Thar she blows!

[Frikkin Evil]

Damn! After only a week on the car, the downpipe is blowing... Aargh! Hopefully just a case of re-tightening the bolts and not a dodgy weld.

Whilst i'm back in there i'm gonna do some lagging. What's a good make/supplier? Also, not done the underside of the CC yet, what's good for that?

[Motique]

what kinda downpipe did you get?? im gonna buy one soon and there are few cheap and nasties out there but i cant afford the really good ones at the moment.

did you use new studs nuts and gaskets too???

[Frikkin Evil]

I went for cheap and nasty cheerful, as funds are temporarily limited. It came with bolts, but the turbo-side ones were the wrong thread so I used the original bolts as they were all in surprisingly good nick. New gaskets. It blew a bit when I first started her up, but with a bit of even tightening all was well, or so I thought!

[flyingtele]

I fitted an xs power dp to my st185. After a while, both of the bolts that go into the side had worked their way out leaving two holes. They are on the side of the pipe, kinda next to the aircon compressor. If these are missing, then replace them with brass bolts. The brass has a higher thermal expansion rate and the brass bolts effectively jam themselves in when its hot, and shrink enough to easily remove when its cooled.
Have you had a good inspection of the pipe to look for any potential leaks? Also, if you have a factory exhaust system, there may well be a gap where the dp (normally 3") meets the exhaust (2.5")

[Coyoteboy]

The brass bolt thought is interesting and I cant make my mind up on it - brass does indeed expand further and as such will get longer too.

[Frikkin Evil]

I'm going to check it out tonight (before the wee one's in bed as the zorst rumble wakes her up!). As for the two bolts on the lower bend, I did torque them up pretty tight at the time, but i'll check them anyways. Cheers.

[Chris_de_Bear]

I originally bought a cheap stainless DP from 2fast2cool2 on ebay for my 185. It needed a cut & weld to make it fit initially as the flange angle was out but has been fine ever since despite getting loads of grief (competition car, gets loads of bashes, heat cycles etc.) My 205 came with an aussie and despite getting mostly gentle road use it keeos cracking. Within weeks of welding up a crack, it cracks somewhere else. Cheap isn't necessarily bad !!!!

My guess is in this case it's a nut come loose. Some of them are difficult to get an angle to get them fully tight.

[flyingtele]

The brass bolt thought is interesting and I cant make my mind up on it - brass does indeed expand further and as such will get longer too.

yes true, but hardly an issue here! Might protrude 1mm extra into the dp and cause a tiny little bit of drag, so just cut it a fraction shorter. I only used a brass bolt for one of the holes, as I couldn't find one the right thread and didn't have any rod to thread my own one. So instead settled for a drywall toggle and a couple of washers and it still works!

[simonst205]

I'm surprised you can use brass bolts. Its melting point is around 900 degC and I thought temperatures would be about this in this area?
Anyone tried one of these downpipes with a flexi section built in?

http://www.gtschris.com/store/comersus_listCategoriesAndProducts.asp?idCategory=67

Simon

[Motique]

i am deffo buying a dp within the nest few weeks, and its looking like ill go for one of the cheap xs-power or 2fast2cool ones, deffo gotta use new nuts/studs cos the original ones are designed to lock in and when they are taken off are never as good again.

also the cheap dp dont come with a bracket to hold it tight and prevent movement which is what leads to cracking, so im gonna get one made up just to be sure.

[Frikkin Evil]

After starting her up tonight, I looked and felt around the joints and couldn't pin down where it was coming from, it's very subtle... So me being me I couldn't resist going for a blat! On returning, all was ok. I wonder if the new gasket material swells up with time? Or perhaps just the expansion of the steel closing the gap temporarily?

[Chris_de_Bear]

I tend to use original toyota nuts / bolts in preference to new as the quality is much better. My 205 had an engine change a few years back before I bought it and I can tell where new bolts were used. Apart from the european head sizes (13mm for M8 not 12 etc.) they were rusted solid and several had to be drilled / cut out.

[flyingtele]

I'm surprised you can use brass bolts. Its melting point is around 900 degC and I thought temperatures would be about this in this area?
Anyone tried one of these downpipes with a flexi section built in?

http://www.gtschris.com/store/comersus_listCategoriesAndProducts.asp?idCategory=67

Simon

I dont think brass has any exact melting point as it will depend on its composition, a higher copper content will generally have a higher melting point. The lower part of the dp is noticeably cooler than the top part I have found, and i havent had any problems.

The gaskets supplied with the cheap dp's are typically some sort of composite material with thin metal either side, and this may well take a little time to break-in properly with the heat and create a good seal.

[Frikkin Evil]

Some interesting comments.

So can anyone recommend a heat wrap for the pipe? Also, what are people using for the underside of the Charge Cooler?

[ChrisW]

Fennies do heatwrap for your dp and lagging for the c/c club member discount