it's pretty well known that the DRAG manifold tends to crack after time. Well, I'm trying to build a reliable drag 3 Civic. I don't want to have to deal with such a problem.

Does the manifold crack due to the weight of the turbo? It's pretty heavy, and if the design of the manifold isn't right, I could see over time (especially with heating and cooling repeatedly) that it could crack. Vibration? Or is it just due to too much heat?

If it's due to heat, how would thermal coating affect the life of the manifold? If it's due to the weight, I could probably fab up something to take off the stress.

Any thoughts anyone?

 

Watercooling the turbo will help alot.

 

its more of design problem with vibration. Usually the downpipe is not installed with some type of flex join. therefore it has no way to stress back and forth. Deepstage out of TX runs a Drag mani fold oon there race car without it ever cracking or having problems. becuz there is no stress on the manifold. since hte dp is just dumped.

 

mine cracked and I had a flexpipe put in before it was installed...

some miata guys told me they were having the same problem with the small greddy turbo kit on their cars... the cast manifold would crack... the fix they found was to cut the flange (top to bottom, all the way through, between the studs) where it meets the head in between each of the ports... I guess it allows for thermal expansion??? that is all I could figure...

what do you guys think about that???

 

Hmm, interesting idea. Wonder how the drag would hold up to that sort of modification?

 

Actually that's a pretty common thing on headers for domestics. Back in the day we used to hacksaw out the pieces of flange between the pipes where the header bolts to the head. Although this was to help the gasket seal (leaking header gaskets are common on those things) rather than to prevent cracking or breaking. I can see how it would let the manifold flex a *little* though since the one piece design makes it stiff.

 

anyone else have any thoughts on this?

 

Why not invest in a strong 8 gauge stainless steel manifold.

 

because some of us don't have that kind of cashola bro. We try to make due with what we have.

 

when a car takes off the manifold and exhaus tnad downpipe flex. If ntohin isgivin way and letting it flex somethin is goin to break after a while.

 

does anyone ever brace the turbo/manifold to the block? like what honda does with the stock exhaust manifold?

like you said, it seems like the weight of the assembly would be alot. that along with the vibration and tugging of the exhaust system is a lot of stress.

when my friends cast manifold broke on the prelude, they said he was supposed to brace it. I can't remember which one he had, not that it matters that much.


[Modified by sjoback, 10:13 PM 6/27/2001]

 

But how would you brace it? I know mine doesn't have any kind of brace. But it does have a heatshield!

 

Well for the price of the rev-hard and drag manifold around $400...you could get the same Stainless steel manifold for the same price.

 

Yes make sure to have a good piece of flexpipe along the downpipe before it bolts tot he rest of the cat-back.

Also something often overlooked. Make sure you keep the stock splashguard under the engine. Water splashing on the manifold will surely crack it.

 

I didn't even think about that! Great point. So, do you think any sort of thermal coating will help prevent that from happening? I'm thinking it would, as the coating would prevent the actual metal on the manifold from coming into contact with the water, thus the water would be less effective at cooling on contact. Your thoughts?

 

Water splashing on your manifold? Mark you didn't tell me you lived in a swamp.

John, from our experience, any type of coating on the manifold has increased it's likelyhood of failing.

 

so Ben, what do you think is the problem, and what type of solution is there?

 

The flex pipe option is sound advise. Whether it be cast or tubular, any manifold will fail if out under enough strain. Of the few DRAG Gen 3 kits over the years, we have warrantied two manifolds due to failure. On a side note, if your manifold does fail DON'T try to have it repaired. Just give me a call and I'll do my best to have it replaced under warranty for you. This applies to everyone who has bought a DRAG Gen 3 kit from us.

 

good to know, thanks Ben