769 replies to this topic

[rob999]

Get in the queue Timothy....

[VXT Tim]

I'm at the front, can you not see me?

[Dave H]

I have made the pre silencer 13.5" long x 5" Diameter. I tried it first attached to the tail pipe to see what difference it makes while stationary as it could be removed while running and it subdues the noise further!!! 

 

Fitted in position now I can hear the 044 pump running while the engine is ticking over standing behind the car.

 

I went for a quick try on the road where it seems quiet, couldn't give it much as the roads were damp. I need to try my other car with the miltec fitted to compare levels but it is a different sound.

 

I have borrowed a db meter, not sure of the accuracy of it but I should be able to get a comparison with the stage 2 car with miltec.

 

Dave.

 

[Gedi]

Dave, are you planning on adding these exhausts to your shop?

[Dave H]

Yes the aim is to supply these if anyone is interested.

 

Hopefully I will have some noise readings soon.

 

Dave

[JohnTurbo]

You're an asset to the club Mr Hardwick.

[redvts]

Very interested!

[Goosenka]

::

[Dave H]

I have done a quick noise comparison against my Sprinter van!

 

Noise meter at 0.5 m and 45 deg.

 

Background noise was between 48-51db.

 

I also applied full throttle and raised the revs to near the limit on both and recorded 94.5 and 81db.

 

Also the engine noise on the sprinter is further away and not inconsiderable!

 

I will do a comparison against the stage 2 Miltec car when there is no chance of rain as its only seen it a handful of times!!!

 

rpm          VX             Sprinter

 

900          68.5           60

2000        76              70

3000        81              75

4000        84              80

5000        89

6000        93

 

 

[fezzasus]

Why has it taken so long for someone to make an exhaust that works!

 

Well done Dave.

[techieboy]

Why has it taken so long for someone to make an exhaust that works!

 

Huh? Turbots have never had a problem with noise limits (assuming they had anything vaguely approaching stuffing in them).

[Duncan VXR]

Great result Dave DG

[siztenboots]

Can you package a cat and a pre-silencer , I have been told there is 0% chance of getting a decat through the MOT next year.

[Duncan VXR]

I have a very compact cat I'm taking over to Dave when there next and would fit with the 2nd silencer. Will leave Dave to confirm but if it can be done obj one Dave is the man You need a better mot tester lol DG

[techieboy]

Can you package a cat and a pre-silencer , I have been told there is 0% chance of getting a decat through the MOT next year.

 

Piper did that for me on one of my 2.5" systems, although they were still two clearly separate components just welded into the pre-U bend section with about a centimetre of space between them.

[fezzasus]

 

Can you package a cat and a pre-silencer , I have been told there is 0% chance of getting a decat through the MOT next year.

 

Piper did that for me on one of my 2.5" systems, although they were still two clearly separate components just welded into the pre-U bend section with about a centimetre of space between them.

 

 

That's the best you can hope for. Catalytic converts like high temperature, silencers like low temp, so making them look like one unit isn't possible, and packaging constraints of the VX mean spacing the cat and silencer out more is almost impossible.

[Arno]

No problem. It exists:

 

http://www.hjs-motor...ldaempfer.html

 

Not sure it will fit though...

 

Bye, Arno.

[Dave H]

Rose and I had a trip up to EFI Parts yesterday so as Chris could tweak the map for the modifications I have made and we could have a tally up of the horses.

 

First graphs show the results with the boost control solenoid disconnected so the boost is controlled by the waste gate spring only which is 9 psi. It is easy to put a switch in the boost solenoid circuit to enable this to be a low power map at the flick of a switch.

 

 

 

The next results are with 22psi of boost. We could have gone further but this is a safe map for the engine and consideration has to be given to the gearbox! 

 

The AFR's were taken at the tailpipe so actual figures are slightly richer (about 0.3 I think Chris said).

 

The hard rev limit is set to 7700 and soft limit to 7600 and it is still pulling strongly up there.

 

On the road the power delivery is nice and smooth and below 3000 rpm quite "soft" and like a shopping trolley!

 

A big thanks to Chris again who has done a stirling job.

 

Dave.

 

 

[MrSimba]

Awesome Dave!

 

Glad to see it's made the 400+ club!!!

 

Nice AFR's too

 

 

 

 

 

 

[Duncan VXR]

It's almost like it was always planned to be that epic ;-) What a spread of smooth power and torque, well done Dave and Simon before. Best spec vx220 zlet/leh out there Love it and great fueling DG