Intercooler - Myth? Or Fact?

[QRI05E]

I dunno Rob... im just going to what they state on their site.. besides, could they post such results if it were a lie? wouldn't that be misleading?

I appretiate your answer Roy, i think the difference between both coolers is minimal... thanks bud

[rob82]

im with roy. the stocker fmic on the xr6 is a garrett OEM core and is fine for stock boost

Apart from the fact that it has closed loop boost control that wont allow it to run any more than standard(unless edited) the standard IC is good 4 300rwkw thats about 100rwkw above standard!!!

[Sydneykid]

What an absolute crock of shite where are they getting these figure from? An XR6T will gain nothing with an aftermarket intrecooler running standard boost. I know that for sure. If thats anything to go by then their figures are just BS!!!! The only car that would really benefit from an IC change would be the subi's as they have active ignition.

Of course the XR6 won't gain anything from an intercoler upgrade, it's a closed loop system, even worse than the R33GTST. Without tuning it will probably lose power. If you make the boost the same at the compressor outlet, then it will make more power (with tuning to compensate).

Every R32GTST we have fitted a FMIC to has made noticeably more power without tuning. Because their boost control system is before the intercooler.

Subi's retard below their set ignition timing, they do not advance above their set ignition timing. If you reset the ecu, they will then only loose power from there, they never gain it.

Chicken and the egg, which comes first, tuning or intercooler?

cheers

[rob82]

Of course the XR6 won't gain anything from an intercoler upgrade, it's a closed loop system, even worse than the R33GTST. Without tuning it will probably lose power. If you make the boost the same at the compressor outlet, then it will make more power (with tuning to compensate).

Every R32GTST we have fitted a FMIC to has made noticeably more power without tuning. Because their boost control system is before the intercooler.

Subi's retard below their set ignition timing, they do not advance above their set ignition timing. If you reset the ecu, they will then only loose power from there, they never gain it.

Chicken and the egg, which comes first, tuning or intercooler?

cheers

Depends which year 02 onwards have an advance mutiplier that will continually add timing on top of there base ignition map until it reaches the "maximum learnt timing" numbers which can be up to 8 degrees at full load from memory. If you reset an 02 onward wrx or sti the advance multiplier will revert back to a factory setting of 8. If you ran the car with an advance mutiplier of 8 it would lose about 20% power. Once the engine is up to temp between 80 and 87deg it will start to learn ignition back in and you will see the advance multiplier go back up to 16(which is the maximum) and it will start to make power again.

Even pre 02 had the ability to learn ignition advance in. I think before they changed over to OBD2 which was 98 the subi's could only retard igntion.

Edited May 18, 2006 by rob82

[QRI05E]

Back to the topic, I think from reading everyone’s theories on the intercooler myth/fact, its safe to say that considering the positioning, size, efficiency rate, heat soaking and other factors of the stock SMIC, a FMIC wether it be a Gktech, HYBRID or Trust should make some sort of improvement to the cars power ability and drivability...

So far, 'Bang for Buck" the Gktech has won me over...

Edited May 18, 2006 by QRI05E

[GTRgeoff]

For an intercooler, the variables affecting performance are surface area (internal and external), mass, surface finish and flow rate. All those being equal, they will perform equally well.

Thus far I have seen little significant difference between the top brands, the Hybrid and Gregs offering (GKTech) so now it comes to price. Aluminium is still aluminium. If the surface finish is matt then heat TF will occur at a constant rate with all other constants. The flow rate is good for the expected power requirement. The mass will allow good heat dampening.

With the fittings supplied and good instructions, for the price the GKTech cannot be surpassed on quality, performance and VFM (value for money). Even the GTR cooler requires substantial stuffing about with piping so at $400 average price is a genuine ripoff in straight comparison.

If the name convinces you, well fine, spend your money on HKS etc. I base my opinions on solid science and engineering fundamentals and if your power budget is easily covered by these then there is no technical justification to buy anything else, price of course being the determining factor.

Amateur technologists and ricers feel free to argue. I am in the mood.

