Great thread Dale. As soon as your check valves come in, I will be doing the hose job and chcking my solenoids since my boost pattern is soooo out of whack.

Trev

 

pmed on Check valves

 

So, they offer high temperature more resilient rubber caps. I purchased the sizes I need but why purchase the chemical caps if we're worried about temperatures? It has a rating of 200f* while the ones I purchased are 500f*

 

You don't need 500 degrees on vacuum caps. I've extensively tested the EPDM caps, they do great.

I only say "get the chemical resistant" because that's how McMaster-Carr lists them. Really, you just need the EPDM rubber.

Dale

 

On the last stretch on my full silicone vacuum job i found out two potential issues that others need to be aware of, if they are fresh at this as i am:

- The Wastegate hose and Turbo Precontrol hose (both comming from turbine housing) have a built in restrictor to them making it important that you reuse those, or get those hoses new from Mazda. Part number for the hose kit should be N3A1-13-ZLY according to my EPC, and cointains both hoses with restrictors. I discovered this by chance researching the hoses on the next point.

-The Turbo Control hoses that mounts on the acutator have a different diameter on each end, making it very hard to replace them with a silicone vacuum hose (its either to tight or to wide). Best option is to use OEM hoses from Mazda, since they are also easy to reach, and low on the engine, away from the worst heat soak. I think the part numbers for them are N3A3-20-346A and N3A3-20-345A. They also have a rubber protector on them with the number N3A3-13-855. I have notverified them yet since the EPC drawings are confusing and i have to order a set to see. Can anyone here maybe verify them?

 

Yeah that problem is very well documented haha. I had that problem as well. If you swap those hoses and don't have restrictors of some kind in them you will only get 7psi of boost. If you swap those hoses you can use carb jets as restrictors, but I don't remember the sizes you need. It should be on the forum somewhere though. I found the info on here years ago.

 

Are the viton check valves still available?

 

Yep, PM"d you on it.

Dale

 

Can you send me the info to buy from you

 

not to beat a dead horse, but is there another reliable place to buy the silicone hose from that has the thick walls? looking to replace the hoses on the rats nest soon and would rather not have to go back in and repeat work. thanks!

-TwitchE

 

I think this is in the thread somewhere -

TurboLogic

They have top quality hose at a great price, and it's in stock ready to ship.

Dale

 

Pineapple Racing sells a kit with thick wall silicone tube and that includes the check valves and laminated hose diagram.

 

What are the two vacuum lines connected to the block on either side of the primary rail. I am trying to better understand the simplified vacuum diagram and see they eventually connect to the intake elbow of the turbo? I was mostly curious why there was no check valve in there and then realized I dont really understand what is happening there.

 

Those hoses bring in air that is atmospheric pressure to help atomize fuel at low speed and idle. Inside the engine it's vacuum, so you have air at atmospheric pressure "spraying" in to help swirl the fuel around.

Just leave that system be, it does a good job and isn't in the way. You don't have to go to the primary turbo inlet, you can just have a small filter or something on those hoses. It just needs clean air that's atmospheric pressure.

Dale

 

@DaleClark sorry to bump this old thread but just wanted to know if you still sell those viton check vavles?

 

I was looking for recommendations on a vacuum hose that has been tried and trusted. I will be using it on the stock turbo system. The last two suggestions are not available anymore. Pineapple Racing owner passed so it closed and the latest site Dale Clark provided closed as well.

Good day,

Cid

 

HPSI Silicone Vacuum Hose Kit - Mazda RX7 Twin Turbo FD3S 1992-2002 al – HPSI Motorsports - Performance Parts and Silicone Hose for Street/Race

 

I did come across HPSI motorsports. I e-mailed them asking what sizes are included in their kit. They said they don't give out the exact specifications of the kit because other companies can copy their kit without doing the work. Did you happen to measure the size? It seems like very good quality compared to others. I was just worried that I would get a 3mm hose. They don't offer 3.5mm. I might go with them since you are the second person to recommend them. I posted the same question on facebooks rotory engine builders page and someone recommended the same kit.

Thank you

 

Back in 2005 I did the hose job. Here's what the Viton kit I ordered had in it and how much I used:
40' 3.5MM x .105" wall (<30' necessary)
15' 4.0MM x .105" wall (<12' necessary)
16' 6.0MM x .105" wall (<12' necessary)
4' 8.0MM x .115" wall

 

Here is what I used to replace my vacuum hoses recently. The more important things are wall thickness and curing of the silicone. You should use "premium" or platinum cured hose which holds up much better and is more heat resistant and kink resistant, particularly when used with a thicker wall.
I believe I ordered about 15' of 3.5mm, around 15' of 4mm, and 10' of 6mm, but I didn't replace everything. I am not quite sure of those amounts but that is close. I will have to look for a receipt. If you replace everything, Dale's numbers are probably closer to the amount needed. You can always order more later if short.

Platinum Cured Silicone Vacuum Hose | Verocious Motorsports

Mike

 

^THIS! Verocious Motorsports is my go-to shop for vacuum hose and a bunch of other stuff, mainly because they are local to me and their prices are pretty reasonable. But really any decent motorsports shop will stock quality platinum cured thick wall silicone hose by the foot, in all the popular ID sizes. Just Google "platinum cured silicone hose by the foot" and a bunch of buying options will pop up. Just read the specs before buying - like Mike said, you want the thick wall platinum cured stuff which will hold up better and not kink when bent into tight bends.