z driver 88t

A few weeks back I installed the 928MS radiator. I had a good chance to put it through its paces yesterday on a one-hour 'spirited' drive with some friends. Lots of long 3rd and 4th gear pulls on some rural country roads up to around 120 and everything seems good - cools well, no leaks, etc.

Overall very happy with the finished product, but it's not quite plug and play - so hopefully this will save some people some time.

First I saw on the packing slip that the radiator is made by Howe, presumably with specs provided by 928MS. Howe has a good reputation and been around a long time and I was glad to know who made it since a lot of aluminum radiators and intercoolers on EBAY these days are coming out of China.

I've noticed some people have had zero issues and other people have had a few. So I'm thinnking the issues are less with the design and more with the tolerances during construction. Therefore, with respect to any of these procedures, YMMV.

First - If you have the 78-86 fan shround and need the tabs on the radiator to hold it in place and you still have your air pump connected there may be an interference between the radiator tab shown at the red arrows:



and the canister in front of the air pump:


The interference is less than a half-inch, but the two cannot occupy the same space. On my car it didn't matter since my air pump was disconnected when I insalled the y-pipe. So I just yanked that canister out. But if it was sitll functional it would be an issue.

Second - make sure to test fit the shroud BEFORE installing the radiator. On mine the rear lip was about a quarter inch too tall:





This necessitated removing the radiator and trimming the lip with a dremel about a quarter inch:



Once that was done the shroud lined up fine.

One other minor issue was that because the aluminum mounting tabs at the top are thicker than the OEM sheet metal, the clips would not fit over them and push down far enough to use the original mounting screws. I could have trimmed the mounting tabs sufficiently to get the clips to fit, but instead I just tapped the hole in the tab for a short M8x1.25 bolt. There isn't much material to tap, but this only needs to be snug and seems to be holding up fine.



Lastly (I didn't get a picture of this) make sure not to forget tot ziptie the lower radiator hose to the fan shroud. I did forget and the lower radiator hose ended up getting a hole in it from rubbing against the nut on the front of the PS pully. Those hoses are not available locally, so the car was down for several days while I was waiting on the new hose to arrive. This was not an issue caused by the radiator, but by lack of attention to detail on my end.

In the end the final product looks good and performs well and at $700 was about $150 cheaper than a new OEM unit.


Just give yourself some extra time. One owner posted that the whole job only took 30 minutes, and for me it was the better part of an afternoon since the radiator came in and out several times to remove the air pump canister, trim the rear lip for the fan shroud, and lastly the tap the holes in the mounting tabs. Had I done all the test fitting beforehand it would have gone much faster.

Randy V

Any improvement in cooling?

z driver 88t

Can't tell if its an improvement. The old radiator always cooled fine, even at track days - until it developed a slight leak near the inlet. My main reason for getting the 928MS was that it was 1) shiny and pretty, 2) $150 less than an OEM unit, and 3) theoretcally an upgrade since it holds more coolant, all aluminum, and 3) eliminates the failure point of the plastic end tanks on the OEM Behr.

It does take a little longer to reach operating temp, so it is definitely better in terms of being a heat sink.

And really, I was just annoyed that Behr charges so much for our radiators. I don't mind paying top dollar for truely superior well engineered products, but the Behr radiator is a pretty simple core with press-on plastic tanks. To put it in perspective, a Behr radiator for a BMW 3 Series or 5 Series can be purchased mail order for $150-$200. To charge $850-$1000 for the 928 radiator is outrageous.

Carl Fausett

Thanks for the excellent write-up and photos. I am forwarding to Howe so that we can tweek the design even further.

Carl Fausett

The response I just received from Howe:

They have always been very good about continued input to improve our design and fitment. Again, thanks for your notes and photos so we can continue to improve the product.