My intercooler and radiator cores arrived yesterday. I got an amazing deal on these cores from CSF, although I personally believe PWR make the best heat exchangers money can buy.

//i.imgur.com/nn7lDqY.jpg?1

The intercooler core is rated to 850hp and I am still trying to decide whether I should trim down the height of the radiator core a little before I weld on the end tanks.

//i.imgur.com/yEFywH5.jpg?1

I have a reasonable amount of space in front of the engine to fit both heat exchangers. They are most likely going to be stacked together and fully ducted with the air venting out the hood.

//i.imgur.com/u0Ws4Pg.jpg?1

So I am just playing with the angle at the moment before I make some kind of support to hold them in place.

My turbo is currently in transit from Full Race Motorsport in Arizona. I have to give a big thanks to Geoff from Full Race and Micah (Homemade WRX) for helping me choose which turbo to get.

My turbo has arrived!

It took me a long time to come to a decision on which turbo to get, it was either going to be Garrett or Borg Warner. Obviously both great options but in the end the EFR series from Borg Warner won me over.

I've always been a fan of twin scroll housings and Garrett don't seem to be offering this on their newer G series turbos, they really do help to get a larger turbo making boost sooner.

I was also attracted to the aluminium housing option that is only available with BW EFR for the weight savings and better thermal properties.

EFR has a significantly lighter weight turbine wheel for better spool and transient response and a properly designed internal wastegate system for simplicity and better packaging.

The IWG is not always perfect though and it will limit my top end power to some degree. Full Race Motorsport have just released a kit for the internally gated EFR that uses a Civic Type R electronic IWG actuator for ultimate boost control, so I have purchased this kit to prevent any potential issues.

Ooooohhh sexy

That is awesome. The IWG control should be amazingly good with that kit. I look forward to hearing how it runs.

Yes it's a great idea! this kit was developed and run on the car that just won Pikes Peak unlimited class.

I've spent a lot of time going back and forth with turbo position this week.
My original intention was to low-mount it just behind the shock and run the dump pipe inside the cockpit just in front of the pedal box behind a steel box enclosure then out the side.

This turbo is much larger than I thought so it does not fit in that position. I then tried to high-mount it and I did manage to make it fit but it goes against everything I've been trying to achieve with this build. The main goal is to move all the weight as low as possible and toward the center of the car.

The only remedy is to move the shocks. It will be a lot of extra work and I will have to cut off the shock mounts that I have already spent a considerable amount of time making.

This photo shows the rough position of the turbo and also the rough position the shocks will be moved to.

//i.imgur.com/BNhiW14.jpg?1

You can see the weight is low and back, the tradeoff is the shocks are now mounted higher up but they are also further back which is good. The shocks weigh 2.6kg (5.7lbs) each and the turbo weighs only 11.15kg (24.6lbs) with its aluminium core so there is benefit to mounting the turbo lower than the shocks. Generally speaking a low-mount turbo is also better for heat management.

This new shock arrangement should also allow me to mount the front swaybar behind the engine.

I have been waiting on some things to arrive before I could settle on a final mounting position for the turbo as there are potential clearance issues with the steering intermediate shaft. I bought a complete steering column from a wrecked 86 and I will be running a motorsport sytle collapsible column from the EPAS unit up to the steering wheel which is moved a long way back from the stock position.

I have already trimmed all the unnecessary bits of the EPAS.

//i.imgur.com/EUpK9fT.jpg?1

The other consideration is the turbo manifold which I am going to try build myself. I ordered a really nice 347ss DIY manifold kit from Hypertune which also includes a beautifully made T4 twin scroll cast collector to suit the IWG turbo. The collector is a critical part and sees the most extreme conditions so buying one like this seems the best way to go.

//i.imgur.com/2UEQ6C8.jpg?1

Since Hypertune don't support Honda engines the kit is actually for a Evo but I can grab any extra bends I need from them if required, they are not too far from my house. I also had to grab a head flange from Mazworx for this reason, its CNC ported already so the holes go from oval to round.

//i.imgur.com/pgHssS4.jpg?1

I don't have a lot of time to work on the car right now as we just had a baby girl but I'm collecting all the parts for when I do get more time.

I've finished moving the inboard suspension. The shocks have been moved from the original position to make space for low-mounting the turbo. Many new positions were trialed before settling on this final position.

This is where the shocks will sit now

//i.imgur.com/lP5qljw.jpg?1

You can clearly see the space that is now open for the turbo

//i.imgur.com/0P1otwT.jpg?1

I was able to use the knowledge gained from the original design to make this a relatively quick process. I went through the whole process again that was previously described in this thread to build a mock up shock and measure the wheel travel versus shock travel and calculate the rising rate of the suspension.