BTW I'll add that Greg is a fairly long term member of the forum with a passion for cars. I recall pics of his CRX and believe he's now in a Skyline. He's a young guy who has seen a business opportunity and taken a risk and to be honest, I've been a bit jealous watching as his business has started to grow as he's taken what I think was a considerable risk for someone so young. He specs and contracts the manufacture of individual items and kits and then sells at good prices. So good luck to him.

[Alien]

off topic... I built the GKTech.com.au website back when I was doing freelance web design lol

[Munna1]

Seeing as my next step is to install a FMIC on my R33 GTSt, I have been trying to research wether a FMIC would actually increase my cars current power output or not. Many sceptics say that a FMIC won’t increase any power but will only be a supporting modification to allow higher power output. Interestingly enough, I was looking into fitting a Hybrid GT spec kit and thought to share some of the claims Hybrid have made.

www.hybrid-power.com

Claims that with their Monster Bar & Plate Cooler kit for a skyline, have achieved a typical Gain: 25-30 rear wheel kilo watt (RWKW) with no other mods!

www.powerdigger.com

Claims:

MY01 Subaru WRX with the factory ECU boost controller gained 15aw/kw (40kw gain at engine)

Holden Calais VL Turbo gained 50rw/kw in the mid range of about 3250rpm with only 12 psi of boost.

Ford BA XR6T gained a massive 17% power of 30kw (about 50kw power gain at the engine) with standard boost.

Please visit the Hybrid websites to view their full claim along with dyno results.

Would anyone like to comment on these claims? Im intrested to see what your opinions are on this issue.

Regards,

Sarkis

Claims that with their Monster Bar & Plate Cooler kit for a skyline, have achieved a typical Gain: 25-30 rear wheel kilo watt (RWKW) with no other mods!

Mate I have this intercooler and it did make a big power difference at the same boost especially after the SAFC2 was retuned

[justin911]

hehe ya it was because of the safc2.....

its like me installing a cheese burger on my windscreen.. and then installing a safc2... probs see the same gains

[Sydneykid]

Depends which year 02 onwards have an advance mutiplier that will continually add timing on top of there base ignition map until it reaches the "maximum learnt timing" numbers which can be up to 8 degrees at full load from memory. If you reset an 02 onward wrx or sti the advance multiplier will revert back to a factory setting of 8. If you ran the car with an advance mutiplier of 8 it would lose about 20% power. Once the engine is up to temp between 80 and 87deg it will start to learn ignition back in and you will see the advance multiplier go back up to 16(which is the maximum) and it will start to make power again.

Even pre 02 had the ability to learn ignition advance in. I think before they changed over to OBD2 which was 98 the subi's could only retard igntion.

Water temp is basically irelevant to intercooler performance, as far as power output is concerned.

cheers

Edited May 19, 2006 by Sydneykid

[Sydneykid]

For an intercooler, the variables affecting performance are surface area (internal and external), mass, surface finish and flow rate. All those being equal, they will perform equally well.

Thus far I have seen little significant difference between the top brands, the Hybrid and Gregs offering (GKTech) so now it comes to price. Aluminium is still aluminium. If the surface finish is matt then heat TF will occur at a constant rate with all other constants. The flow rate is good for the expected power requirement. The mass will allow good heat dampening.

With the fittings supplied and good instructions, for the price the GKTech cannot be surpassed on quality, performance and VFM (value for money). Even the GTR cooler requires substantial stuffing about with piping so at $400 average price is a genuine ripoff in straight comparison.

If the name convinces you, well fine, spend your money on HKS etc. I base my opinions on solid science and engineering fundamentals and if your power budget is easily covered by these then there is no technical justification to buy anything else, price of course being the determining factor.

Amateur technologists and ricers feel free to argue. I am in the mood.

BTW I'll add that Greg is a fairly long term member of the forum with a passion for cars. I recall pics of his CRX and believe he's now in a Skyline. He's a young guy who has seen a business opportunity and taken a risk and to be honest, I've been a bit jealous watching as his business has started to grow as he's taken what I think was a considerable risk for someone so young. He specs and contracts the manufacture of individual items and kits and then sells at good prices. So good luck to him.

All 100% true (I would expect nothing less), but (there is always a but)..........

