121 replies to this topic

[swast4]

Yeh That's why I was looking at reducing down to 1 outlet with a clamp on.

[smiley]

you could grind a split in the bottom tip, and weld a disk in to cut it off.

That way it will still look good aesthetically.

 

Happy with my German filling so far. It has not come out, but did not do as much driving as i wanted after last years frolic.
If it i still in after this years frolic, then i can concur if it is as good as advertised.

 

[The Batman]

we have done that on a 2 or 3 tullet tailpipes smiley

[smiley]

With today's knowledge, Tullet should offer it as a custom option me thinks.

 

[The Batman]

That can be arranged. But im guessing it will cost a few more quid!

[smiley]

After paying 180 euro for a new ubend, nothing from Tullett can shock me.

But it's good info for new buyers.

 

 

Edited by smiley, 06 January 2018 - 09:12 PM.

[CHILL Gone DUTCH]

think it was artic monkey got one of the pipes welded up 

not sure if it was tullet who did it but they welded it up near the top tip and left the lower open so it still looks oem

[CHILL Gone DUTCH]

think it was artic monkey got one of the pipes welded up 

not sure if it was tullet who did it but they welded it up near the top tip and left the lower open so it still looks oem

[Nev]

Ok cheers jet pilot. It currently doesn't have a cat and I've not had clam off yet so not sure what I can squeeze in.

I've been messing around with an idea but not sure if it will do alot? I thought I could also put a 90 degree turn down on it, to point out away from the sound microphones??

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I think you'd get a lot of exhaust back pressure with that design (as it's not straight through), which obviously robs you of power (and builds up temps in the head) as the engine has to overcome the resistance. I tried building a variant of this design myself and my back pressure was up to 5.5 PSI at 6000 RPM. In the end I built another design that now only shows 0.5 PSI back pressure at 8000 RPM. I could even feel the loss of power with my first design, maybe 40 to 80 HP as a wild guess @ 6000 RPM, although in it's favour it was really very quiet with no drone.

 

I published the info here for the benefit of the community: https://sites.google...austdesign/home (use the menu link to see the various measured results).

 

No form of filling will last for a powerfully engined exhaust, the vibration pulses and sheer velocity of flow on top of the temps is just beyond it IMO. I tried installing thick wire wool bundles in my exhaust (trapped behind welded in perforated bulkheads, and even that has disintegrated and managed to thread itself past the bulkheads and thence out of the exhaust tips).

 

HTH.

Edited by Nev, 07 January 2018 - 10:04 AM.

[CHILL Gone DUTCH]

Water injection also keeps exhaust temps down

[swast4]

Ok cool, thanks for the info. Just another thought, knowing that the exhaust system is struggling with being short and close to the engine. Could it be extended for track use with 2 silencers like the tvr sagaris. I know it's still keeping 2 exhaust tips but surely if you've split the 3"pipe as it leaves the car (as it does now), then clamp 2 x 3"silencers (about 700 long} , then the exhaust gases are slowed down and silenced on the way? Sent from my LG-H815 using Tapatalk

[Nev]

Splitting the exhaust prior to the silencers would deffo slow the gas speeds by 1/2 and make a design quieter IMO. However, the Y-piece splitters are quite long and building 2 silencers and fitting them in the VX is not easy. Also, 2 silencers and 2 sets of pipework add weight.

 

Also, I have a feeling that having 2 silencers in series is quieter than having 2 silences in parallel. That's just a gut feeling, as I found each expansion/collation cycle had a marked effect on lowering Db. I remember firing my engine up and putting my hand over the first 2 inches of perforated pipe and being a bit startled by how violently the gas wanted to expand. More itterations of expansion really help with the lowering of dB IMO, hence my view that 2 silencers in series would provide better noise killing than one large one.

 

 

Edited by Nev, 07 January 2018 - 11:22 AM.

[ArticMonkey]

Tullet did mine when I ordered the system from them. Think it cost another £70 😅. Does work well and reduces the sound. Only problem is one exhaust starts to change colour over time and gets covered in soot but the other looks brand new. 🙈

[CHILL Gone DUTCH]

Tullet did mine when I ordered the system from them. Think it cost another £70 😅. Does work well and reduces the sound. Only problem is one exhaust starts to change colour over time and gets covered in soot but the other looks brand new. 🙈

Will soon cleannupnwhen you get on track

[swast4]

If anyone's looking to repack their exhaust, I thought I'd put some details and photos.

I have a 3" full Tullet system a d repacked my rear silencer. (unfortunately it was already fully packed, but didn't know that at the time.)