This video shows the new design in action

https://www.instagram.com/p/CUHmYInP..._web_copy_link

The original shock mounts were cut off once I was happy the new design would work.

//i.imgur.com/48jmNeE.jpg?1

//i.imgur.com/Xi1JifS.jpg?1

Now I have been able to properly low-mount the turbo with plenty of clearance to make my turbo manifold and no more issues with the steering intermediate shaft being in the way.

//i.imgur.com/RP9jY9R.jpg?1

//i.imgur.com/UZeF0t5.jpg?1

I am both excited and nervous to make my very first turbo exhaust manifold now.

Awesome, great work on the suspension layout. Very cool to see the system in motion.

For those not on Instagram here is a sneak peek of the turbo exhaust manifold fabrication.

More progress on the manifold, finished making the runners and tacked it all together for test fitting on the car.

It's been a challenge for sure but I'm very happy with the progress so far!

Still loving the build. Looking to snag a BRZ of my own now.

edit: nevermind. Looks like you have the cylinder pairing correct. I just got a little cross-eyed.

FYI, I bought one of those EPAS controllers from eBay and so far it works as advertised. I haven't done any hard driving with it yet but I don't think that should be an issue.

I have seen and heard lots of issues with the IWGs on the EFRs not working correctly even when properly configured with BW not being able to provide any meaningful support or resolution.

Thank you very much for letting me know, much appreciated.

It looks like I will be getting a Haltech Nexus for this car so I think I should be able to drive the EPAS with that but otherwise its great to have options.

Same here, I think they can be resolved with the Turbosmart actuator but this electronic actuator I'm using should work perfectly.

Go in the borgwarner thread on here. The issue I am talking about is when using the upgraded actuator.

I know that the brackets had a deflection issue and that with pneumatic gates, boost tapered off hard...like they couldn't hold.

What was the cause?

The electric actuator should be awesome on it, provided deflection is eliminated.

No idea why the wastegate arm was bending but I saw it noted by multiple folks with IWG BW kits and it was not solved by upgrading the IWG to a Turbosmart.

With the electronic WG it will be interesting to see if it's resolved. I imagine yes.

The turbo manifold is finished.

There are so many hours in this, such a small piece but so complex to fabricate. If I had my time again I may have just bought one but that is not in the spirit of this build.
Having never welded stainless steel before, this was probably not the best starting point and I was certainly outside my comfort zone. I have followed best practice throughout the fabrication, everything was back purged during welding, fit up was tight, some of my welds probably got a little hot but nothing too extreme. I am confident the manifold is going to hold up to many years of abuse even though it is never going to get featured on weldporn.

I've started on the exhaust system, its SuperGT inspired side exit.

..........

That manifold looks like a biotch to weld up, but as long as it holds, being pretty doesn't matter. Where is the side exit coming out? Nice progress!

It has to exit past the hallway point of the wheelbase under the rules. I'm toying with the idea of a titanium muffler. It will need a muffler of some sort just so I can run at all the tracks without breaking noise limits.

A video showing the exhaust. I will be adding more to it later, I just needed this bit done so I can start on the steering.

https://www.instagram.com/reel/CVmGa...dium=copy_link

new photo

I have been a bit slack with the forum updates, sorry about that. Lots has been happening, I'm mostly working on the cooling system.

I started by trying to make my own radiator but that didn't go so well. The fabrication part was fine, I cut the core down to size and made some end tanks but when the time came to weld the end tanks to the core I had a lot of difficulty with the very thin and hard to clean aluminium.



So I took the easy way out and bought a radiator, its actually for a Mk4 Golf but the size was perfect for my needs and its a dual pass with inlets/outlets on one side like I need, although I will weld on some AN fittings.

I also ordered in all the bits required to build my header tank, swirl pot and connections for the electric water pump. Plus all the intercooler piping.



Next I got to work on mounting the heat exchangers in the car, I played with this a lot as like everything there are compromises to be made and things fighting to fit in the space available.
I ended up settling on a 45 degree angle for the heat exchangers, this should give both inlet and outlet ducting a reasonably smooth airflow with minimal change in angle.

Once the position was finalised I started making the end tanks for the intercooler core. I'm running HD clamps on everything too.



That brings me to the work I'm doing right now, I've fabricated a frame that will slightly space the intercooler off the radiator and also form a seal so all the air is forced to pass through both coolers. The frame has a mix of rubber seals and foam tape to prevent any air escaping. The radiator is riding on rubber mounts that are bolted to the intercooler. I will then run some tube out to bolt to the intercooler and support everything in place.