Exhaust DIY

[Saltdog]

DIY Exhaust Supra

I know there are a lot of hardcore Supra owners out there and they are probably going to bash this because it’s a barnyard job, but I was happy with the power gains so I figured I would post it.

What you will need:

- 1/4 inch plate to make exhaust flange
- Exhaust Gasket Material - Approx $15 CAD Local Car parts dealer
- 10 Ft 3 inch Exhaust Pipe - Approx $ 50 CAD (Semi or Truck parts store are usually the cheapest for pipe and 90Deg bends
- 1 X 90 Deg bend - Approx $15 CAD
- Paint
- 3/8 Rod - ( I used Rebar ) - Anything 3/8 ish
- 3 Inlet Muffler (optional) - Approx $50 CAD ( EBAY )

TOTAL = $ 80 CAD
= $ 130 CAD (with Muffler)

Tools Needed

- Torch to cut Exhaust flange
- Welder
- Chop Saw


Here we go:

1) Remove old exhaust.

You can try to undo the bolts but I would suggest just cutting them. If you are doing this I would suggest swapping the down pipe or at least punching out the cat with a crowbar. Buy a cheap die grinder and a carbine rotary file and port your Turbo elbow as well.

2) Building the exhaust

I think my drawing is pretty self explanatory but I will make a few comments anyways. First I Bolted up my flange on the down pipe and measured exactly what angle I had to weld the flange on. Mine was approximately 93 Deg (as shown in drawing)

Next I cut the 62 inch piece. Then fit and weld my bends, make sure you tack weld first so you get angles that look right


Gixxer750 - DIY Exhaust
“I actually have a different way of doing bends. I own a really good chop saw, so to do a 45 bend, I actually cut two 22 degree sections, and then weld it all up. It works pretty good.

Now before someone bitches about how that won't flow, we tested a bend in the same size for a mandrel, a crush and this on a flow bench. This flows just slightly less than a mandrel, and much more than a crush bend.”
http://www.supramania.com/forums/showthread.php?t=15095


Once the pipe is all welded, I held my exhaust up with Jack stands and built the mounting brackets 4 total. Gave it a little spray paint so she doesn’t rust to quickly and bolted it up.


Performance:

Well according to the butt dyno there is a lot more in the lower end. I actually have usable boost in 1st gear.  Right now I am still using my stock down pipe with the cat punched out. (New DP is in the mail) I hit stock boost at approx 2600 Rpm. As for volume currently I have no muffler. And the car is pretty quiet, and there is a very nice whistling sound from the turbo that you can always hear. The exhaust does hit resonance frequency at around 2800rpm and gets a little loud. I believe it was good HP gains for money spent

 

[7MGTEsup]

Nice job, no mufflers I see gunna be on the loud side.

 

[MassSupra89]

Nice.
I was thinking about doing something like this. A straight pipe to swap out my cat-back with. I like the custom work. Very good job on the measurement and fitment. Definetly not a hack-job or anything.
Any way of getting a video of how it sounds up here?

 

[SupraDreamPDR]

that looks really good. it is gonna scream now and really scream when your DP comes in!!

 

[jmcboost]

Looks Good, plus you saved yourself about $400 compared to a Nur Spec!

 

[souprat]

i agree it does look good on te ground and in the car. only thing is why did you use 1/4inch for the flange? is that just what you had around in the shop? i think the norm is to use around 3/8.

 

[EdgeSupra]

I definitely want to hear how that sounds.

 

[bigal0043]

yea that looks really good.. i have seen some exhausts not even use elbows.. they cut the pipe at an angle... but i think if you mass produce those there would be a market for them.. depending on how it tucks underneath the car


150 cad thats like 90 american right?

 

[Jspec7m88]

Very impressed. I would imagine that it sounds pretty mean. Post up a video of it or at least some sort of sound clip. Nice work, definately not a hack-job...When I first started reading, I was getting prepared for some sort of joke but bang-for-the-buck and if you're willing to work a little, that is an AWESOME mod that will improve your HP dramastically (if done right) and hearing that turbo breathe is great to hear. +1 for you.

Jeff

 

[Saltdog]

i agree it does look good on te ground and in the car. only thing is why did you use 1/4inch for the flange? is that just what you had around in the shop? i think the norm is to use around 3/8.

As for the 1/4 inch flange, ya it was what I had around the shop.

I don't have a Video Camra but maybe I can borrow someones and get something up here for you guys.

Thanks guys for the positive feedback. I am all about the DIY thats the best part about building my car. I think that I want to do my IC piping next seeing as I try turning up boost and it doesn't go up.

 

[cjsupra90]

the angled cuts to create a bend are not the greatest thing to do from a flow standpoint. if done, they should be kept to a maximun of 5 degrees per cut.

 

[supra90turbo]

Yeah, I'm with Chris on the topic of minimal bend angles.
That last one by the subframe seems a bit harsh, but I'm sure it flows MUCH better than stock, so not a huge deal, but if you were to use smaller bends, it would be much better.

I want to hear it too! I love straight pipe exhaust. I had a video of a WRX with a turbo to bumper mandrel bent 3.5" pipe. Sounded so good, like a rally car... mmm... raspy!

 

[turbotank88]

Thats some good work there. I would really like to hear what she sounds like as well. I was thinking of doing something similar except making the exhaust coming out at an angle, probably something similar to the rsr-gt2.

 

[thesandymancan]

i still building mine, three inch from dump pipe back. i'll post pics when its done.

nice job, lets hear it

 

[figgie]

the angled cuts to create a bend are not the greatest thing to do from a flow standpoint. if done, they should be kept to a maximun of 5 degrees per cut.

:werd:

That angle seems to sharp.

 

[IHI-RHC7]

Yeah, if that were more lobster-like it would be much better. Great work though!

 

[jamesdem1123]

hmm, very nice, i want to do something similar, maybe with a muffler tho, doe sthat bolt directly to the downpipe or do u have a cat/test pipe? you siad its not that loud? that cant be....

 

[Saltdog]

hmm, very nice, i want to do something similar, maybe with a muffler tho, doe sthat bolt directly to the downpipe or do u have a cat/test pipe? you siad its not that loud? that cant be....

Nope she bolts right up to the downpipe, as for the loudness, I guess I was a bit wrong about that. It doesn't sound very loud inside the car, When you hit boost I can hardly even hear my exhaust (from inside the car) But I was driving beside one of the guys I live with and he has a Ford Probe with a ZE swap in his and he is quite loud and I was definatly louder then him at times, its just such a low tone compared to all those ricer civics, and Cavs with there 4.5 in mufflers that it doesn't "seem" very loud. I am still debating putting a muffler on just for legal sake.

 

[Allan_MA70]

DIY in this case is what the first police officer will say to his mates "Yeah DIY mate!!" as in "Yes co-worker I Defected It Yesterday, xmas bonus for me!"