Having tested several intercoolers (results in many previous posts) when we were building the first R32 Improved Production car, I can say with absolute certainty that oils ain’t oils Sol.

Do a search if you want the full story, in summary……..

Bar and plate cores are good if you do short power bursts, they have more aluminium (weigh more) so they are a better heat soak. But they take longer to cool down. Hence good for drag cars and road cars that get short burst of power then cruise. They do limit the airflow to the radiator more than tube and fin cores.

Tube and fin cores are good for more constant power applications, they weigh less so not as good for instantaneous heat soak. But they shed heat quicker than a bar and plate. Hence good for circuit race cars and cars that see long periods of sustained power.

When you cut open a few different intercoolers you quickly see how much difference there is internally, particularly with the fins inside the tubes/bars. The air passes over/around those fins and sheds heat as it travels through the core. Some cores have longitudinal (parallel to the airflow) fins, some cores have no fins at all and some cores have lateral fins (across the airflow). Obviously a core with no fins will flow more (for the same ID tube) than a core with longitudinal fins and tubes with lateral fins will flow the worst. But a core with no fins won’t cool as well.

Lastly, the way the airflow is handled as it enters/exits the tubes/bars is important. This includes the end tank design. Rough edges, poor welding and blanked off parts of the tube/bar are indications of a poorly made core.

The ultimate test for us was to measure the boost at the compressor outlet and the plenum. This tells us the pressure drop across the core, how well it flows at that power application. Then compare the temperature at the compressor outlet and the temperature at the plenum. We also kept a close watch on engine water temps as a check of the effect of the intercooler on the airflow to the radiator. Add the two results together and you have a complete picture. We tested a number of 600 X 300 X 65-75 mm cores and the standard R33/34GTR intercooler came out best every time.

It wasn’t until we got to an 85 mm thick aftermarket core that we found any improvement. But because of its much greater internal volume, it lost noticeable throttle response at the power output we were running at the time (around 300 rwkw).

So armed with this information you need to ask these questions;

How much does the core weigh?

Is it tube and fin or bar and pate design?

Which is better for your application?

What sort of internal fins does it have?

What is the pressure drop at the core at your power target?

What is its internal volume?

Then take a look at the end tank design?

And the tube/bar finishing inside the ends tanks?

Then (and only then) can you can make an educated decision on which intercooler you should spend your money on.

cheers

[Beer Baron]

gary what benefit if any is there using a 33 or 34 GTR core over a 32 one?

[Sydneykid]

gary what benefit if any is there using a 33 or 34 GTR core over a 32 one?

There is a well known motoring journalist who started an urban myth that R32GTR intercoolers were thinner than R33/34GTR intercoolers. So I closely compared the dimensions and there isn’t any difference. One urban myth dead.

When challenged on this, the story changed to the R33/34GTR intercooler has more tubes. So I counted the number of tubes and there isn’t any difference. Another urban myth dead.

The current story is that internally they are different. Unfortunately I haven’t had an R32GTR core and an R33/34GTR core at the same time that I can justify cutting up. So until I dispel that urban myth, I can’t answer the question.

If some one wants to donate a damaged R32GTR intercooler and a damaged R33/34GTR intercooler, I will most gladly do the comparison. I like killing myths.

cheers

[Cubes]

So if you change to a freer flowing FMIC and pipework on an R32GTST then you get 10 psi at the plenum. Hence you get more power from just fitting the FMIC without changing the BOOST SETTING (but the boost changes).

This of course doesn't work on an R33GTST because you still get 4 psi at the plenum. The wastegate actuator takes its feed AFTER the freer flowing intercooler and pipework. So the turbo itself is producing less boost then it was with the standard intercooler.

But on an R33GTST, surely it is fair to say that you should return the boost to the same level at the compressor ie; add 1-2 psi at the plenum. So that the turbo itself is producing the same boost as it was with the standard intercooler.

It depends an your opinion as to whether that constitutes MORE boost or not.

cheers

How much of a power increase is the question.

Mine for example was done back to back on the same day.

12psi with the stock smic saw 152rwkw, 2 runs both were the same.

Fitted up the spearco bar/plate fmic with tanks where the in/outlet are 'almost' perfectly centered.

