section.
Going to try the dB killer first to see if it affects back pressure for my "overboosting at high rpm" problem, also will be useful at tracks with a dB limit..
Yes it goes in the tail pipe, I'll secure it with a small bolt through the lower edge so it can be removed.

[madwolf_Uk]

See what I Mean! D

Seriously though, going to get a pull soon, any kind of car park I'm setting off alarms

Bad audio quality, but sounds awesome

Do see what you mean though, my 80 is "just" load enough to be comfortable, without a sterio in, and a tocuh on the quiet side without

My S2 is too quiet at the mo though.....

[newsh]

Bad audio quality, but sounds awesome


My S2 is too quiet at the mo though.....

Bad audio, er cobblers shoes comes to mind, hey it was done on my phone while I was driving

They dont get much quieter than your car Gary

[madwolf_Uk]

Bad audio, er cobblers shoes comes to mind, hey it was done on my phone while I was driving

They dont get much quieter than your car Gary

I knew youd say that, ya git! lol

Yeah i had taken into account it was ya fone and ya were drivg mate

[newsh]

Of course I wasn't actually holding the phone myself Gary

[madwolf_Uk]

Of course mate, we dont do that sort of thing on here do we

[newsh]

T'would be dangerous

[Acidburn]

I'll have to try hear this before you put the box in john, tbh it does not sound bad to me tbh.

when are you planning to get this done?

[newsh]

It is insanely loud at certain rpms even at a tiny throttle opening at 30mph, especially inside the car, my ears seem to start ringing within a minute of driving in traffic. At high speed with the revs above 4k its ok but still loud enough so everybody looks, it sets off car alarms as you drive by, its only a matter of time before I get a pull. Anyway its really very annoying to drive.

Have to report though that I fitted the dB killer this morning and there's a big difference, even without the extra box. A lot of the boom is gone although I'd like it a bit better yet.
Most importantly the overboosting has mostly gone and it will now run mechanical boost up to the redline apart from a small increase of 0.1 or so Bar above 5k. So Doug was right and the extra backpressure has helped the wastegate to work properly which I must say I find really strange..

[newsh]

Did a search on Boost Creep. Lots of stuff out there.

Found this which explains it.

http://www.rx7club.com/showthread.php?t=26389

The best way to deal with creep is to
1) port your wastegate
2) add some restriction to your exhaust.

The creep is present because of too much flow through the turbos despite the wastegate being told by the ECU/boost controller to be 100% open.

You will not have boost creep problems unless you are running a full 3 inch exhaust (DP/MP[with or without resonator]/CB). Adding some restriction such as a hi-flow cat, or a more restrictive catback exhaust, or a restrictor plate in the exhaust flow can help.

A restrictor plate is just a gasket (made of metal) that has a hole that is smaller than the internal diameter of the exhaust piping. For example, having a hole of only 2 inches.

You can place it between the DP/MP, or between the MP/CB. I am not sure of the best location. I ran a plate between the DP and MP. As the gases get further from the exhaust manifold they will cool and become denser. You can also run silencers in your exhaust if you have for example the Apex'i GT or N1, or N1 Duals.

The plates are easy to make if you have the right tools, or you can have them machined by a shop. I had a bunch made up when I just wanted one, but now they are all accounted for.

Hope that helps.

Ulimately, the best thing is to port the wastegates. . But with the plates you can keep the boost down to a reasonable level, (depending on how free flowing your exhaust is, how good your turbos are, and the size of the hole, 10-14 psi [ I tried a bunch of different sizes] but you will need the fuel to compensate for the increased boost.) This is not an issue if you are tuned for 14 psi and run 14 psi max.

The Borla XR-1 is a silencer/resonator. I have it welded in the middle of my MP. It has 3 inch inlet and outlet, is a straight through design, with perforated core, and sound absorbing material inside that is apparently able to withstand the hi temps of rotaries. They are about $125 from summit racing, and my exhaust shop charged about $20 USD to weld it in.

Mike
Last edited by the_saint : 10-18-01 at 09:52 AM.

[Acidburn]

Sounds interesting and something different as I always thought that it was mostly NA engines that needing the back pressure to help with power.

Still interested in hearing it in person

I used to have loud exhausts etc and they was ok but I have noticed that its ruined my hearing a bit