Puff's Turbo 525i Daily Driver

[circuit.heart]

What kit did it come off of or do you happen to know the dimensions? The plan was to go with a treadstone something another. I'm done with the ebay stuff lol.

If you can fit a Treadstone TR8, that is a good core, good balance between all things (coming from a Mazdaspeed3 background). My CX thang is for a Speed3, but let me see what the dimensions are, I haven't opened the box in years.

[CallMePuff]

If you can fit a Treadstone TR8, that is a good core, good balance between all things (coming from a Mazdaspeed3 background). My CX thang is for a Speed3, but let me see what the dimensions are, I haven't opened the box in years.

I was looking at the TR11 from them. Higher capacity and is the right dimensions. I think I have maximum of 3" thickness to play with, and the TR11 is rated to 560hp I believe.

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[moroza]

I also never venture into the FI section (I've owned one FI vehicle ever, and it was bone stock and a diesel anyway), so I appreciate this here. Good documentation, tells a story from beginning to present. I'm particularly impressed that you managed to stuff all four doors into the back seat. And I relate to the E34 being your first car, only car, that you enjoy driving enough to haul across five (?) state lines to pick up some fenders.

What were your previous wheels? The five-spoke ones that look like the skinnier version of AMG Monoblocks?

[CallMePuff]

I also never venture into the FI section (I've owned one FI vehicle ever, and it was bone stock and a diesel anyway), so I appreciate this here. Good documentation, tells a story from beginning to present. I'm particularly impressed that you managed to stuff all four doors into the back seat. And I relate to the E34 being your first car, only car, that you enjoy driving enough to haul across five (?) state lines to pick up some fenders.

What were your previous wheels? The five-spoke ones that look like the skinnier version of AMG Monoblocks?

I will say going from a 250k+ M50 to a boosted M52 certainly changes the car in such a way. Then going from the worn boosted M52 to a properly built M50B32 was another large contrast.

I was also very surprised that the four doors fit into the back seat without having to go anywhere else. I was constantly at risk of decapitation from the one sitting on top lol. The headliner also became saggy after the trip. It went from a tiny loose spot to the entire thing hanging. I didn't have A/C at that time so the entire 13 hour trip the wind was whipping around in the car.

The wheels you're referencing are my winter set that I still use, 17" Borbet Type E. I got them for a steal. They're not perfect, but they look half decent for winter wheels and they fit over my E90 front brakes, so they're a win.

[5mall5nail5]

My eBay unit works well, but...

[CallMePuff]

My eBay unit works well, but...

For the love of God, share the link. Treadstone doesn't even have one that tall. How thick is yours?

[5mall5nail5]

For the love of God, share the link. Treadstone doesn't even have one that tall. How thick is yours?

Heh - its been a while. I had a seriously in-depth build thread for a long time in the FI section.

It's 4" thick.

Ya'll don't know 5mall5nail5?

Shit.

[CallMePuff]

Heh - its been a while. I had a seriously in-depth build thread for a long time in the FI section.

It's 4" thick.

Ya'll don't know 5mall5nail5?

Shit.

Oh no, I've read through it. It's just been a long time lol.

Did you have to push the intercooler into where the AC condenser would go to fit it? I'm not sure if it was you or Darren, but someone cut the threads off of their water pump to get more intercooler in there.

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[moroza]

Newbie question: why not a water-air cooler at that point?

[CallMePuff]

Newbie question: why not a water-air cooler at that point?

I already have a BMW. Don't you think it's prone enough to leaks already?

Lol jk, simplicity. Air to air just works and there's no real moving parts, plus you still need to find room for w2a.

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[moroza]

I already have a BMW. Don't you think it's prone enough to leaks already?

Well, they're more compact, and I'd look at sticking the water cooler ahead of the front left wheel, or way at the back of the car, leaving more airflow for the radiator and AC condenser. I considered leaks (might soon be doing my first FI build as well, with a turbodiesel), and figured that if it does leak, it's not a big deal, I'll just be limited in hoonery-grade power until fixed. For a happier AC and engine cooling system, seems worth it?

[5mall5nail5]

Newbie question: why not a water-air cooler at that point?

You still need a heat exchanger, pumps, reservoir, and intercooler. Having tuned VW VR6 with A/W intercoolers they are great at drag strips and short road tracks because you can put ice in them, but on the street and in traffic they heatsoak. You end up with higher average temps than air to air and takes longer to pull temps down comparatively.

