View Full Version : Exhaust getting very hot 20XE
OK I know the exhaust is going to get hot, but I've done two trackdays now and on both it's melted through the central rubber hangers:
http://iainel.co.uk/images/forums/NovaWIP2a/424.JPG
These hangers are supposedly rated up to 140 degrees C, and it's clearly burnt all the paint off the pipework too.
Questions:
a) Should it be getting that hot back there?
b) Is this a sign there is an underlying issue? Running very lean?
Funk me Ive never seen that happen before :S
Don't think it should be that hot usually caused by runnin lean should be carefull what management is it using
Yeah get the fueling checked mate.
If thats ok maybe a blockage in the system not letting the gasses out quick enough. Seen cats glowing red when blocked before?
It's melted two sets of those now. I have some pics of them off the car, where its melted through and rested on the exhaust it's made a bit melty mess of that too.
Standard management (non lambda) and standard ECU, early one running a distributor.
However the engine is rebuilt with high comp pistons and a fairly skimmed head so is running more compression than standard (other than that and lightening/balancing it's standard internals)
Fueling check... Lambda wideband shizzle?
Must be like a sauna in the car then!
You can feel the heat on the tunnel but it's not horrendous
Doesn't get that hot on the road only track use
Same thing happened on mine but I'm 99.9% sure tension ripped the mounts not heat because it was a ******* to fit them in the first place
I would put standard black ones on and see what happens, they have more flex in them
Do you have a flexi in your system?
Yeah get the fueling checked mate.
If thats ok maybe a blockage in the system not letting the gasses out quick enough. Seen cats glowing red when blocked before?
That's how cats work not when blocked they glow red to burn up any unburned fuel and other gasses
Paul no flexi in the system it's all sleeve joints.
Hmm wonder where I can get some new original black rubbers for the centre then.
I was thinking of moving the hangers on the exhaust to the box too where it doesn't get as hot! But I think this is avoiding the underlying heat problem...
Might look at a wideband, would it be worth moving to a better ECU too (one with a lambda and dispac ignition) so it has a better idea of what is going on?
Are they Flo-Flex rubbers ? Some of there stuff I crap IMO
I have some on the Sport, I'm a little concerned by them too, I've only had it running for ten mins and you can see burn marks
Id get some GM ones and see what there like
I don't know much about it tbh but is the high comp set not making it run hot ?
for now you could put exhaust rap just where the rubber hits to stop you killing sets of mounts and then sort the issue out...
scott.parker
11-08-11, 12:01 PM
Dude Ive already said what to about this, as i had the same thing happen..
First off buy some black Polly sport hangers from RD £16 iirc?
Secondly jack the car up, get the rear on axle stands, place one jack under the mid box nr the hangers, place one jack under the rear box.
Then undo the joints slightly on all the clamps, then work from the front so your hangers are even and in a good place on that section pictured, then tighten the system/manifold joint up, then jack the system high as you can with out crushing things, then get the rear box in a position so it's high up but not hitting the floor/tank/beam on the bend, then tighten that joint slightly, then move back to the center hanger, get it as high as you can with the mounts on, then do a final tighten of all clamps.
If your using standard u clamps change to the stainless boost pipe type ones that I'm using, and after this you should be able to the back box and the center section to be holding the weight in an even distribution, as before it sound like yours was like mine was, back box was too low causing pressure on center, and them black Polly mounts from RD are solid and have done me good so far, but you will get that type of heat from tracking the car all day etc, if it dose it again then use some copper wire to hang it, Dan dose this apparently.
I hope that all makes sense?
Scott
Flexible won't stop it heating up will only stop it braking from movement
Scott thanks for the tips, it did put slightly more pressure on one centre mount than the other but even after its snapped/melted its way through it's destroyed the mount where it was touching the exhaust hanger so it's 100% melting it so not sure if adjusting fitment is gonna fully resolve the problem.
Flexible won't stop it heating up will only stop it braking from movement
Ok
C612DNM
11-08-11, 10:44 PM
Check your timing. It might be a rioter, err I mean retarded. Chimneys glow lovely and red on retarded engines.
If its a lean issue - the manifold will be glowing for the system to get that hot.
aaronc190
13-08-11, 07:36 PM
if fueling is ok id put my money on retarted ignition :)
Cheers guys. How would I fix retarded ignition then as I'm not sure it's adjustable?
It isnt - check the plugs if youre worried. They should be a fleshy colour - and not white..
Timing may be a tooth out too possibly?
It isnt - check the plugs if youre worried. They should be a fleshy colour - and not white..
Timing may be a tooth out too possibly?
Being just a tooth out wont cause that surely?
Being just a tooth out wont cause that surely?
It shouldnt no - am clutching at straws really. If it were on carbs or TBs then I would bet it would be them out of balance. But its on SFI!
We're not even sure if they are snapping due to lack of shock absorbtion or heat - so this is kinda irrelevant! lol
The fact that few members had the same system and had similar issue suggests that there is a fault with the design not heat.
scott.parker
14-08-11, 04:14 AM
The fact that few members had the same system and had similar issue suggests that there is a fault with the design not heat.
thank Q
OK OK point taken I'll have a look at the fitment first! lol
The following picture describes why I think it's to do with heat. The orange one is a complete mess and the red one has melted through halfway but not fully.
http://iainel.co.uk/images/forums/ExhaustHangers.JPG
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