Intercooler Piping... Stainless Steel VS Aluminium

[Kenneth]

I am going to be doing Intercooler piping soon (Don't tell Jo... /haz) and have been debating whether to do it in Stainless or Aluminium.

About the only deffinate i got for stainless was this:
"Stainless steel will not rust or corrode like cheap steel or aluminum. Stainless steel also conducts 200% less heat then steel, and 530% less heat then aluminum. Less engine heat soak and a cooler intake charge equals MORE POWER!"

but of course stainless weighs more... though I could do thiner wall thickness to compensate a little.

What do you think?

[bradc]

If you're worried about heat conduction you could just wrap the pipes in insulation couldn't you?

[Wodjno]

I am going to be doing Intercooler piping soon (Don't tell Jo... /haz) and have been debating whether to do it in Stainless or Aluminium.

About the only deffinate i got for stainless was this:
"Stainless steel will not rust or corrode like cheap steel or aluminum. Stainless steel also conducts 200% less heat then steel, and 530% less heat then aluminum. Less engine heat soak and a cooler intake charge equals MORE POWER!"

but of course stainless weighs more... though I could do thiner wall thickness to compensate a little.

What do you think?

I'm sure the extra weight won't have any desired effect on performance :inquisiti

[mattpage]

titanium? ;)

[Gly]

personally i would go with stainless as its easier to work with and get a better finish on, (i assume you are do this yourself?) compaired to aluminium which is quite hard to weld if you dont know what you are doing

oh and stainless can rust if you get a low grade and scratch it very hard/deep,
but its easily cleaned/polished off, so no really an issue,

[Nutter_John]

The biggest problem with Stainless steel is that it holds the heat very weel so you will be exposed to a lot of heat soak , Aluminum is very quick to dispense the heat so will not hold onto any onf the heat for long .

As an example a lot of heatsinks are made from ali beacuse it is a very good thermal conductor .

As for welding Ali it is a lot more difficult but why weld the pipes ??? whats wrong with good old bonding agents

[Eurospec]

I would go with stainless if poss.

Both will polish up fine, but with ally because its so much softer, you can easily bend it if you use something like a Mikalor clamp to hold the hoses on.

Whilst we are on the subject, has anyone heard of the pulsing effect you can sometimes get on part throttle?

I notice in cars with upgraded turbos AND hard pipe kits, this is much more prevalent. This is where you accelerate gently up to the cruise, and as you arrive there the dump valve goes off just a tiny bit. The turbos re-spool, then the dump valve goes off again etc etc. The result is like a tssh-tssh-tssh-tssh-tssh as you drive along. Only letting your foot off the throttle and then re-applying it will stop it.

I do not KNOW why this happens, but i have my suspiscions. I suspect with nice hardpipes, and even more so with bigger tubs, the airflow into the engine is much more laminar (or less turbulent anyway).

As a result, more air per unit time arrives at the throttle plate. As the throttle is not wide open it piles up there, sending a pressure wave back down the intercoolier piping towards the turbos.

The BOV 'Sees' this difference in pressure accross the throttle and goes off, then shuts again. The pressure in the intercooler pipes is now much lower, so if in the spool range, the turbos will spool to 'take up the slack'. The increased airflow piles up on the throttle plate etc etc etc.

I notice the effect much more in hard piped cars, because those big long fat and relitively soft intercooler hoses mitsubishi used on the Galant, EVO and GTO would have a damping effect on a pressure change. With a nice hardpipe kit, there is zero damping effect in the pipework.

I cant say i have ever noticed this in a VR4, but then i have never driven one with a hardpipe kit on it. It does happen on the other platforms, so i thought i would mention it.

Cheers,

Ben.

[Nick Mann]

I used to get this phenomenon before I knacked my original turbos. I no longer get it. I do not have a hard pipe kit.

[bradc]

Ben, thats unlikely to happen with our small turbos don't you think? And wouldn't adjusting the bov pressure point solve the problem?

[Wodjno]

I used notice this when i had my atmospheric dumpvalve fitted. I thought that it was due to the valve opening as maybe spring was getting weak ??
But as you have stated a lift off the throttle and re-apply sorted the prob :speechles
I haven't noticed it since i installed a recirc.. But then i suppose it wouldn't be as noticeable..

