jrussell

Yeah, that's exactly what I'm saying.

Now if you're talking a nitrous backfire, then yes, but it's highly unlikely all 4 were due to nitrous backfires.

Since you're so convinced these crazy high mystery pressure spikes occur, maybe you fill us in on how, when, and why they happen. I know I've sure never seen/heard of one.

wildcat

Why? Is Nitrous on diesels as rare as you seem to think CFM's are??

Intake valves don't stick, float, or leak in high performance diesel applications?


How are you thinking they are failing? Are they getting too hot, and the elevated boost pressure is rupturing them? It would seem to me if that was the case, they would split open, not "Blow Up".

I think I'm through.

It's been entertaining and educational chatting with you.

rams-n-hogs

I have to agree with this. I have been running one for about 4 months, now, and mine has seen 50-60 lbs of boost numerous times. At most, I could see it splitting at the seams, and relieving the pressure. Once I start getting up into that boost pressure range, I'm more concerned with my head gasket. There's no way one of these trucks could blow one apart like that. I'd be more inclined to believe someone put an M-80 inside of it, and said, "hold my beer, and watch this."

Stevemil56

Does anyone know what mods the trucks had that reported these failures?

DevilzTower

of course not ... that's why the last 4 pages of this thread has been ... "PLASTIC BAD, METAL BETTER"


whatever ... if no one pushes the envelope, we'd all still be using clay bricks to build structures with ...

enafzige

On the competition diesel forum, the original poster said there was no nitrous involved.

There was, however, a small dose of water/meth...

--Eric

wildcat

new ideas and technology take a while to get used to.

A while ago, people thought convection ovens were better than microwaves. Now, most people hardly USE a stove!


There's NOTHING wrong with the CFM, other than a Few "I told you so, good ol' boys" trying to make their case against plastic.

Chevy uses the same material for intakes on just about every gas motor they sell.
Toyota is using this same material on their EXHAUST manifolds!!

And they warranty their motor for 60K.

I think if there was a problem with them melting, or resisting heat, the auto manufacturers wouldn't be using the material so much...

True, once out of the warranty period, they are no longer concerned what happens to it, because now it's your dime.

I'd run one if a GDP Mk-2 would mount under it... Ohh well.

c-hawk

CFM,

As others have asked, i too would like to know:

What psi is the air horn rated for?

Is nitrous use with this air horn ok in your opinion?


I have one new in the box, that i was planning on running with twins and maybe some spray, but depending on if/how these questions are answered, i may be sending it back instead.

Thanks,

Chris

c-hawk

What happened to the post by CFM+ Tech????

Please tell me it got deleted, and not that i dreamed it up.

Convicted1

Well, I don't support a race truck 500 Miles south of the border, and I know that I won't be using this manifold. Just the fact that I run nitrous is all I need to know. I will ot have that weak link in my intake tract.

As for your theory of a spike (such as a nitrous backfire).. How many of these trucks have the RUBBER intake boots still on the IC Piping?? Are you gonna tell me that that nice shiny peice of 400 Dollar plastic is gonna blow up BEFORE a peice of 25 cent rubber hose IF it doesn't have a design flaw?? I think not.

As for THIS statement, have you ever worked in a garage? I've had to replace probably 5 or 6 of these Retarded plastic manifolds because they've come apart. That's in the last 2 or so Years. Granted, the engines in question were not exactly finely tuned peices of machinery and I'm sure backfired through the intake, yet if there had been a metal intake in there the customer wouldn't have had a repair bill for a 600 Dollar peice of plastic.

I'll be anxiously waiting to see what XLR8R's Intake looks like.....

Plastic = Sux

Metal = Safe

soulezoo

He appears to "not appear" any longer... I just posted this on the other pertinent thread...

Can admin tell us what happened?? I, and am sure others, would like to have heard some of their side of this debate and provided clarity.

Lary Ellis (Top)

If CFM wishes to promote their products here, they can pay for that right, just like the other vendors that help keep this forum free for the rest of us

HOHN

This is a pretty interesting thread.

First, the debate of plastic vs metal is pointless. Either can be made all but bulletproof. The thing is that the design must match the properties of the material-- that's all. It would be very easy to make a plastic horn stronger than a metal horn, and vice versa.

The pic posted earlier shows an intake in 3 pieces. This is hardly an explosion. When a carbon composite fails catastrophically, there are way more than 3 pieces! This seems to indicate a manufacturing defect more than a design or materials defect, imo.

The posted pic also shows the sectional thickness of the CFM piece to be pretty thin. Perhaps it needs to be thicker?

Other random comments:

- Most composites will "broomstick" when they fail. This piece is clearly NOT carbon fiber, but rather a carbon composite or FRP. I think you all knew that, but lots of people think these are Carbon Fiber when they aren't.

- The fact that the picture "appears professional" is meaningless. With a cheap pair of studio strobes and my Nikon D200, I can take pics that look "professional" at home with no problems. All the pic means is that the photog knew something about lighting.

-- The effect of engine vibration on a composite piece like this is unknown. Boeing uses a MUCH different way of manufacturing composite pieces for aircraft-- they are actually made ON the plane-- a large spindle with the composite threads rotates around the surface. This way the orientation of the fibers (and hence, their mechanical properties) are precisely controlled. I suspect that the CFM unit is just molded, and thus less precisely engineered.

Four failures in the out of the many units made thus far is borderine on statistically insignificant. It could easily just be attributed to a combination of manufacturing tolerance and cyclic stressing.

The extra cost of the CFM unit would drive me to the ATS piece-- NOT the "failure rate", which is statistically irrelevant.

JMO

rip 112

Thanks for that HOHN, I don't think it could be explained any better than that.

DevilzTower

X2 ... I just don't have the patience to write that much anymore ...