turbo manifold design
#45
http://www.full-race.com/Miata.html
It's not on their site anymore that I see... That link was pulled from a Google search. So the thumbnails might not enlarge. At least I can't get them to...
It's not on their site anymore that I see... That link was pulled from a Google search. So the thumbnails might not enlarge. At least I can't get them to...
#49
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honda engines are hella smooth, you can make a big lanky manifold out of thin steel and the thing will be fine. The BP has some serious vibrational issues, thats why you gotta use sch 40 pipe, that kind of stuff is beyond unheard of in the honda world. Most ppl would say sch 10 is overkill
#50
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http://www.full-race.com/Miata.html
It's not on their site anymore that I see... That link was pulled from a Google search. So the thumbnails might not enlarge. At least I can't get them to...
It's not on their site anymore that I see... That link was pulled from a Google search. So the thumbnails might not enlarge. At least I can't get them to...
#53
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honda engines are hella smooth, you can make a big lanky manifold out of thin steel and the thing will be fine. The BP has some serious vibrational issues, thats why you gotta use sch 40 pipe, that kind of stuff is beyond unheard of in the honda world. Most ppl would say sch 10 is overkill
#54
Or they found out that we are all a bunch of cheap ************* who are unwilling to pay $1500-2000 for a robotically TiG-welded manifold. I've held a T4 twin-scroll Full-Race manifold with twin EWGs in my hand, it made me a little hard, and then the $3400 price tag immediately made me soft again.
#55
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honda engines are hella smooth, you can make a big lanky manifold out of thin steel and the thing will be fine. The BP has some serious vibrational issues, thats why you gotta use sch 40 pipe, that kind of stuff is beyond unheard of in the honda world. Most ppl would say sch 10 is overkill
Just asking.
Is there a reason the honda engines are balanced better? I figured one production inline 4 cylinder would be relatively similar to another.
I would think a thin wall tube manifold would heat soak the same on either. If you get the material into a heat range where it can soften, it will fatigue because of the load it's trying to support anyway. Thin wall tube is real easy to heat up. I cracked my thin wall manifold 5 times before I finally wised up and made it with .187 wall tube. Now no problems whatsoever. It holds the heat in so well, the VHT paint I used isn't even flaking and it spools better.
Just saying. It seems like most of the premium manifolds are made of thicker material also.
Last edited by lordrigamus; 07-26-2010 at 04:53 PM.
#56
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Idk, I really dont think the BP is as smooth. Think about all these weird failures we have at high RPM, breaking throttle shafts and oil pumps and whatnot.
People apply a lot on generalization to honda engines, like assuming they all have good rod ratios which is why they rev safely. But in reality many engines have rod ratios that are extremely similar to ours sometimes even worse. Yet they have no issues reving to 8k+ rpm.
No doubt there are manifold failures on hondas, but from what I gather its because of very light materials, much lighter than any of us would even consider a possibility. Like those "SS autochrome" ebay manifolds. A miata couldnt get out of the driveway without cracking one, while honda guys will ge away with running one for hundreds, even thousands of miles before it cracks (but they still always crack)
Ive always assumes that it has to be vibrational. The only other thing I could think would be that maybe since we tend to run undersized turbos and they tend to run oversized turbos that maybe the smaller turbos are creating a lot more heat in the manifold that is fatiguing them faster.
All I do know is that many members of this forum will say "sch 40 is a minimum", and if you say that youre building a manifold out of sch 40 on a honda people will think that your cheese done slid off your cracker.
People apply a lot on generalization to honda engines, like assuming they all have good rod ratios which is why they rev safely. But in reality many engines have rod ratios that are extremely similar to ours sometimes even worse. Yet they have no issues reving to 8k+ rpm.
No doubt there are manifold failures on hondas, but from what I gather its because of very light materials, much lighter than any of us would even consider a possibility. Like those "SS autochrome" ebay manifolds. A miata couldnt get out of the driveway without cracking one, while honda guys will ge away with running one for hundreds, even thousands of miles before it cracks (but they still always crack)
Ive always assumes that it has to be vibrational. The only other thing I could think would be that maybe since we tend to run undersized turbos and they tend to run oversized turbos that maybe the smaller turbos are creating a lot more heat in the manifold that is fatiguing them faster.
All I do know is that many members of this forum will say "sch 40 is a minimum", and if you say that youre building a manifold out of sch 40 on a honda people will think that your cheese done slid off your cracker.
#57
Then why are there so many posts in Honda forums on cracked turbo manifolds and so many manufacturers offering Honda manifolds guaranteed not to crack?
Just asking.
Is there a reason the honda engines are balanced better? I figured one production inline 4 cylinder would be relatively similar to another.
Just asking.
Is there a reason the honda engines are balanced better? I figured one production inline 4 cylinder would be relatively similar to another.
The manifolds crack most of the time because they're not back purged when they're tig'd. Good luck to the guy that has to tig a manifold back together once its been used.
M.
#58
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I haven't heard of too many thick wall manifolds cracking though. Just my 2 pennies.
Last edited by lordrigamus; 07-26-2010 at 05:21 PM.
#59
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Ive always assumes that it has to be vibrational. The only other thing I could think would be that maybe since we tend to run undersized turbos and they tend to run oversized turbos that maybe the smaller turbos are creating a lot more heat in the manifold that is fatiguing them faster.
All I do know is that many members of this forum will say "sch 40 is a minimum", and if you say that youre building a manifold out of sch 40 on a honda people will think that your cheese done slid off your cracker.
All I do know is that many members of this forum will say "sch 40 is a minimum", and if you say that youre building a manifold out of sch 40 on a honda people will think that your cheese done slid off your cracker.
Dem Honda bois do luv dem huger turboz.
And I hate when the cheese slides off my cracker, someone needs to address this issue! Some cheesy weld or something.