[circuit.heart]

I was looking at the TR11 from them. Higher capacity and is the right dimensions. I think I have maximum of 3" thickness to play with, and the TR11 is rated to 560hp I believe.

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I know people push 500+ on a TR8 core just fine, but if you are already looking at TR11's, forget I said anything about a CX core - mine is less than 9" tall I think.

[CallMePuff]

I know people push 500+ on a TR8 core just fine, but if you are already looking at TR11's, forget I said anything about a CX core - mine is less than 9" tall I think.

That's good info nonetheless, I was worried about the TR11 lol. I believe my current one is 9" but I'd have to check.

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[moroza]

You still need a heat exchanger, pumps, reservoir, and intercooler. Having tuned VW VR6 with A/W intercoolers they are great at drag strips and short road tracks because you can put ice in them, but on the street and in traffic they heatsoak. You end up with higher average temps than air to air and takes longer to pull temps down comparatively.

Yeah, it's a lot more crap than just an air-air, but most of that crap isn't mission-critical, and the packaging opens up the possibility of cooling the charge far more than any air-air you might possibly fit in the engine bay. I look at the intercoolers above and have to wonder 1. is there AC at all (Jon) or do you plan for it to coexist with an air-air intercooler (Puff), 2. if it is there, how well does it work, and 3. how's the coolant overheating margin with that much heat being dumped right onto the radiator?

I've no experience with this stuff, just reasoning aloud... surface area held constant, air-air will be more efficient, but with a water-air, you can have an order of magnitude more surface area to dump heat to the ambient air. When the water has to absorb heat from the intake air, I would think it should be possible to get it to negligibly above ambient temperature, and still holding surface area constant, water's much higher thermal conductivity should make for a much more effective heatsink, furthermore one that itself need not be in an area with good airflow. Those VR6 you worked with - what did their water cooling circuits look like? I'm envisioning something like looping pipe/hose with alu fins running back and forth the whole length of the car, several times, and maybe a small radiator way behind the gas tank or something. It doesn't carry the intake air charge so doesn't affect throttle response, and the lines can go wherever's convenient underneath.

Something tells me that if you need an intercooler in traffic, you're doing it wrong.

[5mall5nail5]

Yeah, it's a lot more crap than just an air-air, but most of that crap isn't mission-critical

Unfortunately most of the crap is mission critical. Tubing and hoses punctured/ruptured could equal engine damage. Heat exchange damage could equal engine damage. Pump... same. If A/W core leaks... hydrolock.

and the packaging opens up the possibility of cooling the charge far more than any air-air you might possibly fit in the engine bay.

Yes but only when pair with a sizable reservoir (think trunk) with ice

I look at the intercoolers above and have to wonder 1. is there AC at all (Jon)

No A/C

how's the coolant overheating margin with that much heat being dumped right onto the radiator?

That's the best thing - A/A intercoolers flow well and the thing only gets as hot as the air around it +2 -3C over ambient. I can idle my car to the Jersey shore without overheating on a stock radiator with ~850 RWHP on tap. No water temp issues with a 9" SPAL puller on radiator and 16" SPAL pusher on FMIC. A heat soaked A/W setup in SE PA summers I need to consider IATs and so heatsoak is quite noticeable on the tune.

I've no experience with this stuff, just reasoning aloud... surface area held constant, air-air will be more efficient, but with a water-air, you can have an order of magnitude more surface area to dump heat to the ambient air.

You don't. In fact, because of the fragility around heat exchangers, you have a relatively small area and they're not usually very thick. On top of that, water has a much higher thermal mass. Idle a car for a bit, or rip and reach slow speeds, and you will need a LOT more air flow sustained for a LOT longer duration to bring the water back down to +2-3C over ambient.

