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Slash cuts, whos got the info?
Hey guys,
There is a bit of info on googles, not much, whos done one, specifically I want to know angle, location in downpipe, and how long the metal tube needs to be so the rubber hose isnt heat affected. Thanks, Dann |
I'm doing this right now. I got a vibrant performance slash cut with an angle cut o2 bung. I'm cutting off my secondary o2 sensor mount that is on my FM downpipe, and that's where I'm welding my new bung. It has a -10AN fitting on it cause I'm using a stainless braided line instead of a rubber hose with clamps.
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actually, faefae of all people is the one person I distinctly remember running this.
and it sucks (both literally and figuratively) |
And the rubber hose just 2 inches or so from the main exhaust will be fine?
Im talking about heat travelling up the metal components. Dann |
Originally Posted by 18psi
(Post 1043358)
actually, faefae of all people is the one person I distinctly remember running this.
and it sucks (both literally and figuratively) Dann |
Originally Posted by nitrodann
(Post 1043360)
More info please.
Dann |
True miata turbo style you give me almost 4000 posts to wade through.
Ill try to search from here, thankyou. Dann |
Originally Posted by nitrodann
(Post 1043360)
More info please.
Dann it introduces lots of potential failure points and clutter it makes your exhaust stink and smoke at times you spew oil outa your exhaust pipe at times Ive never ran one so this is all info I'm getting from the interwebz ask Brain or soviet who have both seen fae's setup in person
Originally Posted by nitrodann
(Post 1043368)
True miata turbo style you give me almost 4000 posts to wade through.
Ill try to search from here, thankyou. Dann |
Originally Posted by nitrodann
(Post 1043368)
True miata turbo style you give me almost 4000 posts to wade through.
Ill try to search from here, thankyou. Dann :dealwithit:
Originally Posted by 18psi
(Post 1043370)
Not really. OPen thread, go to tools, search within thread, profit
Wow, I've never used that because I assumed it was rubish like the other search tools on the site. That's useful, because Google indexes the threads @10/page and I view at 60/page, so it's useless for finding things within threads. |
Nah, he had it way before then, even with his begi 30r setup.
I think he revised it with check valves or something, but in typical fael fashion just made it worse LOL |
I intend to run a big catch can with it and stock pcv valve as check valve.
I can make the can myself so I can do whatever I want in terms of design, hence trying to narrow it down a bit. 1/2 inch hose, big baffled catch can, both sides of cover vented to catch can... win? Dann |
To make it not smoke you need good baffling in the head, and you need to not pull from the intake manifold side. You dont want a catch can on it because that will reduce the effective vacuum. My ultimate crankcase vent system goes a little like this.
-12 port on the rear intake side of the block where Bundy has one, this is the block not the head. -10 port on the head where the exhaust side port is -10 port on the rear exhaust side of the head, add a baffle in the head here Run the -12 port to a slashcut with a check valve in the downpipe, no catch can. Run the front exhaust side port to a good baffled catch can and then to a slash cut in the turbo inlet. Run the rear exhaust side port to a pcv valve to a different baffled catch can to the intake manifold (can be substituted with a vacuum pump if you really want to ball hard, but you ditch the pcv and put a vac regulator on the turbo inlet slashcut line). Hopefully over the winter I'll switch to this setup, I need to pull the engine and the oil pan anyways to fix the multitude of leaks so I might as well drill a massive hole in the block. |
Originally Posted by Leafy
(Post 1043391)
To make it not smoke you need good baffling in the head, and you need to not pull from the intake manifold side. You dont want a catch can on it because that will reduce the effective vacuum. My ultimate crankcase vent system goes a little like this.
-12 port on the rear intake side of the block where Bundy has one, this is the block not the head. -10 port on the head where the exhaust side port is -10 port on the rear exhaust side of the head, add a baffle in the head here Run the -12 port to a slashcut with a check valve in the downpipe, no catch can. Run the front exhaust side port to a good baffled catch can and then to a slash cut in the turbo inlet. Run the rear exhaust side port to a pcv valve to a different baffled catch can to the intake manifold (can be substituted with a vacuum pump if you really want to ball hard, but you ditch the pcv and put a vac regulator on the turbo inlet slashcut line). Hopefully over the winter I'll switch to this setup, I need to pull the engine and the oil pan anyways to fix the multitude of leaks so I might as well drill a massive hole in the block. |
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I take it a vacuum pump is not an option?
