Dommo

Hello,

I don't own a Subaru, though I almost bought a Forester in 2014 if that helps. I joined to find answers to my questions on the vast array of turbos that Subaru have used over the years and so probably don't have a lot to offer back to this forum. As we're all car enthusiasts here I thought maybe one or two would be interested in my track car. If anyone here does track days with Motorsport Events I've probably inadvertently met some of you!

Back in 2008 or 2009 I sold my BMW 328i and bought a Nissan 200sx with the allure of cheap turbo power upgrades, or at least relatively cheap compared to trying to extract meaningful power from the 328. The problem I had with the 200sx was that it would cost thousands to make it handle as well as the BMW (I'd concentrated on suspension with that car), and the 200 wasn't worth it. You'll see a problem I have is that I logically decide a project isn't worth doing on cost and so man math myself into a more expensive project. I excelled myself with what I did next.

I sold the 200sx and picked up this:



and turned it into this:



and then took one of these:



and...



until almost car-like:


convert more money into things:



and...









Then the nice man from VOSA say yes:


The not so nice man from DVLA however took a very long time to register the car properly.

So, I had a Westfield with 1.8 MX5 engine and running gear, complete with pretty much bang on standard power



It soon became apparent that this wasn't enough (when is it ever?). Track days were fun but did rely on the person you were passing properly getting off the power on the straights. These Westfields aren't exactly aerodynamic and so whilst the light weight helps, when you're up to speed it counts for nothing.

Something had to be done, so I built a new engine from a Mk2.5 bottom end (higher compression) and a Mk2 head (the mk2.5 had VVT and the solenoid doesn't fit under the bonnet). Also added a set of motorbike throttle bodies for the noise.



This netted me this power (at the wheels):



About 160-170 at the fly depending on which dyno I went to.

However, whilst I was building that engine I'd also spoken to someone who builds turbo manifolds and downpipes for MX5s just to see if something could fit in my engine bay. Things kind of snowballed and before I knew it someone in Slovakia had put this together from a bunch of measurements sent over the internet:



And it fits!

I picked up a good condition TD04L-13T as an unused upgrade from someone on the Forester forum and got to work:



All good stuff. After a stern argument with the circlip from hell I got the compressor housing rotated and everything came together. I had to move a few things but nothing major. I replaced the radiator with a RadTec unit that had an aluminium radiator with intercooler bolted in front of it. It is specially designed for Westfields and fills the nosecone nicely. Not a not of room for air to go around rather than through the radiator now!



Power exceeded expectations with 12psi producing the following (at the wheels):



Which will be around 260 at the fly.

I've run like this for nearly a year now and frankly it's ballistic. It's not as 'nice' as the throttle bodies, any engine note is drowned by the turbo and of course you don't get that lovely induction sound. Power delivery is a little too focused down the mid-range. It's great for leaving corners at low-ish rpms to save a gear change but you're not rewarded for revving it out.

I'm building a forged bottom end now so considering what turbo options will fix that.

Much more build details at mazdafield.wordpress.com if anyone is interested.

Dom

JTaylor

Brilliant write-up and great car. Well done, sir!

yabbadoo4

iTrader: (8)

great work there bud! love reading these write ups regardless of what car it is. please feel free to update the thread with any further changes.

bustaMOVEs

iTrader: (31)

Great build, look like a stuvuo turbo kit that, he still doing them?
IMO all you need is a gt2560r that will be a great finish point for your car IMO and not sure on management your using but mega squirt '3' would be advantageous if tracking all the time as they have really good safety features.
How much power do you want at end result? Or is it mid range you're after to keep it pulling all the way?
Do you wish to keep a Subaru fitment for easier install?
The td04s will blow out of puff very quickly, a vf34 BB turbo will see a gain continually to top end, or a vf35 is simlar but doesn't pull as hard at top end as a 34. Both spool will and will make 300+

Dommo

Yeah it's a Sturuvo kit! He's not doing them anymore, but his partner in crime is so still available. I just sent him a few photos of my engine bay with measurements photoshopped onto them and got a manifold and downpipe made from that. It's ridiculous it all fits really, especially the downpipe going around the chassis triangulation.

Looking at the dyno chart it shows that power is pretty flat from 5,750rpm onwards, and it's this I'd like to address really. Well, as well as bumping it all up a bit seeing as the forged bottom end will take it. I also want to be able to rev it to 7,600 to give me a bit more flexibility, and remove the 2nd gear change needed from the 60 sprint of course.

I think it's revving the engine to 7.6k and still making power is where the TD04 won't be happy. There's no definitive power goal, though if I was setting one I'd say 320bhp as that will see me at 500bhp/ton without having started stripping weight from the car. However, in the real world I know I'll be just as happy at the high 200s.

