This was my big splurge, I bought a Borg Warner efr 7670. I plan on keeping the external wastegate so got the divided t4 flange, there is no ewg t3 housing option (that I could find anywhere).
Initial test fit with a junk 531 head while the good head was at the shop. I had Full Race ceramic coat the exhaust housing, and requested silver ceramic on the compressor cover. When I got it I realized they had accidentally ceramic coated the CHRA instead of the cover. I called them up and they were really good about it and ended up refunding me the cost I paid for the cover coating, so I ended up with a coated CHRA for free which was a nice bonus.
Compared to the HX35 the efr is 8lbs lighter overall.
I also planned on keeping my blow off valve/IC piping so I bought an sxe style compressor cover (this is the cover they forgot to coat). The first cover they sent was the Friday afternoon special, it had some sloppy clean up work and the 1/8" pipe thread for the wastegate reference wasn't even close to on center. I went back to Full Race again and they were, again, really helpful and their borg rep ended up sending me another cover at no cost. This one was much more acceptable for the cost.
Since I had to buy a t4 housing, and I was way to tapped out to build a new header, I had to get over my hang ups and buy an adapter plate. Now that I've put it on and run it I think it works fine, not ideal but fully functional. I do have a devil on my shoulder whispering about a new t4 header with dual wastegates and a cnc collector and I'm weak to temptations. (the devil's name is Tate).
I ended up porting it out a bit for best fit.
the efr is up and forward a bit compared to the Holset, and also needs a different flange. Making the new downpipe was relatively straightforward, I added a band on the rise of the 90 for the height and just added a new leg on the run with the efr flange. I did all of that in the car and tacked it into place, then put it all on the bench to do the wastegate tube. The bellows had cracked last year.
We did the fitting and tacking then brought it to a friend of ours to weld. Everything looked great when it came back.
Then I put it on and started banging my head against the side of the car, it wasn't even close. The guy is a good welder, and nothing moves that much from heat, so I can only figure that I neglected to fully tighten the v-band clamp where the exhaust meets the down pipe, so everything pulled back when that was all fully clamped down.
I didn't want to waste the flange, and was low on pipe, so I made a small section at the rear to push it forward. I was pretty embarrassed to go back to the welder and ask him to do it again, glad it was at $0/hr!
Next I had to think about fluid plumbing. Obviously I needed to add water cooling which I was not set up for. I thought about routing and originally planned to feed from the coolant bottle line and return to the water pump, as stock. I was looking at tapping into the overflow hose and welding a hard pipe with a fitting to the pump inlet. I didn't like the plumbing on the overflow side, and it also offered no pressure for water flow. On the water pump side I decided I didn't want to make it a one off part. So I changed my mind and decided to feed from the NPT petcock fitting on the side of the block near #4 for positive flow. For the return I put the fitting onto the heater core return pipe, so the pump could be stock.
return pipe tacked up with an extension and a -6 male fitting.
finish welded (this one fit after welding..)
the feed line is a -6 fitting in the block with a 90* hose end (obscured), it follows the heater pipe then crosses over with the oil cooler lines and runs up the frame rail. Between that hose and the routing of my new oil drain line the filter is trapped, I'll have to pull 3 hoses to replace it. I change the oil once a year and they are all an fittings so it's not a huge deal, but I'll probably end up doing a remote filter now.
here's a shot of the water return line line in place, and the oil feed line run. All of the hose and ends are -6 aeroquip startlite, it's considerably nicer than the Summit stuff.
all plumbed up and ready to party
downpipe installed finally. I was glad to gain an air gap on my spark plug wires, I was constantly rotating the roached boots before.
At this point it was just a matter of reassembly. The whole thing was such a big push because I really wanted to get it out for the annual eEuroparts car show at Lime Rock on June 8th. I was able to get the engine back together the Tuesday before for first start. After 7 months and a lot of changes I was pretty anxious about it. We primed the oil system gave it fuel and it fired right up. Ran it fast for a minute or two to run things in then it fell into a nice idle. The new valve train sounds much better than the old one (lash is at .016" btw).
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Everything proved out fine. I did get a huge oil leak at the flange of the stock pcv box which I could not get to seal, so I threw on a Yoshi breather plate that I had around and made a new hose for the catch can. I got the rest of the car together, did some quick tuning on Friday and made the 1hr drive out to Lime Rock on Saturday. It ran great on the drive down, and sat and collected pollen in the car show all day. I ended up winning best modified Volvo (basically beating a bunch of fwd cars), it's fun to get to take the car to a winner circle.
I took a bunch of pictures when I got home from the show:
needs rear wheel spacers, bro!
I'm trying to decide where I want to put the inlet to the air filter, looking at places to put a duct up in the front then run brake cooling hose to the airbox.
random note, I replaced all of the cheap t-bolt hose clamps in the car with stainless ABA band clamps and I like them much better.
I'm really happy with the interior, loving the change.
when I was bored I also put in a Stack pro control fuel pressure gauge in my open lower gauge slot. I think I'm going to slowly replace all of the other gauges with the same, I like the classic look of the stock VDO's but I don't find them very easy to read; that oil temp gauge especially.
driving impressions: I've only run ~18psi up to this point since I haven't gotten a chance to drive and tune much. Seat of the pants is confirmed by MAP lines that the efr actually builds positive pressure a little after the holset (huge hot side), but responds much quicker and hits peak boost ~150rpm earlier. In real driving it outperforms the holset in every way. It's making more power at lower boost, and transient response on the twisty roads is completely different. It feels so quick at this boost it's going to tear at 25psi. I also think I'm seeing real benefits from the head work. The engine is pulling more vacuum, feels smoother all around, loves to rev. I need to make a few changes to really make the most of these upgrades, but I'm already happy with the results. Really fun to drive and I can't stop digging into it in 2nd and 3rd every chance I get, smile every time!
The steering rack and pump need to be rebuilt. I'll take care of that, do the trailing arms, and otherwise hope to just drive and enjoy it until the snow flies again.
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