My Major Project PrtII - Single turbo Conversion

[leeroy_25]

Don\'t worry Mitch.. I picked up the mainfold dirt cheap and have my own TIG welder to do the fabrication myself. It was by far the cheapest and most sensible option to go.. It would cost a few quid just to get the flanges machined not to mention getting mandrel bent pipes.. I know this as I aslo made my own down pipe which I\'ll do a post on later.
I considered doing the job lot but cost didn\'t work vs modifying what I had and jigging it when I was working with a very small amount of room to play with would have been next to impossible!

Would be interested to hear what your manifold costs none the less.

I\'ll post some pictures later!

Lee

[BlitzBoy]

With the compressor hosuing on this fouled the water pipe that feeds the heater system and also the chassis rail.
!

yip this is a common problem, we rerouted my water pipe and replaced the metal water pipe with flexiable hosing. A lot of single turbo conversions done have had to reroute the water pipe.

[leeroy_25]

Right.. So big decision made I had to be very sure before I put a saw close to my trusty Trust that I was ging to be able to jig it correctly for welding back up. Ideally I would have cut the manifold and somehow jigged it in siture but clearly that posed many practical problems like to room to do anything around the turbo once it was in position.. My only option was to take a damn good guess at where the manifold and turbo needed to be. So I got my better half to take a pic of me holding the unit where I thought it was going to fit.


So looking at the picture I decided I need to get the manifold to sweep around about 35-40mm and move out about 10mm!
I tried to mock this up with spacers but could not get enough sweep on the manifold in this way.. But at least it gave me an idea.
In the end there was nothing for it but to go for for it!
So I got my saw out and about and hour later and a seriously aching arm the manifold was almost in two parts!
At this point I decided I would leave the flange just attached and bend it around at the angle I wanted to sweep the flange to and try the spacer method again.
Unfortnuately this was a busy day so no pics.. but Once I had test fitted with various spacers I had a sweep angle and found I needed about 20mm of packing to get the turbo on.
Next I had to sort a Jig to hold it all before I cut it completely and lost my positioning.
So I found a good hardwood base and some gash bits of steel and voila!



Jig sorted! Note the spacers under the main flange..

Now with all positions held I was safe to cut the flange completely away!





Now take the spacers out and bolt the flange direct to the base board.



So now I could see the gap that need filling!
I had already measured up the OD and ID of the pipe and accertained that firstly it was not round! And secondly it was not close to a stock tube size. So again I would have to make the joining section up from a cut and shut piece of oversize tube! I was going to be using a thinner wall section so I made sure to keep the Internal shape and diameter matched up nicely to avoid any flow disruptions for the exiting exhaust gases.
After some light tickling I had formed my tube sections and tacked these into place for the initial fit.





After a quick fit up on the engine I found that although very close the compressor housing was just clashing with the LIM so I would need to space it out a bit more! There was not exatly acres of room on the chassis side either! Back to the drawing board! I cut another section about 8mm long of straight tubing removed the flange and tacked this in place.


Aftera test fit on this it looked very promising! Compressor cleared and so did the turbo on the chassis side!
So time to weld it up properly.. Please bare in mind am only just starting out with the TIG welding!




Now bearig in mind the original tubing was at least 2mm thick and I was on 1.6mm thick I thought it would be wise to reinforce the new section with a little gusset. So I added this in too:



Now I just need to get inside the tubes and grind off any nasty bits on the inside to keep it nice and smooth..


Now time to test fit again!..


The bloody thing had moved! Well when I say moved I guess that welding the gusset in had pulled the tubes around slightly. Just enough to have the compressor touching the LIM by a fag paper! It had fitted perfect before I put the gussets in. Very annoying!
So I decided I would scollop a small area out of the LIM to overcome this and also mean I would not have to move the turbo any closer to the chassis rail. I litterally only had to hand file about 2mm in depth and it was clear. As a additional bit of spacing I decided to run two gaskets when final fitting the manifold. Sorted!
Next mod for the manifold was the wastegate fitting. I had a 45mm gate to run and it wouldn\'t fit in the current position as it was to close to the engine mounting. I would leave completion of tis until the downpipe was in place to make sure I had no further fitting restraints.

