Any progress on V8 engine swap options?

[1thenaton1]

Mine is up and running, though still working out plenty of kinks before she is track ready. Still workin on tach with a Dakota Digital tach adapter, need to wire coolant temp to the cluster, and having some trouble getting good O2 sensor readings for some reason. Spending lots of time correcting sloppy work from the shop that mounted the engine. In retrospect I would say this is a much better project to DIY than depend on any third party, ymmv

[strombomb]

1thenaton1 - what sort of exhaust layout do you have? Any pics from the bottom of the car? I’ve been racking my brain to figure out how to incorporate a crossover but haven’t come up with anything very good.

[1thenaton1]

Exhaust is one thing the shop did a very nice job on. I provided them with downpipe flanges (from a 2.8, they are the same) to mount to the manifolds and they welded custom pipes to a set of mufflers another customer had taken off his car, 718 cayman I believe. Here's an in process pic before it was finished and wrapped, so you can see the approx routing.


What turbo setup are you thinking of on your 2.7? I saw your tease picture but couldn't make out what it was, some newfangled electric assist no doubt

[1thenaton1]

Was able to get the tach going with the help of Dakota Digital. The standard settings would not work, regardless of if we used engine speed sensor, coil, or injector pulse, but with their help we were able to get a workaround in place. Posting it here in case it can help anyone in the future getting their early non-CAN 986/996 tach working.

Using the SGI-100BT, we tapped into the Diesel input, and selected Flywheel. The TTV flywheel I and others have used is 58 teeth, and with that info the converter was able to send an accurate signal to the tach from the engine speed sensor. Other settings were low voltage and original engine cylinder number was 6 as expected.

On to some shakedown runs ahead of end of July track day.

[Gilles]

Cool, congratulations!

PS: I miss my white faced gauges..

[strombomb]

Glad to see the tach working, great job! Do you have everything else in the cluster worked out? I’ve got grand ideas about getting the oil level readout working, but that’s low on the list. Let us know what you run into in shaking out the box before your track day.

For my 2.7t, I’m going a direction I haven’t seen anyone take before (due to spatial constraints in the Audi engine bay)… I’m starting with OE 2011-12 f150 (3.5L) ecoboost turbos mounted tight to the cylinder head. They are k03 frame, but nearly RS4 k04 wheel spec with billet compressor wheel - there’s good aftermarket support to go bigger later on. Also, recirculation valve is integrated into the compressor housing which is great for packaging. For intercooling, I’m using OE BMW 4.4l turbo units mounted to the timing belt covers - directly between turbos and throttle body. The whole build is focused on using OE parts that are readily available. With these turbos and the tight layout, this setup should rip between 2-6k rpm. I’ve currently got the drivers side fab’d up and am transitioning over to the passenger side next.

Also, looks like the pic of your exhaust broke; can you fix it?

[Escy]

Impressive packaging on your 2.7t. Those charge coolers will be a tight squeeze. Interesting choice on the turbos. Interested to see how you get on, post updates.

Here is mine.

[strombomb]

Looking great Escy, I can’t wait to see those rs6 turbos in action. It’s going to rip!

According to my measurements on the mock engine in the Boxster bay, the charge coolers should fit, but it will be tight for sure (the coolant fittings stick out towards the front and will be close to the front of the bay). With the air-water intercoolers, how big of a heat exchanger are you running up front? Are you satisfied with its size/capacity?

[1thenaton1]

^ psyched to share a page on the internet with you two.

My shakedown runs went well, no problems to report. Ahead of the first track day I sent the car in for a corner balance alignment at a well known race shop in town. On the very first lap at the track, something came loose in the suspension, the car went super squirrely and I limped it to the pits. Turns out the rear right adjustable lower control arm was left finger tight and that pulled the stud out of the inner piece, ending my day before it started. Did technically hit the track though, for 2 laps lol. Back to fixing ****************.

