Price is not astronomical if you run the smaller sizes. It will likely come down and you can try to catch it on sale as well. If it works for what i need it for then well worth it

im not getting a new tank. If it kills it as u say then it kills it. I'll be sure to report back when that happens.

What makes you say that the lifespan is only 5 years? I haven't seen anything documented to support that.

What kind of pump is everyone using with these? I'm assuming you need a pump that a fitting can be installed on the inlet. I think my Denso Supra pump just has a filter sock that pops in place with an O-ring.

We're using that sock in a fully baffled and foam filled trapdoor tank with a walbro, can't imagine it being very submerged in the standard plastic bucket if much G is experienced. Someone has used this adaptor on the pump -

https://www.efihardware.com/products...-Extension-KIt

with a Denso - slight modification req'd - and a hydramat over here successfully though. I think some Mitsubshi evo forum in the last couple of years had something similar shown from a vendor a bit closer and more convenient to you.

Radium Engineering makes a better adapter for you, but again, these Hydramats are garbage unless you're changing them out every few years. They are also NOT e85 compatible...

Walbro E85 Fuel Pump Outlet Adapter

Thank you both for the links. I had seen the Radium but think it'll actually be too deep into the tank. My existing sock had debris from the bottom of the tray on it when removed, so I'm hoping this will sit low enough to work.

I've tried multiple in-tank fuel slosh solutions and refuse to put a swirl tank in the passenger cabin, so if I have to buy a new $160 Hydromat every few years that's honestly better than some of the other things I have to do for this crazy car.

Okay, I don't get it... Why aren't you supporting an Rx7Club legend and getting a proper Internal Surge Tank?

Home Page

^^
Great product!
I too would 100% buy the Coachman set-up if it was legal for my racing class.

Nope, its stock tank or fuel cell with no reservoir/surge tank allowed for me.

Any fuel filter is allowed though as long as it doesn't act as a reservoir, so... Hydramat.

How much do these cost and do they offer an FC solution? I don't see any order/application information on the site.

How to Order

Available for FC but I think it is a weld in application not the cnc bolt in like the FD.
$495

You also need to purchase an external pressure pump for the Coachman set-up.

I've run an in-tank surge tank and wasn't happy with the results, so I'm going to give the Hydramat a try. It's also a much more simple solution which I'm in favor of.

Did you have an issue boiling the fuel with the in-tank surge tank or what?

I'm going to say that Coachman (Elwood on this forum), knows exactly what he is doing and has done extensive testing on this. There are SO many knockoffs including Built2Apex which is inferior by design and doesn't create the small pressure head inside of the system to eliminate cavitation issues. What do I know though, I'm just a designer/engineer myself. There's a reason behind why I purchased every part on my car.

It's the only swirl pot on the market that actually de-aerates.

Not that I could tell. I was using a setup that only had a single pump (no in-tank lift) and filled with the return line. I just wasn't getting any better results with it than when I used the updated in-tank baffle over the tray.

I'm sure it's a great product, but it's more complication than I want to take on right now and I don't want to run dual pumps if I don't have to. Perhaps that will change down the road.

Unless there's something weird there I'm not getting, that Radium piece is on the wrong side of the pump to fit the hydramat - you need it on the inlet side. Stock and 280 litre Denso only has only a couple of mm lip plus the locating tit for the star washer thing to hold the sock in place, 400 litre walbro petrol is similar....and the 460 ethanol must be the same, but memory of that is a bit rusty! I'd worry more about dirt and debris blocking the pores of the hydramat than worry about ethanol issues. The original poster's tank if he ran E85, I could see that causing problems, I'd be looking at a phosphoric acid slosh or some sort of mechanical removal of the surface rust before using in that situation!

No, you're totally right about my suggestion with the Radium piece. The idea is to keep the pump further submerged using a standard lower filter element/hydramat, extending from the top rather than from the bottom.

I have unintentionally buried the fuel gauge needle on track in my FD and have had no fuel starvation issues with just a little 3"x8" hydramat in the oem baffle. using a walbro400. ive been tracking it for 4-5 years now, with premix, no issues. imo no need for overly complicated solution

Actually the inside of my tank is not rusty. There is no surface rust. There is a little bit on the baffles yes, but the tank inside surface itself has no rust or loose debris. I've spent enough hours with my arms down in the damn thing to know. Regardless I'm not worried about it with two large hydromat sleeves. I dont run E85. Couldn't even if I wanted to as my nearest pump location is 40 min away even if our ridiculous DC traffic somehow magically disappeared.

2+ year follow up bump to see if there’s further consensus that premix is fine with their recommended several year maintenance replacement limitation?

I've been using one for 2 seasons now successfully. I don't premix on the street and only 1oz/gal on track so not a ton of premix through it, but have not noticed any issues.

So I had submitted the question directly to them about a month ago and never heard anything back. Was just on their website today and they now list them rated for two-stroke premix down to 20:1.