The pistons/rods/bearings should arrive this week then I've got next week off work so hopefully by mid April I should have the new engine in and get it mapped. I'll probably not have decided on a turbo by then so we'll see what the TD04 can give. Probably not a lot more than now! One other restriction I've not mentioned yet is the downpipe is 2.75" but reduces to 2" for the exhaust. It's a smidge undersized so it's booked in for the rest of the exhaust to be made 2.75" in May.

VF34/35 looking like good candidates, thanks. The VF35 also seems to pop up for sale quite regularly on this forum too. Always a bonus!

hodgy0_2

yes fantastic stuff

I so nearly bought an MX5 engine and running gear on ebay the other day to covert my 7 kit car

it makes so much sense - that engine is a corker

looks great byw

Dommo

Making progress on the forged bottom end now. This lot arrived last week:









Nothing too fancy. A set of Eagle H beam rods, ACL standard bearings and CP 9:1 pistons. I wanted to stay a bit higher in compression really and found some Wiseco 10.5:1 pistons but they required an overbore and were possibly a bit too high so settled on the CP 9:1 efforts. They were standard bore and my bores were well within tolerance so didn't see the need to spend on a rebore.

Got the pistons and rods assembled on Monday night:



and all fitted yesterday afternoon:



Just the mundane tasks now like refitting the oil pump, rear crank seal and all that. Whilst the engine is out I want to tidy the engine bay up too - get all the wires hidden out of the way and so forth. Three fairly major engine projects in 12 months has left it all a bit messy so now I'm not under any time pressure it's the ideal opportunity.

RS Grant

Great build, great thread, hope that the updates continue...


Cheers,
Grant

njkmrs

Yep very impressive ..
I do like to see someone with the skill to do a build correctly..
Well done fella.

boosted

Nice! I turboed a MK5 escort xr3i 130 (1800 zetec) with a subaru IHI turbo about 10 years ago, it made 204bhp at 12 psi.
Did you hone (or de-glaze should I say) your bores for the new pistons and rings?

Dommo

Yes all honed - not sure why they look so shiny in the photos. Probably a combination of the flash and oil.

boosted

[QUOTE=Dommo;11818426]Yes all honed - not sure why they look so shiny in the photos. Probably a combination of the flash and oil.

yeah they do look very shiney in the first pic! Looks like you know what your doing though, can't beat a nice Matt bore to break in those rings

Dommo

Further progress made over the last week or so, but probably not as much as I should have. I'm sure it's only sunny because the Westfield has no engine in it.

I got the head back on (turbo is fitted because I didn't remove it):



Then I refitted the standard cam pulleys. I'd fitted the adjustable ones back when I had throttle bodies and was n/a tuning. However, with the turbo I can't see me messing about with cam timing so it wasn't worth having them on. The intake had slipped before and whilst everything was threadlocked now, I still didn't see much point in any risk.



I also picked up a VF28 turbo from this forum.



I'm not sure there's much point in comparing it to a TD04 on this forum! My aim for it though is for it to help shift the power higher up the rev range.

I removed the compressor housing and mocked up where it would have to be rotated to.



I think I might have to see what I can get away with shifting that actuator down a bit too as it's in danger of hitting the bonnet there.

When it came to removing the restrictor, I was thwarted.



I couldn't get a hacksaw in there. Unfortunately I killed my dremel when cutting the tub way back in the initial build. I think it ate too much orange fibreglass dust. I'll have to pick up another one.

I also came a cropper when refitting the sump, largely thanks to my carefree mixing and matching of Mazda parts.

The mk1 MX5 engine has a windage tray looking like this:



Nothing controversial about that. Just a thin plate that is sandwiched between the sump and the block. Notice how it doesn't stretch around the whole block just the sides of it. There's a cut out in the sump for these plates to sit into.

The Mk2.5 version looks like this:



It's thicker, goes all of the way around and bolts to the main bearing caps. It gets called a Main Bearing Support Plate as it helps provide rigidity. Note the dimples along the edges, presumably to provide strength. These are cast into the Mk2.5 sump, but not the Mk1 sump, leaving me with this problem:



It doesn't fit. The stupid thing is, I knew this as I'd checked it when I did the last engine build. I just forgot. I can't go back to the mk1 windage tray as I've had those cutouts milled out in preparation for this Mk2.5 one. I can't simply bolt on a Mk2.5 sump because it gets ridiculously close to the ground:



So I had a lowered and winged one made:



The guy doesn't want to make any more due to the time involved, so I'm stuck with it (no bad thing) and also stuck with having now modified it. I'll grind down the sticky out bits on the main bearing support plates rather than try and modify the sump to accommodate them. I don't think they'll have to be ground far.

Dommo

Good news - the restrictor is off the turbo!

Bad news - the standard intake tube wasn't within in:



Not much to attach the air filter to there...

