Intercooler pipes - aluminum vs stainless

[T0nyGTSt]

I wonder about this. Since it is only passing cool air, why does one need super strong mandrel bent pipes?

Air won't place much stress on any material. I have SS pipes on my FMIC (ARC brand) but I don't see why cheap PVC or whatever wouldn't be just as good.

T.

[GTS-t VSPEC]

Nice to hear a few extra view points. I agree that titanium is way over the top, but the weight saving for some of the top Jap cars is worth the expense to them.

I think the idea of using the mild steel and having it HPC coated is a good idea, but the aluminum also does have appeal for it's weight advantage, but in the end 2-3kg will make stuff all difference.

I'm not sure as to the power difference between mandrel and press bent pipes but the smoother the airflow the better the power. I try and remove any restriction in the pipework, don't now whether it makes any difference but as least I know it is not the cause of any power loss, helps me sleep at night.

See'ya:burnout:

[macka]

Aluminium all the way

Lighter

Quick to dissapate heat

Welds are mint u just need a good welder!

Polishes way better than stainless.....even tho scratches easier

and costs alot more........

hhmm i will just stick with my titanium pipes i think..

[GTS-t VSPEC]

Titanium? You wish, you can't even afford a decent clutch.:lol:

The titianium exhaust can save quite a bit of weight, so in conjunction with the aluminum pipes could improve overall weight enough to make a difference on the track.

See'ya:burnout:

[Clint32]

Lowlux someone who knows what there doing will not leave any dags at all in the pipes, look at the way the japs do some pipes with streight pipe cut on an angle and welded together. You should be able to weld the pipes with a tig and not get a single lump on the inside of the pipe. The affect this has on performance may be very small but i always do it properly, never want to cost yourself .2HP.

[Doctor]

I think alot to do with performance of mandrel vs press bends has alot to do with what type of bends you are using WHERE.

For example if you had a 90 degree bend before the throttle body you would want a mandrel bend. Why? so that air is more evenly distributed inside the manifold than say a press bend. I really think you could you a mixture of both in a pipiing set up as some bends it would not matter what type they are.

Doc

[BOOSTMEISTER]

www.are.com

Go the mild steel with HPC coating, best compromise in weight and best heat properties...Also, manderal bent pipes are way way way better than press bent versions....read Corky Bell's book "Maximum Boost" to see why, he also explains why haveing your pipe joins to far apart where the silicon connectors are will drop your power and also why at the front of your car you shouldn't have a angled bumper to aim the air into your intercooler...this actually reduces the efficiency.

Read and learn folks

[Guest INASNT]

y not go for look and performance.

I got stainless steel which is ceramicly coated inside and out, flows and stays cool beautifully!!!

and the cross over for the engine was all 1 piece so no nasty welding marks

[GTS-t VSPEC]

Ceramic coating is great, I am doing it to my exhaust manifold, but it is quite expensive, therefore I think that the mild steel HPC coated or the aluminum are the best options.

I always go for mandrel bends, might not make much difference but there is some difference.

See'ya:burnout:

[Roy]

read Corky Bell's book "Maximum Boost"

Not a bad book if looking for explanations and a general understanding. Bit disapointed by lack of technical info though. I read a review saying it was the bible so didnt bother asking to remove plastic so i could peruse before buying. Thought it would have more info on fluid and thermodynamics to assist in race car design.

No doubt mandrel is better (FACT) for its constant radius and flow characeteristics. But if you are plumbing up a 2nd hand IC, and only ever going to run OE turbo with no head, manifold work, then i doubt a press bend 45 over mandrel 45 (give ir take a couple of degrees) is going to hurt power. But hey im talking guys on a budget, if your not on a budget then get mandrels, just to be sure. Im big on over engineering if you can afford it.

Of note is that books like Maximum Boost , whilst being on turbocharger systems, references a lot of pretty serious machinery, lots of V8s and open wheeler engines. But i suppose we can all strive to apply this technology on our road cars.

Why? so that air is more evenly distributed inside the manifold than say a press bend

...well dont forget that intercoolers require turbulent flow (NOT laminar flow) thru the core to ensure max effeciancy.

[Hicks]

Mild steel, alluminium, and stainless will all polish to a mirror finish. Mild steel wont stay that way for long though. And as far as welds go, alli welds look just as good as stainless welds, but you need someone whos not a complete spastic to weld it.

[Hicks]

And I think ali pipes is a stupid idea, they would heat up so quick, and the heat would spread to the intercooler. Have you felt the inlet plenum after driving, that heat would go straight to your cooler!! Stupid idea.

[MrMayhem]

alloy transfers heat faster than stainless

soaks faster and disapates faster

stainless take longer to soak but will retain that heat longer

mild steel is what you use when you dont care about what gets inhaled into your engine coat it you;d be surprised how much rust wants to pop back out of welds

as for flow material co-efficient i dont really think thats relevant in the practical world

also boost meister mention of forcing "extra" "un-natural" flow by having the bumper angle in is excellent like a cooler ram scoop

[GTS-t VSPEC]

So the consensus so far is that everyone has a different opinion, Well at least we have stimulated a good debate.

So it seems that were are in agreeance that a decent welder, you Hicks?, can make aluminum/stainless/mild steel all look good, polished and with nice welds.

It would also appear that mandrel bends are better, on most car the difference may be small, but on a race setup the difference may count for a 10th or more on the track, worth the extra cost.

Still haven't come to a definate conclusion about the material. Yes aluminum will heat up quick and dissipate quick, but we have to consider that going around a circuit what would happen. In general I don't notice the heat sink until the car comes to a stand still, then the pipes get very hot, with air flowing through them they seem relatively cool.

See'ya

:burnout:

[Guest INASNT]

ceramic coated piping might b expensive but it works really well!

U can hold a oxy torch on my pipe for 5 minutes then pull it away and the pipe can be touched straight away and u wont burn your hand!

[MrMayhem]

now that sounds interesting

[GTS-t VSPEC]

Yes, totally agree, the ceramic coating is fantastic, but at the price only for the serious racer.

I'm planning on ceramic coating both my exhaust manifold and turbo exhaust housing. It is also possible to get pistons and valves coated aswell, this produces an engine that can handle 50+ laps around a race track, and the internals won't crack.

Between $500-$600 to coat and exhaust manifold.

See'ya:burnout:

[Ballistic]

I agree,

If alloy pipes are prepped right and welded by someone good with a tig, there should be no inner dags at all with very smooth change from one pipe to another.

I'll always use mandrel bent alloy, when i/c pipes are concerned. Some say it look s/house, but it can be polished very nicely... to some, polished alloy has a better "colour" than stainless steel.

Of course i think pipe route (length, number of bends) plays a bigger factor in power saving, as well as the actuall intercooler core and end tanks themselves. No use having the perfect pipes with million dollar welds and glamorous polishing if your intercooler is what is going to cost you the power!

[Guest INASNT]

Ballistic

Thats right, lots of people go out and get a cheap (ex truck core) then spend sh*it loads of $$ on expensive piping then wonder y it runs so crap!!!

[Ballistic]

and most of those people with truck coolerss are just in it for the wank factor of such a big cooler

"everyone check out my intercooler with rear mounted TX3 Turbo"