Intercooler - Myth? Or Fact?

[GTAAAH]

Yeh it would have less lag, theoretically, and would probably be just as efficient as a bigger cooler for mid level modding. Unfortunately every kit i could find, for a decent price, with straight bolt up piping had a big assed 600X300X75 core on it, or around there. I would have prefered something like a 400X300 core but i cant see my 600X300 being to much laggier and who knows one day i might actually need a cooler this big. Only other problem is running only 2 psi over standard it is almost superfluous in my application and i have a type M front so you cant even see it

Edited May 18, 2006 by r32 gts-turbo

[QRI05E]

most people associate more power with a FMIC installation as they crank up the boost at the same time. ie: go from stock boost to 12psi and yeah you'll make 20rwkw of course, more PSI you dial on the compressor means more airflow. airflow makes power.

you will gain 0rwkw fitting a FMIC and nothing else

Just to comment on Paul's opinion, the dynos performed on the hybrid cars DID NOT have the factory boost turned up.. please read the article on the hybrid site... due to the larger FMIC the boost automatically went up 1 - 2psi... therefore considering the engine receiving a cooler and more free flowing air suply as well as the turbo being able to breath a lot better, some sort of power gain should be expected.. Who would have thought a split dump pipe would give me 12rw/kw over a 3" bell dump pipe? There were heaps of sceptics who said a split dump won’t make a difference including many performance shops that I asked… however I do believe that a smoother, cooler and freer flow of air the turbo and engine gets should result more power...

Anyone got any dyno comparisons to prove this fact or myth???

[paulr33]

boost pressure is regualted by the standard wastegate

as soon as target boost is reached in the manifold the gate opens.

so if the intercooler core somehow magically increases pressure, the wastegate will simply open sooner and maitain pressure

and of course a split dump will yield a power increase, you reduct turbulance and backpressure on the internal gate, reducing pressure means its more free flowing and takes away resistance. if you can take away any resistance, you should gain power

[GTAAAH]

hmm but if your getting 2 PSI less pressure lost instead of that 2 psi dissipating due to insufficient intercooler flow then you would be able to run the (rb20 for example) turbo on 14 psi with only the same strain as it would have on it at 12 psi? Or would that mean the {Impellor???} would have less strain on it than the {Compellor???} I forget the correct names for each turbine

Sorry if that train of thought is wack but try answer it plz sum1

Edited May 18, 2006 by r32 gts-turbo

[Warpspeed]

I would say ..... it depends.

My car used to absolutely fly on those cold humid winter nights, but in 38 degree mid summer heat, and after long periods of idling in city traffic it would be an absolute slug. That was with the crappy factory intercooler.

After fitting a GTR front mount it was much more consistent.

Did it increase power, probably not much in winter, but in mid summer it made a hell of a big difference.

There are too many conflicting factors to know for sure exactly what a FMIC is going to do for you. Maybe nothing, maybe a lot, it depends....

A pretty good guide is, does your car go harder with a stone cold engine ? If it does, then a more efficient intercooler is exactly what you need.

If it goes better when the engine is fully warmed up, whatever you have now is working fine.

[d0p3y]

As Bezerkley mentioned the best gains will be had with smarter piping, remember - if the cooled air is having to travel back through the hot engine bay over a great distance then it's just going to get warmed up again and the FMIC will deliver little if any benefit to the cooling.

I would also say that on a stock turbo you may notice a difference but it would also alter the cars torque curve and throttle response in most cases.

Does depend on what cooler, what piping, what boost, etc as well. No "text book" rule for this one in my opinion.

Edited May 18, 2006 by d0p3y

[paulr33]

the air wont heat up when travelling through the pipework as its moving too fast. sydneykid once posted that it moves at 800km/h and it wont have chance to gain any heat from the hot pipework. the fmic core is only as good as the airflow going through it. at idle in traffic it provides no benefit

[GTRgeoff]

Paul

what you say is true, but only if on stock or low boost.

Add boost and the SMIC will limit power, and at 14psi I have measured outlet temps of almost 70deg from the stock dunger on a 30 deg day. Same temp I've measured 30.7-31 deg with a Hybrid 800HP cooler. Driving at under 60kmh the temps would creep to 37 deg from the heat radiating off the road. I could calculate the reduction in power due to the limited oxygen available/heat causing detonation and timing pullout but, well I CBF.

I also once parked facing the sun. Started, drove off gently and got some pinging. Checked the temp log and had hit 75 deg as the sun heated the cooler which then heated the air charge.

Surprisingly I never noticed any lag with the bigger cooler running 220rwkw.

[Roy]

boost pressure is regualted by the standard wastegate

as soon as target boost is reached in the manifold the gate opens.

LOL we have had this discussion before.

But what you have posted is wrong in many cars.

The wastegate doesnt care about the pressure in the manifold. Its typically measure the pressure at the outlet of the turbo. BIG difference as there is a larger pressure drop accross the std cooler

Its near impossible to isntall a good qulaity FMIC and not make more power. Simple reason is the turbo that makes 10psi worth of airflow hgets choked and heated in that crappy std intercooler. So your manifold ends up seeing 8-9psi.

Put on a better FMIC and all of a sudden your turbo is still making the exact same boost, but now with a better intercooler the air is better cooled and has less pressure drop across the core. So now your engine is seeign 10psi.

To say an intercooler by itslef will not make more power without isnt true...as without touching the boost your turbo is running, your engine will see more boost/airflow, at a lower temp.

