Confused About Intercooler Upgrades

I have Van's dual fan heat exchanger, ATI 10%, CIA, off road, and tune. Pretty standard stuff. What I never did install was the Bob's oil separator that has been sitting in my closet for the past 7 years. I want to clean the system out and as long as I have it apart I am going to upgrade.

The problem is I really don't know where to start. Kenne Bell has his Bigun intercooler but that is usually mated with a highly modified lower intake. J2 fabrication has its own set of intercoolers with modified inlet/outlet hose diameters. Fisher Motorsport has some ungodly expensive setup. DOB has it's own setups that seem to be vaporware. I guess VMP is coming out with something?

What has worked for you guys? I am willing to modify the lower intake and upgrade the whole system.

Thanks

I have the Kenne Bell Bigun intercooler with basically the same heat exchanger as you. My lower manifold isn't modified, yes it helps to open it up more, but it's not a complete necessity. I recommend the bigun, my IAT2 temps driving around stay about 105 to 110

best thing to lower IATs is meth. cheap and effective.

2011 gtcs said:

I have the Kenne Bell Bigun intercooler with basically the same heat exchanger as you. My lower manifold isn't modified, yes it helps to open it up more, but it's not a complete necessity. I recommend the bigun, my IAT2 temps driving around stay about 105 to 110

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Thanks for the input, but just driving around the bypass is open and air is not going through the intercooler. What I am interested in is wide open throttle IAT2 temps. If you get a chance and could log IAT2 along with IAT1 at WOT and post the log file that would be awesome. That would give me and everyone some hard data to compare against.

After looking at some old log files of mine my IAT2 seems to hover around 30-40 above ambient at WOT. I need to get out and collect some more data. I am putting my ATI 10% balancer back on Monday and will log more then.

I wish we had E85 around here. Would be fun to try.

nxhappy said:

best thing to lower IATs is meth. cheap and effective.

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Meth is not cheap. Ask my dentist.....

VMP Triple-Pass Dual-Fan H/E works well for me - IAT2 is usually around 30 degrees above ambient.

SteveWK said:

Thanks for the input, but just driving around the bypass is open and air is not going through the intercooler. What I am interested in is wide open throttle IAT2 temps. If you get a chance and could log IAT2 along with IAT1 at WOT and post the log file that would be awesome. That would give me and everyone some hard data to compare against.

After looking at some old log files of mine my IAT2 seems to hover around 30-40 above ambient at WOT. I need to get out and collect some more data. I am putting my ATI 10% balancer back on Monday and will log more then.

I wish we had E85 around here. Would be fun to try.

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If you have livelink2 i can send you my most recent WOT log, if I recall correctly my IAT2 temps through the log were mid 90 degree temps. When it was 65 degrees out.

2011 gtcs said:

If you have livelink2 i can send you my most recent WOT log, if I recall correctly my IAT2 temps through the log were mid 90 degree temps. When it was 65 degrees out.

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I do have livelink2. I think you can just post the file here, but I will PM you my email just in case.

Steve I’ll get you some datalog info once I start street data logging.
I have the Bigun, modified lower, rear large 8-10 gal ice tank (just water on the street), two stock pumps (one on each side of system), 1” lines, stock HE with tubular bumper support and custom twin Spals, 170 stat.
My IAT2s are crazy low at the traps with ice, but still very good on the street without ice.
I don’t want to misquote them, so I’ll get new datalogs.
Only improvements I’m doing later this year are 1” fittings on the HE, plus VMP will have an interesting option on the brick soon with 1” fittings.
That’s as far as I’ll take it, or I’ll use the NOS fittings as intended
E85 tolerates higher IATs anyway.
-J

biminiLX said:

Steve I’ll get you some datalog info once I start street data logging.
I have the Bigun, modified lower, rear large 8-10 gal ice tank (just water on the street), two stock pumps (one on each side of system), 1” lines, stock HE with tubular bumper support and custom twin Spals, 170 stat.
My IAT2s are crazy low at the traps with ice, but still very good on the street without ice.
I don’t want to misquote them, so I’ll get new datalogs.
Only improvements I’m doing later this year are 1” fittings on the HE, plus VMP will have an interesting option on the brick soon with 1” fittings.
That’s as far as I’ll take it, or I’ll use the NOS fittings as intended
E85 tolerates higher IATs anyway.
-J

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That would be very helpful. Are you running a larger inlet/outlet on the Bigun? Also what electrical circuit are you using to power the second pump? I had a similar idea floating around in my head but running them in parallel with a Y connection on both ends to a 1" system wide hose but maybe running them in series is better.

