long story short, it works but its not going to work.
with having the stock sump cut out once you accelerate the fuel all goes to the back of tank where it cant get sucked up by the fuel sock. If you have a hydramat the SIZE OF THE TANK it will work but the cost of these hydramats just jumped from 250 to 600 and not too far from that price is surge tank territory, so this is a bust. I had to put to the unmolested tank back in and clean up the sending unit (fix another leak). The other issue is that this inlet and stack up of fittings and hoses + the size of the pump doesn't work out to well because this makes the whole system too tall and causes the inlet on the hydramat to be squished to the tank floor so it doesn't do a good job of sucking up volume of fuel because its inlet is jammed to the bottom.
so all in all like most things I do, it was countless hours wasted and money down the drain just to end up exactly where I started from, well berkeley me I guess for having an idea.
oh and quick update on the brake caliper adapter, it is a failure. I need to do too many custom things and brackets and spacers and its just going not going to work out so that idea is scrapped, moving towards a wilwood lug brake if possible.
on the otherhand, some things do work!
Inconel 625 exhaust manifold time!
and Central UP Rally was a blast! a sloppy awesome blast! Lots of new exhaust leaks and dents so this will be a much needed change.
In reply to fidelity101 (Forum Supporter) :
berkeley yes!
Wait, isn't inconel the stuff that is damn near impossible to melt? Like rocket nozzle stuff?
Were you MELTING exhaust manifolds? If so, you are my new hero.
In reply to Dusterbd13-michael (Forum Supporter) :
this is specifically inconel625. (BIIIG THANK YOU TO NONACK! for the modeling help)
This is rocket/F1 car tech type material a super alloy that can withstand 1000C of extended duration, we also can do inconel 718 which is better, (lighter, stronger, better heat/corrosion resistance) but costs more and we don't do much 718 at work, 625 does the trick for our applications that need the properties of inconel. I think this design as is will be plenty capable in 316L, (which would cost a hell of a lot less) there is room to optimize this further by cutting the weight down but I don't know enough about the science behind and simulation software to figure that out, I may be able to one day through work but that may be a while.
I was not melting exhaust manifolds but I was using mild steel header and its been rusting away and flaking, even with the wrapping it just heat soaks everywhere, the trans, floor/body and especially the intake manifold. I have seen it cherry red though before from some dyno events lol. The floor and inside cabin area has bedliner throughout for protection, it has melted this before on numerous occasions by the co-driver footwell where the exhaust runs near.
this is straight out of star wars! lol
Next steps? polish the ID and then take vehicle to my friend for custom exhaust, the whole thing goes in the garbage but the muffler and we start from scratch. The plan will be re-do some of the underbody and this way the exhaust will be thicker walled (and jethot ceramic coated) and can be placed in-between the underbody protection and the chassis itself.
I was following until the last sentence about the exhaust being between the underbody protection and the floor.
what is the underbody protection made of? Seems like sandwiching it like that would just trap the heat and cause the same issue of hot floorboards. OR melted underbody protection.
Also, the 3D printed inconel is bad ass!
Yeah, the exhaust heat needs to be freed!
Hell even with no panels to lock the heat in place, I can feel the transmission shift stiffer/worse from exhaust heat, and the fuel pump doesn't like it much either.
thats why the outside will get ceramic coated, cut down on the radiant heat that would usually just soak the cabin.
underbody is made of HDPE it takes quite a lot to melt it (mapp gas test)
none of the pro's have exposed exhausts:
this would be the goal.
None of the pros are running a naturally aspirated rotary either 
Seriously the EGTs on a modern race engine, especially a restrictor motor, are really low... I have heard of some as low as 800F!! They can't get more air in so they work to minimize how much heat gets thrown away.
There is probably a wind tunnel effect also, where the radiator exhaust gets blown down the middle of the car.
Ceramic mostly looks good. Ceramic coated headers glow red and orange just like uncoated.
There already is a lot of shrouding and underbody I'm just tired of the exhaust dragging on everything but then again its a rally car, and exhausts get beat the E36 M3 up. even if its higher up and doesn't get covered it will be an improvement.
I was thinking along the lines of this:
https://www.jet-hot.com/offroad/
local car cafe had a dyno day over the weekend, not bad for no changes and constant weld repair on the crushed exhaust.
2 years ago we made 190-200whp. (page 10?) no changes to tune or setup. Similar temp/humidity too
things are happening!
So right now the first 12" are sch40 piping so its a true 2" ID, the inconel outlet flanges taper gradually to this size for a perfect flush fit. the rest of the tubing will be done with 1.875" 16 gauge, my overall runner length is now 1 foot shorter but I have also now made it equal runners.
oh yes, things are coming together nicely! 
EDIT: only the flange is inconel, im not totally made of money. these are sch40 304ss piping from mcmastercarr.
more weld porn:
I wish I could say I did this but Its good to know people who can do this since I can't.
Exhaust goes from SCH40 (true 2" ID) to 1.875" ID 16 gauge wall tubing where it will collect with a Y into a slip fitting that is 2.5" for the remainder of the exhaust to re-use the muffler.
Very cool. I had no idea you could weld inconel to stainless. What's the rod being used?
Very cool. It looks like we had similar ideas in mind for ideal exhaust manifold geometry.
Except mine is combination of 304 and 321 SS with .062" wall. I work in the gas turbine industry where IN625 is somewhat common but not generally used in HP applications. IN718 is more common in structural components away from the flowpath where temperatures are 2000-3000F. That's where the fun ceramic-coated, single crystal nickel alloys come into play.