One thing I haven't sorted yet is oil pressure switch. The Porsche cluster expects to see a reading btwn 0.3-0.55 bar according to the sensor. The Audi oil pressure switch uses a higher resistance. Since you can't remove resistance, is anyone aware of a sensor that would fit the Audi oil pan location and run at the lower resistance? Or another creative solution to getting the oil switch to work?
I know I can just unplug it and the light will go off - seems like a good thing to have in place in case oil pressure is lost.

[Qingdao]

Originally Posted by 1thenaton1

^ psyched to share a page on the internet with you two.

My shakedown runs went well, no problems to report. Ahead of the first track day I sent the car in for a corner balance alignment at a well known race shop in town. On the very first lap at the track, something came loose in the suspension, the car went super squirrely and I limped it to the pits. Turns out the rear right adjustable lower control arm was left finger tight and that pulled the stud out of the inner piece, ending my day before it started. Did technically hit the track though, for 2 laps lol. Back to fixing ****************.

One thing I haven't sorted yet is oil pressure switch. The Porsche cluster expects to see a reading btwn 0.3-0.55 bar according to the sensor. The Audi oil pressure switch uses a higher resistance. Since you can't remove resistance, is anyone aware of a sensor that would fit the Audi oil pan location and run at the lower resistance? Or another creative solution to getting the oil switch to work?
I know I can just unplug it and the light will go off - seems like a good thing to have in place in case oil pressure is lost.

Why not use the Porsche pressure switch that came with the car?

EDIT: I see you got a different thread pitch/design. Brass adaptors, with thread sealant.

[strombomb]

I agree with Qingdao, thread adapt to use the Porsche sensor. I think I’ll go that route too.

[Escy]

I'm using this, fitted my Audi and is the right resistance for the Boxster. FACET Oil Pressure Switch 7.0108

[Escy]

Originally Posted by strombomb

Looking great Escy, I can’t wait to see those rs6 turbos in action. It’s going to rip!

According to my measurements on the mock engine in the Boxster bay, the charge coolers should fit, but it will be tight for sure (the coolant fittings stick out towards the front and will be close to the front of the bay). With the air-water intercoolers, how big of a heat exchanger are you running up front? Are you satisfied with its size/capacity?

Yeah, hopefully it'll make good numbers. It's on the dyno the 13th of August but I'm not overly optimistic.

I've copied and pasted a bit on my build thread on another forum about my charge cooler radiator. It was a Chinese special, off ebay, it's large and only just fits. It's really heavy. I don't think it's particularly good at cooling. Compared to OEM stuff the core design doesn't look as good, plus it's so thick I couldn't mount it with as much angle I wanted for the air to easily escape behind it. I feel like with this stuff you are better off using OEM parts where possible, cheap aftermarket is typically ****************e.

I monitor the inlet and outlet temperatures of the coolant (pre and post turbos), I thought my system was performing quite well but since I had my engine out recently I'm not so sure. My current usage isn't ideal, it's currently about 20c ambient and I'm tuning it which means make a pull, then pull over for 5 minutes while I go through the logs making changes. The whole lot heat soaks. I've got no fan on the radiator at the front but I do turn off the pump when the car isn't under positive boost pressure or at low speed to try and stop heat soak. During a pull I'm typically seeing between 30 - 35c for the coolant entering my charge coolers, so 10-15c over ambient, not awful but I think room for improvement with a better radiator. The coolant temperature coming back from my charge coolers can go as high as 65c but there is a lag on it, during the pull it's similar numbers to the inlet temperatures (my sensors aren't that close to the coolers). It seems to show the Mercedes charge coolers are doing their job, putting heat into the coolant (the ones you are using will be more efficient than mine). Constant throttle around a track, I think this system get's overwhelmed fast but it's alright for street driving. My IAT's aren't brilliant typically around 50c at the top of a pull, did see one where I turned the boost up to 28psi which is probably past the efficiency of the turbos and saw 90c which is crazy.

