I though this mat wasn't good for the rotary because I saw someone say they contacted them about it and the mat won't work with the premix and will not go through the filter.. I could be wrong but if that's not true I'll throw one in my car asap.. I been looking into a surge tank but don't want to put it inside the car or hear the pumps.. and it will prob save money and time dabbing stuff up and stuff.

I think I'll shoot them an email of my own

 

I'm surprised you got that one. It's so small. I figured if ppl would get one, they would get the larger one that would prob cover almost the whole bottom or even the skinny one that is like a large cross so during any turns it won't starve no matter how low the gas is

 

FD3S2005

I though this mat wasn't good for the rotary because I saw someone say they contacted them about it and the mat won't work with the premix

Mazda production rotary never premixed in the gas tank, always some sort of oil injection.

Yes, I do understand many rotary owners do premix, but it isn't a necessity for rotary.

 

I sent Holley an email a while ago and yeah, they said it wasn't compatible with premix

I had the same problem and ended up mounting a radium surge tank in my engine bay.

 

check my link, it says it works with 2-cycle oil blends up to 20-1. maybe they made a design change since you last contacted them? when was that?

 

I came across this because I sent my gas tank off to get refurbished and it turns out that they removed/destroyed the stock fuel bucket thing. Im kinda wondering if I should put one if these hydramats in or what. I told them that they messed up and I kinda need that. (they should have called me saying that they couldn't remove it without breaking it). but now they are fabbing up a replacement that I hope will be adequate.

 

Which one do you have? The one with the tank inside? And I don't have room in the engine bay... speaking of which, don't you worry about the fuel heat soaking up in there?

I saw that and called yesterday, and was on hold for 20 mins or so and hung up recalled and put my number on the call back system to which I never got a call back..... kinda a dissapointment I wanna get a surge tank if it won't work but don't want it mounted in the car.

 

Weird. They must have actually tested it and realized it was fine. I contacted them in December (of 2015)... so not that long ago

the regular one?
https://www.radiumauto.com/Standard-...anks-P515.aspx

yes, it has a walbro 400 E85 inside.

I measured the temperature of it today actually after I drove it home from work the long way and trying to tune some odd spots in my fuel table (lots of high rpm stuff) and it was about 120*F so not terrible... we'll see what it's like when I autocross it next weekend.

 

I installed one of the larger units. Some minor trimming allowed one leg of the mat to sit in the stock baffle.

 

I was looking at the one that will connect right up to the pump. its 3"x15" its a kinda weird size I think. I don't know if there would even be an advantage over just putting a cover over the stock box

 

Hey ninesixtwo, did you use the Holley fixing kit to bolt the mat in? Magnetic or epoxy?

 

im just too lazy to mod the baffle to get a larger hydramat fit, especially if this one works fine. the 3x8 part fits perfect within the baffle, any larger and it wouldnt fit, so if there is any fuel left in the oem baffled area, the hydramat will pick it up, especially with the return dumping right on top of it. the factory sock depended on it being submerged at all times, so just having the hydramat within the oem baffle, while not as good as a larger unit that covers the whole tank, is a huge improvement over oem setup for minimal work

awsome, i didnt see that one. that looks like the way to go, you could fit the long section out the side of the baffle like niesixtwo did

 

I've thought very long and hard about slosh problems. I ended up using radium internal fuel surge tank. It's made for a fuel cell but was i was able to cut out our factory flange and just weld in a plate and cut out the new flange.

 

That's a pretty nice setup. Is the other pump in the swirl pot? Do you have a fuel sender?

 

I have one walbro feeding two walbro 255's in the surge tank. If i really needed it the tank does hold 3 pumps but at my current power level that would be just over kill. i also added a dual pass fuel cooler (not shown) in the return line to help with any added heat. This set up runs its own fuel sender, i'm running a universal auto meter gauge for fuel level. Its hard to see but its right behind the lift pump. In all i thought it was the best option still have a factory fill point and i even have an additional fill cap to add my pre mix right in to the tank.

 

What flange? weld in what plate ? And that actually seems like a great fix for the sosh and no need for an external tank inside the car.

I just noticed they dont have a cross version of the hydramat that has 2 fittings for 2 pumps.. and the one that does have 2 fittings seems to big to fit properly.

 

The radium FCST is the ****. Only thing is...by putting it in the same place as OE......you'll get the same issue. I like the hydra mat idea...but not if it's not compatible with pre-mix. I went with a couple lift pumps on the CJ-motorsports Dual pump hanger ...and an all External Set up with the Radium Surge tank and Dual Bosch 044's.

drove it at the track all the way down to 6 Gal of E85. Had No Issues.

 

Would there be any restriction if I did the cross hydramat and put a y in the tubing for 2 fuel pumps?

 

I cut out the factory flange then welded in a steel sheet and just stenciled out there flange drilled the holes and was pretty much finished. There kit uses a flange which bolts internally and has both a gasket on the inside of the tank and out side of the tank. Manny I just tacked there 3way universal catch tank and that's where the lift fuel pump sits, so in addition to having the surge tank I also have the lift pump in its own baffled system. Plus for me I wasn't going to mount a surge in the interior as with most rules you have to have some kind of barrier between the driver and a fuel tank. Also as most have noticed there really isn't much room under the 7's to mount a universal surge tank. This way provides all of the positives with no down sides as I haven't changed anything outside the tank. 😝 I will say though I read through your fuel system build and am very jealous gorgeous work.

 

If you are running 2 pumps why not just get the bigger hydramat with the 2 plugs in it? You'd have a lesser chance of fuel starvation.

 

Reason being. If this is an fd tank in this picture below which that hydramat is 15 x 8, I believe. How would the 30 x 14 with 2 fittings one fit. Let alone the smaller 24 x 15 with 3 fittings. The baffles in the car seems to make it hard to place, the cross one would of been perfect if they can add another fitting.

 

Man to bad they couldn't make a direct fit into our tanks or else I'd have no choice but to grab that since I don't want (like you said) the tank in the car and then have to block it off.. unless we can figure out out a way to fit it all into the spare tire area and just make a small cover for the spare tire area... to bad that thing is $700+ not including the the 1 or 2 pumps you need so let's say a lil over 1k.

You go hydramat, most you'd spend would be max 600 but most likely lower

 

I dont think it would be too hard to put one of those big boy mats in there. just bend the stock baffles a bit, and run the fuel line on the far side through or above the baffles With a bracket to secure the line. But then again the larger mats you'll run into cost issues (those things get real expensive) and you could just get a swirl pot setup.

 

I too am using the hyperion cover and never felt any fuel starvation on track as long as I keep above ~1/3 tank. Just wanted to mention that, as maybe something else was adding to the issue. Im using a Walbro 400 pump/ stock hanger also.


Either-way, looking forward to your results!

 

Actually you prob break even or pay more for a swirlpot/ surgetank unless you can fab everything yourself, you forgetting the extra pump or pumps you will need, along with lines and fittings.



I also have the hyperion cover and never felt starvation when I had 1 pump only. Then again I didn't put the car sideways enough times back In the day.. I have 2 walbro 450 in the stock hanger with the cover and I get fuel starvation still.