When the water has to absorb heat from the intake air, I would think it should be possible to get it to negligibly above ambient temperature

It's the fact that your most effective heat exchange is in the engine bay (the A/W IC) and it's hard to shake the heat out of water which has a much higher thermal mass. If we could always remain moving you're right, A/W is a great solution. A street car though is a not so great experience A/W. Drive 25 miles and park for gas. Turn the car on. IATs are insane. Drive 3 miles, not much drop w/ A/W... you can follow me here.

and still holding surface area constant, water's much higher thermal conductivity should make for a much more effective heatsink

sure but thermal conductivity and thermal mass are very important to consider

furthermore one that itself need not be in an area with good airflow

not true

Those VR6 you worked with - what did their water cooling circuits look like? I'm envisioning something like looping pipe/hose with alu fins running back and forth the whole length of the car, several times, and maybe a small radiator way behind the gas tank or something. It doesn't carry the intake air charge so doesn't affect throttle response, and the lines can go wherever's convenient underneath.

that's pipe dream stuff. The reality is you're talking more like ~16x8x1.5 5 radiator front mounted with a 10 - 15A water pump that can fail.

Remember - you need to circulate the water at a reasonable rate - amperage isn't free on 12 - 16v

Something tells me that if you need an intercooler in traffic, you're doing it wrong.

The issue with this is if you need A/C you're doing it wrong. Fast cars are fast. A/W is fine for lower HP, less dependent setups. If you can envision the IAT graph, while A/W will take longer to heat soak, it takes at least twice that to cool again.

In my experience A/A is the best for pump gas cars. E85 and no IC is the best after that.

[moroza]

Unfortunately most of the crap is mission critical. Tubing and hoses punctured/ruptured could equal engine damage. Heat exchange damage could equal engine damage. Pump... same. If A/W core leaks... hydrolock.

Are you talking about engine coolant used for the intercooler, or a separate circuit? If separate (what I meant)... the AW core leaking would be a serious problem, sure, but if the rest of kit craps out, you just have no intercooler, and your power is limited, in the worst case, to what the engine does naturally aspirated. Going from 850hp to 150-200 may feel like immobilization, but it won't keep you from getting home.

I appreciate the explanation. You obviously know far more about this than I do, I'm just trying to square theory with practice. Does the analogy of a parabolic mirror or radio signal collector dish hold up? Water is easy to rout wherever it's needed, and per volume it contains far more thermal mass than air does. Couldn't large areas of the underside and various nooks & crannies amount to essentially a collector dish, multiplying inefficient heat transfer (to the outside air) over a large area, and concentating the resulting thermal mass where it's most needed?

You don't. In fact, because of the fragility around heat exchangers, you have a relatively small area and they're not usually very thick.

I meant the exchanger of heat between the water and atmosphere, not between water and the intake charge. Simply routing the water plumbing to the rear bumper and back up front increases surface area with which the system can dump heat to atmosphere.

It's the fact that your most effective heat exchange is in the engine bay (the A/W IC) and it's hard to shake the heat out of water which has a much higher thermal mass.

Wouldn't the most effective heat exchange be somewhere colder than in the enginebay?

If we could always remain moving you're right, A/W is a great solution.

Ok, that make sense. Is that the heart of the issue, that the engine fans ensure some minimum of airflow across an AA, but AW can't as easily/practically have booster fans?

not true

No? Suppose you stuck the AW cooler inside the cabin or in the trunk, with air and water plumbing going through the firewall. Hot air and cool water in, cool air and warm water out, no ambient airflow required.

The issue with this is if you need A/C you're doing it wrong. Fast cars are fast.

Drowning in sweat is either a unpleasant price worth paying for track performance, or just plain unpleasant and awful half the year. I suppose reasonable people can disagree, but for me and where I drive, a car without AC is doing it wrong.

If you can envision the IAT graph, while A/W will take longer to heat soak, it takes at least twice that to cool again.

In my experience A/A is the best for pump gas cars. E85 and no IC is the best after that.

I can't argue with your experience, but unless I'm missing something, that heatsoak comparison doesn't hold up. Thermal mass just slows down temperature changes, and it doesn't care in which direction. That'd be like a flywheel that takes less time to spin up but longer to slow down. Conservation of energy is violated.

[circuit.heart]

I can't argue with your experience, but unless I'm missing something, that heatsoak comparison doesn't hold up. Thermal mass just slows down temperature changes, and it doesn't care in which direction. That'd be like a flywheel that takes less time to spin up but longer to slow down. Conservation of energy is violated.

That's exactly what happens... the flywheel takes twice as long to spin up and twice as long to spin down with air/water.