Am I happy? Not really, think there is room for improvement in all aspects of my system but the gains are marginal and not worth re-doing everything for. I think the reality is air to water systems disappoint in nearly all applications I've seen. Even OEM systems over-heat and end up in reduced power modes. One thing I've looked at are systems like the interchiller which uses A/C to cool the liquid. It looks good but I think the same rules apply, you'll over heat the system with hard use, you just start from a lower base temperature.

I've got water/methanol injection (not used it properly yet), this should take care of my charge cooler shortfalls. I sometimes wonder if I'm better off with just this and ditch all the weight of the charge coolers.

--------------------------------------

I fitted the radiator up front. Everything on the 987 is slightly different so like pretty much the rest of it, I had to start again with mounting this and making brackets. One benefit of the differences are the radiator ducts on each side are smaller so I didn't need to cut them like on the 986.



The pump hidden away and mounted nice and low. After having the radiator inlets and outlets mounted on the passenger side I realised there wasn't enough space to run the coolant lines down the sides and behind the wheel arch liner/down the side of the fuel tank like it'd done before on the 986 so I had to work it out a different route.



The charge cooler tank is going to be mounted inside the front boot, there was a handy rubber blanking plug just above the radiator so the hose feeding the radiator runs through there. Then it goes through the rad, to the pump, back over the top of the rad and down the drivers side chassis rail and into the engine bay. On the way back there was another handy little blanking plug, I hadn't noticed it before as it was covered in seam sealer, the hose comes back into the front boot through that and back into the tank. I do my best to not cut holes all over the place, I'm pleased with the pipe routing.



Here is the tank mounted in the front boot. I spent a bit of time making up some brackets to raise it up and angle it slightly. I raised it as the higher it is the better in terms of any trapped air making it's way back into the tank. I angled it slightly so it looks better under the cover.





All hidden away, you'd never know.




The next big job was the tank for the meth injection. Having fitted the charge cooler tank where I initially planned to mount a meth tank I could now put the meth tank on the battery tray where the charge cooler tank was on the 986. I added in the fitting for the meth line.



My meth tank and the little race battery both fit on the battery tray. There were no mounting points on the tank so I used a battery clamp I'd bought years ago and never needed. The battery is held in place with a metal bracket. I bought another of those Battery Brain's the first one I had seemed to be playing up so I returned it. It took a bit of fiddling to get it all in place without needing to cut the battery cables which I wanted to avoid. I had to move the alarm siren to the other side where the original earth point used to be.




All hidden away. I'm happy with how it's turned out, it's been really time consuming planning where to put things and make the best use of the available space but I think it's worth the extra effort.

[ike84]

escy - a couple of things about your intercooler setup.

1 - you'll notice the difference in spacing between fins on the oem and your ebay one. way bigger gaps on the cheapos. thats why theyre cheap though. not trying to criticize, just pointing that out.

2 - what boost pressure are you running? you should be able to run a setup like this up to 7-8 psi without any raise in temp above ambient. If youre running low to mid teens and only seeing +10C on your temps then I would consider this to be a success. i noticed in one post you mentioned 24psi? if youre running anywhere near that routinely then you will absolutely see intake temps rise, no matter how good of a setup (water-air or air-air) you have setup.

3 - what flow rate is your water pump? slow pumps can cripple a system like this. often underestimated how important that is.

4 - are all your data coming from stationary pulls? im assuming that youre using a big ass fan when you do that, but even still your data on the street at 100mph will be vastly different.

5 - you already figured it out but water meth will help. (beautiful work on the setup, btw) im sure you already know all the details about its pros and cons but I will say that it always makes me nervous to use it to "fix" a suboptimal setup rather than using it to "improve" an already good setup (unless, again, youre running high teens and low 20s, then its going to be almost mandatory.). what concentrations are you planning on running?

[Escy]

Yeah, I did notice the larger spacing on the fins compared to good OEM radiators. Would go with something else if I was to do it all again but finding something that fits in the space is hard. Bought it 3 years ago, there's more options now (electric and hybrid cars have good auxiliary radiators). My water pump is a Davies Craig EPB40, I think it's considered a decent pump, it wasn't cheap (although looks it). It's 40 litres per hour.

