how much boost can the 2mm apex seals handle???? cause i'm amaming to hit 15psi after a rotorsports stage two engine rebuild

 

theres people making like 900 hp on 2mm seals, its all in the tuning

 

Peter Farrell's drag car was hitting 28 psi plus a 100-shot of nitrous. That was on race gas, though.

 

good god

 

better question:

what make and material 2mm seals

 

buy whatever 2mm 2 piece seals you get a good price on, and spend the money you save on a good tune. There really isnt that much force on the apex seals from normal combustion, its only severe detonation that destroys them. A good tune will never have severe detonation, so any seals are fine. 15 psi is a good number, you should be pretty safe there. Its only over 20 where things get sketchy. Also if this is a TII, dont forget to get either solid mounts or a torque brace, most people break the rear housing before they blow apex seals, usually due to a broken stock motor mount.

 

Except Hurleys. Generally Atkins or stock are the favorites. For what its worth, Atkins seals aren't quite as likely to demolish stuff if they are broken from detonation.

 

Wait, what?

Not all apex seals are good. Mazda OEM, RA, or Atkins -- Hurley's are peices of junk.

No psi can be said for certain - as we don't know what size turbo you are running (15psi on a stock turbo and 15psi on a GT42R is NOT the same).

I've never heard of anyone breaking the rear housing??? I think you mean cracking the rear iron -- and thats due to too much twisting/stress on the motor, not anything to do with a motor mount???? The S4 rear iron has less bulk (less ability to flex) then the S5, which is the common fix..

 

you're right that 15 PSI is not the same between the 2 turbos but the heat they generate at the same boost levels is similar, i usually say 15-16PSI is safe on pump fuels but with a good setup you probably could run 20PSI on borrowed time on pump fuel. i was running into detonation at 18PSI on a hybrid S4 turbo.

 

yeah i probably shouldnt have thrown that 20psi number out there..that was based on having all the supporting mods tho..**** you can blow an engine at 10psi if you dont have the mods to run it.

yeah, i meant rear iron, my bad. as for the motor mount, what do you think resists the twisting on the engine? If you break a motor mount, all the torque of the motor is transmitted through the rear iron into the bellhousing, which would now be the only major thing holding the engine from spinning. In a high powered car, that results in a broken rear iron almost all the time. With a brace or the motor mounts in place, the torque is held by both the mounts and the bellhousing, so the stress is more evenly distributed between the intermediate iron and the rear iron, so you have way less chance of cracking it.

by 'bulk' i assume you are referring to the bracing around the s5 dowel pin, which has nothing to do with 'flexing', but does increase the strength by a significant amount. however, not many people are gonna tear down a motor and swap irons just for that, so just getting better mounts is a much easier fix. this does not guarantee that it wont break, but it drops the chances by a lot. I dunno how many engines you have seen that blew the dowel pin, but every one ive seen has had either a separated or partially separated mount.

 

Stock Mazda seals.

 

so would a solid mount solve or exaggerate the problem?

 

it should solve it, because it wont break, so it will not allow the engine to roll so much that all the stress is on the rear iron. I personally am not a fan of solid mounts, as they make the car vibrate, and cause increased stresses elsewhere- its better if the engine can move a little, just not too much. I made my mounts out of polyurethane, with a through bolt, so unless it breaks a 7/16 grade 8 bolt, they arent going anywhere.

 

ill probably be looking into the condition of my motor mounts just for self-assurence.

 

Ive been running 25 PSI on stock 2mm seals, but like previously stated, tuning is what saves your seals.

 

OEM seals ONLY

 

http://www.rotorsportsracing.com/per...ng/engines.htm

this is the place i plan to have the work done at (its about 30-40 minutes away from me), the stage two rebuild is what i plan to have done. id like to have you guys check it out and tell me what u think. my project plan is to run a turbonetics t60-1 with front mount intercooler, as far as the turbo set up...if that helps any. running 15 psi at most... the only reason i want the stage two is realy for the oil and spring upgrades...and street porting almost forgot

 

man, i paid less than that for my 20B longblock...

 

You get what you pay.

 

patman the stock 2mm are rated for at least 500hp reliably but luckily or unluckily it's all about tuning. Ken scheepers uses stock atkins rebuild kit and makes 900hp on All stock internals and seals as a testament to how tuning is key.

 

im not sure why that was addressed to me? that pretty much summarizes my first post in this thread...

 

I know just letting you know It's more than 1 person doing it so it is proven thats all.

 

6 years ago Ari was making 620 rwhp on stock 3 piece 2 mm seals. It's all in the tuning. If you tune it properly, the seals will be fine. 3mm seals just give you a little more room for tuning errors and mistakes.

I agree with the Mazda seals only comment. I wouldn't use anyone else's unless they are Ianetti Ceramics. Those 2 companys only. I don't care who makes the rest or what they are made out of.

 

I second that statement but would add that it's also important to have an engine builder who knows how to properly check seal groove clearances. There are far too many clueless people stacking rotaries in my opinion.

 

Yeah that's definitely something important that needs to be emphasized.