I haven't got a full hardpipe kit :thinking: But a sort of bits of hard pipe kit :inquisiti

But it has done away with ballooning pipes and is alot more responsive :2thumbsup

[Kenneth]

possibly the spring pressure is great enough to close the DV when in vacuum at very light throttle (how most have theirs set) and therfore you rely on boost to open the DV. In this case, pressure will build, the DV open and then close when pressure is lost. and repeat.

now, back to pipe work...

I don't really care which is easier to work with... I have a marine engineering workshop to play with which means the gear is all pretty good and there are people who can help :)

What I want to know, is what is BETTER. I don't care that much about the weight to be honest.

Yes, the stainless WILL have more issues getting rid of the heat, but that property makes it much more resistant to absorbing the heat also.

I COULD bind Aluminium with heat wrap... but that would look ugly as.

[Kieran]

I COULD bind Aluminium with heat wrap... but that would look ugly as.

You could always apply a coat of that Thermo-tec heat paint on top of the wrap.... Would help with the looks.

[Kenneth]

You could always apply a coat of that Thermo-tec heat paint on top of the wrap.... Would help with the looks.

thinking more about the heat wrap... It would also make disassembly of the pipe work a real mission.

Kieran: Would you do it to your car?

[Kieran]

Kieran: Would you do it to your car?

With the heat issues I'm having, I intend to. Admittedly, I would prefer shiny pipes, but in terms of engine bay, that, along with the underneath of the car is where "Operational, not decorational" takes precedence.... I think though, painted and wrapped neatly, it could look okay. And if it keeps intake temps under control, well, that's good enough for me!:happy:

[Kenneth]

With the heat issues I'm having, I intend to. Admittedly, I would prefer shiny pipes, but in terms of engine bay, that, along with the underneath of the car is where "Operational, not decorational" takes precedence.... I think though, painted and wrapped neatly, it could look okay. And if it keeps intake temps under control, well, that's good enough for me!:happy:

true. I am hoping shiny pipe work will be good at reflecting heat away from the pipes.

It MAY be worth while doing the pipe-work shiny first, then heat wrapping to see what difference it makes.

[psbarham]

what about ceramic coated stainless , now that would look cool :afro:

[mattpage]

I'd go for anodised aluminium myself.
But only because of the funky colours you can get :)

[OSiRiS]

Price will be the deciding factor ;)

[Kenneth]

Price will be the deciding factor ;)

Not really. I can get the material at a good price and access to the welding equipment is free.

[Wodjno]

what about ceramic coated stainless , now that would look cool :afro:

I can coat it in Royal Daulton :inquisiti

Might not smell to good though /help

[mpau009]

Not really. I can get the material at a good price and access to the welding equipment is free.

/pan Make one of each.. Accessorize baby yeah:afro: /toycar

Shiney stainless for the strip and fancy dinner parties, Anodized Aluminum for the shows and track:scholar:

[Kenneth]

/pan Make one of each.. Accessorize baby yeah:afro: /toycar

Shiney stainless for the strip and fancy dinner parties, Anodized Aluminum for the shows and track:scholar:

Ok, maybe cost IS a factor... but you never know, if it isn't too hard I may be willing to make some more ;)

I reckon ill go for stainless at this point. I guess i should think about getting an intercooler eh... :P

[Wodjno]

Ok, maybe cost IS a factor... but you never know, if it isn't too hard I may be willing to make some more ;)

I reckon ill go for stainless at this point. I guess i should think about getting an intercooler eh... :P

STAINLESS INTERCOOLER :pimp2:

[Eurospec]

If you can get the materials and fab work done cheaply, then i would go with stainless and use the £ to get a ceramic coating on it.

You can actually get stuff that has a chrome effect on it, so it looks the part too.

Anyone who knows though will open the bonnet and go ooooh, ceramic coated, :pimp2: nice!


As to the pulsing question, Yes its worse with bigger tubs in my experiance and it is certainly worse with an atmos DV. I had it in my car on 15G's, but i tightened my recirc dump valve right down which lessened the occurance a lot, but never got rid of it. If i removed the hardpipes and FMIC, and went back to std, it didnt do it.

Surprised to see that people have had it on the std set up though. I could see a pottential issue from a dump valve. You know the way that sometimes you see a dump valve hovering open? I think the stock one does this but many aftermarket ones- particularly atmos ones dont.

Anyway- sorry, i diverted the thread with something i dont actually know the answer to, but i thought it was interesting.

Cheers,

Ben.