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where in FL are you? Im in the Ft. Lauderdale area, boosted GS as well. My car runs 192 - 195*F coolant temps 99% of the time without AC cruising or city driving in 100* temps. With AC on, cruising temps is 195*F, city driving can range but have seen it go 210*F. I have pro-speed fans only. Car is always running E85.
Originally Posted by baxsom
I've got a 13 grandsport manual. I've got an ECS kit and a tsp stage 2 cam going in. I live in FL and it's hot as *****. It's looking like at the minimum a new fan may be necessary if not a new radiator also. I'm seeing that prospeed is the main choice in fans followed by GSspeed. Then dewitt and mishomoto radiators. It has been recommended to me to upgrade the fan first then the radiator if necessary
but i just wanted to see if there was a proven combo I should be looking at. I've also seen where getting an 05 fan for it's more enclosed shroud will make a huge difference too. What says the masses.
I do not have any issues with cooling. Most of the pictures I have seen when people go to the short radiator is they either remove the plate cover that comes with the kit which pretty much lets the air go where it wants OR they put the plate back on but there is a 3" or more gap between the plate and the top of radiator. So all the air coming in isn't forced into the radiator. I gives it a path at the top of the radiator to escape. By blocking off the top of the radiator it forces more air through the radiator but it allows the fan to pull air much easier through the radiator. At least that's how it all works in my head. If you look at some race cars they will create a V with the IC and the Radiator which forces air to go through both.
So you’re running the A&A kit with a shortened radiator and you have a shroud that’s covering the 3”gap from the radiator and the cover plate? Do you have pictures of your setup from all sides so I can see how this was done? I have the exact same setup but am also running the dual Prospeed fans. What did you use for a shroud to cover everything? I’m very interested in this….feel free to private message me as well.
Last edited by biznessguy99; Jun 27, 2025 at 05:32 PM.
So you’re running the A&A kit with a shortened radiator and you have a shroud that’s covering the 3”gap from the radiator and the cover plate? Do you have pictures of your setup from all sides so I can see how this was done? I have the exact same setup but am also running the dual Prospeed fans. What did you use for a shroud to cover everything? I’m very interested in this….feel free to private message me as well.
So after doing some research on this topic through all the forums I had yet to find a solution for the airflow escaping over the top of the shortened radiator with the A&A kit installed. So after thinking about ways I could approach this to block the air off I came up with this solution. I wanted to post in this thread for others who might have this issue. I went to Home Depot and picked up some 2 inch rigid insulation, high heat foil tape, some heat shield for wiring from O'Reillys and some double sided 3M tape and went to work. I measured the length between the inner edge of the radiator to the edge of the intake pipe and cut it to be about 2 1/4 inches high and it was 2 inches thick. I took off the metal shroud and wrapped the rigid insulation putting the heat shield on the bottom creating the barrier between the radiator and the insulation and then wrapped the whole thing in about three layers of high heat foil tape (basically the same tape you use for dryer vents). Once I had it wrapped I now had a shiny block and placed it on top of the radiator and then put the shroud back on and just admired how well it sealed up that 2 inch gap. I put some double sided 3M tape on top and then put the shroud back over it and it sealed it right up. So now I'm driving around and the temps have come WAY down because air is now being forced to go through the radiator instead of taking the path of least resistance which was over the top of the radiator. Again, this was the fix I found running a shortened CSF Radiator (same as the DeWitts Shortend radiator) with the Prospeed dual fans and the A&A kit. If your running one of these radiators then you might want to try something like this to keep that air from escaping into the engine bay. If DeWitts or CSF is in this thread they should manufacture something like this that can seal up the gap for customers. You can see the 2 inch gap Area between the air filter housing and the intake rigid foam insulation cut to fit wrapped with foil tape notice the heat shield on the bottom. That was the barrier between the radiator and the insulation brick The finished product. Completely sealed up the gap. No more air flow loss
So after doing some research on this topic through all the forums I had yet to find a solution for the airflow escaping over the top of the shortened radiator with the A&A kit installed. So after thinking about ways I could approach this to block the air off I came up with this solution. I wanted to post in this thread for others who might have this issue. I went to Home Depot and picked up some 2 inch rigid insulation, high heat foil tape, some heat shield for wiring from O'Reillys and some double sided 3M tape and went to work. I measured the length between the inner edge of the radiator to the edge of the intake pipe and cut it to be about 2 1/4 inches high and it was 2 inches thick. I took off the metal shroud and wrapped the rigid insulation putting the heat shield on the bottom creating the barrier between the radiator and the insulation and then wrapped the whole thing in about three layers of high heat foil tape (basically the same tape you use for dryer vents). Once I had it wrapped I now had a shiny block and placed it on top of the radiator and then put the shroud back on and just admired how well it sealed up that 2 inch gap. I put some double sided 3M tape on top and then put the shroud back over it and it sealed it right up. So now I'm driving around and the temps have come WAY down because air is now being forced to go through the radiator instead of taking the path of least resistance which was over the top of the radiator. Again, this was the fix I found running a shortened CSF Radiator (same as the DeWitts Shortend radiator) with the Prospeed dual fans and the A&A kit. If your running one of these radiators then you might want to try something like this to keep that air from escaping into the engine bay. If DeWitts or CSF is in this thread they should manufacture something like this that can seal up the gap for customers.
You can see the 2 inch gap
Area between the air filter housing and the intake
rigid foam insulation
cut to fit
wrapped with foil tape
notice the heat shield on the bottom. That was the barrier between the radiator and the insulation brick
The finished product. Completely sealed up the gap. No more air flow loss
Have you noticed any type of melting of the foam even with the foil? That radiator will get to 210 or so degrees and usually foam starts to melt around 170-180
Have you noticed any type of melting of the foam even with the foil? That radiator will get to 210 or so degrees and usually foam starts to melt around 170-180
I've been running it now for 3 weeks in 95+ degree heat and they've been holding strong. I put lots of heat shield on the bottom piece between the insulation and the radiator so I imagine thats been helping. So yeah, so far they've been holding up pretty good.
I've been running it now for 3 weeks in 95+ degree heat and they've been holding strong. I put lots of heat shield on the bottom piece between the insulation and the radiator so I imagine thats been helping. So yeah, so far they've been holding up pretty good.
That's good. After doing the blocking, how much of a difference did it make in coolant temps?
That's good. After doing the blocking, how much of a difference did it make in coolant temps?
It's lowered it quite a bit. During the days when it's 95+ degrees I'm running between 207 and 210. However, I also removed a bottom flap from underneath the front fascia that the air dam uses to force air up to the radiator. I don't know why GM closed that off but opening up that duct way forces even more air from the bottom of the car which comes in handy since my intercooler block so much air coming from the front of the fascia. Opening that up while closing off the gaps has decreased my road temps to be around 205 on average. Doing those two things has helped force so much air into the radiator.
