Pre-cat Gutting Tool

[rolskii]

3"test pipe ...

Damn big down pipes ...... should be 3" centre section....
David

[rolskii]

Fitted my downpipes on today, nice little job that is .....
Eventually just cut the milltek behind the reducers they weld on, inserted some 60mm ext. dia. pipe(lengths ad-hoc, but enuff to use orig. 5" clamps) into the milltek y section with the exhaust and downpipes in place, lined them up, pulled system down - welded the inserts onto the y-section of milltek, put rs4 ex/clamps onto the new inserts, slid them over the downpipes and lined system up tightened the clamps, so now if needed, I can put the standard rs4 exhaust system I have on..
shame about the dents on the y-pipe from someone with a big hammer ... and my welding ...

Car spools up much quicker, feels not so boggy low down, it seems a good mod, but time comsuming due to fitting rs4 downpipes to s4 milltek system, but its done no knocks or piggs ears ....
Its a little bit louder on low down revs, but thats what you expect with milltek,
just got the oil temp. up about 5-10deg.C.... something I got to watch, can anyone say if they had oil temp. rise after gutting pre cats ...?

Verdict:
Faster Spool (have noticed a slight differ in the instant mpg reading not being as positive now, vauger accuracy probably due to the lambda sensors not being forced gases, from no back pressure at pre-cats stage) no dtc's present, lambdas are good.
Not as boggy in low revs
Little bit louder
Fit std rs4 system if i ground out mine on speedbumps or pedestrians.....

[rsdreamer]

rolski, I recently had Doug and Mihnea at MRC gut my pre-cats and had a custom re-map at the same time on an otherwise stock 2000 S4.

My oil temp is also generally up by 5 / 10 degs, but I put it down to the re-map !!!

Worth keeping a close eye on though.

Regards,

rsdreamer.

[rolskii]

Cheers for that info... interesting ..... I hope to have some more comments from other gutted owners.....

Perhaps we could have a theory quote on this, like timing is retarding more than required now by less backpressure ..?
Or due to more spool .. but I will stop there before i look a wally...... I will leave that to the pro's ...
Hopefully someone will come up with a reason..... not too worry about too......
cheers
David

[Paulm]

gutted mine over the weekend and have not seen any difference in the oil temp. I will keep an eye on it though.

here is my weapon of choice for gutting. My Auger just overheated this flat blade although it kind of destroyed its self it went through the cat easy and fast

[rolskii]

Hi Paul,
I tried one of those, 25mm i think, but it was a bit too much for it, my first auger went soft(10mm), also rs4 cats are double the density of standard s4 units, so twice as hard theoretically........ nice effort ... how does it improve in your view mate....
cheers
David

[Paulm]

Going by my RS meter I would say 10 -15 bhp easy. I also advanced my timing which makes for a very fast S4. It is much more responsive and the turbos seem to spool up quicker now. It is deffo worth doing.

[saf]

Paulm Does your car sound any different since you did the gutting?

Im in for precats and dual miltek all at once sometimes soon. Did you have your miltek before or after the pre cat gutting. im custom remap done too at same time. Whats an RS meter?

Do you also fine your mpg meter a bit vague like Rollski?

Cheers guys. Can anyone comment on sound difference on exhaust as well please?> Especially if anyone has had dual milteks and then had pre cats gutted.

Is fuel consump the same?

[s4woody]

i have a duel milltek and just gutted my precats..the sound is much more crisper than before..and as for fuel i aint noticed anychange at all...even my oil gauge aint shown any real rise..i,d recommend them getting gutted all day long..

[Paulm]

I had my single Milltek on before I gutted and yes there is a diff. I sounds a wee bit louder and it now has a raspy kind of noise now. I like it a lot although I think it could still be a bit louder.

I only have a generic chip in mine although Mihnea is helping me with tuning. Very nice chap.

RS meter. my backside It feels quicker

No idea re fuel as I have been thrashing it for 2 dyas or so doing FATs so cant tell yet.

I agree with woody well worth the work

[saf]

Cheers guys.

WelIll be getting mine down next week so ill let you all know how its going.

Is Mihnea going to Custom remap it for you Paulm?

[Paulm]

I would love a custom map but I live in Aberdeenshire so you are looking at around 1000mile round trip

I got it chipped by MRC (Mihnea / Doug) on the way up the road the day I bought the car and am not sure if I will ever be down that far again. So will prob just work away with what I have at the moment. must admit though it is going very well.

[harry]

RS meter. my backside It feels quicker

LOL quality chat

[ajsl]

I got a quote (via a mate who up there) from StarPerformance for £300 labour for the downpipe swap (not including supplying the gutted pipes etc), saying it takes 6-8 hours to do. This seems really high to me labour wise?

Jim also said that some cars don't run right when the OEM downpipes have the CATS knocked out?

Bear in mine this reported to me 2nd hand.

[rolskii]

Well it could take that long if you have a siesta half way through.... hehe
Can you get your mate Jim to elaborate on the 2nd hand quote too please.... or whoever made it, about the not running right .... just interested.

My oil temp rise is actually only minimal, getting 28-30mpg @ 95-100 on cruise, instant mpg is still iffy, but im not bothered about that,
aRSe meter is saying have-it ......