Re: Ceramic coating EM's - II

[Gerard <gerard@poboxes.com>]

> Not sure the point, but good question given my basic ones.  Why do the
> manifold at all?  What expectations do you have?  In theory, you are
> increasing the exhaust velocity to the turbine, after that really isn't a
> heat v velocity problem, remember a turbine is a heat generator all it's own.
>  In practice, coating the inside of the EM didn't do a thing for 0-60 times
> measured, but I didn't expect it to.  Look, the longest runner to the turbo
> is maybe a foot, pretty optimal for a turbo application.   A 10% increase in
> power?  I should been able to measure that (tested stage II fwd autobox, no
> accel preload).  So I'm thinking 5% or less.  That's the case, even the DIY
> can hardly justify the time, better mods elsewhere in the system.  Where one
> sees big gains in CC, is with v6/v8 turbo cars that have a huge crossover
> pipe that can lose a lot of heat.

This CC thing isn't going to get you loads of power as far as I
understand it. I recall the one website for a coater who claimed
some 40HP+ gains, but left the fine print to indicate it was done
on a 1000HP+ car. To increase times and speed the money needs to be
spent on the real things like upgrading turbo and doing tonnes of
work on the motor and electronics. The point here with CC is to try
and extend the life of a really expensive part (and the 2-piece EM
really is about 1/5 the value of the car! :) ).

> So doing it for heat to the turbo, I suppose is valid theory, IME not
> measurable results.  Personally, I'd save the money and put a bypass valve in
> my 10vt car first.

Don't need that with the auto I guess, but I'm still keen on
going the manual conversion route and get rid of my buggered
slushbox instead of rebuilding it.

> Do it for underhood temps.  Well, ok, I suppose.  Given that the highest heat
> under the hood is the turbo, and CC the EM moves the EM heat to the turbo,
> now what?  Measure the temps off the hot side of your turbo (CC'd or not),
> that thing cooks.  What you need, is someone with some BTDT measure on
> underhood temps.  If that's what you are going after, by the time you go all
> the way to the cat, a more effective mod would be some hood vents, ala Sport
> q, and every audi race car.

If I coat the EM inside then I'm going to coat the turbine housing
inside as well. That should keep the heat inside and to me it
seems logical to do it like that to perhaps stop any unwanted heat
exchange from housing to coated EM.

Oddly enough, I was thinking of the hood vent as well, but right
now I need to work on what to do to make the investment in the EM
last (when I do get the thing).

> Might help, might not see anything.  I tried heat dispersion coating on G60's
> and rotor hubs, and found no real measureable gain with or without.  Bad
> example?

Probably not. I guess I'll skip this and just do the inside. I'd like
to clean the thing up and prevent it showing oxidation and scaling, but
it isn't essential.

> Look, I'm all for good mods.  CC coatings have some advantages, but the
> location of the turbo on an audi really makes it a minimal gain.  My
> experience with coatings, is that porsche has a reason for CC in their turbo
> apps.  But, it's not the manifold the turbo or the downpipe.  IF they saw
> some gains elsewhere, then I'd bet they'd use it.  My own btdt tests really
> show little (and no measurable) gain in the areas you guys are proposing.
> 
> CC is not bad.  I just question how "great".  That would depend on the
> definition and the intention.

The "great" here would be aimed at trying to extend the life of the part
concerned. Seeing as the EM and turbo seem to be in such a location
ideal for heat build up I'd like to reduce the build up on the parts to
prevent the dreaded warping and cracking as much as I can. If there is
any sort of power gain then that'd be even better, but first and
foremost
is protecting the part.

CC the downpipe seems, to me, like it will help get heat away from that
location and that is my aim with this whole thing.

G.