Well, I just finished up the installation of a Koyo into my stock 94 FD. I am going to summarize some of my notes about what's involved. Overall the install went pretty smoothly. No trimming or fabrication was involved.

First I got the car up on stands and went at it from underneath. Per the FSM, I removed the sway bar, all the brackets and let the AC condenser and PS lines hang loose. I drained and removed all the radiator hoses, naturally.

From the top, I removed the airbox and the battery and tray (again, per the FSM). I eventually had to remove the IC and ducting to resolve a clearance problem (see below). If you remove the IC, it's a good idea to remove both hard pipes that are attached to the IC (the throttle body elbow and the cross-over pipe). Also remove the two rear brackets on the IC completely - this will help with the clearance when pulling it out. Unbolt the brackets holding that front relay box in place and push it aside. Unhook the two fan control lines underneath it. Unbolt the two hangers on the top corners of the radiator.

If you can, unbolt and remove the fan assembly and remove it from the top. I did not do this - and it will come out the bottom if left attached to the stock radiator.

Get under the car and pull the radiator out through the bottom rear. If for some reason you want to keep your stock unit, insert a piece of heary cardboard between the condensor and the radiator to protect the surfaces. Once you get the radiator out, tape cardboard to the top of the condensor to protect it during the install.

Look at your stock radiator. Look how thin it is. Look how thick the Koyo is. There's no way that going to go back in there in the same place! If you haven't already, remove the fan assembly from the radiator.

Remove the hangers from the stock radiator and mount them on the Koyo. Important: the "ears" in the hangers should be turned around so that they are flush with the side of the radiator that faces upward. Since the Koyo is so thick, we need to make sure that it is dropped as low as possible in the mounting brackets to allow for clearance. I'll try and post some pictures. Take the rubber spacers off of the bottom of the stock unit and put them on the Koyo.

The Koyo comes packed wrapped in heavy cardboard. I kept the cardboard taped to the unit throughout the install to protect it.

The two lower brackets (where the bottom of the radiator rests) need to be "unbent" slightly so that they don't rub against the bottom edges of the thicker Koyo.

Slide the Koyo into place from underneath. I had already mounted the fans when I did this and it *will* fit. If you can get the fans on from above after you have the radiator positioned, do that instead. Having a second set of hands (and eyes) really helps here. Tighten all the bolts down.

Some people have posted that they needed to trim the plastic at the top passenger side in order to make it fit. I did not have to trim anything, although the radiator touches the plastic along the top edge.

Now for the secret sauce - go to home depot and pick up some steel 1/2 inch spacers (3/8" diameter), some washers and longer bolts. You will use these to drop the AC condenser down to clear the now lowered radiator. Use a spacer and a washer in between the rubber bushing and the frame on all four mounting points. You should end up with about 1/2 inch of space between the radiator and the AC condenser. You will also have to use a spacer on the passenger side rear mounting bracket for the power-steering line.

The only clearance issue that I had was that since I had the fans already attached to the Koyo when I installed it, one of the control wires for the driver side fan got pinched in between the back of the fan assembly and one of the mounting bolts on the bottom rear of the IC. By the time I saw this problem, I already had everything bolted back on the underside of the car. It was easier to pull the IC and duct from above, fix and reposition the fan wires and then reinstall the IC.

That's it. Button everything back up, fill with coolant and start her up! Burp coolant repeatedly.

The only issue that I see at this time is that there are significant air gaps between the sides of the Koyo and the rails. Some block-off plates woudl be very useful here.

Hope this helps,

-bill

 

nice write up

prolly useful to those nOObS that dont use the soych button

 

hmm...gives me sumthin to look forward to when i get my "Money Pit" werking again...

 

Well, when I went throught the search process here (several times), one of the issues was that there were a lot of conflicting posts about whether or not the unit would fit in a stock FD, how much fabrication was required and if you should come in from the top or the bottom (the answer: both! ;-).

The bottom line is:

- Yes, it does fit.

- You may have to slightly trim the top plastic. I did not. You will have to bend the lower brackets.

- the AC and power steering lines have to have spacers installed to give clearance for the thicker radiator.

- the fit between the top of the fans and the bottom of the IC is tight, but manageable.

That's all I wanted to point out.

-b

 

good write up.
I will be needing this when I get my Koyo.

 

Any Pictures


Sorry for reviving an old thread

 

i just installed the koyo rad and it was HARD. holy ****, but i got it done. hahahaaha im a mad fool.

 

I also have the Koyo. Dropped temps by about 10c overall....It's a great reliability mod.

 

No problem. I'll go look around for some today.

One addendum: There is no need to use a spacer on the PS line mounting bracket. There should be enough clearance without it and in fact if you use one then the PS line will interfere with remounting the belly pan.

-bill

 

Great writeup, I need to post in here so when I do this install I can find this thread easily

 

Or, you could take the easy way out and click Thread Tools -> Subscribe to this Thread

 

I recently installed my radiator, a Fluidyne, it was a nice fit but tight. I don't know if the Koyo would have fit correctly in my car. I think like most things some cars will fit a koyo fine and others will have a monster of a time. I was going to do a write up with pictures but then became to involved with the removal and install and forgot about the PICTURES.

Still interested in the pictures if you can find them.

Thanks

Victor

 

Only problem i had with the koyo is the opening where the IC duct goes though is too small. So i had to basically cut alot of it down to make it fit.

 

yeah it scewed my I/C duct a bit, but i made it work. I didnt use the top brackets, the rad just fit snug into place, resting on the A/C condensor bracket, it does not touch the condensor though. My greddy pipe kit fits better with this rad then the stock one. hahaha whatevers.

 

My koyo fit, and I didn't have to space anything or move the a/c condenser. It just took a little elbow grease and a little rubber mallet action to line up the mounting holes when it was in. I would recommend the koyo, it is HUGE compared to the stock radiator. It also looks like it could take way more abuse.