Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: grinder on September 30, 2004, 11:09:15 AM

Title: Intercoolers
Post by: grinder on September 30, 2004, 11:09:15 AM
Now we all know that intercoolers cool the air from the turbo ( or summat like that ! )

from what i understand the air comes thru the air box , thru the turbo , thru the cooler - and then into the engine

so that the car runs on cooler air

i have a 1990 Turbo II ( FC ) and it has a standard top mount intercooler ( under the vent in the bonnet )

just been looking on ebay and there are a fair few intercoolers for sale

SO

1 - what size is a standard one ?? ( like mine )
2 - Does size matter ( yeah ok wide open question )
3 - Would you mount a new one in the same place
4 - Would you mount infront of the radiator
5 - Does it actaully matter how long the pipes are from the turbo to the intercooler
6 - how many pipes should there be ( 1 in and 1 out ?? )
7 - do you work on the core area only
8 - what difference does it make with a bigger intercooler

i think that about covers it

thanks

stu
Title: Re: Intercoolers
Post by: Fish on September 30, 2004, 02:22:58 PM
Here\'s my views.

1 - what size is a standard one ?? Dont know, sorry.
2 - Does size matter ( yeah ok wide open question ) ?? Yes size matters, if you go smaller than stock you can either a) blow the welds, or b) heat soak the intercooler. Due to not enough mass to dispensiate the heat. If you go to big, you get lag.
3 - Would you mount a new one in the same place ?? Nope, put a front mount in. ;)
4 - Would you mount infront of the radiator ?? Yes, see #.3
5 - Does it actaully matter how long the pipes are from the turbo to the intercooler ?? Can do, but it more comes down to the size of the pipes. If you go to big, you increase the amount of air needed to push air through the I/C.
6 - how many pipes should there be ( 1 in and 1 out ?? ) ?? Depends on the amount of turbos.... :D
7 - do you work on the core area only ?? How do you mean?
8 - what difference does it make with a bigger intercooler ?? Bigger mass against thickness means that the cooling air has a bigger object to hit, rather than a thick unit which it has to try and get through.

Fish
Title: Intercoolers
Post by: grinder on September 30, 2004, 02:35:10 PM
thanks fish !

sorry point 7...

the IC comes in a size and then a core size - i take it you work from the core size

is there a recommended size on for a TII ?? ( core size that is )

so say i go and stick a volvo intercooler into my car ( its been suggested by someone off here ) - what would it do ?? does the car run better or faster or spool longer ???

so if i front mount it - would i need to move the oil cooler - or just squeeze it in somewhere ???

your anser to point 8 makes sense ( ish !!! )

so (in laymans terms here) if my cooler is 10 * 10 * 5 ( 5 thick ) , would a size of 20 * 10 * 5 be better ??

same thickness but larger surface area ( 500 as opposed to 1000) ???

big thanks again matey !!

stu
Title: Intercoolers
Post by: sadgoth on September 30, 2004, 02:45:59 PM
A mate had a 323 4x4 turbo with a Volvo T5 IC haning off the front, wasn\'t pretty but did the job!

My understanding (correct me if I\'m wrong any of you lot with a more mechanical bias) is that although a FMIC has the advantage of more space and a better target for cold air to hit, it also involves lengthening the pipes (exposing the air to engine heat) which = more lag. So in theory, if you could

a) get a bigger top mount intercooler
b) which you could somehow insulate from the engine heat soak
c)  get enough air into it

that would be the best solution, I suspect b is a bit of an issue and c would involve sticking a huge funny car stylee bonnet scoop on the car but hey?

How much lag doe the increased size and length of piping actually create?
Title: Intercoolers
Post by: grinder on September 30, 2004, 03:40:42 PM
im just hoping this thread produces some good answers

i dont know who is the top guru for intercoolers !!
Title: Intercoolers
Post by: travellinbob on September 30, 2004, 05:38:46 PM
Top thread grinder. So many people seem to rush out and slap the biggest IC on the front of their acr but probably have very little clue as to wether or not it is the right one for the job.
  I did see a guy in oz who put a turbo II motor into the back of a bug and he modified the original top mount IC to become a watercooled unit instead of air. Yes this does mean that you would have to run pipes to it to run water to it, and have a radiator of some kind to disperse the heat from the water, although it wouldnt have to be too large.
   Every clown and his mate have a front mount IC in oz these days, think it is some sort of pre-requisite for owning a rotor;)
  actually, tim, the dude with the VERY fast gen 1 rx7 doesnt run an IC at all.Something in this?
Title: Intercoolers
Post by: sadgoth on September 30, 2004, 05:58:24 PM
Tim\'s Gen 1 is cooled by Water Injection
Title: Intercoolers
Post by: Schtoo on September 30, 2004, 06:10:07 PM
Can I take a stab?

