Advice needed on de cat & restrictor ring

[Guest damo-eire]

Hi All new to the Supra world, I recently got a jap spec TT. pretty much standard apart from k&n cone filter and Stainless 3" cat back exhaust, upgraded brakes.

 

Anyhow Im a stainless steel fabricatoe by trade and was going to fab the de cat pipes myself. Reading through the forum I see that i need to fit a restricter ring to prevent the turbos over spooling?

 

Any info on this would be great

Cheers

Damien:innocent:

[scotty71]

Yes a restrictor ring will fit between the first and second decats to give some resistance as you have taken the cats out otherwise as you stated the turbo's will overspool. The RR's hole will be drilled out smaller the the exhaust diameter. 2" is the norm I think and should stop the turbos going beyond the safe limit of 1.2 bar (ceramic turbos)

[Nic]

The restrictor ring is a flange shaped plate that is sandwiched between the decat pipes or ahead of the first decat pipe. The hole in the restrictor ring is smaller than the pipe diameter, this causes a restriction in the exhaust to limit the turbo boost to a safe level. It'll take a bit of trial an error to get the correct hole size to limit the boost to the required level.

 

http://images.bilgalleri.dk/uploads_alb_large_wm/1158580_l.jpg

[monsween]

Kinda on topic and you may know nic,

 

Does it matter if its between the first two, after the 2nd, before the 1st?

 

As in your going to have a larger volume to restrict meaning the pressure will lower or greater the closer you put it to the downpipe. (cant figure that bit in my head lol)

[Guest damo-eire]

Thanks for the answers looks like ill order my pipe and get to work.... Am i correct in saying 2.5" pipe from the manifold? The cat back system is 3".

Thanks

[pedrosixfour]

Damien, make me one too while you're at it.

 

Thanks,

Damien.

[Shane]

Kinda on topic and you may know nic,

 

Does it matter if its between the first two, after the 2nd, before the 1st?

 

As in your going to have a larger volume to restrict meaning the pressure will lower or greater the closer you put it to the downpipe. (cant figure that bit in my head lol)

 

I fitted mine between the second decat and the exhaust. But also wondered whether it should be closer to the turbo to help reduce spikes. Maybe I have got this all wrong, but surely in the time it takes to build up pressure between the turbos and the restrictor ring it could for a moment overboost? Until the pressure is there, surely it's the same as not having a RR in? Maybe I am missing something obvious here.

[Guest damo-eire]

..

[Nic]

Thanks for the answers looks like ill order my pipe and get to work.... Am i correct in saying 2.5" pipe from the manifold? The cat back system is 3".

Thanks

 

2.5" or 3" decats, doesn't really make a difference either way as the restrictor ring will keep boost pressure in check.

[supra-ireland]

Chris Wilson used to selll decent restrictor rings.

I bought one from him before and it was spot on.

Might be worth giving him a shout if you're after one.

 

[email protected]

[Guest damo-eire]

restricter ring made in 10 mins.... now for the fun part