Yep, it’s not missing or anything so nothing’s wrong (I’ve been learning “if it’s not broke DON’T TRY AND FIX IT FFS!” )
My leads went a long time ago…
In fact, the Audi doesn’t have any leads !!
BRW, question for somebody.
When I reached the top of the mountain yesterday I got off the car, opened the hood to have a glance at the engine (don’t know why, didn’t have a light anyway ), but apart from the glowing red manifold (still lean obviously) in the pitch black I saw that blue light was dancing on top of the sparkplug wires. Looked cool, but may not be the best.
Uldis
I would say this sounds like the insulation on your plug-leads is breaking down. I would say it’s time to change them… and if you buy new ones then why not go for the Magnecour KV85’s (reds)… however, i’ll have to have a look at mine sometime because if RemarkLima says they all do that then �60 for Magnecours could be a waste of your cash…
-one positioning light fell off (the very small one, inside the clam)
Now the bad news… Its SNOWING!
Uldis
What light are you talking about here ? ‘positioning light’ ??
Also at least you got 60miles before the snow came… after all your set-backs it would have been another bummer if the snow fell just before you were ready to go out the first time… but then… when did snow ever put you off I saw your car-park pics last year
Yes, in fact even with the roads covered in ice and snow, I managed to put in another 200 miles this afternoon.
Just came back.
Car feels much better each time, smoother.
Will put another 700 miles tomorrow
what about the light tho ?? what’s this ‘positioning light’ you lost ??
also have you sorted the manifold ‘blow’ ??
Ive got some red magnecors if you want them Uldis??
Ooops guys, somehow I missed these last two posts.
The bulb I lost was the very small one (5 watts or something) that is inside of the dipped light, just below it.
It looks like it was loose, so tried to tighten it and it slipped through my big fingers and fell in the clam
So instead of taking off the front splitter, I just went and bought another one
And the manifold blow by, it’s funny, I was just taking off the undertray to do some bits and started taking things off, one by one and got carried away.
Ended up taking the whole manifold off and the exhaust heatshield (to fix the rattle), also engine mounts, etc.
Just wanted to install the CAT for the MOT, honestly
Well, one thging I discovered is that the manifold definitely was leaking BAD. You can see all the black blowbys in cyls 1,2 & 3. Don’t know if the EBD flange is not flat or what, but if I tighten the studs anymore I’m going to strip the threads!
Will have to use some sort of sealing element.
Also, the CRP was leaking, and it’s a special one (to have a continuous bore throughout) with a small flexi section. Well, the beginning of that flexi section was coming loose
Looking inside you can see the corrugated part starting to get blown like if it was a mantlesheet.
All this making a good heatshield was to avoid using exhaust wrapping, but now I could see some heat damage done to the gear linkage, the boots that cover them were starting to melt!. So, this EBD manifold somehow runs much hotter, probably because it’s thinner-walled? or because of the extra power?
Even so, I had it ceramic coated and should be cooler, but this wasn’t happening before.
And bear in mind that one of the axle gaitors is very close to the manifold.
that can’t be good in the long run.
I’ll have to wrap the exhaust at least in the lower section if I want the wires and plastics to survive down there.
And Randy, yes, I’d be interested in trying the Magnecors, I’ll send you a PM.
Uldis - remember how my manifold ran very hot because of poor balance on the TBs ???
Yes, no worries.
Mine have been checked for that and the engine recently mapped. Better than that it cannot get.
I’m referring to the very rear of the manifold, where the lambda sensor ie, just before it turns to the left.
The gearbox linkage is about 4" from the exhaust and the plastic boots were melted.
Need to do something about this.
But this is due to me being curious, I wonder how many EBD manifolds are out there installed and the owner has looked under the car to see how everything is going…
The section of manifold under the plunge joint gaiter must be wrapped or the boot will be toast in no time.
The is a load of guff talked about material thicknesses and types affecting the surface temperture. The temperature gradient across the tube walls is only few degrees whether its made from stainless or mild steel. When they already run at 700 to 800 a few degrees is not worth worrying about. The effect of thickness is also negligable as the materials are not insulators.