2 Size does matter. but efficiency/mass matters more.  You might have an enormous cooler that weighs a ton, but has no flow inside or out. Alot of folks prolly don\'t get much benefit out of a larger intercooler, and some probably get a reduction based on their driving conditions and type of driving they do.

3 New one in the same place as your old one? Maybe, depending on what the new one is.

4. Maybe, also depending on how the car would be driven and in what conditions. If you drive around lots of loose stones/debris, then that lovely front mount animal will become a sieve in pretty short order. That\'s just one situation.

5. Shorter is of course better, The best is to find a balance of short runs, smooth transitions and adequate flow while still making the turbo/cooler/engine all connect together, without going too far in the wrong direction. If you use enormous pipe, you increase the amount of air you need to compress before the engine gets force-fed. That is, lag.

6. Depends on how many ins and outs there are in the sytem. Minimum is one out of turbo into cooler and one out of cooler into engine.

7. Core area affects how quickly/easily it can waste off the heat. So a bigger core can dissipate more heat, but depending on how everything works together a bigger core might not actually be better. Again, it\'s a balancing act.

8. Bigger? If it has more thermal mass, then the inlet charge will stay cooler, longer. If the mass is in the core area, it can dissipate the heat absorbed more easily. If the core is larger, then you can generally assume  it has more surface area to both absorb and dissipate heat.

In a perfect system, the cooler would be cold all the time, heat up only a little under boost, dissipate all the heat during the gear change and be the size of a coke can.

If you plumb in a liquid nitrogen bottle to the intercooler core, you might just get that... ;)

I\'m going to bed now, but if you want me to elaborate further, then I shall. With any luck, someone who really knows what they are doing and has some experience under their belt will beat me to it and I won\'t need to be corrected as most of my info comes from a multitude of sources all mixed together in my head. Luckily, my head has a knack for working out how these kinda things work out.
Title: Intercoolers
Post by: Fish on September 30, 2004, 06:12:26 PM
Sadgoth, I think the thing is to not make the pipework either a)to long, and b) to big (ID).

The length issue could be sorted out, by using a smaller ID pipe. ;)

But I am sure that Bill S. will come along with some technical stuff soon.

Fish
Title: Intercoolers
Post by: 88GT-R on September 30, 2004, 09:13:04 PM
Hi
Agree in a way about the length and diameter, but more importantly you should consider the pipeworks route. Idealy it should be as straight and direct as possible, regardless of the length. Too many corners slow the air velocity and cause a drop in pressure.

I am a strong believer in V or horizontal mounted intercoolers. As a package i see them as more efficient than front mounts, even if you only consider the restriction of air to the radiator and oil cooler(FC) with the front mount.

John
88 GT-R
Title: Intercoolers
Post by: Schtoo on October 01, 2004, 06:43:26 AM
Fish, yer right about Bill S coming along. He shoulda been here from the start. ;)

John is correct with the bends and stuff too.

TBH intercooling and piping for them is probably something a HVAC (Heating, Ventilation And Cooling) engineer would be able to break down and make the thing work better than some car guy who happened to luck across something that works.

After all, that\'s what they study and do for a living. Make air move around, cool it down, heat it up and make it all as efficient as possible.

Anyway, gotta work right now so no more regurgitated stuff from me for a little while. :)
Title: Intercoolers
Post by: Fish on October 01, 2004, 03:34:54 PM
Schtoo, anyone thats good with physics should be able to work it out. It\'s not that hard after all. ;)

Fish
Title: Intercoolers
Post by: Schtoo on October 02, 2004, 05:45:14 AM
That\'s true, but a lot of the guys who flog this kinda gear would have trouble spelling physics, let alone actually using it to accomplish anything. ;)
Title: Intercoolers
Post by: mattmaclennan on October 02, 2004, 11:07:17 PM
Charge cooler off a Celica GT would fit just lovely in the original location. Small electric water pump and a radiator later... cool charge sod all pipe work. Or just a bit of pipe straight off the turbo into the throttle body and water injection... but then I\'m slightly bias! This (http://i15.ebayimg.com/03/i/02/7b/17/05_1.JPG) is pretty useful, but the sharp bends into the cooler would put me off... I bet it\'s bloody cold though
Title: Intercoolers
Post by: Fish on October 03, 2004, 10:22:26 AM
Matt, I agree on the bends. Just look at the one after the samco on the intercooler itself. :eek: :eek: :eek:

For those who are to lazy to click, here\'s the picture.

