4.0L WHIPPLE- <-Official thread.
I guess the reason for using the 2.9's intercooler core is they already have a lower manifold built for it that works with the front drive and drive shaft.
The same rail core is BIG but not perticularly thick if i remeber. Whipple say its 14”L x 7” W x 3.0” H. So its core great core volume than the GT500 and a larger surface area. So it should cool pretty bloody well! lol
Be nice to see what two of these cores stacked would do!

Chris.
Kurt
Was this under normal driving conditions or extended load periods? If under extended load then i can see what you mean and its not good!
With these cores is there no way to tap in to the back of the intercooler and run the core as you intended? With the core in a single pass config. is ther eno worry about the back (or fornt depending on how its plumbed) getting hotter air than the front cylinders?
Chris.
I was testing on engine dyno. I was parking the engine at 850hp and waiting for the water to stabilize, but it would not. The core now has the water go in on drivers side and travels forward on that side, then crosses over to the passenger side and travels back. If I could use the whole core without the double pass I believe the water flow will double and the inlet air temp will stabilize at a lower temp. When that happens the water out will be lower and stable, at least that's what I think!
Kurt
Was this under normal driving conditions or extended load periods? If under extended load then i can see what you mean and its not good!
With these cores is there no way to tap in to the back of the intercooler and run the core as you intended? With the core in a single pass config. is ther eno worry about the back (or fornt depending on how its plumbed) getting hotter air than the front cylinders?
Chris.
I was testing on engine dyno. I was parking the engine at 850hp and waiting for the water to stabilize, but it would not. The core now has the water go in on drivers side and travels forward on that side, then crosses over to the passenger side and travels back. If I could use the whole core without the double pass I believe the water flow will double and the inlet air temp will stabilize at a lower temp. When that happens the water out will be lower and stable, at least that's what I think!
Kurt
Kurt
The Best V8 Stories One Small Block at Time
http://forums.corvetteforum.com/1576564286-post10.html
Kurt
http://forums.corvetteforum.com/1576564286-post10.html
Also have you seen the double stacked ZR1 intercoolers? Cant remember which company did it now. It was in a ZL1 though as these would never fit in a vette!
How about remote coolers? The BMW mini cooper s ran a air to air intercooler with the supercharger and the Aston Matrin Vantage (not the v12s) ran dual eaton supercharger with twin air to water charger coolers mounted in front of the engine! Just thinking this would give MUCH greater flexibility for bigger cores to be used. Maybe even air to air!
Also have you seen the double stacked ZR1 intercoolers? Cant remember which company did it now. It was in a ZL1 though as these would never fit in a vette!
How about remote coolers? The BMW mini cooper s ran a air to air intercooler with the supercharger and the Aston Matrin Vantage (not the v12s) ran dual eaton supercharger with twin air to water charger coolers mounted in front of the engine! Just thinking this would give MUCH greater flexibility for bigger cores to be used. Maybe even air to air!
Anyways I think what the guys did with the ZR1 is retain the use of the dual-pass which is supposedely more efficient BUT solve the issue thats inherent with dual pass coolers which is lack of flow volume (half of a single pass)? Man this topic is probably one of those things that not necessarily wory by common sense until you start doing real life testing.


Because of how big the heat exchanger is, I also went with a custom Ron Davis radiator to compensate for the airflow blocked towards the radiator since this has to be drivable here in Dubai.
On the air to air and air to water thing, most turbo application from manufactures are air to air. As long as you can get a big enough core and sufficent airflow it's really the best way! Obviously if it's harder to get airflow to (mid engined) or hard to package (top mounted supercharger) it's often raiser for them to go air to water. The other thing with supercharger and air to air is the risk of leaks. If you split a intercooler boot on a SC MINI the engine runs away with itself as it's no longer throttled.
I think the marine stuff that whipple offer is a copper based core to prevent corrosion when using salt water. The Marien cores are big from what I have seen. Be interesting to see if one would fit on your car though. Did you ever look into the 4.5 ltr blower?
Chris.
On the air to air and air to water thing, most turbo application from manufactures are air to air. As long as you can get a big enough core and sufficent airflow it's really the best way! Obviously if it's harder to get airflow to (mid engined) or hard to package (top mounted supercharger) it's often raiser for them to go air to water. The other thing with supercharger and air to air is the risk of leaks. If you split a intercooler boot on a SC MINI the engine runs away with itself as it's no longer throttled.
I think the marine stuff that whipple offer is a copper based core to prevent corrosion when using salt water. The Marien cores are big from what I have seen. Be interesting to see if one would fit on your car though. Did you ever look into the 4.5 ltr blower?
Chris.
We started working on this car on November and there was no 4.5 liter blower at that point in time, plus lots of talk about a front feed 4liter blower that will have the small 2.9liter intercooler core in an effort to make it fit.
The problem with the 4liter blower is based on Whipples website its more like a 3.85 liter blower and not a 4, the 5.0 however it truely a 5.0 and the 8.3 is simply a 5.0 driven by the other rotor so it spins 66% quicker per one engine rev (5.0 x 1.66 = 8.3) and thus does not flow more CFM at max RPM than the 5.0 but does so at a slower blower speed.
I know that big core is corrosion resistant but I thought they could produce the same thing without the necessary corrosion protection for our vehicles, BUT the issue is fitting this stuff under a hood, the blower pulley sticks out far ahead and is very high the cowl has to ramp up really quick to clear the blower, I had a custom hood made to clear this monster, dont be fooled by the pictures its HUGE. lol
I upgraded the core so it had two -12 inlet fittings, the factory was -8 thread into the core with a -10 hose connected. With that factory hook up I had:
5 gals minute @ 10PSI water pressure.
6.8 gals @ 20 PSI
8.5 gals @ 30 PSI
9.5 gals @ 40 PSI
After revising the fittings:
5.8 gals @ 10 PSI
7.0 gals @ 20 PSI
Did not test above as it shows the core is the major flow restriction. I did run it again on the dyno at 20 PSI water pressure, the curve moved over a few seconds but it will not stop climbing inlet air temps still.
I just got the 4.0 sand rail kit and took that apart for water flow testing:
9.5 gallons @ 10 PSI
13 gallons @ 20 PSI
16 gallons @ 30 PSI
Much better with a similar core size, but still requires high PSI for flow and still falls short of my desired flow. I did notice the 2.9 core is made in China, the 4.0 is made in USA.
I reset the PSI @ 10 and put the two fittings from the intercooler together without the core in the test rig, just flowing the fittings. Fittings alone:
9.5 gallons @ 9.8 PSI
The fittings flow the same volume although I got a small drop in my set pressure, so it looks like the core flow could increase if the fittings can be made larger. Next week I will change the fittings out for something larger and retest.
Looking good for getting 1000hp engine that can run multiple laps on a road course!
Kurt
For whats is worth I believe my intercooler is smaller than the one they put in the 2.9 kit, but I do have -12an inlet/outlet on opposite sides instead of directly beside each other. Should be driving mine this coming week, I will get a log with IAT and see where its at.