I've ordered a new housing instead, which I probably should have done from the start and sold on the one with the restrictor fitted!

Back to good news - the main bearing support plate has been 'adjusted' and fitted - siliconed to the block and bolted to the main caps:



And the sump went happily on afterwards:



If the new turbo housing looks easy to fit with the engine fitted, I may refit the engine tomorrow.

alcazar

iTrader: (2)

Very interesting build, thanks.

Of course, you DO know that all our Scoobs will leave you in the twisties?

Steve T

iTrader: (14)

Great read. Steve.

elgassi

great thread, keep up the good work

johned

Magic keep it up.

Dommo

I'd hope they'd stop and pull me out of the hedge I've inevitably dropped it into

Right, lets top this up with the week's efforts. I popped the original compressor housing back on to protect the wheel from damage, or worse, cutting myself on it. I fitted the oil lines whilst the engine was on the stand and access was good.



Then refitted the engine. This was weird because it went straight in and slotted straight onto the gearbox. It usually takes me many attempts! I think it's because the car is level where as previously it's just been the front jacked up which makes things tricky.



The slightly bigger housing of the VF28 makes things a lot tighter with the catch tank. That could need moving, or the housing clocking over a bit more.



A bigger potential problem was the height at which it left the actuator:



This could well foul the bonnet! In my head I'd thought that all Subarus were created equal and I could reuse the TD04 actuator that had been modified to sit against the head rather than on the turbo. Yes... oops.

Given that this was a fairly important issue, I decided to refit the bonnet early and check. Thankfully, it fits. Just! I can push down on the bonnet and it will contact the actuator but I don't think it's naturally resting on it. I popped a camera down the gap at the back (as you do) but it doesn't show too much.



Could do with another photo taken whilst a torch is under there, or use a boroscope.

With that job done, I refitted the downpipe... and found the wastegate wouldn't open very far. It fouled on the downpipe flange and would only open this far:



I hooked the actuator up to a footpump and fortunately it doesn't even open it that far, but it was close!



On Tuesday my remanufactured compressor housing arrived from Turbo Dynamics:



By remanufactured, I think they meant painted but it was cheap so I'm not complaining! It's got these pitting marks inside but they're the experts so I'm presuming that's not a problem.



With the compressor housing on I could set about refitting everything else:





I've bypassed the boost control solenoid and will just run actuator pressure for now whilst running it. It will still be running the TD04 map so better safe than sorry.

I think the engine bay is a bit tidier but there's still a long way to go to sort out that wiring.

With everything finished I filled it with fluids, removed the plugs and cranked it until I saw oil pressure. This took 20 seconds or so in total - I wasn't brave enough to crank it for more than 5 or so seconds at a time. It got to 2 bar whilst cranking so happy with that. I refitted the plugs, crossed my fingers and cranked it again. It cranked, then backfired and I got scared. Cranked it a few more times and nothing but the occasional backfire.

Admitting defeat I grabbed the laptop and loaded up the ECU software. It wasn't very good at cold starting before the build so I couldn't rule in something I had done. I did a few tweaks - retarding the ignition, advancing the ignition, less fuel, more fuel but eventually the battery ran out. Another factor to add to the mix then - ECUs do funny things when the battery isn't giving many volts.

I replaced the battery:



That should give me enough cranking to work out what was going on! Immediately it cranked much quicker... but still wouldn't fire. The best I could do was get it to fire a little bit or 'lock up' and release a bit of smoke from the starter motor.

Back to basics I reloaded the map to undo all the messing around I'd been playing with. I could see that the ECU was losing sync every other revolution which suggested it wasn't happy with the signal it was getting from the cam sensor in relation to the crank sensor. I checked the error code which suggested the same.

Then, embracing the 21st century, I resorted to data logging. Here's one I prepared earlier, from last May, when it was working:



So the blue line is the crank sensor, and the green is the cam. The crank sensor has 4 nodes, with the cam having 1 then 2.

Here's what I was seeing last night:



The cam signal has shifted in relation to the crank, which is probably the source of my troubles. Either the inlet cam has moved whilst I was refitting the cambelt, or I've fixed the trigger wheel on the crank wrong. There's only four directions it can go so it's unlikely but I'll investigate that today.

Looking at this photo it seems the inlet cam might be out by a tooth, but it could also be the angle it was taken:



That amount of shift suggests there's more than one tooth at play here too. It's moved around 40-60 degrees I think.

elgassi

coming along great, any events in mind that you'd like to have it ready for

Dommo

Summer would be nice, but that might have been in the week so could have missed it. Stoneleigh kit car show next weekend is probably the biggest target but really I should just be driving it.

Anyway, good news, the timing issue is fixed!