The silencer is 70cm long, 17cm diameter and the center perforated pipe is 8cm outside diameter.

I bought the ZT-1 wadding from thermal dynamics. Which is the high temp stuff 850 degrees. I spoke to Chris Tullet, who said they use the same stuff but they use it on the raw form (loose fibres) so not on a sheet. He said full wadding should be 1.5kg.so you can weigh the exhaust when empty to see how much you have left. (just as I write this I remembered I didn't do this, doh).

When you type the sizes into the online calculator on their website, it says you need 2.18m @700 wide. But with the ZT1 you can only get 600 wide and then you can only buy it in complete meters, so I bought 3m @600 for about £110 Inc del.

This is what it looks like and the exhaust broken down. (note the perforated pipe is dog legged, which makes it a right pain in the arse to pack).

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[swast4]

With an exhaust that had its perforated pipe central, you would simply wrap the blanket around and insert into the tube and bolt it together. When the exhaust gets up to temperature the threads that are holding the wadding fibres together would burn off and the wadding would fluff (?) out filling the space. It is important not to over fill it as it out needs a certain amount of space to work.

Anyway as I only have about 1cm at the ends between the perforated pipe and can I can only get 1 full wrap on the perforated pipe, so I did this cutting a width of 700mm, to give one complete wrap, then used some masking tape to hold (this will burn off when it gets hot)
I then got another complete wrap using the roll in the opposite way (600mm wide) covering the previous joint, then tapped it, and cut short on the length avoiding the 2 dogleg ends of the pipe.
I then inserted the perforated pipe, lining up the other end to where it needs to be, otherwise it would be a mare to twist it when packed.

Because I'm a tight arse and the other wadding was in good condition, I weighed how much I'd used on the 2 wraps (400g deducted it from 1.5kg. Then I got 550g of the old wadding in 2 bags and started stuffing. The reason I divided into 2 was so I new how dense, so 1 bag for half the exhaust etc.
Stuffing it was a right pain as the dog leg made it very difficult to get it in. If I didn't have the loose fibre from the old stuffing it would have been even harder to pack. (PS I still didn't manage to get the 1.5kg of wadding in, I was about 100g short as it was too packed!)
I then sprayed the exhaust can end with a light coating of WD and slipped the end of the can on. Making sure that the line I drew on the can before I took it apart lined up.

2 of my bolts sheared off, 1 also sheared the nut that was welded to the inside of the can. So I drilled and tapped 1 of them (M6) and used a rivet on the other (not ideal as the biggest I had was 4.8mm and the hole was 6mm)

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[swast4]

Did this make my exhaust wonderfully quiet, and a good level of satisfaction achieved no! Like I said it was already fully packed and I didn't have X ray eyes.

Just abit more info for you, when I was speaking to Chris Tullet, I asked the question about using a layer of 1200 SS wire wool to stop or slow it from blowing out and he said the manufacture didn't recommend using it as they say it ends up superheating the wool, which increases the likely hood of burning up the wadding. This seemed logical to me and as the wadding is the highest temp that I can get, plus none of it had gone when I opened it up, maybe its right?!? I don't think my car had been tracked since it was built so its not seen that much of prolonged abuse, so time will tell when I eventually get on track!

What's next?
Running out of options, but I fitted it all today, measured all around the cat straight through pipe and think I can just about get a 5" silencer im there.
The measurement is 34cm flange to flange, so a 12" x 5" can be fitted, I've taken to my local exhaust fabricator (cybox) and they are ordering one in for me, then modifying it to be repackable, then I will take my exhaust into them and they will fit my flanges to it, pack it with zt-1 and weld a new bung in for my wide band.


As you can see from the pics there isn't much room for a silencer, but maybe an inch bigger than the existing pipe.


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[swast4]

So I'll have to wait for the cat silencer, then after that I've run out of ideas, apart from the 2 bolt on elbows to put on the tips to point away from the sound meters on track, but I've heard today, that Oulton my local track has meters on both sides of the track, so would have to point down and I'm not sure how effective that is. There is welding up one of the tips, but I have this nagging feeling that this will cause back pressure due to the actual tip being smaller than 3" because of the gauze lining to the chrome tip. Sent from my LG-H815 using Tapatalk

[CHILL Gone DUTCH]

Don't worry about a bit of back pressure the car needs it

[Jetpilot]

As said elsewhere and you have noted yourself, the tullet design is flawed because of the angle perforated section, probably only 2/3 rds is adequately silenced and to be fair, any car with one straight through silencer is going to be on the loud side, we are restricted by room and pipe run.

 

I do hope Matt Bentley manages to release his improved design with noise cancelling mufflers.