3" Exhaust for HDJ80

[70sguy]

That really is a reasonable price IMO. Ya, ya.. I know they do cheep stainless in Quebec but that doesn't help anyone out side of QC. I was quoted $3500 by a local shop to do a 3" stainless w/Aero turbine using all mandrel bent elbows and straight stock TIG welded together. OUCH! And that system would not have been modular where you can remove a section or two if you are pulling the tranny or something.

[lshobie]

Damn, go on ebay, buy 3 inch stainless mandrel J bends for 26 each, go buy 10 feet of straight 3 inch mandrel from a local shop. Then use a metal chop saw and cut and tack the pipe with a MIG. Do it in about 2 or 3 sections so you can dissasemble to have it TIG'd by a pro for $100.00, get the ends spread at midas muffler in a couple of spots so it will slip in and you can adjust as needed. The areoturbine costs 170. So, for about 600 or less and some sweat you can have it done just about as good as a pro - maybe better.

eBay Store - Mandrel Bending Solutions: Silicone Hose Products, Straight Pipe, 45 Degree Bends

You can get everything from these guys to set it up. You will also need a flex section and possibly a 2.5 to 3 inch reducer.

Veyr easy to do - 3500 is retarded - I'd consider that an insult if someone quoted that to me - or it had better come with a turbo (installed).

[70sguy]

Ya, good point for sure. But for me, for the extra $1150 I can just get a nice clean system that I can just bolt in and even more importanly unbolt and remove when I have to do some work or something.
Call me lazy or whatever.. I don't mind spending the money on a good bolt up product that would use up days of my time to create myself.

[lshobie]

Ah, you under estimate yourself, a mandrel system can be done in a day the first time you do it - the next one would take a couple of hours. But I know what you mean about the time factor. And It can be done just as well as the pro's if you get a pro to TIG them up.

[83bj60]

Very, very interesting development. Towpack's system is EXACTLY what I'm planning to do

Towpack, do you get any exhaust smell when the rear windows are open?

As for getting cheap stainless steel here I still haven't been able to source some. The largest place i used to deal with many years ago appear to be only into fabrication now (they don't sell materials anymore) and they havent'returned my calls (Monsieur Stainless). If any of you send could send me some godd adresses, I'd appreciate, the new exhaust's got to get in before this summer.

As for making a system bolt-on I don't see a probem welding flanges... Or am I mistaken?

[wussyPup]

Originally Posted by Towpack

Apparently the system cannot follow the same route as the OE as it will not fit between the floorpan and the chassis member where the system crosses the back axle without much more extensive fabrication of some sort of wide flat pipe section which would add a lot to the cost and not be as effective.

Originally Posted by railswitcher

Putting a larger tailpipe on would do nothing for the turbo as the pipe is crushed by Toyota where it passes over the rear axel.
...
This setup follows the stock exhaust pattern...

railswitcher, do you have any pics showing how well your new piping clears the tight space over the rear axle? Does it touch the floorpan or chassis anywhere back there?

oh, sorry that I drooled on your parts; they look great!

-Steve

[Towpack]

Originally Posted by 83bj60

Towpack, do you get any exhaust smell when the rear windows are open?

Not that I've noticed.Was driving round most of yesterday with both rear side sliding windows open a few inches and got no smell.Running 50% bio from WVO I would have noticed it right away 'cos it smells deliciuos!

[83bj60]

This is GREAT! Perfect exhaust setup and perfect fuel setup

[Adam B]

I did my whole 3" in a day. I used 3 mandrel-bent U-tubes, a straight 7' pipe, the nicest flex joint I could find, and I already had an Aero Turbine that I got with the truck.

There's nothing magic about the muffler and I wouldn't pay for one. The hype annoys me.

I think I spent about $250 for everything and even if I had paid the 170 for the muffler that's just over $400. I did everything with a MIG welder because....well....what advantage is there to TIG welding aluminized steel? I think stainless is kind of pointless.

It's in 4 sections that can be removed in minutes. I used stainless wrap-around band clamps at the joints. No gaskets, no leaks, no stupid crush clamps.

The one thing this kit has that I want is the turbo elbow / dump pipe. Mine still has to go through the factory elbow and that first 2.5" ID flange that bolts up to it. I'd love to see how ATEB and others deal with this...or ignore it...

[canucksafari]

Originally Posted by Adam B

The one thing this kit has that I want is the turbo elbow / dump pipe. Mine still has to go through the factory elbow and that first 2.5" ID flange that bolts up to it. I'd love to see how ATEB and others deal with this...or ignore it...

