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R1 silencer on MX5 1.6 engine
Charlie C - 27/7/17 at 08:19 AM

For anyone that’s interested (that’s probably not many) I've just fitted an R1 silencer to my haynes with a 1.6 MX5 engine running ITB’s, piper cams, megasquirt, Westfield exhaust manifold and no cat.

Previously i had and Westfield silencer it weight about half a tonne and the sound is a bit rubbish, it was just under the IVA DB limit back in January. So, I wanted a change and shed some weight off the car.

Last night I fitted a standard R1 silencer (it’s the oem blue one with titanium written on the side) to the Westfield manifold via a link pipe made up of 2” tube, a flexy pipe and step up to 2.5” fitting for the silencer inlet. The R1 silencer is so much lighter, but I need to adjust the angle of the outlet as it not pushing the exhaust gasses past the rear wheel arch.

I took the car for a spin and my first impressions are good, there is a nice rasp to the exhaust noise now and it is a little bit quieter, I haven’t lost any noticeable power if anything it feels more responsive but that could just be me wanting it to feel better.
I paid £50 for the silencer and about £30 making the link pipe, I’m please the results and have a titanium case silencer for £80.

I’ll try and get some photos up soon if any ones interested.


r1_pete - 27/7/17 at 09:05 AM

The R1 can is a good choice, it isnt as restrictive as many stock bike cans, because the bike runs the exup valve which adds restriction at low revs.


miskit - 27/7/17 at 09:57 AM

Good info. I just fitted a couple of Hayabusa (GSXR1300) cans to the VW 1600 on the sandrail - much better than the awful loud cannons on there. Since the next engine will be an MX-5 1.8 VT this is helpful to know.


40inches - 27/7/17 at 10:42 AM

I used a mandrel bent elbow, sealed with silicon and a self tap screw on the back.
Description
Description


SPYDER - 27/7/17 at 08:37 PM

Hi Charlie. Here's my effort. I bought two cans to give me two support clamps and two sets of end fittings. I paid £18 for a clean one and £8 for a tatty one. I took the back end off together with the little curved outlet pipe inside it and replaced with a slash cut 45 degree bend. They look restrictive inside but the real world performance of my car on and off the rollers would suggest otherwise. Yamaha must have spent millions of yen getting the performance/noise compromise right.

Edited to add...
This is on a 3SGE Toyota engine on ITB's making just short of 200bhp.
It shouldn't pose a problem on a 1.6




[Edited on 27/7/17 by SPYDER]


Charlie C - 28/7/17 at 08:50 AM

Hi

that looks like a really nice job, is the exit pipe welded to the end plate (i don't mean the cover)?

Thanks


SJ - 28/7/17 at 08:56 AM

I found it impossible to mig stanless to the titanium pipe on my R1 can.

Stu


SPYDER - 28/7/17 at 09:27 AM

quote:
Originally posted by Charlie C
... is the exit pipe welded to the end plate


I tried MIG ( like everybody does ) and managed to make it stick but not very well so I added a riveted tab or two.
I understand that braze might be more successful.