Intercooler Question?

[firstwizardshawn]

can a stock intercooler from a rb25 be used on an rb20? and if so is it better, can it handle more hp?

[Sil240]

Hey,Can't tell you for sure, but I believe they are the same.Plus if it fits a intercooler is and intercooler.I'm gonna guess it's probably the same, I don't think anyone has mentioned the 25 IC to be better. If you want my friend has a FMC IC for sale, pretty cheap. And its not a ghetto Ebay special either.

[Joe]

they probably interchange but there is no noticeable difference between them

sidemounts suck.

[Darius]

Not for the sleeper look though

[Joe]

paint your frontmount black.

sidemounts are inefficient.

[Armysweitzer20]

ive found that a front mount increases turbo lag on my mostly stock rb20. I enjoy my sidemount and never notice temps increase even after long amounts of boost. Once i run a larger turbo or other mods ill switch over.

[rb240det]

I've never noticed any substantial lag when I went to a front mount. But it definently helped out with my temps a ton.

[Shocker]

I noticed really no lag.. only more power as with the front mount came more booost.

[Yellow4g63]

The side mount is good for about 10min after you start the car. Then the 1st time you hit boost it's starts to heat soak. I didn't notice any lag going from sidemount to front mount. What I did notice was the jump in HP and the car felt good all the time and just right after it warmed up.

[wawazat8402]

paint your frontmount black.

sidemounts are inefficient.

Thats what I did. You can get some black radiator paint from Eastwoods. You can see where the stock bumper rubbed on the core a little, but I bought an extra can for touchups.

[Bronze MFP]

I hear a ton of trash talked about the stock sidemount, but for a stock setup it works. I've been running mine ever since the engine went in the car and only have had it heat soak in the middle of summer when I was beating the piss out of it. If your car is going to see the track, yeah you might want to upgrade, but for most street driving, the sidemount is fine.

[Carl H]

i would rather airflow to the radiator than a hulking fmic...fmic isnt the best way to solve the charge cooling problem its the cheapest.

[Darius]

paint your frontmount black.

sidemounts are inefficient.

Wouldn't painting your intercooler reduce the heat transfer efficiency of it?

Don't get me wrong here. I'm not promoting the SMIC, I just have the one that came with the clip because I'm saving for a house and retirement at the moment and can't move on to Phase 3 until winter of '07. That is, unless someone wants to sponsor me.

[Cpt_Impossible]

Some company did a test a while back. It showed a coat of radiator paint didnt effect cooling enough to be measured but powdercoating did. I plan to spray my fmic black before too long.

[Cpt_Impossible]

my SMIC experience was about like yellow4g63's. After one pull it would be heatsoaked and the car would become noticeably slow under boost. The fmic Made a huge difference. I didnt feel any extra lag although I am sure there was some small amount. Also, I am using a core with the inlet and outlet on the same side.

25"x11"x3" with 2.5" inlet and outlet

[Cpt_Impossible]

Also, the shop that did my swap suggested putting a bumper vent from the silvia in front of the smic if I planned on keeping the smic because on the stock usdm bumper, it gets no direct air flow which is most of the problem. Ducting or FMIC is your best bet. A moderately sized FMIC seems to be the best choice though since you are going to need one eventually anyway. Why cut up the bumper when you dont have to?

[skillzilla]

i would rather airflow to the radiator than a hulking fmic...fmic isnt the best way to solve the charge cooling problem its the cheapest.

Agreed for the most part, but Im really looking forward to LESS flow then I have now. I have a SR swap now in an S14, stock SMIC. I have a Koyo, dual FAL fans, Nismo thermostat, and an HKS fan speed controller. It is DEFINITELY over kill, my fan controller is set to turn on at 185 degrees and off at 175. Unless I am at a light for a long time it never turns on, car stays steady at 165 (way below operating temp, aka runs kinda rich all the time). If my fan does turn on, even in the GA summer heat, it stays on for about 45 seconds til the sensor reaches 175, then shuts off and the temps still drop to about 163-162, then back up to 165. This is with no upper cooling panel and no splash guard under the motor. Ive seriously considered blocking some rows on the radiator just to keep it around 180 steadily.

Once I upgrade to a front mount Im hoping the decreased airflow will even everything out really nicely.

[Darius]

^^Sounds like a thermostat is stuck open to me^^

[skillzilla]

It warms up from 60-ish to 125-ish in a few minutes, then from 125 to 165 in no time (I dont drive it under 125). After that, it stays at 165. Thermostat is brand new. No signs of a stuck thermostat IMO.

[Yellow4g63]

Also, the shop that did my swap suggested putting a bumper vent from the silvia in front of the smic if I planned on keeping the smic because on the stock usdm bumper, it gets no direct air flow which is most of the problem. Ducting or FMIC is your best bet. A moderately sized FMIC seems to be the best choice though since you are going to need one eventually anyway. Why cut up the bumper when you dont have to?

I did that to mine too. I cut a hole for air to get to the intercooler behinde the pignose bumper. Also drove my car with the stock sidemount for a long time too. My 13.7 1/4 time was on the stock sidemount.

[wawazat8402]

i would rather airflow to the radiator than a hulking fmic...fmic isnt the best way to solve the charge cooling problem its the cheapest.

That is exactly why I decided to get the GTR grill. Plus it meant I had to ditch the popups for Silvia headlights, so it was kind of a done deal.

[Armysweitzer20]

where do they sell these? ive been looking for a double sided IC...

[firstwizardshawn]

thanks for all your help guys i will use the smic until money comes along so i can get me a fmic.

[RB20Skyline]

From what I understand (I could be wrong) it depends on the boost levelyour running and the turbo size. Front mount is ok if your thinking of doingsome track days (racetrack) or running high boost for long periods.

You usually don't change an intercooler until you reach the flow limits.Around 1.5psi pressure drop is what you should aim for. One of thethings to look at when picking an intercooler is to note what boost levelthis pressure drop is at.

For stock turbo or a mild increase in turbo size, the stock sidemountintercooler is ok. It's downfall is air flow. On the R34GTT they solved thisproblem with ducting that sits on the face off the intercooler (high pressurezone) so air doesn't get around the sides of the intercooler, only onto theface and through the intercooler. Nismo has a similar carbon like ductingfor the front mount intercooler on the R34GTR N1 racecar.

On the rear side of the R34GTT sidemount intercooler, there isn't anyducting (low pressure zone) but had a vent in the side of the frontbumper to release the built up hot air behind the intercooler.

If your exceding 20 seconds of sustained full boost, like on a racetrackat full throttle, then change the intercooler. If not and your onlydoing drag racing with a turbo not much bigger than stock, it'sbetter to keep the stock sidemount. This dude in Australia achieved12 sec 1/4's (270hp+ at the wheels with a R3325T) with a sidemountintercooler + stock turbo vs other cars with front mounts that wereslower on the 1/4 mile. I guess the pressure drop was too low.

Also the S15 intercooler is a slightly thicker and taller side mountintercooler. With the S15 intercooler fitted, it should raise boost toaround 14psi (with no boost restrictor fitted), as it's less restrictiveand is slightly better at cooling (more fins than S14 cooler, becausethe S15 sidemount is slightly taller). R34GTT uses a similar sizedintercooler and is fitted to R3325T or R32 GTS-T as an upgrade.

I noticed with not much air getting to a side mount intercooler ofthis size (S15. R34 GTT) on a R32, it last's around 2 laps (hard driving)on a racetrack before it becomes a problem.

There's a business in the US that can custom make frontmount orsidemount intercoolers to you application.

I hope that is of some help.
Modified by RB20Skyline at 5:11 AM 1/23/2007