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After searching for hours I found one guy who cut the whole shelf behind the downpipe to fit a 3 inch downpipe. I need about 2 inches of clearance and was hoping to see some pics of people who have hammered back that shelving area to fit a 3” downpipe.
ive got an older BEGI style manifold and my turbine exit has a 3” V-band flange. EWG
Cut it! Or buy a kraken downpipe. No cutting required for 3"
Are you sure? Maybe it depends on the turbo used and mounting style, but I just ordered the 3” efr top mount manifold and full exhaust, and I was under the impression that it’s kind of a 2.5” bend that flares to 3” because of the clearance — correct me if I’m wrong!
I have a Kraken high-mount manifold with a Garrett-clone churbo, that has a 5-bolt to 3-inch adapter with a "low-profile" 3-in DP bolted on. With all of that, I had to cut the shelf back to the FW and I have about 1/2-in of clearance. It's tight, yes, but the AWR engine mounts keep the engine pretty well located so rattling from the DP will no be a factor (because it'll be swamped by vibrations from the engine mounts).
I have a Kraken high-mount manifold with a Garrett-clone churbo, that has a 5-bolt to 3-inch adapter with a "low-profile" 3-in DP bolted on. With all of that, I had to cut the shelf back to the FW and I have about 1/2-in of clearance. It's tight, yes, but the AWR engine mounts keep the engine pretty well located so rattling from the DP will no be a factor (because it'll be swamped by vibrations from the engine mounts).
Hi, do you have any pics of the shelf you cut? And did you weld some sheet metal back in place to keep the steering shaft concealed in there or did you just leave that open?
Once I get off work I will take a picture of my shelf. It is unmodified, running the high mount Kraken, with the 5 bolt adapter. 3"vband downpipe and no cutting required.
Hi, do you have any pics of the shelf you cut? And did you weld some sheet metal back in place to keep the steering shaft concealed in there or did you just leave that open?
Here's the "best" pic I could find (and it's not very good). What you can see is the shelf cut leading into the FW with the steering shaft showing above and slightly to the left of the lower vband. This is before everything was tightened up, but you can tell that there is already not much clearance between the vband and the steering shaft (it's better when things are tightened up, but not by much). You can't see the actual cut parallel to the FW because the brake proportioning valve is in the way. Hope this helps a little.
PS - I didn't put any new metal back around the steering shaft. All of this was done with the engine in-car and there's ZERO clearance. The next time that the engine is out (which, hopefully will be years from now) I'll fix that.
What turbo do you have OP? MKTurbo, Kraken, TSE manifolds all need the rear shelf bent down for DP clearance with 3" down pipes. So a Begi/FM manifold is going to be even harder.
What turbo do you have OP? MKTurbo, Kraken, TSE manifolds all need the rear shelf bent down for DP clearance with 3" down pipes. So a Begi/FM manifold is going to be even harder.
All the major parts I have came from a 1.6 parts car with the exception of the manifold and small parts. The turbo is a eBay T3 with a 3” V-band flange welded to the turbine housing, and the 3” downpipe I got from the other car as well. I’m sure I will have to modify the downpipe to fit properly but with the TiAl F38 underneath the turbo it already almost makes contact with the downpipe, so I wouldn’t be able to snake the downpipe around the shelf like ive seen some people do. I’m just gonna chop the shelf when I take out the header and when I swap in the VVT engine I’ll have that stuff welded up.
Originally Posted by crash12190
I think you can message Kraken and buy them by themselves. It is a very nice piece, fitment is fantastic!
You can for sure, it’s $100 for that elbow. It’s a no-brainer if you’re running a Garrett turbo
Here's the "best" pic I could find (and it's not very good). What you can see is the shelf cut leading into the FW with the steering shaft showing above and slightly to the left of the lower vband. This is before everything was tightened up, but you can tell that there is already not much clearance between the vband and the steering shaft (it's better when things are tightened up, but not by much). You can't see the actual cut parallel to the FW because the brake proportioning valve is in the way. Hope this helps a little.
PS - I didn't put any new metal back around the steering shaft. All of this was done with the engine in-car and there's ZERO clearance. The next time that the engine is out (which, hopefully will be years from now) I'll fix that.
Not quite. The upper part of the shelf, yes. The lower part was sliced into "fingers" and massaged back to the wall. I couldn't reach it well enough with the Sawzall.
I made the cut & added metal back in. The steering shaft "boot" from the inside firewall closes up the hole fine. The metal I added back in is cut almost exactly to the shape (for the steering column) of the metal behind it. It was relatively thick 1/8" (11 Gauge) if memory serves me. I think you could get by without adding the metal back in. That said...the Miata is a wet noodle before cutting metal out of it & you are adding ponies, so my vote is to reinforce.
metal welded back in...before paint etc.
Steering column views:
You can find more details & pics on doing this cutout on any of the LS & LFX swap build threads, we all had to do it. (mine included)
What turbo do you have OP? MKTurbo, Kraken, TSE manifolds all need the rear shelf bent down for DP clearance with 3" down pipes. So a Begi/FM manifold is going to be even harder.
You dont need to cut anything with the kraken setup
So the next question, for those of you that had to cut the shelf to fit the DP and still using the miata engine. What was your solution for the heater core hoses? How did you route them to get them out of the way, did you source hoses from another vehicle and modify it to make it work or modify the stock hoses?
I had -10AN fittings brazed to the inlets to the heater core, and the WP inlet. I'm running a reroute, so there's another -10 fitting on the adapter. Then I've got hoses running from the adapter, to the core, and back to the WP. The line from the core to the WP (that's closest to the DP) is covered with a "sacrificial" fire sleeve that gets replaced when it starts getting toasted. Here's a not so good pic of the -AN lines during the last re-assembly.
The line that goes to the reroute adapter loops up through a gap in the brake lines that run along the FW, and the brake lines are protected by a piece of rubber tie-wrapped to the AN line.
12-28-2020, 12:20 AM
Rear shelf modification for 3” downpipe
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