Lastly while the welder was barked up I made a drain/return pipe for the turbo and for the fitting at te front of the block.

[m1tch]

This is why I want to learn how to weld lol

[gander]

nice work. im so glad you only live round the corner. brain picking time

[Laurenzo]

Oi! Gander about time you bought a"real" car :rollin
 

nice work. im so glad you only live round the corner. brain picking time

[gander]

Oi! Gander about time you bought a"real" car :rollin

i haven\'t bought a shoe box just doing a rotary conversion in my new crazy build :chat
 
lee what wastegate you going to be using?

[leeroy_25]

Hey there Gander! Nice of you to join us! You definately need to get researching! We will have a chat soon..
Mate the RX7 is one of the nicest looking cars ever! But then it\'s always nice to be different too.. So convert away!

Keep reading the thread and you will see what goes on shortly!

[leeroy_25]

Right so been a few days since my last post as I have been a bit busy.. And I managed to blow the alternator on the Rx7 which is another story!

To finish off the manifold I had to finally modify the external wastegate section to fit my wastegate.. So I did a bit of measuring up and pieced it together bit by bit spotting it on and test fitting as I went!





Then it was time to bolt the manifold on to the engine properly!



And bolt the turbo on so I could start measuring up for the downpipe!



Right lets make a downpipe!
Again this was a bit by bit job tacking parts in as I went. So a lot of on and off of the turbo and crawling under the car welding in very akward positions. Unfortunately for me I was stuck doing this on a driveway with the car on a jack and a couple of blocks! Great fun!!
First of all was weld the initial bend to the flange on the turbo:


Next I tacked in a reducer and a straight section going down towards the floor:



After that I lined up the mid pipe section and the bend to run under the car and tacked this in also:


From here I had to bolt the flange onto the midpipe and then cut a piece of straight pipe to fill the gap and tacked this to the flange and the main downpipe section to give this:




Now I could carefuly start welding it up properly taking care not to distort anything!



So I just slowly worked my way along the joints welding opposite side 1" at a time to avoid getting too much heat into one area and having the pipework ll around.



Lastly I drilled out a position for the exhaust gas sensor and welded that in.



So While I was waiting for that to cool down. I needed to make a small mod to the midpipe to put the Exhaust temp sensor in. I wasn\'t sure if I needed to have it but thought I may as well while I was under the car so I made up a little flange and tube section for it and drilled a small hole in the mid pipe and welded it al up!



Oh and I made a little screamer pipe for my Wastegate!!



Finally I test fitted the final assembly!


I bolted up the wastegate to check all was okay as well:


All looked pretty good.. The only thing I would say is I think the downpipe sits a little low and will scrape bumps to easy so in due coarse I may mod this.

Final thing to do to the manifold was give it a bit of heat wrap.. As much as anything as to protect cables and gaiters nearby in the engine bay.


Jobs a gooden! ready to be fitted!

[Rx_sam]

daaamn ! nice work !

[karl_tate]

done a great job on that bud :yes

what is left to do??

[leeroy_25]

This thread is being done restrospectively.. I finished just before Christmas..Car is running! and this thread is getting close to you all seeing the \'finished\' product! Are these sorts of projects/cars ever finished?!

Keep coming back!

[ronaldlo]

i love i can do all the work too...so cool bud...very great job A+

[MaLicE]

doing an amazing job! wish i had access to some of the equipment you do!

one thing i thought i would say, your exhaust gas temp probe should be up on the mani... really in the collector just before the turbo... otherwise there will be a pretty huge heat difference to where you need the readings from to where you have it mate... at the least it should be right after the turbo on the elbow/downpipe... thats where you need to read from so you can see when the engine is running to hot and warning for det etc...

[jackaleks]

so cool to see someone doing all their own fab\' work. wish i had those skills!