heinzboehmer's 2002 Topaz 6MT Coupe

[heinzboehmer]

Was pretty hot here yesterday, so took that as an opportunity to torture my car's cooling system on the highway and grab some data with the new rad. Ambient temps were ~40C and AC was on full blast.

Did my best to go WOT wherever I could to really stress the engine. Was able to get it hot by doing one of two things:

1. WOT at 2.5k-3k rpm in sixth going up a hill
2. WOT from 5k to 8k in third, then engine brake back down to 5k and repeat ad nauseam

Here's the data with a couple interesting points highlighted:



Was seeing 5-10C across the rad, which seems totally acceptable given the conditions. Think the most important part is that this drop was consistent, regardless of whether I was cruising or really beating on it. Sounds like the car is ready for another hot track day stress test.

Here's the full data if anyone is interested: https://datazap.me/u/heinzboehmer/ho...y-new-radiator

[heinzboehmer]

How are you securing the line from banging around?

Racecar grade zip ties is my guess

[Slideways]

IIRC, Its an M12 banjo bolt with a -6an male connection. Then a length of -6AN hose and a male thread -6AN plug. IIRC, I had to remove the VANOS pressure canister to get the banjo bolt in.

How are you securing the line from banging around?

[bigjae46]

That's a pretty great idea. What fitting did you use?

IIRC, Its an M12 banjo bolt with a -6an male connection. Then a length of -6AN hose and a male thread -6AN plug. IIRC, I had to remove the VANOS pressure canister to get the banjo bolt in.

[heinzboehmer]

I installed a drain line on the block drain. Super easy. Just blow some air through the radiator to get the rest out.

That's a pretty great idea. What fitting did you use?

[bigjae46]

I installed a drain line on the block drain. Super easy. Just blow some air through the radiator to get the rest out.

I used to have access to a flush machine. Hook up to air, it sucks the coolant out, flip a switch and refills. Takes about 10 min.

[heinzboehmer]

The least NRF could do is add a drain at the bottom of their radiator

Getting the block drained is a whole other mess.

Oh man I definitely considered drilling a hole in the bottom of the old radiator. Maybe next time.

And yeah I'm not looking forward to having to drain the block...

[Slideways]

The least NRF could do is add a drain at the bottom of their radiator

Getting the block drained is a whole other mess.

[heinzboehmer]

Thats pretty much how I do it too, nice work.

Hell yeah! A thumbs up from you means more than you think

[George Hill]

I think I've finally perfected the technique to drain coolant on this car without making a mess of my garage floor. Documenting the steps here for future reference:

1. Remove all shrouds and belly pan
2. Set catch pan underneath general lower radiator hose area
3. Slightly lift up temp sensor on lower radiator hose
4. Let coolant drip out
5. Slowly undo expansion tank cap
6. Let coolant drip out
7. Squeeze upper radiator hose a million times to get as much coolant out as possible
8. Slowly disconnect lower radiator hose
9. Let remaining coolant drip out

Key is to always have a very small stream coming out of the sensor port. This will keep splashing to a minimum. Yes, it is tedious and does take forever, but I find this preferable to cleaning up a huge coolant spill. Example of how slowly coolant should be coming out:

Thats pretty much how I do it too, nice work.

[heinzboehmer]

I think I've finally perfected the technique to drain coolant on this car without making a mess of my garage floor. Documenting the steps here for future reference:

1. Remove all shrouds and belly pan
2. Set catch pan underneath general lower radiator hose area
3. Slightly lift up temp sensor on lower radiator hose
4. Let coolant drip out
5. Slowly undo expansion tank cap
6. Let coolant drip out
7. Squeeze upper radiator hose a million times to get as much coolant out as possible
8. Slowly disconnect lower radiator hose
9. Let remaining coolant drip out

Key is to always have a very small stream coming out of the sensor port. This will keep splashing to a minimum. Yes, it is tedious and does take forever, but I find this preferable to cleaning up a huge coolant spill. Example of how slowly coolant should be coming out:



Anyway, whole point of this exercise is to swap in a new radiator, so let's get to that.

There was a bit of debris in between the condenser and rad, but not a ton:



Vacuumed all that out and then blew out the condenser as best I could. There are still some small rocks really wedged in there, but this is as good as it's gonna get without complete replacement.

Original rad had definitely seen better days:




As others have noted, OE radiator is still being listed under the Modine brand by most online retailers, but is actually labeled as NRF:



Forgot to take a picture of the shiny new rad in the engine bay, but whatever, everyone knows what a radiator looks like.

Initial tests look good. Seeing ~10 C temp drops across the rad around town, so similar to before. Will test further, but I likely won't see a huge difference (if any) on the street, since the previous rad was working fine in those conditions. Need to book another hot track day to see how the car does there.

And since I had all this stuff out of the way, I replaced the idler pulleys + hardware on the main belt.




Nothing super interesting there, except for maybe that black "protection cap", which my car did not come with when I bought it. I'm assuming some previous mechanic lost it at some point.

[tlow98]

So when are we making that custom rear subframe?

I’m in to help with this project!

[George Hill]

No exhaust, no problem, lol.

[heinzboehmer]

Yeah exhaust clearance is definitely the biggest issue. I bet you'd end up needing to build a custom section 2 to get around the lower pickup points.

[Bry5on]

Could this be as "simple" as cutting off the old RCA pickups on the stock subframe and welding on new ones but lower? I suppose you could then use two pairs of ARCAs with coilover rear suspension. I might be able to do some scanning with the Einstar and experimenting on my track car over the winter.

A scan would be awesome if you’re willing to share it! The issue is exhaust clearance, but yes that approach could get you there.