MK5 Golf GTI

General => Random Chat => Topic started by: FJ1000 on June 14, 2016, 02:12:55 pm

Title: JC Weldfab Exhaust Vid on my RS4
Post by: FJ1000 on June 14, 2016, 02:12:55 pm

Had a new full exhaust system fitted to the other car a week ago. Love this thing, had to share. Enjoy:

Anyone had a JCWF on a GTi?


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Title: Re: JC Weldfab Exhaust Vid on my RS4
Post by: AJP on June 14, 2016, 02:55:56 pm

That sounds ridiculously good.

Got to be honest, I've never heard of JC Weldfab exhausts. I've got a turbo back Powervalve (formally known as BCS) on my mk5 GTI. Valve is actuated by boost from a line to the inlet manifold. Powervalve are pretty much regarded as the top of the pile when it comes to TFSI exhausts.

It'd be interesting to see what JC can do for the TFSI/TSI. I'm sure there's room in the market for another valved exhaust. I think Scorpion now do a valved option for later cars, but I'm not sure how good it is.

Love the sound of that though. Proper angry V8.

Title: Re: JC Weldfab Exhaust Vid on my RS4
Post by: FJ1000 on June 15, 2016, 02:10:12 pm

Thanks fella!

I'll ask them what they offer for the GTi and report back.

The RS4 has valves per OEM, which are vacuum operated. So it's fairly easy for them to incorporate into their system (although they use Bentley valves rather than the RS4 ones which are prone to seizing up). The BCS method of valve operation for the GTi seems quite bespoke?

Title: Re: JC Weldfab Exhaust Vid on my RS4
Post by: AJP on June 15, 2016, 04:39:00 pm

Quote from: FJ1000 on June 15, 2016, 02:10:12 pm

Thanks fella!

I'll ask them what they offer for the GTi and report back.

The RS4 has valves per OEM, which are vacuum operated. So it's fairly easy for them to incorporate into their system (although they use Bentley valves rather than the RS4 ones which are prone to seizing up). The BCS method of valve operation for the GTi seems quite bespoke?

I think it is unique, to the VAG cars I know of anyway. @Powervalve Nige would give you a much better explanation, but basically it maintains flow velocity sympathetically to the turbo, so the turbo has optimal backpressure through the revs. They provide some hefty torque and power increases as a result.

If you were to have a manually actuated valve on a turbocharged car I'd imagine you'd be opening the door to potential turbo problems - sudden increases in backpressure if the valve closes etc. I might be talking nonsense but I think that's roughly the theory!!!