On the same 12psi the car saw 155rwkw. So a small increase but nothing really.

It was interesting to note that on 12psi the boost level after the fmic hardly changed. I was told they appear to flow ok but heat soak really quick at this boost level ON the R32's. Tim at that time featured an article in Zoom where he fitted one of these fmic's up to an R33 and saw a decent improvement in power. He did the complete measure before and after the fmic to measure the boost drop.

So .... It appears the stock smic supports airflow levels up to around 150rwkw before it starts to become a restriction to the point where boost/airflow is affected. A super super mild R33 makes this power on std boost, an R32 needs boost.

On the dyno there was no increase in spool time.

On the road however the boost snap on felt slightly software and throttle response was slightly dulled.

I then pushed 1bar in to it and had a quick power check done to ensure the afr's were fine, which they were not so I fitted a fuel pump.

Thats what I experienced. A 3rwkw increase in peak power with slight loss of throttle response.

[Beer Baron]

thanks gary. i think i will stick with my trusty 32 GTR cooler for now then!

[dezz]

Hi QRI05E

I noticed your interest in the GKTech group buy. I am about to send a PM to all of those that have expressed their interest, and I have added a list of those members in the thread

http://www.skylinesaustralia.com/forums/in...howtopic=117938

[GTRgeoff]

Always great input Gary but....seriously that's really down to splitting hairs for a Racecar (does BSM really mean Buckets o'Spending Money?? )

I know I can be accused of the same often enough when I need to make a point, and dammit my fault for not quantifying the type of use but the purpose of my exercise is to establish the best VFM for general road users and occasional trackies. I don't recall outlet temps ever getting more than 1 degree above ambient with the 800HP (monster) Hybrid. Also water temps seemed fine but I was on road rubber so couldn't get into it harder.

Hey have you seen the new race magazine for racers and race car builders? Worth a look guys, unless you are SK.

GKTech seemed on close inspection to be as good and clean in construction, with finned internally bars much like what you see front on in the cooler. The settling chambers have good radiuses and the pressure drop values are good enough for me. I worked with some good fluid chambers and a mach 7 shock tunnel and possibly the only person in the world to put an armoured vehicle in a wind tunnel so I have a keen eye for what shouldn't be there.

You realise there is a percentage loss value attached to each bend and length of straight pipe? Of course you do so why not shorten pipe and use water/air? just to get off topic. Weight is usually the answer, as well as plumbing complexity and more electrics but I think there is good scope on a line.

Anyway why were you looking at non standard in the Nazi classes? Shame!!!

[Busky2k]

Then compare the temperature at the compressor outlet and the temperature at the plenum. We also kept a close watch on engine water temps as a check of the effect of the intercooler on the airflow to the radiator. Add the two results together and you have a complete picture. We tested a number of 600 X 300 X 65-75 mm cores and the standard R33/34GTR intercooler came out best every time.

Hi SK,

Would you be able to elaborate on the results? What kind of pressure drops were you seeing with the GTR cores and the aftermarket ones? And at what boost pressure/kw?

[Andi]

Use the cooler but not the pipework, have some custom pipes made, preferebly with the long pipe before the cooler and short pipe after. can use standard piping down into inner guard, run turbo outlet around behind the cooler, and cooler outlet up to throttle body. the shorter cooler pipe will see you more power. Better quality kits use this system.

The Hybrid piping that runs up behind radiator is long and gets heated. Works more like a interheater.

These pics are from a VL with an RB25 but the same applies to Skylines and we've done the same to R33's.

This is exactly what I'm planning on doing, I've sourced a great K&J tube and fine core and want to use it on the GTT. Now I was planning on doing the above or get one end tank modified so it sits similar to the ARC coole.

Now would it better to try to get the end tanks to be of similar design to ARC coolers or would that little bit of extra piping extension (as in Berserkly's pictures) hardly make a difference in lag/responsiveness?

P.S Sorry didn't want to butt in but didn't think it was wise to start a new thread while theres already about 2-3 active ones.

[wolverine]

and possibly the only person in the world to put an armoured vehicle in a wind tunnel so I have a keen eye for what shouldn't be there

that seem a bit like putting shane warne in a monastery.