View Single Post
Unread 12-17-2014, 11:42 AM
Fair!'s Avatar
Fair! Fair! is offline
I blame the internet
Join Date: Jul 2004
Posts: 6,077
Default Re: Vorshlag Scion FR-S LSx Alpha Project

continued from above

Cooling Solution

While we could have just left the stock radiator in place, we knew that was a bad idea so we sourced a Mishimoto radiator early in this project. We had already test fit the Mishimoto radiator in place earlier, but now that needed it to be bolted down so some radiator hoses could to be built. We also needed to alter some other factory cooling systems parts to gain clearance for this big V8 up front.

The change in power level from the stock 2.0L engine to this 5.7L engine would be substantial, and unlike on some of the the BMW LS1 swaps we have used, I doubt the Toyota/Subaru engineers added a LOT of extra cooling capacity to the stock radiator. It was also a plastic/aluminum assembly, which, in our experience, fails quickly with track use.

We use Mishimoto radiators on a lot of OEM powered and V8 swap builds for street and track use, including our TT3 prepped 2011 Mustang. They are 100% TIG welded, all aluminum radiators (avoiding the cheaper, failure prone, OEM style bonded plastic tank ends) with usually at least double the stock fluid capacity (with thicker cores). This means it can help the big V8 engine run cooler, which is always a safe choice for track use here in Texas. We can see 100F or more in the Summer, and Texas racers want to run on our many road courses year round, so we have to make our cooling systems capable of this heat. Additionally this car's owner wanted air conditioning to get him to and from the track, so we have to make provisions for a the factory A/C condenser - which luckily bolts right to the front of the Mishimoto radiator using the same OEM hardware (above right).

The Mishimoto looked like it had all sorts of room until you consider where the balancer would end up. The factory double fans also work in a "puller" configuration, so they sit behind the radiator (whereas a pusher style sits in front). And the two factory fans, mounted in a plastic shroud, were VERY DEEP (about 5"). Running right between the two side-by-side fans was a stamped steel brace that bowed inboard and bolted between the upper and lower radiator support structures (shown sitting on top of the motor in the above right pic). No way would the fans or this stamped piece fit with the V8.

So we came up with a "compact" fan solution using "slim line" electric fans. They will move PLENTY of air but we wanted a nice shroud to mount them to, to ensure that the fans draw through the entire surface of the radiator. Olof built the aluminum fan shroud above to fit to this radiator with the 12" Mishimoto fans.

A piece of aluminum plate was measured, marked, sheered, cut, bent, drilled and welded to make a shroud that stood about 1/2" off the back face of the radiator - with a foam rubber gasket isolating this metal structure from the aluminum radiator. The tabs we added are bolted to the OEM radiator mounting holes for the factory shroud, and the end result was pretty much perfect - and about 3" inches shorter, front to back. This set-up now allows room for the front engine balancer.

The stamped steel brace was removed but our guys will fabricate another bolt-on brace that doesn't "bow" into the way of the pulley - there's plenty of room, it just needs to be a different shape. The upper radiator support is VERY weak without this top-to-bottom support installed, and it needs to be strong because the hood latch mounts up there. As you can see in the above picture the full front accessory drive layout is complete, with the balancer and serpentine belt in place, and there's room to spare. I've also shown one of the two main radiator hoses mocked-up using Mishimoto silicone bends and some aluminum tube - we've used this arrangement many times.

These two 12" Mishimoto electric fans pull 1150 CFM each and will be controlled by the GM engine computer, based off of the GM temperature sensor that is placed in a cylinder head.

What's Next?

We've been getting a lot done to our two current Alpha swaps, the Miata and FR-S, and some solutions figured out on one car have helped us on the other. We are trying to keep both of these going in between "day work" and other non-development builds.

The FR-S needs a driveshaft, after-header exhaust, some plumbing and wiring, then the CAN-BUS programming. Its getting there...

Until next time!


Last edited by Fair!; 05-12-2017 at 09:12 AM.
Reply With Quote