Take the new M4/Supra (S55/S58/B58) performance envelope. BMW put in quite an overkill A/W setup by most people's standards, but once you've got it hot (depending on your tune level/power level, that's 1-5 laps) your session is pretty much done, you go back to the pits to cool it down.

In my experience A/A is the best for pump gas cars. E85 and no IC is the best after that.

Heh, the unpopular approach. E85 is so good for cylinder cooling, with a supercharger even cooler.

[moroza]

Take the new M4/Supra (S55/S58/B58) performance envelope. BMW put in quite an overkill A/W setup by most people's standards, but once you've got it hot (depending on your tune level/power level, that's 1-5 laps) your session is pretty much done, you go back to the pits to cool it down.

I wonder what it uses to cool the water, and whether anyone's looked into upgrading that system, perhaps by something as low-tech as taking the relatively short hose carrying hot water out of the cooler, running it all the way to the back of the car and forward again, and fastening some alu fins to its length. Unlike an AA, this would have no effect on throttle response, and cost nothing beyond some trivial weight gain.

[5mall5nail5]

I wonder what it uses to cool the water, and whether anyone's looked into upgrading that system, perhaps by something as low-tech as taking the relatively short hose carrying hot water out of the cooler, running it all the way to the back of the car and forward again, and fastening some alu fins to its length. Unlike an AA, this would have no effect on throttle response, and cost nothing beyond some trivial weight gain.

I had a really really in-depth response queued and my PC bonked out.

The problem is that running that sort of length of tubing requires significantly more pump, lines, water, complexity, and for not much gain what so ever. On a track car the front mounted heat exchanger is in direct, ducted airflow at > 45 - 120 MPH on an S55 car on most tracks - no amount of anything at the rear of the car is going to see that kind of airflow without insane ducting as well.

Like I was saying if you can keep a car moving at a good clip then they can be more equal, but water, once heated, is very tough to get back down toward ambient temperature. It's different than engine cooling because engines can grind power out at 250F so long as clearances are setup for it and materials don't shift. But charge air doesn't work well that hot - it's much more sensitive. And, since you have a very narrow timeframe that the charge air crosses through the A/W core, unless the core is close to ambient, the benefit diminishes quickly.

When you start talking car-length hoses looping around, something tells me you've never had the joy of bleeding a system like this

Even on the "short" systems it can be a nightmare.

A/W is great for drag strips where you can dump in ice. But attend an event with cars using A/W and you'll see them in the pits with bags and bags of ice on top of the engines between stints. It's just not that enjoyable.

[moroza]

I've never touched an AW system, it's true. The extent of my hands-on time with intercoolers is pouring oil out of them on clapped-out TDIs.

In addition to straight conduction, water has another cooling mode that's quite effective - evaporation. I wonder if that's ever been exploited for intercoolers?

Ok, plain old hose with fins might not do much, but what about a radiator at the rear bumper taking advantage of the negative pressure behind a moving car, much like air-cooled 911s? Track cars don't need trunk space, and in many cases there'd be plenty of room for booster fans as well, to help with low-speed operation.

[5mall5nail5]

I've never touched an AW system, it's true. The extent of my hands-on time with intercoolers is pouring oil out of them on clapped-out TDIs.

In addition to straight conduction, water has another cooling mode that's quite effective - evaporation. I wonder if that's ever been exploited for intercoolers?

Ok, plain old hose with fins might not do much, but what about a radiator at the rear bumper taking advantage of the negative pressure behind a moving car, much like air-cooled 911s? Track cars don't need trunk space, and in many cases there'd be plenty of room for booster fans as well, to help with low-speed operation.

Evaporation, yep - water injection

[CallMePuff]

I'm baaaaaaaaaack!

I finally got to throw the car on the dyno, thanks to a buddy. The dyno was inertia-based, not load-bearing, so we really only got to do back-to-back WOT pulls. All that being said, my own tune got me to 484whp/495wtq @14psi. I'm quite happy with the results, especially since we didn't really fine tune anything and I couldn't steady-state tune anything. Next plan is to turn up the boost and see where it lands!

Video link: https://youtu.be/wBmsZF2_EkE

PXL_20210518_225859608.jpg

[a777fan]

Nice!

[circuit.heart]

Video link: https://youtu.be/wBmsZF2_EkE

Nice little backfire at the end. Is the turbo maxed out up top already and that's why torque falls off?