4722 replies to this topic

[Nev]

Nope, I've finally bitten the bullet and bought a ton of exhaust bends, flexis, flanges, v-bands, straight pipe, hang rods, bungs etc to start building an exhaust pipe (assuming my welding skills are up to the job, which they may not be). The gas + rods will be another £100 on top of that too, and I have yet to buy the sheet steel to roll up into the silencer or the perforated sheet + tubes.

 

I think the whole design will be unlike anything else in a VXT that I've seen (with the exception of that inspirational Volvo engined exhaust). I am probably going to make my own silencer box with an unusual routing/design I've come up with, as anything off the shelf wont manage with the noise in all likely-hood. I am also going to try and experiment/prototype with a few variations to see what back pressure and noise reductions suit best (I have gauges and noise meter to measure this). The core pipe will remain 3.5" for goodish flow but this will split into 2 separate 3" sections within the silencer, with twin tailpipes that will be deep enough to install further db killers into, in case track noise limits require it.

 

I'm not really keen on building it over the summer, as will mean the car will be off the road (which I hate as I drive it a lot obviously). But, the whole thing (and people's snide comments) is irritating me so much now, so I guess sooner is better than later. I will be staggering the project into 2 phases to allow me to get it back on the road ASAP, but work on the silencer as a separate phase, as that is going to be the hardest part.

 

I've never even welded anything close to this size before, it will be quite a step forward for me, as it obviously has to be strong and well made to cope with the heat and over-run explosions. Just to give an indication the gaskets on the 3 bolt (M10) flanges on the current one have been blown out(!!), which is quite something.

 

This will be Nipper's 4th exhaust.

 

 

 

 

 

Edited by Nev, 22 July 2016 - 02:28 PM.

[Mike (Cliffie)]

Good luck with it Nev and good on you for having a go. Vocky did the same for his car (ITB NA) and made a cracking job of it.

[Mike (Cliffie)]

BTW, if you are welding a manifold up, make sure the flange is clamped to a head otherwise it will distort with the heat and never seal.

[siztenboots]

does the manifold still use the double shear bracket from the original , to allow heat expansion the fixings between each runner are slotted / cut through on the oem manifold.

 

picture of the bracket which fits around the manifold

 

[Nev]

does the manifold still use the double shear bracket from the original , to allow heat expansion the fixings between each runner are slotted / cut through on the oem manifold.

 

The exhaust manifold uses all the normal studs in the head (so is double shear) if I understand your question, but it does not have cuts between each port on the main flange like the OEM unit. TBH, the manifold looks fine where it mates to the head, the stressed bit on it is the merge collector where all the heat builds up.

 

BTW, I am not making a new manifold if that's what you're thinking, just a new exhaust, I'm not sure how you guys got that idea...  

Edited by Nev, 22 July 2016 - 03:40 PM.

[Nev]

Most of my metal has arrived, note the 9 volt battery for scale. The majority of the pipework is 89mm (3.5") with the wastegate pipework being 45mm. Am just waiting on 1 more flange and some 10mm steel rod to make the hangers.

 

I will need to order a load more for the exhaust silencer itself of course, when the time comes.

 

Edited by Nev, 06 August 2016 - 06:29 PM.

[Mopeytitan]

looking good Nev! not long and she'll be finished and in the car

[Nev]

looking good Nev! not long and she'll be finished and in the car

 

Only another year or two probably ! LOL

 

Would you still be able to "aquire" and roll a sheet of steel into an ovaloid shape for me please mate, if I finally work out the dimensions?

 

Edited by Nev, 07 August 2016 - 09:27 AM.

[Mopeytitan]

How slow are you going to make this thing!!! Yh should be able to mate ::

[Nev]

How slow are you going to make this thing!!! Yh should be able to mate : :

 

Sorry, too busy driving it or doing outdoor sports during the summer. Am going out tonight to Wales once the traffic dies down as it was so damp this morning.  

Edited by Nev, 07 August 2016 - 09:33 AM.

