[TallAndy]

On sunday my exhaust was making a strange noise under full load, a nasty blowing grizzly kinda sound, but it sounded like it was coming from underneath near my feet.

I went to Lohen who originally fitted the GTT Manifold thinking it may just be loose and needed tighening, unfortunately on inspection several things were wrong

The manifold was fitted correctly with brand new BMW Mini gaskets. And has only covered approximately just over 2000 miles.

I'm not trying portray any manufacturer in bad light by this post. I'm merely trying to establish if this has happened to anyone before with any maifold or CAT?

CAT facing the manifold header



Manifold Flex (blowing out of the sides) - creating the horrid blowing noise


Anyone any ideas how the damage to the CAT and Flexi could have happend? The manifold was purchased second hand with 1000 miles on it and i've done a further 1000. Very dissapointed I basically need a whole new manifold and CAT now

Cheers,

Andy

[Pobsey]

Ouch! So it wasn't very healthy then on Sunday!!

[Damo]

Gutted mate

You spoken to Roland?

[TallAndy]

Tried ringing at 5:00->5:30 no answer from both numbers / no answer phone either

[robbo mcs]

Hi,

It looks from the photos like you have melted the cat. This has never happened to me, but I know of a couple of people who have done that. It is due to the cat not being able to cope with the huge heat produced. Once this starts to happens, it gets worse, as a huge back pressure can build up, producing more heat, and putting more stress on the manifold. Maybe this is why the flex or manifold has blown out??? It's a bit hard to tell from the pics exactly where the leak is.

What mods are you running on the engine eg pulley reduction and ecu? From the limited number of cases I have heard about some set-ups seem to have more problems with excessive heat, causing problems with cats and exhausts than others. It's like oil temperatures, some pulley and ECU combos seem to run incredibly hot, and others dont

I now run with a straight through pipe, which removes this problem. If your car is road registered and you want to run a cat, look at getting the highest flow sports cat with the lowest cell density you can legally run

Early on in the days of racing my mini I cracked a couple of headers (manifolds) that needed replacing. The problem wasn't really with the manifolds, but with the engine mounts. When racing the engine was flexing so much on the mounts that it was flexing the manifold. With the extreme heat of the manifold, and repeated stress, it kept cracking. I fixed the engine mounts, and everything was fine for a long time. After around another 15,000km of racing and rallying I finally cracked another one, but I guess that is not surprising after such a long time

As I said, this wasn't really the fault of the manifold, the first 2 were actually from different manufacturers. It was more the stress placed upon them due to the excessive engine movement. It would be worthwhile checking your engine mounts, and seeing how much the engine is flexing under load.

BTW in the early days I also burnt out several exhausts as well

Cheers

Robbo

[TallAndy]

Thanks Robbo

The car is a Works 210, no other engine modifications or remaps. So:

Works exhaust
Works cylinder head
Works 14% reduction pully + supercharger
Works air intake
Works spark plugs
Works remap

What I also notice is that in 1st gear if I let the car pull itself along, and I tap the throttle to jolt the car (leaner dirve stlye) you got a metallic knocking sound. This happens every time u blip the throttle and i've noticed you can hear it when you start up the engine.

[duncanbanana]

My cat failed (Milltek)before Christmas and Reduns(cant remember what make his is) cat failed too , i wonder if these so called Sports cat are upto the job

[TallAndy]

Redun's was a Larini Systems who make exhausts for Ferraris etc..... going to try and speak to GTT today to see what their opinion is!

[robbo mcs]

Quote: Originally Posted by TallAndy

Thanks Robbo

The car is a Works 210, no other engine modifications or remaps. So:

Works exhaust
Works cylinder head
Works 14% reduction pully + supercharger
Works air intake
Works spark plugs
Works remap

What I also notice is that in 1st gear if I let the car pull itself along, and I tap the throttle to jolt the car (leaner dirve stlye) you got a metallic knocking sound. This happens every time u blip the throttle and i've noticed you can hear it when you start up the engine.

Hi,

The works tuning is very conservative, and I would be extremely surprised if you could melt a decent cat with a properly functioning car with spirited road driving

Cheers

Robbo

[TallAndy]

Spoke to Janspeed this morning, they apprently supply GTT with manifolds. Not sure if GTT further modify them.

I could have the manifold repaired and get a new CAT, this would save me about £150.00.

But i'm thinking its probably better to get a brand new one, as if its already damaged something may go wrong with it again in the future!