It occurred to me that the cam timing could be correct and those pulses from the cam triggers could be true. What if the crank was incorrect? Pretty hard to do, it's held on by four bolts so could only be out by increments of 90 degrees and as the engine occasionally tried to fire, it wasn't 90 degrees out. This occurrence came at the same time as the guy who made the ECU suggested the same. What a coincidence. Ahem...

Here's the timing wheel on the back of a spare crank pulley:



Not a great idea photographing it on a tyre, but you can make out some of the triggers. Just. Here they are marked up:



The blue is to help me find the centre. Green is TDC and red are the markings. If I've put that trigger wheel on back to front, all of a sudden that red line close to TDC becomes the other side which is what the logs were showing. Or in this case, as that photo seeing as we're looking at the back.

I removed the alternator belt, unbolted the oil cooler and removed the crank pulley. I swapped the timing wheel around (now spotting there's a dimple at TDC which should be on the back), reassembled it all and hey presto. A working engine! Needs a bit of throttle to start but that's a fuelling issue which can be sorted.

Got a bit of running in done on the way to the MOT this morning, which it duly passed. I had made one mistake though - when moving the oil cooler out of the way for the crank pulley I must have rotated it slightly and undone one of the pipes... it was leaking a good 'un! If that's all the issues it's going to give me though, I'm happy.

As expected when going from a TD04 to a VF28, it isn't as happy boosting from 2k rpm. This is all I've spotted so far. Even on actuator boost levels it's still ridiculously quick which makes running it in on public roads quite tricky. It's booked in for mapping on Thursday when it should have a few more miles on it. It'll be interesting to see what it will give!

JTaylor

Well done, pleased for you.

Dommo

So with running in done it was time to prepare the car for being mapped. I drained the old oil out and set about replacing bits and bobs... somehow not dropping them into the oil. First off was the injectors. I wasn't a long way off the limit of the RX8 injectors I was using and wanted a bit of flexibility. I ordered a set of 700cc Deatschwerks injectors for £260. I think the Deatschwerks injectors are remanufactured Bosch units



Photographing them in situ is easier said than done!



Another job I had was to replace the battery. It has been using a Varley Red Top 25 ever since the Mazda one tried to fall out on a track day a few years back. Unfortunately it's gotten a little old now and wasn't cranking particularly well, as mentioned in an earlier post. I was unable to find the Powervamp PVR20 battery but did find what must be its replacement, a Powervamp Clubsport EP. This is the same size as the Red Top 25 but with 16ah capacity instead of 20ah. It had 600CCA though which is plenty.





Slots into the same bracket nicely and cranks the engine at a much more suitable speed! I updated the ECU with the new injectors settings and it fired quickly... then cut out. With all the messing around trying to get it to start on the old battery I think I've taken too much fuel out so added some more by telling the ECU the injectors were slightly smaller than they actually were.

Oh, and this happened whilst I was running it in:



It's a common-ish problem with these wheels as they get older. They're designed with the IVA in mind so all nicely covered with no hard bits that might hurt you in an accident. Perhaps I should ignore that the steering wheel is surely not a major concern in a crash. The rim is riveted onto the spokes and over time this can (and did) give way. Fortunately I got myself back home with a cable tie and have since borrowed an OMP wheel for the time being.

Today was mapping day so this morning I took the trip down to Skuzzle Motorsport... stopping once to check I wasn't leaking any fluids. And again because I only had 3l of fuel left. That'll teach me for patching a cold start issue with more fuel globally

I'll gloss over what happened on the dyno. Suffice to say no major surprises. Once the cruise sites were mapped it was ready for a power run. This went up and up with the below being 20psi (VF28 turbo).



Those figures are at the wheels, so with a conversion factor of 1.2 (what the tuner usually finds) we were looking at 338bhp. Looking at the chart, it was clear that whilst there were impressive figures on both power and torque, the shape was a lot like it was before with the gains in the top end being minimal. As the figures were so high it meant we could achieve what I set out to do... sculpt the curve to make it more driveable.

The boost controller was reconfigured to provide 11psi rising to 17psi at the redline. This gave the following:



So down on the headline figure to around 334bhp, but the shape was much nicer. Of course, I've given up a large chunk of torque to do it but if it makes the car easier to drive it should be net quicker.

The final task was to give it a badge of honour:



We probably should have dyno'd it again. I'm sure a sticker is worth 10bhp...

elgassi

great post, keep posting pictures and up dates of your track days flowing

boosted

nice, what management are you running? Megasquirt?

Dommo

It's running Megasquirt yeah, an mslabs unit that just plugs into the MX5 loom. Or what's left of it!

Done a few road miles on the car now. Will err... definitely be leaving it at just actuator pressure for the road!! First track day booked for June. Got a few jobs to do before then.

A brake upgrade might not go amiss, and need to fit a swirl pot too.

boosted

Cool, I run microsquirt on my blobeye Impreza. Been using megasquirt ecu's on various projects for about 12 years now.