I'm running 50/50 water methanol (capacity rather than weight). Boost wise, actuator base pressure is around 10psi. Currently up to 26psi while testing although not sure I'll run this much in the end, depends on the power it makes on the dyno.

All my data is coming from pulls on the street. The last time I was on the dyno I found things actually stayed cooler as in-between pulls the fan was cooling the charge cooler system. On the street I stop to make adjustments and it all heat soaks.

[strombomb]

Escy -

You’re spot on with using OE parts. That is the theme of my build. OE quality and reliability is definitely not always present in the aftermarket, but can be pretty cheap in the used OE part market (dismantlers). So I started by sourcing the 750i intercoolers (about $40 each)… I’ve since sourced the circulation pump from a 750i (a Pierburg CWA50 which states 25 l/min @ .53 bar back pressure for $55)… being that I’ve source these other parts from the 750i, I think I’ll also use the heat exchanger too. With that, I’ll be using the whole intercooling system from the 750i (4.4l hot vee bi-turbo) which seems like it should be ok for my measly 2.7l bi-turbo running at 18-22psi. Only difference being the distance the fluid has to travel through lines from the engine in the back of the box to the heat exchanger and reservoir in the front.



Thanks for posting the pics of your intercooler heat exchanger setup. Very helpful.

Also, at 26 psi, you should be seeing 500 hp at the rear wheels (being that the b5 S4 guys with rs6 turbos are easily seeing 450 at all wheels). I can’t wait to see how your dyno session goes. I’m sitting in the edge of my seat!

Also having now fabricated my custom exhaust manifolds, here’s a pic from below of the turbo placement of the passenger side ecoboost turbo in the bay. I really like the placement, though the stock engine bay cooling fan won’t fit, I will need to source thinner fan. Now I’m on to determining air intake and filter location. Are you satisfied with you air filter location in the bay? You have your intake filters down low right?

[Escy]

I also really like you turbo placement. Would have done similar myself if I had a bit more skills (happy to modify a manifold but wouldn't like to make them from scratch).

I should see 500 at the wheels in theory but I'm not holding my breath. Will find out soon. It didn't make the power I expected last time.

Air filter placement has been an issue all along. I did have them low mounted in a few places but they get soaked when it rains. I've recently moved them up to the side vents, one per side. Should be colder air there plus they sound great with the windows down. The downside is, I have no engine compartment fan at all. This isn't something I'm too happy about, I'd like one but can't find a spot to put one that'll do any good. Airflow through the engine compartment is the real achilles heal of this platform.

[strombomb]

I hear you! I have lost a lot of sleep trying to figure out how to get air into the engine bay. I’m currently considering putting a high output 6” fan (maybe two?) in between bay and trunk, pulling from the trunk blowing into the engine bay… then maybe having some sort of vent to allow air to be pulled into the trunk. Idk. I will probably talk myself out of that too haha.

I’ll run 2x MAF’s (2x 1.8t units and read them in with Arduino and feed out a single signal to the ecu) and place cone filters right inside the side vents (symmetric). Like the UK, it rains A LOT here in Oregon, so I don’t like having low filters either.

[Qingdao]

Originally Posted by Escy

I also really like you turbo placement. Would have done similar myself if I had a bit more skills (happy to modify a manifold but wouldn't like to make them from scratch).

I should see 500 at the wheels in theory but I'm not holding my breath. Will find out soon. It didn't make the power I expected last time.

Air filter placement has been an issue all along. I did have them low mounted in a few places but they get soaked when it rains. I've recently moved them up to the side vents, one per side. Should be colder air there plus they sound great with the windows down. The downside is, I have no engine compartment fan at all. This isn't something I'm too happy about, I'd like one but can't find a spot to put one that'll do any good. Airflow through the engine compartment is the real achilles heal of this platform.

I got air flow for days.... I just don't put the cover back over the engine.

[strombomb]

I like it!!