Ceramic coating is also a waste of money, as the effect of an insulating layer a few tens of microns thick is small. Ceramic coating the manifolds white would help a little by reducing the surface emissivity. Highly polished stainless would be better but it won’t stay bright and shiny for more than a few hours.
Wrapping is the only effective way to reduce the convection and radiation heating effects.
As the engine is producing more power then the exhuast gasses are likely to be hotter assuming the mapping is the same.
Bernard
I agree.
The only thing is that the coating guy told me it was the dogs b*llocks and even better in black! go figure.
He also told me NOT to wrap any manifold as it will make the manifold crack easier.
Maybe expansion/contraction rates will be different in the covered and the uncovered part, but I really don’t see them cracking because of that.
What do you say of wrapping the individual tubes just after the flange then?
Waste of time?
Wrap them all the way down as far as you can go. It helps reduce the engine bay temp and definitely reduces the chance of the alternator frying. Although I would fit a heatshield to it as well.
Black is best ? Well it will dissipate the heat a little better than white, but that is not what you want in an engine bay is it ?
Wonder if there any independent figures available for these coatings ?
Bernard
Black is best ? Well it will dissipate the heat a little better than white, but that is not what you want in an engine bay is it ?
Bernard
Black abosrbs heat better and radiates less out.
IMHO: So in an engine-bay you are looking to absorb as much heat and “transport” it into an area that is exposed to high air-flow where it can release and convect the heat-calories. For exactly this reason all heat-sinks on amplifiers and other electronic equipment are in mat-black paint. The black makes it abosrb more heat faster then if this heatsink would be naked aluminum.
You can try to use smart aerodynamcis as well. No need for forced cooling as air travelling over a opening that is faced into the travelling direction of the wind will cause a small vacuum in the opening and suck out the air from that one. It’s the reverse way of how most of the regular cars use openings to actually “catch” air for cooling.
I know that RUF (Porsche tuning house and independant builder) uses this technique too when they created worlds first Turbo-Cabrio, but only it has 550 bhp over the 420 bhp of the stock item.
GReets,
S.
Black abosrbs heat better and radiates less out.
Er… that doesn’t work… Specific heat capacity is SHC and can’t be cahnged for absorbing and radiating heat
So black absorbs heat much faster but also radiates much faster! Although it’s not “much” TBH… It’s the material that is underneath that’ll really determine the SHC (ergo the speed of heat absorbsion, remember SHC is measured in C/KG/Min so the amount of energy required (in joules) to raise the temp of 1KG of a substance by 1 deg C).
So I can see bearnards point, one it’s all hot, it’s all hot and makes no difference… But then the same rationelle woulkd apply to heat wrap shirly???
The point of both is to keep the hot exhaust gasses in the manifold and spat out before they radiate too much heat to the rest of everything else… Also hot air is thinner and should be forced out under more pressure.
Maybe
You are confusing radiating heat and reflection. Check out: web page
A black surface does not reflect heat very well but its VERY good at both absorbing and emitting it. At 700 C an exhaust is not going to absorbing much heat its going to be emitting it, mostly as as radiation and some convection. If you can force some air over it that will obviously make a huge increase in the heat lost. But you don’t really want to cool the manifold, as RemarkLima says, you want to keep the gasses hot and get them out.
Specific Heat Capacity doesn’t have much to do with it as most of the time the hot parts are at steady state.
Bernard
shamikaze…
I know physics quite well and it is not like this.
Black absorbs better like u said…but it also dissipate better.
The more black a surface is, the more heat exchange capacity. For this reason all electronics rads r black!
If the environnement temp is higher than the black rad, the rad will absorb energy. the opposite, if the environnement temp is lower than the rad, the black rad will give much more energy than a white one.
Nicolas
RemarkLima,
so the result of your theory is to ceramic coat the inside of the mainfolds…
Nicolas
Nicolas…
To put a point on it… [censored] knows LOL!
Surely this must have owrked in the past for other people??? Otherwise it wouldn’t have been done in the first place IYSWIMK
I stand corrected
Too long time ago since I used the knowledge actively and then these kinda mistakes happen. My bad