Nice straight pipework, but let down by that bend.

Fish
Title: Intercoolers
Post by: sdminus on October 03, 2004, 12:22:06 PM
i aint no expert on intercoolers but i am planning on going with the theory of the most direct ducting ( least bends as poss) on a thin intercooler. My reason for wanting a thin intercooler is based on heat soak. once a thick intercooler gets hot it is harder to get cold air through the fins ie reducing the surface temp. a thin cooler will heat up quick but will cool equaly as quick. + a little water injection or a nx ntercooler kit would not go a miss. front mount seems the way to go but are way expensive. demon tweeks do universal intercoolers for about £250 quid. i\'m thinking its gotta be worth a try. gotta do some more research though. if not they also sell cores seperatly.
cheers scott:bandit
Title: Intercoolers
Post by: Schtoo on October 03, 2004, 03:41:48 PM
Yes, but how long do you actually have the car \'on boost\'? By that I mean cranking in large chunks of hot air, not just having the turbo ticking over.

As a good experiment, get someone to time how long the boost is over, say, 5 psi out of a typical drive. For some folks in some conditions the percentage of over 5 psi might be 10-20%, maybe even 50% or more, but typically I doubt that during a drive to whereer that you have 5 psi for more than 5% of the time that the engine is running. Unless you are running and running fast from Joe Law... ;)

So, while having the intercooler cool down fast is great, it will also heat up real quick, stuffing hot air into the engine, right when hot air is likely to do the most damage, high revs and high load.. A larger and heavier cooler will heat up less quickly, so when you lift, it will still be relatively cool while yer friend with the lightweight just stuffed a gut full of hot air into his engine and made it go pop (maybe?!)

Now, if you could find the happy medium where the cooler is just starting to go south when you really have to lift off and coast for a bit, bringing the intercooler temp down ready for the next fang, then it would all be very nice. Myself, I would tend to err on the side of caution. Waaay over on the side of caution.  And put a temp probe in the cooler\'s core to see what\'s going on in there...
Title: Intercoolers
Post by: sdminus on October 03, 2004, 04:16:32 PM
I see your point. I think i overall solution to intercoolers is down to a individuals driving style and getting it tp perform to that requirment. i wasnt thinking of making the intercooler thinner than the stock one, but longer. i have located this on the net. see what you think.
http://www.sdsefi.com/techcooler.htm
cheers scott:)
Title: Intercoolers
Post by: Fish on October 03, 2004, 04:40:30 PM
I a having some bits made at the moment, and speaking with the guys who are making it, they would rather go for a medium thick (circa 60-80mm) core with a bigger foot print, than a thicker smaller foot print core.

They have been making this sort of stuff from many years, for all sorts of uses, but mostly motorsport. So I think they know what they are doing and how to work out dimensions. I took my FD down to them, told them want I wanted (along with borrowing a sample setup from a very nice chap. ;)) and they worked out the best sizes from there.

I hope to have this fitted by Santa Pod this Sunday, but we shall wait and see as I still need to get some mapping time sorted out. ;)

Fish
Title: Intercoolers
Post by: sdminus on October 03, 2004, 05:31:59 PM
nice one. if you dont mind me asking how much are they charging you.:)
Title: Intercoolers
Post by: Fish on October 03, 2004, 05:41:07 PM
Cheaper than getting it imported from Japan. ;) Thats all I am going to say for now. I still have to sort out the samco piping and such.

It is designed for a single turbo, but with a little work and core size change, it could work with a stock setup.

Fish
Title: Intercoolers
Post by: sdminus on October 03, 2004, 05:44:03 PM
ok mate. sounds good stuff. its always good to take a deeper look in to things instead of just bolting on what the shop says.
r u going to the pod
Title: Intercoolers
Post by: Fish on October 03, 2004, 06:36:47 PM
Just found a picture of a setup that is close to what I am fitting. And yes I will be at the pod, but not sure if it will be fitted by then. :confused:

Fish