Custom top mount intercooler for twin turbo

[stirlsilver]

Hi all, I just wanted to share some progress of some work I had been doing for the last 6 years. I'm on the fun part at the moment which is the engine (I cut down a land rover discovery into a Ute, you can read more on the AULRO forum if interested).

4.0L four bolt block
T hat liners
4HP22 with 4HP24 internals
2 x Subaru TD04L turbos
And... my custom intercooler plenum

The engine shown in the photos is just a trial engine (which is why its filthy!). I'll be fitting the final engine (with the T hat liners) early in 2016 after I finish tuning the ECU.














Thanks,
Stirling

[SuperV8]

Interesting project,
One question, have you thought about how you'll get good cold air flow through the intercoolers? I hope they don't act as an air heater sat on top of the engine?

Tom.

[stevieturbo]

Was going to say if you havent done it...dont.

It's definitely the worst possible location for an intercooler even if you are blowing air down through them.

But neatly executed

I'd also make sure you mount those with something taking the weight off the ends yet also allowing for expansion/contraction of the parts. That's a lot of weight to be bolted solid to a centre section.

2 throttles and ISCV's are also a lot of air for a 4.0 engine in boosted configuration.

Just cant help thinking a single large IC, better placed and single throttle would make life a lot easier with no downsides.

[stirlsilver]

Thanks for the feedback guys. Yes, I'm completely aware of the drawback of using a top mount intercooler and it soaking heat from inside the engine bay. That is partially dealt with by having thermal insulators which I designed and later I'll add some extra insulation on the underside of the cooler to protect from radiant heat.

The major reason I went top mount is because on a 4wd the fine passages of the cooler will be blocked up by mud. Having the cooler higher helps minimise that.

[chodjinn]

Thanks for the feedback guys. Yes, I'm completely aware of the drawback of using a top mount intercooler and it soaking heat from inside the engine bay. That is partially dealt with by having thermal insulators which I designed and later I'll add some extra insulation on the underside of the cooler to protect from radiant heat.

The major reason I went top mount is because on a 4wd the fine passages of the cooler will be blocked up by mud. Having the cooler higher helps minimise that.

As stevie said, nice bit of work but seems to be a lot of effort for not much benefit. Top mounts are not just bad, they're terrible. No amount of insulation or shielding is going to stop heat soak.

Looks like you have a fair bit of room at the front, if you're worried about mud couldn't you just go for a v-mount or normal front mount and some decent ducting etc?

[SuperV8]

Maybe a phase change intercooler would suit a 4x4 application?

http://www.autospeed.com/cms/article.ht ... r&A=110772

Tom.

[stevieturbo]

Presumably it's going to be a lowish boost setup anyway, so air temps may not be a big concern ?

TBH a water/chargecooler might have been a better option

By sounds of things you're going properly off road with this.....even more need for strong support for those cores.

Make sure you have an overrun fuel cut active or some means of shutting engine down should the core setup ever fracture and allow air in after the throttles so the engine cant go nuts on it's own

[v8250]

Stirling, that's some serious work going on there...it's not an ideal design but I see no reason why it should not work with correct tweaking. Here are some notes that I hope will help.

1. Are you having open vents above/near the TMIC fans? If not, do consider this for heat extraction and/or cool air induction; are the fans suckers or blowers?

2. As others have rightly said, heatsoak is going to be the biggest challenge. To aid heatsoak control be sure to insulate the exhaust manifolds with a good proven material. I can recommend Thermal Velocity's Magma Wrap, it's exceptionally good product.

http://www.thermalvelocity.co.uk/produc ... =&P_ID=408

3. The TD04's are a good choice, readily available and relatively under stressed units...I have one on my Forester XT and they're good for 270bhp on a baby 2.5ltr flat four. Again, heat control is key here so blanket wrap these with good quality turbo blankets.

4. Thermal Velocity also produce another product that I've used sucessfully many times, making heatshield thermal boxes for MAF's and air intakes, you may find this useful http://www.thermalvelocity.co.uk/Heat-S ... p-113-476/

5. Thermal dissipation and its control is key. If possible, be sure to have greater air exit volume than air intake volume within the engine bay. This is particularly important at the rear of engine bay leading into the gearbox tunnel. The trick is to reduce high pressure build areas as much as possible...run some rough calcs which will give you a benchmark to work from...then, if necessary reposition some wing mounted items to aid better flow and/or add extra air escape routes to rear of engine bay.

6. We can assume you've carefully chosen your radiator...if not, oversize the water volume by 25-30% and then add sucker radiator fan/s. Oh, and although alloy rads are lighter and look good they are far poorer at thermal transfer so go along to your local radiator man and get a good old fashioned copper core with max' sized/straight upper and lower brass headers.

Good luck with the project...btw, what's the expected power output?

Rgds, Andrew

[Eliot]

Some nice work there - but like others, I think they are going to really struggle.
Have you considered boxing in the lower part of the intercooler then some duct work to draw air from the wheel wells?
Here's my musings when I had the same problem:
http://www.mez.co.uk/turbo8a-new.html





I run a pair of turbo's on a 5.7 in a range rover (Dakar kit) and had the same concerns - I went with a chargecooler initially:


(which is for sale)

But ultimately replaced it with a cheap Chinese FMIC, which is pretty tough and is easier to clean than the copper radiator(s):


However - I no longer do heavy off-roading, so i'm not concerned with blocking it up - because it would get blocked in that location, but then again the normal radiators get blocked which would stop play before a lack of intercooling is a problem - such as this:


If I ever do take it off-roading again, I would make a grill for the front and monitor air inlet temps.