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LOL I wasn't gonna ask, but now I gotta: are you seriously measuring a ton of pressure in the crakcase?
I mean if we're gonna go as far as suggesting vacuum pumps, this better be some 800hp monster that creates massive crankcase pressures |
Originally Posted by triple88a
(Post 1043430)
I take it a vacuum pump is not an option?
You dont need a 800hp monster to benefit from always having the crank case under vacuum. Even a normal car should be able to gain a noticeable amount of power due to better ring seal. |
When this was first brought up a year or two ago the info showed that it wasnt about crankcase pressure, it was that vacuum helped the rings seal better.
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Originally Posted by Leafy
(Post 1043434)
You dont need a 800hp monster to benefit from always having the crank case under vacuum. Even a normal car should be able to gain a noticeable amount of power due to better ring seal.
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I don't think I'll have The opportunity (read budget) to do an awesome setup, because its not on my car and Ill be getting paid a finite (read tiny) amount to do it, basically because I volunteered myself to build a catch can.
I have alloy on hand, and the correct drill and tap to use cheap brass push fittings, so I can build the catch can however I want with all the ins and out i want, and I can drill and tap the cam cover all I want but I have to keep fancy fittings to a minimum. I was thinking 3/8NPT x2 out of the exhaust side of the cam cover, with 3/8NPT x1 outlet from the top of the can to a slash cut, with a single 3/8NPT at the bottom to either go directly back to the sump like an MSM or to a tap. I can baffle the can however I want. Make suggestion I'll build it. Dann |
Originally Posted by 18psi
(Post 1043437)
wat?
Dann |
Dont send it directly back to the sump. Part of the job of the crank case vent is to evacuate combustion acids, gasoline, and water from the oil. Most of those are vapors at operating temp, but a good bit of them will cool down to a liquid and get left in the catch can. These are things you dont want going back into the crank case. If you REALLY want it to auto drain I would put a coolant loop through the liquid in the catch can to keep it above 180*F and put a restrictor in the drain line so it takes a long time for the can to drain. Otherwise just make it easy to take out and drain into the waste oil bucket.
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So far with the keywords i'm using this is the only site with dynos i've found. Motorcycle dyno testing...
Red is stock. Blue is with vacuum source applied to the breather hose. Green is with it just flowing out to the atmo. https://www.miataturbo.net/attachmen...ine=1376493416 |
hmm so we're talking 1 or less hp. Noticeable is an overstatement, but looks like there might be at least some merit to doing this
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Originally Posted by 18psi
(Post 1043455)
hmm so we're talking 1 or less hp. Noticeable is an overstatement, but looks like there might be at least some merit to doing this
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This is supposedly a big part of why dry sumps make more power also.
Ok, so if miataturbo can collectively design a catch can setup Ill build it and run it on a customers car, lucky bastard. Obviously Ill post results. And then everyone will say I faked them of course. Dann |
Originally Posted by 18psi
(Post 1043455)
hmm so we're talking 1 or less hp. Noticeable is an overstatement, but looks like there might be at least some merit to doing this
Thats 5hp on a serious BP. Which also likely has way worse ring seal than a tiny n/a bike, so could be more. Dann |
Originally Posted by triple88a
(Post 1043456)
On a tiny 2 cyl 600cc motor yes.
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Originally Posted by nitrodann
(Post 1043457)
This is supposedly a big part of why dry sumps make more power also.
Ok, so if miataturbo can collectively design a catch can setup Ill build it and run it on a customers car, lucky bastard. Obviously Ill post results. And then everyone will say I faked them of course. Dann Also if you stopped whining about people calling your bs dyno's long enough to actually get legitimate results we'd like you a whole lot more on here. |
Drove it yesterday, came from the dyno retune for spool with a hair under 500tq.