You can order just that one piece from them. Some people really want SS for the looks and have the money for it. What I find funny is people who then use regular steal clamps on SS and then complain about rust on their SS.

[Tapage]

Pretty simple .. 3" downpipe home made ..

[83bj60]

Originally Posted by Adam B

I think stainless is kind of pointless.

you wouldn't think like that if you'd lived where we are... in the salt belt!!!

Originally Posted by Adam B

I used stainless wrap-around band clamps at the joints. No gaskets, no leaks, no stupid crush clamps.

What do these look like? I have been looking for something smart for years without success... Then again, what do you expect, I live in a third world province!!!

[ElectricDyck]

Tapage, did you use the same stock flange?

[Tapage]

Originally Posted by ElectricDyck

Tapage, did you use the same stock flange?

Yes !!!! quite simple uhh !

[ElectricDyck]

Yes very simple. What material is it made out of? Is it cast? What type of welder was used?

Sorry to hijack, but some what relevant.

[mr snrub]

anyone interested in a full bolt on 3in. stainless exhaust system for HDJ81 cruisers, requires no welding or cutting, bolts right on and makes a noticeable difference in response and power. MPG gains are debatable but it is a substantial upgrade in low end and hwy speeds. all that for $995 roughly and its all brand new. my friend is selling some so let me know and i'll give you his info. he only has a few left so hurry if you are interested,
cheers

[Tapage]

Originally Posted by ElectricDyck

Yes very simple. What material is it made out of? Is it cast? What type of welder was used?

Common cheap stick 6011 ...

[dblugly]

Sorry for the hijack

Will a 3" exhaust do me any good on my non-turbo'd 2b?

[83bj60]

On a diesel, anything that reduces backpressure and exhaust temperatures will increase engine efficiency to at least some extent. If you can do it, why not! If you are not using mandrel bent, that extra size will be welcome as bending does reduce effective diameter quite a bit...

[Tapage]

Originally Posted by dblugly

Sorry for the hijack

Will a 3" exhaust do me any good on my non-turbo'd 2b?

actually in a NA engine you need some backpressure ( even it's a diesel engine ) saing that .. 3" are by far much more than you can run in a NA engine ..

I feel the lose of backpresure when I go for 2.5" in my 2H when it was NA ..

[Adam B]

Tapage,

That flange is cast, isn't it? I tried MIG welding to it and it just ripped apart when I threw it on the floor.

What did you use for a gasket then? The stock one that mates with the elbow is only 2.5"

[Tapage]

Originally Posted by Adam B

What did you use for a gasket then? The stock one that mates with the elbow is only 2.5"

The gasket inside the flange that mated to the turbo outlet it's the factory one ..

it can't be much apreciate in this pic .. but I just use the flat part of the flange and weld the 3" ..



But yes I keep the factory gasket ..

[83bj60]

Originally Posted by Tapage

actually in a NA engine you need some backpressure ( even it's a diesel engine ) saing that .. 3" are by far much more than you can run in a NA engine ..

I feel the lose of backpresure when I go for 2.5" in my 2H when it was NA ..

How did you feel the loss of backpressure on the pre-turboed 2H and what were the effects, Tapage?

Maybe I don't understand all the engineering reasons behind the necessity for some backpressure, but thermodynamically, backpressure opposes engine efficiency... Would you care to explain why backpressure is so good?

[Tapage]

Originally Posted by 83bj60

How did you feel the loss of backpressure on the pre-turboed 2H and what were the effects, Tapage?

Easy .. it rev up faster .. but usually I just pull the clutch to start moving my Tencha .. ( no acelerator nedded ) without back pressure it simple shut off .. when after not.

Originally Posted by 83bj60

Maybe I don't understand all the engineering reasons behind the necessity for some backpressure, but thermodynamically, backpressure opposes engine efficiency... Would you care to explain why backpressure is so good?

Some usefull info ..

Scavenging (disambiguation) - Wikipedia, the free encyclopedia

Scavenging, automotive process of pushing exhausted gas-charge out of the cylinder and drawing in fresh air

Torque Production - Exhaust Scavenging And Friction - Stock Car Racing Mgazine

Auto Exhaust Science

[railswitcher]

I don't have any pictures of the install,but I can tell you there is plenty of room over the rear axle. It is close to the floor board over the resonator and requires some effort ;ie. patience; where goes between the frame and the body and runs along the inside of the frame. I will attempt to get some pictures of the system on the truck.

[83bj60]

Tapage, great links! Thanks