JM fab smim questions

[95redgsx]

your going to need alot more than a welder and a band saw for building manifolds

 

[DSM90AWD]

Add that the JMF / Magnus were built with countless hours of R&D and include warranties from defects and the price is very resonable.

I've the JM (actually Sweet97s old one) and it is beautifully built and fitment is excellent

 

[90blacktsiawd]

1Slocolt - where did you see the info on the JM Fab picking up 33whp over the Magnus? Do you have a link?

Thanks

I need to correct this statement. I believe it was actually more than 33whp last time i looked at the dyno chart posted in Jim's office that the TurboTrix car gained. But the manifold wasn't the only change. They also switched to 1mm oversized valves.

 

[Pube Stache]

A ported head as well. As far as i'm concerned, you can't go wrong with either a JmFab or a Magnus. I don't really care for the warped flanges that sometimes happen on the JmFab mani's though. My friend's brand new one is warped.

 

[DSM90AWD]

I don't really care for the warped flanges that sometimes happen on the JmFab mani's though. My friend's brand new one is warped

Speaking with Jim of JM Fabrications, he explained that despite bolting the flange down to a solid work surface during welding, even with super-thick flanges there will be some degree of warpage due to aluminums high heat treansfer properties. There is a tolerance as he does pressure test each unit after manufacture.

As is the case, he recommends use of a tube-style RTV sealant (e.g. not copper spray) on both mounting surfaces during assembly. This is especially important if using an OEM Metal gasket as they are very particular about both surfaces being true and smooth

 

[DSM90AWD]

Mine had a bit of interferance on the throttle cable side which the previous owner had corrected by grinding a notch in the flange (coudl just as well have trimmed the throttle stop). Jim said he'd corrected that issue by moving the TB mounting holes around. Definitely drop him a line to let him know so he can correct his design if needed.

BTW.. be sure to pressure test at the TB elbow to ensure no leaks at either flange. Mine had a slight leak at the D/S end of the flange at the head which I corrected with some high-temp Copper RTV