[duncanbanana]

Quote: Originally Posted by TallAndy

Spoke to Janspeed this morning, they apprently supply GTT with manifolds. Not sure if GTT further modify them.

I could have the manifold repaired and get a new CAT, this would save me about £150.00.

But i'm thinking its probably better to get a brand new one, as if its already damaged something may go wrong with it again in the future!

Youve got an excuse to buy Lohens Janspeed manifold now

[TallAndy]

It is certainly one of the options available!

[cooper7]

Andy did you have like a grumble beneath the handbrake type area? It's just that since having my Milltek exhaust fitted there has been some grumbles coming from beneath that area. I haven't had any other engine modifications done. Just wanted to know if the noise might be similar to yours?!

[TallAndy]

It was around that area, maybe a little further forward like under the stereo.

It maybe you have a loose connection, maybe get it checked out?

[duncanbanana]

Quote: Originally Posted by cooper7

Andy did you have like a grumble beneath the handbrake type area? It's just that since having my Milltek exhaust fitted there has been some grumbles coming from beneath that area. I haven't had any other engine modifications done. Just wanted to know if the noise might be similar to yours?!

its properbly the bolts loose which connect the manifold/cat to the centre section , mine was alwasy comming loose until i really tightened them and put locktite on the bolts

[roland2003]

WHOOOOOOOO! there.
Right talk about unfair bad press and jumping the gun. Here are the facts as I know them.
1) The manifold was not bought from us ,it was bought secondhand from a guy 'supercoopers' on this forum', and fitted by Lohen .
'Tall Andy' then raves on about the performance gains from it on M2.( complete with damaged cat)
2) The cat ALREADY HAD THIS DAMAGE when he bought it from 'supercoopers', I assume he told him of this damage before selling it? (but thats between them ). Supercooper even phoned me up to ask for a price just for the cat as he was selling it on M2 and could see it was damaged.
3) I had already spoke to the original owner who knows the damage is down to big backfires from his car (accompanied by 3 foot flames from the tailpipe he says) . No cat can withstand this!!!!!!!!!!
Come on guys a little fairness please. We did shut at 5 yesterday as we had to deliver a car. The blowing (horrible noises) could be down to whoever fitted it (if at the flange). We use genuine new BMW gaskets and they never blow, you do need to ensure the flange bolts are tightened well though . The damage to the cat if anything would make the car quieter.Yes the manifold is made to our design EXCLUSIVLEY for us by Janspeed. It is much higher spec and design ,its fully tig welded for a start and has a larger diameter secondary pipe section, than the new Janspeed exhaust with removable cat that you can buy 'anywhere' ( eg Lohen.)
Regards Roland GT Tuning

[Damo]

Roland, I don't think anyone here was trying to put you in bad light, just trying to get some info

[TallAndy]

From my first post
>> I'm not trying portray any manufacturer in bad light by this post. I'm merely trying to
>> establish if this has happened to anyone before with any maifold or CAT?

Also: the gaskets were genuine BMW as I have already said and the manifold was fitted correctly! I have had the manifold on the car about a month with no problems at all, all this occured last sunday..

Now I am getting mixed stories. supercoopers stated:

Before selling the manifold, I had it checked over by the M.D. of Turbo and Nitrous Developments UK up in Cheltenham and he gave it a full bill of health. The cat itself was not as encrusted as it appears in the pics, but there was slight 'indentation' which he said was perfectly normal given that it was a race cat

Roland now says it was already damaged, which would now explain maybe why the flex has failed and is blowing???

Firstly thanks Roland for putting forward that information, as I said before i'm merely trying to find out what happened i'm £390 + fitting + postage out of pocket with a screwed manfiold and CAT

[roland2003]

Is the flexy leaking ? or just a bit of external fraying (which is fine) .I have never seen or heard of a failed flexi joint on our systems unless it grounded out on something. The additional backpressure from the 'partly blocked' cat could encourage a leak to occur upstream of the cat I suppose ?

HOT NEWS!
There is a new GTT design 'fat cat' (made bespoke for us by Janspeed) Mark 2 Cat/Manifold which we are just starting production of. A lot more changes ,and improvements (mostly power related ) to ensure that we maintain the lead the product has always had over the competition.
(New thread with details within the next few days)
Regards Roland GTT

[TallAndy]

We also fitted a decat pipe, so to remove the damaged cat but the horrible blowing sound was still occuring

The flexi is leaking you can hear and feel it leaking. We had the car up on a ramp with the engine running to check