Eat a dick :fawk: Shreds 5th gear with 18" reemz. I dont need your approval. So catch cans. I dont want photos of cylinders with pipes in them , I meant internal design, where the hoses go, how the baffles look etc. I'll do it all and post results and everyone gets a bit smarter. :party: Dann |
Originally Posted by 18psi
(Post 1043461)
Google images is your friend.
Also if you stopped whining about people calling your bs dyno's long enough to actually get legitimate results we'd like you a whole lot more on here. Keep at it Dann, I enjoy your posts and silently soak up as much info as I can even if you posted a wonky looking dyno. |
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Thankyou Ryan. I know people appreciate it because I would have not too long ago.
The main upshot I have is that my time is worth fuck all to anyone and there are plenty of enthusiastic people who want to try shit out, so in the process of making a buck and building parts I can learn by doing, and teach by documenting. I enjoy it. Anyways, This is my plan so far, Fit catch can in this location, using oem weld nuts to secure it. https://www.miataturbo.net/attachmen...ine=1376494701 I want to run 2x1/2" hoses into it, It seems one from the OEM hotside and another from the rear of the hotside, other one blocked somehow (welded I spose). One outlet on the bottom, the MSM drips straight back to the sump but perhaps that isnt ideal. And one outlet on the other side of a baffle to a slash cut on the downpipe. But Im concerned about the fitting welded to the exhaust getting very hot and damaging the rubber hose which connects it to the catch can. Dann |
Why not build a cover for the header and eliminate 2 problems with 1 stone?
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Originally Posted by triple88a
(Post 1043479)
Why not build a cover for the header and eliminate 2 problems with 1 stone?
Dann EDIT: Now I cannot post again for weeks, until the awesome seen here wears off, fuck. https://www.miataturbo.net/attachmen...ine=1376496984 http://upload.wikimedia.org/wikipedi...ol-hacksaw.jpg |
Yeah i thought it looked familiar.
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Originally Posted by nitrodann
(Post 1043464)
So catch cans.
I dont want photos of cylinders with pipes in them , I meant internal design, where the hoses go, how the baffles look etc. Dann Saikou Michi OCC Explanation |
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The customer has agreed to my terms which include dyno testing this setup with the slash cut fitted and slash free back to back.
Im pretty sure this will suffice. https://www.miataturbo.net/attachmen...ine=1376692330 Anyone? Probably around a quart. maybe 2. 1/2" hoses. Dann |
I would put the hotsides on the bottom corner by the sump. Also would make it more vertical.
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why on the bottom?
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I really don't think you want to return to sump in that fashion. Catch cans, and all that steel wool will act as a wonderful condenser, condensing the water vapor out of the blow by gasses and then dumping that nice oil/water mixture back to the pan along with whatever unburnt hydrocarbons the catch can/condenser has managed to collect.
At a minimum it needs to be heated by the coolant. |
Yeah its unlikely to get returned like OEM does it, Ill just use a tap.
Dann |
Unless you have that tank above the valve cover it wont run back. You will however get a bubbling effect that should splash oil up the mesh to increase its efficiency. Clumped oil is good, fumes on the other hand will go straight out the exhaust.
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Also watch out with steel wool. I've heard of it breaking up and finding its way into places it shouldnt. Supposedly the brass wool is better, its what I used.
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Sweet.
