Richard Quinn
|
| posted on 20/4/09 at 01:57 PM |
|
|
SVA Emissions testing help...
My main fail point at SVA was emissions and the car has now been to a rolling road for sorting but they have identified one issue that definitely
won't be helping. I'm using an R1 can with a 90 bend on the tail pipe. Where this bend joins the can there is a slight internal lip and
the MOT type probe follows the outside of the bend and doesn't trip over the lip and when it was tested the examiner pushed it as far as it
would go then tried to rest the remainder of the probe on the floor which caused it to drop even further out of the exhaust. As a result the tip of
the probe is only a couple of inches inside the tail pipe and the lambda was about 1.4. The engine is a v twin so the exhaust pulses are a lot more
pronounced so there will be nearly as much air being drawn back into the tail pipe as there are gases coming out.
The RR people got around this in two ways; one was to make a bit of a shroud for the end of the tail pipe to reduce the air going back into the
exhaust but let's just say it was not particularly SVA friendly and the other (as is their normal practice) was to use 3/16" brake line as
the probe which can then be bent in such a way as to allow it to pass the lip.
Ideally I would like for the tester to be able to get a standard MOT type probe passed the lip and where it should be in the can. I have looked at
inserting something into the tail pipe that would allow the probe to pass through it, past the lip and into the can but things that are flexible
enough to go in will not take the temperature and things that will take the temperature are not flexible enough to get around the radius of the tail
pipe bend.
Has anyone else had a similar issue and got around it or does anyone have any (constructive) suggestions as to a possible solution given that my
retest is on Wednesday morning?
|
|
|
|
|
Dangle_kt
|
| posted on 20/4/09 at 02:04 PM |
|
|
90 degree bent alu tube?
I have one in my cooling system, it just needs to be thiner than the lip doesn't it? sensor fed through the alu tube whilst he tests it, then
with drawn with the probe.
|
|
|
Mr Whippy
|
| posted on 20/4/09 at 02:05 PM |
|
|
if you cut the ends off one of these, would it allow the prob to be fed in? their for bending copper pipe and come in a range of sizes and are quite
flexable, called a pipe bending spring
there's also external versions too -
[Edited on 20/4/09 by Mr Whippy]
Fame is when your old car is plastered all over the internet
|
|
|
welderman
|
| posted on 20/4/09 at 02:20 PM |
|
|
After my first fail at Chadderton, i was also asked to make sure the probe would go into the exhaust without fouloing on the lip, sounds very much
like your problem. The probe is very flexible unlike the probe my car was tested on, the tester did say that he could fail the car if he struggeled to
get the probe in again.
I ended up having to take my exhaust off  and i welded a small formed piece of ally into the 90 bend so then the probe would fit. After that took
it for the retest and hayho the probe slipped in to the exhaust, and i passed too.
Thank's, Joe 
I don't stalk people
http://www.locostbuilders.co.uk/forum/23/viewthread.php?tid=172301
Back on with the Fisher Fury R1
|
|
|
Richard Quinn
|
| posted on 20/4/09 at 05:43 PM |
|
|
quote:
Originally posted by Paul TigerB6
Have you rung and spoke to Dave at Chadderton at all Richard?? I'd think they will allow the shroud to be in place as its only there to assist
with the emissions test, and they have already checked the exhaust can for sharp edges.
I want to be a little canny about this for the reasons Welderman gives above. Not guaranteed to get Dave again either.
|
|
|