Did some logging today. Just to recap I have Van's Super Competition C&R heat exchanger with dual Spal 13" fans. The blower pulleys are stock and I have a Lund tune with CIA and off road pipe. Also, worth mentioning is I never got around to installing my oil separator 23k miles ago. Attached are my results. I made three consecutive pulls, meaning WOT and then hard on the brakes rinse and repeat 3 times. I drove the car for at least 30 mins prior to my pulls and let it sit and idle until my IAT1 (air charge temp) as displayed in the car reached 100 degrees. You can see all of this in my plots. Outside air temp was approximately 77 degrees. I tried to replicate a worse case scenario.

1) First pull did amazingly well. My IAT1 temp was roughly 97 F and my IAT2 hovered around 111 F and then climbed to 113 or so. I was really surprised with this considering how hot my intake air temp was. I guess my oiled down intercooleer is performing ok.

2) Second pull IAT1 temps dropped significantly, 84 - 79 degrees. But unexpectedly my IAT2 temps went up significantly ranging from 120 -123 degrees. Hmmmm.

3) Third pull IAT1 temps still in the low 80s but IAT2 temps increased to 126-128 range.

At this point I can only speculate why the IAT2 temps increased despite the intake air charge temp dropping significantly during the consecutive pulls. Heat from the engine could be getting transferred to the intercooler and affecting its performance or the heat exchanger on the front of the car can't keep up. I suspect the later, but to prove that I need to monitor the water temperature entering and leaving the intercooler. I am looking into how to do that.

Your log is very short and you seem to just be getting on and off the throttle, so I don't think you can expect much cool down between pulls. It would have been interesting to see what a 4th stab of the throttle would have done. I suspect the high IAT1 was the result of the car either sitting at idle for a while or running at low speed cruise just prior to the pulls. With low load you don't have a large volume of air being pulled through the MAF tube and unless you're moving at a good clip, air is coming from the engine bay as opposed to air going through the radiator support. Not to mention air is moving fairly slowly through the tube before you subject it to WOT. I'm guessing ambient air was around 80*.

How warmed up was the car before you started the log? Were all pulls done in the same gear?

SteveWK said:

I made three consecutive pulls, meaning WOT and then hard on the brakes rinse and repeat 3 times. I drove the car for at least 30 mins prior to my pulls and let it sit and idle until my IAT1 (air charge temp) as displayed in the car reached 100 degrees. You can see all of this in my plots. Outside air temp was approximately 77 degrees. I tried to replicate a worse case scenario.

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The whole point of the test was to stress the system to see if it could keep up. It did really well with the first pull, but went down hill after that. What I'm trying to decide is if I want to upgrade the system or if this is good enough for the type of driving I do. Monday my 10% ATI goes back on and I will repeat some of this testing with a bottle of Torco in the gas tank and a retune from Lund. We only have 91 octane here.

All pulls were made in 3rd gear. I have 3.73s.

Catmonkey said:

... It would have been interesting to see what a 4th stab of the throttle would have done. ....

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Here is a 4th gear pull with 3.73s. IAT2 temps hit 126 at end of pull with 84 degree air charge temp. Thats a delta of 42 degrees.

Installed my 170 thermostat. Did another 4th gear pull and no change. See attachment for more information.

Department of Boost has some reading that may interest the OP.

I'm still researching this, but all signs are pointing to removing the intercooler and cleaning it and/or replacing it plus other mods.

I think I should tell you a little history about my experiences with blown head gaskets and why I am becoming more paranoid about this. My first car was an 88 GT and within a year I bought the mass air conversion kit and Paxton supercharger for it. The Paxton kit back then was the old ball bearing planetary drive system just like they used on the old 60's T-Bird. Long story short, it would audibly detonate and then turned into a WWII fog machine, aka coolant in the combustion chamber. I replaced more head gaskets on that car than I care to imagine thinking this time it would be ok.

Here in Kansas we only have 91 octane gas which is not conducive to performance minded people. I have finally relented to my stance on no additives, and I am now the proud owner of twelve 32 oz cans of Torco.

SteveWK said:

I'm still researching this, but all signs are pointing to removing the intercooler and cleaning it and/or replacing it plus other mods.

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If you are removing might as well upgrade. With that in mind, know your goals and weakest link in the chain is the best advice I can relay.

I will most likely upgrade the intercooler brick when I have it apart and do the mods to the intake to increase the surface area of the intercooler both in width and by removing the area that shrouds flow in the back. I can do this myself with a Dremel 4000, flexible tip, and some aluminum carbide tools. I'll get someone else to weld the aluminum plate in the back for the bypass circuit. I might port match the lower to the heads and do some very minor cleanup there. I'll have to look at when I get it apart.

My end goal is to accelerate at WOT from roughly 40 to 130+ without my IAT2 exceeding 20 degrees over ambient. I know the big restriction is flow rate and flow rate is being limited by the diameter of the hoses and back pressure, but I may be ok for this brief WOT.

If this fails I will need to do more analysis. Adding a second stock pump on the exit (hot side) of the intercooler is a possibility for more flow through the intercooler. More research is needed.