sparkwirez06

iTrader: (18)

I've seen a few threads with aluminum down pipes. do egt get high enough to melt the pipes?

WS6HUMMER

iTrader: (19)

I have one, I built it out of 11ga. Not finished with my build yet though but not very far from firing it up. I have 2 friends that have them made out of aluminum and have no issues so I decided to go that route this time. I would think an aluminum DP would stay cooler being that it takes twice the heat to weld aluminum because it dissipates heat so fast. My old DP I built out of 304SS and being 4" it ran so cool that the first 10" was the only part that even slightly changed colors.

sparkwirez06

iTrader: (18)

always makes me thing of videos like these. melting point for aluminum is 1221f 660c. egt temp has got to be close to 1500- 2000f???

WS6HUMMER

iTrader: (19)

Yeah but look at the actual dp and notice that it barely glows and only about 4" of it. It may be making EGT's that high but that's on the engine to turbine side. My friends that are already running aluminum DP's have them on X275 cars making over 1300WHP I'm sure they would melt one before I or you would and they haven't so far. I'm obviously not afraid of that happening because I've already built my DP out of aluminum lol.

73turbo53

5" down pipe on mine, works great and a ton of weight saved

sparkwirez06

iTrader: (18)

that's what I'm looking for, actual use, I've seen a few but only on builds that haven't been fired yet. thanks

cjmatt

iTrader: (4)

just dont put the downturn right after the turbo and youll be fine

THADD

iTrader: (12)

I just ordered aluminum piping to make my down pipe. 5 inches straight out of the fender

MATTREDSS

iTrader: (16)

I have a 5" aluminum downpipe on mine that Huron built for me with my hotside. My car isn't finished yet so no actual results with it but I am more than confident that I will have zero issues with it. It's a weekend car that will see multiple trips to the track


Matt

DEFYANT

Quite a few people do obviously, but yes the do melt. I read an article about LMR's Firebird melting the downpipes and having to repair them before a race, use a thicker gauge aluminum for the first 6"-8" or so and then go to the thinner stuff.

WS6HUMMER

iTrader: (19)

That's why I mentioned using 11ga in my above post.

Wnts2Go10O

iTrader: (12)

speaking of using different materials for down pipes... couldnt one in theory use a thinner steel with silicone impregnated carbon or something of that nature?

Krom

Instead of trying composites, I'd just go thin wall Ti

for the same thickness its a little heavier than Al, but it takes the heat exceptionally well.

WS6HUMMER

iTrader: (19)

What filler do you use on Titanium? I know silicon bronze does most all exotic metals but I've never got the chance to play around with it, do you have to backpurge Ti?

Torqueshaft

Yes...You have to back purge when welding Ti.

Sarg

iTrader: (6)

Think some folks are using an argon bath for ti. Expensive tubing to screw up!

skinnies

iTrader: (33)

I didn't go aluminum as I've got vids of my exhaust glowing like the vids above. The low timing and high egts on my street car trying to hook big power on the street or on street tires on the track IMO is way harder than a x275 car does to a downpipe.

MustangLS

iTrader: (5)

I run an aluminum down pipe on my car. It's 4" and made from 11ga for the first foot or so and then goes to 16ga. No sharp bends in the first foot just a 45* to route it towards the fender opening. I had it ceramic coated, no wrap and it's been fine. It's about 40" long with a bumper exit and it will get hot enough to melt the bumper cover when it sucks in at the top end of the track but that's about it. I'm sure my EGTs would be pretty high I'm running non-intercooled with E85 and 12* of timing at the top end.

T76s10

iTrader: (6)

X275 guys run huge turbos in result have lower egt's. Plus their not making as many back to back pulls like street cars.

V-seriesTech

iTrader: (5)

For any kind of street car, aluminum will not hold up. Thats what we tell peoples wanting to run that setup anyways. It's just too hit or miss. I would recommend some length or stainless or mild, then go into the aluminum. But, to give you an idea, 11 gauge aluminum in comparison to a 16 gauge or .065 wall thickness piece of comparable stainless.

The 5" SS 90 weighs in @8.9lbs

The 5" AL 90 11ga weighs 4.4lbs.


I run mild steel, then aluminum. I have no problems,...I run a thinner 16 gauge aluminum,..pretty far back down stream so, heat doesn't seem to be an issue currently.