Wondering if anyone has/is running one of these. Reasons you like it, reasons you don't. Is it snake oil? Is it the best thing since pants with pockets? Lemme know!

My car never came with an AST, and I saw these awhile back, but installed the engine without the AST. Currently, they are unavailable on the website, but it looks like they will make-to-order so I sent an email. With some recent thermostat issues, I am considering this. If it's a gimmick, I'll pass and continue with my current stock configuration.

 

No personal experience with it but it looks well made. It strikes me not so much an ast “delete” piece as a more robust substitute.
Are you tracking your car or is it just street driven? I ask because I deleted the ast as a result of my choice in SMIC and just been using Banzai billet extension for some years, and before that the FC extension, and never had any issues. But I don’t track and maybe Himni piece is the way to go in that case.
http://www.banzai-racing.com/store/product1476.html

 

Raceonly over here seem to have sold a fair number of their version locally.....machined piece not fabrication, https://www.raceonly.com.au/product/...-kit-fd3s-rx7/ it might even be reasonable on current exchange rate! An AST still seems a functional way to go to me though - and inexpensive.

 

I've been running no AST for probably 15 years now, never had a single issue or had the car running hot. I haven't felt there is a value to having one.

BTW link for those wanting to look -

https://www.himni-racing.com/mazda/m...k-upgrade-fd3s

It is a cool piece, though, and it's worthwhile if nothing else to dress up the engine bay.

Dale

 

To answer a couple of questions...
Yes, I primarily track my FD. I never had an AST in-place, and have not had any known issues with cooling...until recently.

This past weekend, on Sunday morning, I started the car but noticed that coolant/oil temperatures were rising quickly. I let the car run until the coolant temperature read 190F, then shut it down. Noticed that my fans were not running, the coolant fill cap was cold, and that the radiator was cold. I have one of two problems: A stuck thermostat, or low coolant. Obviously, the fan will not come on unless the sensor signals it to. This weekend, I plan to first check the coolant level, then replace the thermostat if the coolant level is not low.

I figured maybe this himni unit would be a nice addition if the thermostat did prove to be the culprit. I just wanted to know if it was worth it before plunking the cash down.

 

A sticky t-stat is gonna behave the same regardless of what t-stat housing config you use, that’s why it is important to monitor coolant temp, either via a gauge or ECU fail safe features. If you primarily track your car, do you really need a t-stat?

 

I didn't propose needing this to fix a problem, just wondering of anyone experienced any advantages of using it. Also, I primarily track my FD, but still street it now and then. Definitely need a thermostat for that. Even if just primarily tracking, I'd still retain a thermostat!

 

Oh ok, in that case the Himni piece is just the same as an OEM 2-piece housing with a Banzai upper piece, no difference other than the look.

 

Your coolant level is likely fine.
Unless you’ve played with the threshold fan temp with a standalone, it may not haves warmed-up enough to initiate them. Stock, the fans don’t come on until something like 220F. A FC thermoswitch would lower that to 205 F.
Also, can’t recall exact numbers but isn’t 190 F. close to the full-open temp of the stock t-stat? If the gauge and/or t-stat was just a little slow or off…again you may have just not let it warm up enough.

That Himni piece looks cool and MAY give you slightly more volume than the stock housing. But other than that it appears to just be a really pretty, and pricey, AST substitute.
I agree with ZE Power MX6. The Banzai piece I mentioned earlier is pretty bulletproof, should give an ample dead-space and is 1/3 the price with no waiting. You also wouldn’t have to add back in the hose to the lower radiator and it’s potential failure points.