[mad082]

saying that a front mount won't add any power is untrue. if you blow a baloon up then put it in the freezer for a while. it will shrink. so think about the air going through the cooler.

cool air is more dense. so say for example the air going into the motor is 10 degree's cooler. and say that air 10 deg. cooler is 10% more dense (not real figures, just example till i find the exact figures), then at the same throttle position you have 10% more air going into the motor, and extra fuel to match. more air + more fuel = bigger explosion

bigger explosion = more power.

[mad082]

and another example of air changing density with heat is car tyres. manufacturers give you a recommended tyre pressure for cold tyres, then you add about 8psi for the pressure that they will be when they are hot.

also if you drop the temp of air from 60 degrees to 40 degrees (which is possible considering the location and poor airflow to the stock cooler) the air density rises by 5.6% (at sea level).

what you have to keep in mind is that the stock cooler receives air to from a hole about 4 inches across. when people put a front mount on they usually modify the front bar so it gets maximum air flow. so you are going from about 100cm2 air intake hole to on average about 900cm2 air contact.

Edited May 18, 2006 by mad082

[paulr33]

my r33 actuator takes its manifold pressure signal from the intercooler pipework, after the intercooler core, before plenum

[GTAAAH]

LOL we have had this discussion before.

But what you have posted is wrong in many cars.

The wastegate doesnt care about the pressure in the manifold. Its typically measure the pressure at the outlet of the turbo. BIG difference as there is a larger pressure drop accross the std cooler

Its near impossible to isntall a good qulaity FMIC and not make more power. Simple reason is the turbo that makes 10psi worth of airflow hgets choked and heated in that crappy std intercooler. So your manifold ends up seeing 8-9psi.

Put on a better FMIC and all of a sudden your turbo is still making the exact same boost, but now with a better intercooler the air is better cooled and has less pressure drop across the core. So now your engine is seeign 10psi.

To say an intercooler by itslef will not make more power without isnt true...as without touching the boost your turbo is running, your engine will see more boost/airflow, at a lower temp.

Thats wat i was trying to ask thanks

[Roy]

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

That is a hell of a lot of pipe, which means weld, which means cutting fabricating which means dollars. And is there really a need to be running so much piping to and fro at the front of the car.

Paul, thinking about it the R33 i was looking at the other night had the solenoid plumbed in as you said...so is a little different to the R32 that comes straight off the compressor housing.

...but perhaps the reason so many R33s pop turbos compared to R32s, even though they are not as old is because the R33 turbo actually iscrankign out more boost then the manifold is readying which speeds up the turbo failure?!?!?!?!?

[wolverine]

and another example of air changing density with heat is car tyres. manufacturers give you a recommended tyre pressure for cold tyres, then you add about 8psi for the pressure that they will be when they are hot.

also if you drop the temp of air from 60 degrees to 40 degrees (which is possible considering the location and poor airflow to the stock cooler) the air density rises by 5.6% (at sea level).

what you have to keep in mind is that the stock cooler receives air to from a hole about 4 inches across. when people put a front mount on they usually modify the front bar so it gets maximum air flow. so you are going from about 100cm2 air intake hole to on average about 900cm2 air contact.

how do you explain the openings on V8 supercars?? they are much smaller than the cores. the aperture doesn't need to be the exact size of the core for maximum efficiency.

the standard cooler has an aperture that is adequate to allow flow across its core as air is slowed as it passes thru. the extra advantage that a SMIC has is the lower pressure area behind the core (even a negative pressure into the wheelarch). the limitation is the size of the core and internal design more than anything.

[QRI05E]

Hmmmm some interesting information to consider! I still believe that a FMIC opposed to the stock SMIC will provide some sort of power increase.

Thanks to an SAU member, who PM'd me and informed me about the Gktech FMIC kit which is a bargain at $400 for a full kit... Now im not trying to cause any dispute, but has anyone fitted this kit? what’s you opinion of them? How do they compare to the HYBRID GT Spec in quality and performance?? im aiming for 280 - 300rw/kw after all mods... will the Gktech FMIC kit be enough?

Regards,

Sarkis

Edited May 18, 2006 by QRI05E

[paulr33]

yeah the r32 i think (from what your saying) gets its signal from the compressor outlet cover 2835 proS style, where as 33 gtst gets it from the pre plenum pipework. so there would be a difference there. i know compressor outlet is the best place to measure it from, not sure why nissan/garrett changed it

[mad082]

the openings on a V8 supercar can be smaller as they are naturally aspirated. so they suck the air in. the opening doesn't need to be that big as they only use the amount of air that the engine can suck in.

[Roy]

Dont even worry about comparing it to a V8 Supercar. You dont want to run an opening bigger then you have to as the larger the flat frontal area on a car the crappier the cd. So V8 front ends are a compromise between drag, airflow to the radiator, plenum inlet and brake ducts.

R32s, i assume R33s have crappy cd to start with, so throwing a big fmic in there whilst it isnt going to improve anything, for "Joe Average-Street Burnout Specialist" the hp gain is more important then any cd compromise.

[QRI05E]

Common guys, please advise!!

HYBRID GTspec vs Gktech FMIC

Recommendations?

Experiances with either brand?

"Same shit different smell"?

Haha I would appretiate any help!

I dun mind paying the extra $200 for the Hybrid however is it worth it?

Cheers

Edited May 18, 2006 by QRI05E