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-   -   Weld turbo to manifold - bad idea? (https://www.miataturbo.net/diy-turbo-discussion-14/weld-turbo-manifold-bad-idea-9238/)

akthor 04-22-2007 08:48 AM

Weld turbo to manifold - bad idea?
 
Now wait I know this would be a bad idea under most circumstances but listen.

I got the old style Begi manifold that fits the areodyne turbo. I got a T3 turbo believing the manifold could be modified to fit "any" turbo. After getting both I learned from Begi that they couldn't modify it to fit a T3 only a T25.

In measuring and looking at both the main issue would be no room for bolts and nuts on the backside of the manifold to attach the T3. So I thought perhaps holes in the front and have a shop drill and tap studs in the back. Well in calling welding shops it is extremely expensive to use the right welding rods to weld mild steel to cast iron and with the labor included it would cost about as much if not more than a brand new cast 1.6 T3 manifold. So not really an option.

See the problem is I began this DIY turbo build with the idea of getting a basic turbo setup going for as little dough as possible. So my options:

#1 Send the mani to Begi to be modified to fit a T25 - $100 + shipping back and forth. then find a T25 (nissan type) which so far I haven't been able to find for less than $200 so lets so all together this option will be around $400.

#2 If I can have the turbo welded to the mani cost $??? I don't know but I cant imagine more than $100.

The issue is that while I think I can get my money back on the T3 at this point if I use option #1 if I don't use the manifold I don't think anyone else would want it so I would be eating the $150 I paid for it.

So I am leaning towards just welding them together (if it's possible) and running the turbo until it goes and then I will find a different mani and turbo. I only paid $110 for the T3 and with the cost of the manifold it's $260 even if this just gives me one summer of turbo fun and I replace them over the next winter it seems worth it as opposed to spending any additional $$$ now (money is short).

Time is also a factor modifying the mani and finding a T25 or finding a T3 mani that fits my budget ( i am trying to stay away from the cheap SS ebay manis )will take who knows how long as well, warm weather is here so......

So what do you guys think? Crazy or plausible?

akthor 04-22-2007 09:45 AM

3 Attachment(s)
Here are some pics:

It looks like the oil lines are almost vertical the way the turbo would mount as is would I still need to clock it?

Also on the exhaust side if I take that thing with the three studs off would I then be able to use the standard T25 dump pipe/j pipe thing down pipe? I know mine is a T3 but that looks like the T25 exhaust side if you take that off?

y8s 04-22-2007 11:55 AM

it works for the SRT-4
http://www.turbochargers.com/store/images/srtturbo.JPG

y8s 04-22-2007 11:56 AM

wait, sorry. what I meant was

welding cast iron is a crap shoot at best. chances are you'll get a few hundred miles and then it'll crack. and then it'll crack enough to make you regret doing it. even done right, it's still not very strong / crack resistant.

Loki047 04-22-2007 12:36 PM

I dont understand why you dont just make an adapter plate?

With half inch steel with studs coming out each way..

Mechazawa 04-22-2007 01:15 PM

Loki has the right idea, IMHO, buy a cheep drill press and make it yourself.

akthor 04-22-2007 03:24 PM

1 Attachment(s)
I would like to do that but look at this picture, on what I call the back side where the two studs are coming out if I drill into there its right inside the manifold. Could I drill the mounting plate for the turbo to fit the existing studs and drills holes in the mani on the other side to accomadate the T3 holes or would this weaken the mani too much?

Loki047 04-22-2007 05:25 PM

You can still do it using those studs. You would have to recess the nuts inside the adapter flange. If you give me dimensions I could draw it up for you.

akthor 04-22-2007 05:50 PM

dimensions of the manifold?

cjernigan 04-22-2007 05:55 PM

Dimensions of the flange with locations of the studs.

akthor 04-22-2007 06:12 PM

The manifold flange or the turbo flange?

cjernigan 04-22-2007 06:17 PM

The flange that the turbo bolts to on the manifold. The one you just showed a picture of.

akthor 04-22-2007 06:43 PM

1 Attachment(s)
It's an odd shape:

Loki047 04-22-2007 09:34 PM

Whats the pattern on the turbo?

Trent 04-22-2007 09:42 PM

for what it's worth, the previous owner of my car welded the turbo to the manifold. It has survived being on a heavily run turbo car for almost 2 years on constant abuse, drag strip runs, and autox. In fact, i really wanted to break them apart and use hardware, but the weld appears to be very well done. Hey, if it's lasted this long......

iWeasel410 04-22-2007 10:08 PM

For dissimilar metals or cast iron I'd recommend brazing with silver solder.

Markp 04-22-2007 10:23 PM

Just make an adapter plate. Make sure that the plate and the manifold are perfectly flat and it will all be ok. If you want to be clever about it you could put a o-ring in there but that's overkill.

Mark

akthor 04-23-2007 07:01 AM

The turbo is a T3. I think I understand how an adapter plate and I can't figure out how to attach it can you explain?

Braineack 04-23-2007 08:11 AM

http://www.turboneticsinc.com/downlo...rs/t3_dims.pdf

akthor 04-23-2007 10:17 AM

I have a mild steel T3 flange that I got from Ebay.


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