Cleaning out the CAT

[CMF_Glenj]

Hi guys just wondering if this would have any benefit to performance, iam assuming it will due to air flow, just wondering what thoughts you guys have,

Pics shows the honeycomb cleaned out of the CAT that meets the manifold

 

[CMF_Glenj]

another pic

 

[CMF_Glenj]

another pic

 

[CMF_RTK]

you will lose back pressure!

 

[CMF_Glenj]

In what way bud, sorry forgot to explain this is for a grass track car so will be revving the nuts out of it

 

[CMF_frank2]

RTK WROTE:

"you will lose back pressure!

heh, the old back pressure myth
what downpipe do you run glen ?

 

[CMF_Glenj]

Will just be the standard 1 bud, a buddy of mine give me this to try thought i would ask if it would benefit me first, but ahh well from what i have read elsewhere, its going on

 

[CMF_frank2]

i doubt if the stock peashooter downpipe flows half as well as the cat tbh glen (and this is the front/bigger end of the d/p
some legitimate flow figures would be interesting tho

 

[CMF_Glenj]

so your thoughts are keep with the cat intact?, still got my orginal one just need to drill the bolts out and stick back on. Iv no idea on how to get any figures bud

Was also looking to replace the other with a straight piece of pipe

 

[CMF_frank2]

dunno tbh mate, you have created a big void prior to the downpipe, (maybe helps, maybe hinders ??)
i think i would fit a pipe inside the void to maintain flowrates personally (i fitted a perforated tube into my n/a mani/cat, to try and lose some decibels)
the 2nd cat exits at about 60mm iirc, then hits a flat plate/flange with a much smaller hole in the middle, that cant be good for flow, so maybe re-design that area eh
or else fit a coilpack (post 2000) middle section (those have no 2nd cat)

 

[CMF_Glenj]

Yeah see what your saying bud, will play around see what happens,

or else fit a coilpack (post 2000) middle section (those have no 2nd cat)[/quote]

Would this need cutting to size or straight swap for cat

 

[CMF_Glenj]

Yeah see what your saying bud, will play around see what happens,

or else fit a coilpack (post 2000) middle section (those have no 2nd cat)[/quote]

Would this need cutting to size or straight swap for cat

 

[CMF_Glenj]

Yeah see what your saying bud, will play around see what happens,

or else fit a coilpack (post 2000) middle section (those have no 2nd cat)[/quote]

Would this need cutting to size or straight swap for cat

 

[CMF_Glenj]

Yeah see what your saying bud, will play around see what happens,

or else fit a coilpack (post 2000) middle section (those have no 2nd cat)[/quote]

Would this need cutting to size or straight swap for cat

 

[CMF_frank2]

aye, the longer coilpack middlepipe is a direct fit mate, just bolt the flanges together (some brands have an integral silencer built in)

 

[CMF_Glenj]

will look into it cheers bud

 

[CMF_Wallie]

interesting read. so the post 2000 only have 1 cat? does the coil pack replace the 1 just below the manifold or the 1 under the car? and is there any significant difference?

 

[CMF_frank2]

Wallie WROTE:

"interesting read. so the post 2000 only have 1 cat? does the coil pack replace the 1 just below the manifold or the 1 under the car? and is there any significant difference?

its a deeper primary cat wallie, with a slightly shorter mani and downpipe, when i compared the 2 the later one had finer pores in the core too

 

[CMF_Glenj]

ok managed to get on today despite the snow i missed out putting the springs in for now, was getting to cold and bloody annoying (do i need these) there was a bit of smoke coming off/out of the cat (crap probably burning up)

Did sound a bit dull today, could putting this part on cause this?
(including a link to vid for you to listen not to sure if the quality is good enough tho)

Cheers

 

[CMF_frank2]

sounds fine to me glen

 

[CMF_Glenj]

you think bud? you reckon try the other back on and see or will you be only able to tell on a dyno

Hmmm whats next

 

[CMF_frank2]

Glenj WROTE:

Hmmm whats next

flywheel ?
is your speed sensor disconnected ?
or disconnect the lambda ?
or disconnect the coolant sensor at full throttle maybe ?

 

[CMF_Glenj]

cant do anything to flywheel bud
Speed sensor- where is this?
disconnect lambda- What am i hoping for here?
and again sorry- where is coolant sensor and what will this do, also is this a good idea if the car is at full throttle in 2nd gear for 2mins

Cheers

 

[CMF_frank2]

there should some threads on here and MSC about the speed sensor wire and how it over-rides the closed looping of the ecu mate, and ecu,s usually run from the basemap if there is no lambda feedback (safer/richer mixtures).
and one of my dyno printouts on here shows me doing a run with the coolant temp sensor disconnected, giving a (coldstart) constant 13:1 fuel ratio as a result
these are things that you could try out

 

[CMF_Glenj]

food for thought cheers bud