[Nev]

Spent the last 6 days doing this sort of stuff:

 

[TFD]

Take care with the v-band clamps. When welding these things they can warp and need to be re-surfaced for a correct mating surface.

Not say they will (or how good the welder is), but be warned 

 

Looking forward to the result.

[Nev]

Take care with the v-band clamps. When welding these things they can warp and need to be re-surfaced for a correct mating surface.

Not say they will (or how good the welder is), but be warned 

 

Looking forward to the result.

 

Thx, good tip, will do.

[Nev]

I've got absolutely nowhere with the exhaust, just too damn busy with rock climbing, MTBing, kayaking & surfing. It will likely become a winter project as I am keen to drive it for the remainder of the summer and don't want it up on bricks for even 1 day.

 

Edited by Nev, 12 August 2016 - 09:03 PM.

[Nev]

I've discovered that I need to re-wrap the exhaust manifold I think, as the smell of general "melting" from the bulkhead area (by the manifold/turbo/downpipe) is quite strong. Also, I had a case of making too much boost one day (ie > 10 PSI) when it was super hot, probably due to the vacuum pipes melting/softening and hence letting the pressure signal to the waste-gate escape.

 

I know some people don't like heat wrap because it doesn't look blingy, but it sure does work well, so I've ordered up 10 metres of it.

 

Apart from that the car is driving wonderfully, I went for a lovely Sunday morning drive the day before yesterday, just ambling along enjoying not being at full tilt, with the rising sun warming my face and wind in my (diminishing!) hair.

Edited by Nev, 16 August 2016 - 06:27 AM.

[VXT Tim]

Have you thought about a turbo jacket Nev? I happened across a YouTube video the other day that was discussing them. Not too sure on the reality but they seem to make sense to me. I'll try and find the video although I'm sure there are thousands out there.

[harboged]

I've discovered that I need to re-wrap the exhaust manifold I think, as the smell of general "melting" from the bulkhead area (by the manifold/turbo/downpipe) is quite strong. Also, I had a case of making too much boost one day (ie > 10 PSI) when it was super hot, probably due to the vacuum pipes melting/softening and hence letting the pressure signal to the waste-gate escape.   I know some people don't like heat wrap because it doesn't look blingy, but it sure does work well, so I've ordered up 10 metres of it.   Apart from that the car is driving wonderfully, I went for a lovely Sunday morning drive the day before yesterday, just ambling along enjoying not being at full tilt, with the rising sun warming my face and wind in my (diminishing!) hair.

Which brand for the heat wrap did you go for?

[Nev]

 

I've discovered that I need to re-wrap the exhaust manifold I think, as the smell of general "melting" from the bulkhead area (by the manifold/turbo/downpipe) is quite strong. Also, I had a case of making too much boost one day (ie > 10 PSI) when it was super hot, probably due to the vacuum pipes melting/softening and hence letting the pressure signal to the waste-gate escape.   I know some people don't like heat wrap because it doesn't look blingy, but it sure does work well, so I've ordered up 10 metres of it.   Apart from that the car is driving wonderfully, I went for a lovely Sunday morning drive the day before yesterday, just ambling along enjoying not being at full tilt, with the rising sun warming my face and wind in my (diminishing!) hair.

Which brand for the heat wrap did you go for?

 

 

I don't think it matters as they are all roughly the same, simple glass fibre weave, I doubt there is much variance.

 

What does matter is that I actually put some on and how thickly I overlap it.  

Edited by Nev, 16 August 2016 - 09:51 AM.

[Mopeytitan]

Have you thought about ceramic coating Nev?

[Nev]

Have you thought about ceramic coating Nev?

 

Far too much money, when you can achieve the same thing for 5% of the cost with heat-wrap and eliminate the hassle of taking your car apart and sending off parts, and having it off the road.

 

I have thought of getting one of those turbo bags, but even they are stupidly expensive for what they are (roughly £100).  

Edited by Nev, 16 August 2016 - 09:53 AM.