In reply to infernosg :
Was it okay with having the O2 sensors so far back? Mine are about 2' from the port and it eats them like candy, but i recently learned that some of that has been due to the timing on when the O2 sensors are supposed to turn on AFTER the moisture from the cold start is gone that had been frying my sensors in the past. So now I'm not exactly sure where I will put them yet.
Right now I'm balancing the underbody protection coverage, avoid boiling the trans fluid, a future floor drop, and equal length for each wall thickness section. Overall I'm going from 5' primaries unequal length to 4' primaries equal.
IN718 is 3x the price for parts for me so it was out of the question, we rarely do that material, that stuff is truly a rocket science super alloy. If you work in the turbine industry, PM me if you need stuff 3d printed for work we do a lot of furnace material parts with IN625, id be happy to help you out if you needed a contact.
I'm curious on how the sound and tune will change once this is done... I think it will be a power loss on this engine as the intake is the restrictive part and the exhaust ID just got larger in some areas...
next engine should be a 10krpm screamer though :)
In reply to fidelity101 (Forum Supporter) :
I've been running them just forward of the collector now for 3-ish years and I think I'm on my setup set of sensors. The heater circuit burned out on my first set but that was with the older manifold on the bottom in the picture above so they were actually a little closer. But in that manifold the sensors were pointed downward so that may have contributed. I'm at ~1.5 yrs with the current setup. I've also heard about the cold start thing. I think I read the heaters turn on with ignition so if you sit there with the ignition on but the car not running they heat up, but when you start the car the initial blast of condensation can cause thermal shock, which kills the sensors.
I've gone the opposite as you. I went from ~4 ft primaries to ~5 ft. I saw a pretty good bump in power with the new manifold but that was also combined with a new intake setup so I'm not sure how much it's actually worth. It's a much better design though. The straight section in the middle was originally supposed to have slip fittings so I could add/remove pipe to lengthen/shorten primary length but in the end the added cost wasn't worth the possible extra HP.
mke
HalfDork
9/26/20 6:49 a.m.
fidelity101 (Forum Supporter) said:
So right now the first 12" are sch40 piping so its a true 2" ID, the inconel outlet flanges taper gradually to this size for a perfect flush fit. the rest of the tubing will be done with 1.875" 16 gauge, my overall runner length is now 1 foot shorter but I have also now made it equal runners.
As I scrolled through the pic I thought I was seeing things thinking to myself "wow, that tubing look really thick, must be something with the way he took the pic..." or it IS really thick! That will teach it cracking is not allowed! :)
What were you running muffler wise for your old exhaust?
BTW, I am cringing inside when i see the header wrapping under the trans. I mean, yeah, space is tight if you want reasonably long primary lengths, and my prejudice is for expecting the transmission to be replaced more often than the oil filter...
infernosg said:
In reply to fidelity101 (Forum Supporter) :
I think I read the heaters turn on with ignition so if you sit there with the ignition on but the car not running they heat up, but when you start the car the initial blast of condensation can cause thermal shock, which kills the sensors.
I've gone the opposite as you. I went from ~4 ft primaries to ~5 ft. I saw a pretty good bump in power with the new manifold but that was also combined with a new intake setup so I'm not sure how much it's actually worth. It's a much better design though. The straight section in the middle was originally supposed to have slip fittings so I could add/remove pipe to lengthen/shorten primary length but in the end the added cost wasn't worth the possible extra HP.
That is exactly my issue.
I'll be curious on re-tuning with keeping the intake the same and see how the power changes. I may print an adapter to bolt to my lower intake manifold to use an EFI throttle body that utilizes a carb IDA/IDF/DCO footprint to prep for the next engine (semi PP). something like this but I may turn it on its side like a side draft instead of a downdraft:
this would better suit the engine characteristics with a shorter intake and a more flowing engine.
I need to figure out what length I want to make the adapter though so I can balance it with the exhaust manifold that will already be done. This part is unknown to me and books I have on rotary tuning don't go into detail on this and any motorsport calculator doesn't translate well because there are no pistons or cams! I may need a lot of homework to figure out how to translate it all so I can half ass design something instead of just wingin it (like I always seem to do).
Pete:
I'm still running the rotary shaped muffler from racing beat, the 2.5" ID version. It has been on the car since about 2011 and boy does it have some DENTS! I will be re-using the muffler and cat for this project, better baseline and I'm cheap - this muffler still works fine!
My old intake setup sounds like what you're planning. I had one of the older EFI Hardware 55 mm IDA-style throttle bodies in a custom wrap-around manifold. It certainly looked neat but ended up causing a whole host of issues:
The first was the TPS and throttle body now wanted to occupy the same space as the alternator. That was solved by a side-mounted alternator. The second issue was the rear secondary intake runner was like 1/16" from the rear exhaust primary. As a result, both the intake manifold and exhaust manifold got ceramic coating. Lastly, in this arrangement the car fell on its face at ~7000 RPM. No matter what we did it peaked at ~190 whp at 7000 RPM then fell off a cliff. Last year I switched to a down-draft style and got one of EFI's newer 55-52-50 tapered billet throttle bodies:
With this intake setup and the new exhaust the car pulls all the way to ~8200 RPM and makes a ton more power (different dyno - take it for what it's worth). It still kind of falls on its face after peak HP but I'm thinking that's a tune issue. The only thing I don't like is my current intake manifold is meant for an IDA carb so the rear runners are longer. Designed to keep the carb vertical. I think this is partially why my rear rotor runs leaner than the front.
In reply to fidelity101 (Forum Supporter) :
No presilencer, just rotor muffler and cat? Wild!
In reply to infernosg :
What porting is that engine? 190whp at 7000 is nothing to sneeze at! Did you ever try running it without the individual air filters
