Good Rb26 Single Turbo Manifold?

[Adriano]

Find a manifold made from stainless steel, with individual runners and a wastegate flange angled into the exhaust flow. Make sure the runners are seperate where they bolt into the block to allow them to expand. Proper design > brand.

Why stainless, steampipe ones dont crack wheras stainless ones are far more prone

[Roy]

Why stainless, steampipe ones dont crack wheras stainless ones are far more prone

It has far les to do with it being stainless. Its actually a function of not the metal but the fabrication technique. There isnt a reason why you cant have the best of both worlds

[R31Nismoid]

Stainless ones generally need to be better made, thats all really.

Supporting bars, welds etc. After 20 years my GTS-R manifold is still working and hasnt required one repair

[r33_racer]

stainless goes brittle after its been exposed to too much heat. Its the same when welding it. It seems to be hard to find a properly constructed manifold these days. Plus the stainless manifolds go dull and grey from the heat and only look good (bling factor) for the first month or two. It wouldnt matter if it was totally wrapped though. Without the wrapping the mild steel radiates less heat and helps keep underbonnet temps down where the ss radiates it massively if not wrapped, so i guess a wrapped ms would be ultimate. That was the biggest difference i noticed when changing from ss to ms manifolds, the radiating heat. Not only that but with the 6boost manifold we saw a straight out 300-400rpm earlier boost and power incline. That was the biggest thing our tuners complimented on when the car went back to them.

[Adriano]

It has far les to do with it being stainless. Its actually a function of not the metal but the fabrication technique. There isnt a reason why you cant have the best of both worlds

Hows that when the coefficient of thermal expansion for stainless steel is like 10 times that of mild steell(depending on the grade.

[Roy]

Thermal expansion? Ok, but its not an issue. The amount of bends in a manifold allow it to grow. Its only an issue if you have a long length of striagh tube which is fixed at both ends and it cant grow.

So good point, but my 2c is thermal expansion is not an issue. I worked for about 5 years in the specialised welding insudtry, and still work in a related industry. So whislt i cant weld for sh1t, i know a good weld and have wokred with great welders. I have only ever seen a few manifolds that from a welding perspective cut the mustard.

General practice is pretty poor. Does the job, but not a good weld, and im sure would fail many of the xray and tensile tests etc required for it to become a qualified weld procedure as per AS requirements.

Steam pipe will work, but its a ball ache to get smooth internal bore. The right grade of stainless steel welded properly and isntalled with a bit of care will give you a light and great performing manifold....my choice should i need one.

Main advantage of cast manifold is you get to play with bore and tweak gas velocity. Tube doesnt give you that flexibility. But short radius and long radius elbows dont give you the same fabrication flexibility as tube.

Although all this talk of welding...thats another point. A good manifold will use mandrel bent sections with only around the collectors requiring welding...ala every racign manifold you see and manifolds liek Gibson and Nissan gave the R31 GTSR, or you see on a lot of drag boats etc

[govich]

Are you guys serious? 304 grade stainless as an example is pretty easy to weld, crack resistant, low in thermal conductivity and long-term corrosion resistant. The only potential worry is the high coefficient of thermal expansion but that can be accounted for. In theory, and with a proper design, stainless should be one of the top candidates. If using mild steel you'd want to coat it with chrome or some sort of ceramic to help with corrosion resistance.

Edited October 6, 2006 by govich

[gawdzilla]

no response to my email to 6boost. i really dont want to make an international call. are they typically responsive to emails?

[Warpspeed]

no response to my email to 6boost. i really dont want to make an international call. are they typically responsive to emails?

Try again and be patient a while longer. He maybe away from the computer as he runs a pretty busy business these days.

[saliya]

no response to my email to 6boost. i really dont want to make an international call. are they typically responsive to emails?

More responsive to phone or SMS IME.

SMS should not cost you the world; but then again neither should an international call... particularly not

compared to the price of the manifold.

Regards,

Saliya

[T04GTR]

tube8 ones are the shissel.