osuhunter07

iTrader: (10)

Hey everyone I got a little bored so I took my autotap and hooked it up. I had massive misfires so i had to test it out and see which cylinder it was. So i decided to run the car. At cruising the AIT was 75. at 10 psi my AIT was 81-82. So i see like a 6-7 degree increase in air temp at 10 pounds. Seems like it works well to me!! If anyone wants the autotap file to look at it I can email it to you. Just wanted to share some numbers

P.S I was an idiot and didn't put on RPM. D'OH!

onfire

iTrader: (17)

Did it jump 7 degrees in one run or after multiple runs?

osuhunter07

iTrader: (10)

after about 5-6 runs it was a total of 7 degrees more heat, so less than 1 degree per pound increase.

Zombie

iTrader: (2)

Those results match my results at 10.5 psi. At only 5-6 psi there is basically no increase. When I first get on it there is a 2-4 degree drop in temp before it will start to increase in a 2-5 gear pull. Even back to back the temps stay low.

gogogadgetcar

are you saying at a manifold pressure of 10psi your intake temps are only 7 degrees higher than ambient? I don't think that is possible...

at sea level you should see a temp of about 120, and that would be if the intercooler was 100% efficient. with only 7 degrees of tempeture rise your intercooler is way above that.
I must be confused...
are you only talking about how it handles heat soak?

osuhunter07

iTrader: (10)

noo, i am saying in a run my AIT shows a 7 degree heat incease at 10 pounds

2001WS6Vert

Mine at 10 lbs. would go from ambient (say 80-85) to (130-140). That is still a lot better than the 170 I was seeing with the Vortech aftercooler (icing the water first). I am a big cube motor so thats moving a fair amount of air through the cooler.

GrannySShifting

iTrader: (10)

you may be exceeding the max airflow (volume/mass) that the intercooler can handle possibly with the big motor?

NA$TY-TA

iTrader: (21)

WHAT R U TALKING ABOUT...... He is saying his AIT is only 82 degree's..... have you never logged your car before???? I logged mine all the time here in hot *** S. Texas weather and my motor alone temps it was around 100 degree's.... and while cruising on the freeway my temps would drop as low as 92 degree's............... No with this kit.... (this exact kit it was mine i sold it to him....) i would see 120-150 degree temps after blasting off a few WOT runs...... thats with the stock twins...... now with the FMIC that I FABBED UP my cruising temps would only be a few degrees above ambient... and only rise a few more say 5-9 degrres after many WOT blasts. There were nights when it was cool here this winter that the intake side of the IC would be warm and the outlet side would be colder to the touch then the outside temp..... These OBX IC's work very well for the $$$
Now that my .02
Kyle

GrannySShifting

iTrader: (10)

Has anyone ever recordedthepressure drop thru one compared to the fancier stuff

Zombie

iTrader: (2)

Does it even matter? If it drops 3 psi, just turn up your boost 3 more psi to make up the difference. The ATI guys are saying they see a 1 psi increase in boost by getting rid of the ati twins.

gogogadgetcar

this makes sense to me. the key word is after. when I read the first post I thought he ment durring. my bad

I'm not knocking these OBX intercoolers, they're obviously a good deal. People have been going crazy over them. I'm sure with good reason.

i don't think air to air IC's can be cooler than the ambient temp, it has hot/warm air going through it and uses ambient air to cool it.

gary

GrannySShifting

iTrader: (10)

Are you serious? Yes it matters. Turn the boost up and that intercooler has to deal with cooling more. The compressor has to compress the air regardless if you see it on the boost gauge or not right? if its working to produce 12 psi and motor only gets 9 psi, then youll only get the power of the 9 psi, with the intake charge temp of 12 psi AND not to mention the extra power consumed by the blower to turn that extra 3 psi of pressure up. Losses due to blower drive add up as the rpm goes

Zombie

iTrader: (2)

Well with a supercharger it's not as easy to turn the boost up, but with a turbo it is. You can look it from several different angles on a turbo setup.

What if your target boost is 9 psi, but the compressor is only in the 60% effeciency range with 0 psi drop. You now have a drop of 3 psi through an intercooler but have to boost to 12 psi pre intercooler to see 9 psi at the outlet, but now your compressor might be at the 65% effeciency range. So which causes less heat? The boost increase due to the restriction, or running at a lower effeciency range? Really depends on the situation I guess.

I think way too many people like to argue on these forums and just end up splitting hairs, especially at the power level most try to run (low 500s). In the end as long as you get boost in the motor, don't detonate and keep your a/f's reasonable, it's gonna make power (within reason of course).

For the $250 price does it matter if it has 1psi more drop than the $750 intercooler if they both work well?

S_J_H

I'm pushing a g-trim to 70,000 rpm. For the majority of the time my car has been supercharged, it was with NO intercooler using alky injection. Ran it like that for 3 years.
I would see about 13psi peak boost with IAT of around 160- 170' on a 80' day with a hefty amount of alky flowing(20gph).
So that's 13psi with 160-170' IAT with totally unrestricted piping direct from blower to throttle body. Iat's without the alky were around 200'F.

Now I install the obx with about 12 feet of 3" piping.

IAT would now only run about 3 degrees over ambient and I am only seeing 20' rise at peak boost, which has dropped to 11psi.
MAF flow readings are up even though boost is down.
The obx dropped my IAT a good 100'F over no intercooler at all, and bested the alky/no intercooler setup by 60-70'f, Sorry alky lovers.
Dropping the temperature of a gas by 100'f will also drop the pressure by around 2psi. That is pure physics. Simply use the ideal gas law equations to calculate pressure drop from temp drop.

What this means is the OBX intercooler is showing little pressure drop from "restriction" over having no intercooler at all on my combo.
I don't care what the so called experts say, It's a very nice unit for the buck!

Steve

Avengeance

iTrader: (4)

Damn Im glad I got one of these OBXs.... cant wait to have it all installed.

GrannySShifting

iTrader: (10)

Without getting into the effeciency ranges of a turbo, i was just asking if it is a much different effeciency intercooler with some backed up facts. A 2 psi change isnt going to get a turbo out of a very ineffecient range and into where its happy

SJH math makes sense it lost 2 psi with a temp drop, havent sat down to figure it out though, but seems reasonable. looks like its decently effecient then

onfire

iTrader: (17)

What's the core size on the obx? Bar and plate design?

NA$TY-TA

iTrader: (21)

Do a search for OBX and frcfed98 and thedimensions ill come up... and yes it is a bar and plate design.
Kyle