[stirlsilver]

Presumably it's going to be a lowish boost setup anyway, so air temps may not be a big concern ?

I was thinking of aiming for about 12-14 psi of boost. For some reason the engine builder still insisted on 8.3:1 compression ratio despite only using Lpg as a fuel why normally has a higher octane value. I would have preferred to stick with 10.5:1!

By sounds of things you're going properly off road with this.....even more need for strong support for those cores.

This is something I have though about quite a bit over the years, vibration will be a killer, but I don't know if you can tell, the cores are very very deep, I had them custom built so they have a fair bit of strength in that direction. But yes not worth risking, I'll build a brace when I get to putting in the new block.

Make sure you have an overrun fuel cut active or some means of shutting engine down should the core setup ever fracture and allow air in after the throttles so the engine cant go nuts on it's own

Thanks, that's a very good point!

[stirlsilver]

Stirling, that's some serious work going on there...it's not an ideal design but I see no reason why it should not work with correct tweaking. Here are some notes that I hope will help.

Thank you for you very constructive feedback Andrew!

1. Are you having open vents above/near the TMIC fans? If not, do consider this for heat extraction and/or cool air induction; are the fans suckers or blowers?

Absolutely going to have the fans sucking fresh air from a large scoop on the bonnet. They are set up in a pusher configuration. In a sucker configuration they would have acted as s heaters!

2. As others have rightly said, heatsoak is going to be the biggest challenge. To aid heatsoak control be sure to insulate the exhaust manifolds with a good proven material. I can recommend Thermal Velocity's Magma Wrap, it's exceptionally good product.

http://www.thermalvelocity.co.uk/produc ... =&P_ID=408

Thanks for the recommendation, I used to/still work for a company that designs and builds exhaust systems for large industrial gas turbines so I was thinking of getting my hands on some ceramic fibre and glass fibre woven blanket and thermally insulating everything I could. By making my own blankets.

3. The TD04's are a good choice, readily available and relatively under stressed units...I have one on my Forester XT and they're good for 270bhp on a baby 2.5ltr flat four. Again, heat control is key here so blanket wrap these with good quality turbo blankets.

I spent a lot of time trying to work out which turbo to use, so good to hear that they are reliable!

4. Thermal Velocity also produce another product that I've used sucessfully many times, making heatshield thermal boxes for MAF's and air intakes, you may find this useful http://www.thermalvelocity.co.uk/Heat-S ... p-113-476/

Thanks, I'll keep them in mind.

5. Thermal dissipation and its control is key. If possible, be sure to have greater air exit volume than air intake volume within the engine bay. This is particularly important at the rear of engine bay leading into the gearbox tunnel. The trick is to reduce high pressure build areas as much as possible...run some rough calcs which will give you a benchmark to work from...then, if necessary reposition some wing mounted items to aid better flow and/or add extra air escape routes to rear of engine bay.

Definitely something to keep in mind, thing is, the time when the engine will have most load on our is when the car is travelling slowly. Putting in some vents would do no harm. I could run a Cfd model to find where low pressure zones are for venting.

6. We can assume you've carefully chosen your radiator...if not, oversize the water volume by 25-30% and then add sucker radiator fan/s. Oh, and although alloy rads are lighter and look good they are far poorer at thermal transfer so go along to your local radiator man and get a good old fashioned copper core with max' sized/straight upper and lower brass headers.

The radiator is yet to be purchased, using the stock radiator for now for using. I have remote fan forced oil coolers under the tray for cooling of engine oil and transmission oil. I was starting to be tempted with those aluminium aluminium radiators so I really appreciate the heads up on them!

Good luck with the project...btw, what's the expected power output?

I'm aiming for around 400hp I think?

[stirlsilver]

Some nice work there - but like others, I think they are going to really struggle.
Have you considered boxing in the lower part of the intercooler then some duct work to draw air from the wheel wells?
Here's my musings when I had the same problem:
http://www.mez.co.uk/turbo8a-new.html

Hi Eliot, thanks for your feedback, I actually referred to your work quite a bit in the early stages of design. I think taking the air from the bonnet would be the best area, but I may duct the air exits. Though it may get too congested in the engine bay!

[stevieturbo]

I think you'll be safer with the lower compression. It may not be needed, but will give a ton of safety margin which is never a bad thing.

LPG does have good points, but thinking a CR of 10.5 would be usable with that boost is being a bit optimistic.

[v8250]

I'm aiming for around 400hp I think?

As per stevieturbo's note, keep the CR as low as possible, be careful with anything over 9.35:1 unless suitably beefing up the internals.

Also, thinking of the turbo spooling...what ECU are you using and where in the power curve are your set points i.e. the RV8's a relatively lazy low revving engine. Logically you'll want to retain torque low-mid range...and all 400bhp in at what rpm?

[stevieturbo]

I'm aiming for around 400hp I think?

As per stevieturbo's note, keep the CR as low as possible, be careful with anything over 9.35:1 unless suitably beefing up the internals.

Also, thinking of the turbo spooling...what ECU are you using and where in the power curve are your set points i.e. the RV8's a relatively lazy low revving engine. Logically you'll want to retain torque low-mid range...and all 400bhp in at what rpm?

TD04's should spool quite well even on the RV8