So it occurs to me that if the exhaust pressurises you will quickly end up with a system no better than stock. You can run a check valve, but then if it closes the engine will just pressurise the catch can. Any ideas here? There really isnt a lot of info out there. Im also concerned about the cat... Any feedback? Dann |
Fae saw this thread and sent me an email. I wasn't going to post it because Dann is a lying douche canoe but since others will probably stumble on this thread, here goes:
Saw the thread. https://www.miataturbo.net/engine-pe...ot-info-74425/ Here's my report: I used the stock baffling and ran 2x -12 lines from the exhaust side of the valve cover to the slashcuts directly. The center and exhaust baffles were retained, with the connecting passage hole enlarged. I used Moroso slashcuts and Moroso check valves. After a few hundred miles or so, the check valves no longer worked. When the car was idling, I can feel exhaust coming through the hoses. Fail. The slashcuts do work- I know this because I measured crankcase pressure by attaching a vac/boost gauge to my oil cap and saw negligible pressure under 30+psi of boost. Also, if I just rev up the car with it standing still I feel vacuum on the hoses. Annnd I also know they work because my exhaust has tarrish buildup lining it after the slashcuts. Unfortunately, after a long cruise, like over half an hour or so, the exhaust heats up and the tar starts to smoke making it look like I lost a piston. Fail. One's crankcase evac solutions should be dictated by a) how much boost you are going to run and b) how you are going to use the car. For a low boost under 10psi car, assuming you use the baffles and don't have compression issues, a slashcut may not smoke very much. For a low boost car, why even bother. Just run the stupid crankcase vent line to the intake and be done. Yes the oil will lower the detonation threshold but who cares cuz you're not making allofit HP anyways. Note that many drift cars run slashcuts and you probably don't notice the smoking exhaust because of the holocaust of rubber smoke. Really, I think it was a waste of time and money. If I do-over I would do it like high-hp hondas and gangrape the valvecover with 4x -8 lines and send them to a gigantic catch can box with 4 breathers or something ridiculous. Something like this NEW ANODIZED & POLISHED CATCH CAN KITS!!!!!!!!!!!!! - Honda-Tech I don't think the bump-in the line valvecover-catchcan-slashcut will work. The slashcut will suck the moisture out of the can. Faefae |
props for your sense of humour and help :)
I was thinking 2x3/8 hoses from the hotside of the cam cover and PCV valves on each of them and then the hose directly out to the exhaust with no valve there. Thanks, Dann |
Check valves are very hard to find with low cracking pressure GRR.
Any ideas what else can be used? Dann |
Make a flapper door?
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Ok Im putting one of these check valves on, and modifying the spring to give a lower crack presure.
http://liveimages.quicksales.com.au/...adcolor=ffffff Customers happy to pay for what it takes to build the ultimate catch can setup and test it, Im doing it for cost because i wanted to learn and offer a really good catch can solution specific for NA/NB chassis, so this is a good place to start :) Can anybody think of a cost effective solution to view oil level without paying huge money or using that god damn useless shitty plastic tube like most cans have. So far the idea is a 1" alloy cap with an alloy tube below it so you have a clear section of the can without the steel wool blocking your view. https://www.miataturbo.net/attachmen...ine=1377138160 http://s13.postimg.org/t7szal5yv/Catch_can.jpg Dann |
So catch cans.
I dont want photos of cylinders with pipes in them , I meant internal design, where the hoses go, how the baffles look etc. I'll do it all and post results and everyone gets a bit smarter. :party: Dann[/QUOTE] Here's what I did in my build thread. I addressed engine block venting and modified a cheap catch can from ebay. Refer to posts 4,9,26. https://www.miataturbo.net/build-thr...-thread-70913/ |
Props awarded for info.
What model is the 1 way valve from? From the honda. Dann |
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Just confirming that this is the exact same spot bbundy and the others who are doing twin ventilation from this side are using?
https://www.miataturbo.net/attachmen...ine=1377159877 thanks Dann |
Cost effective solution to view the level would be a screw in site hole. Its just a piece of clear glass or plastic that fits through a hole with gaskets and some threading, like a bulkhead fitting. Should be able to get them from an industrial supply place.
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Yeah available on ebay.
Dann |
It'll be called a sight window or something like that. Doesnt upsidedown land have something like mcmaster?
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I edited, and yeah we do but its all WAY overpriced.
Cos we have too much goddam money here. Dann |
Lol, I can get them for like 6 bucks. McMaster-Carr Not sure if that link'll work mcmaster and linking is iffy.
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I can get them shipped from china for a similar price, thismay be the go.
Dann |
Did you check Australasian ebay? If not, maybe buy a shitload of them and mark them for some price between the crazy local price and the china price and make some extra dough.
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