I'd never used a welder before prior to this, so I'm pretty happy with these extractors (and the resultant dual exhaust system) being the fruits of my labour. I've been told some of my welds look ugly but rest assured there's good penetration, and I checked inside the pipe after each one to make sure there's no internal blobbing. I went over most of them 2-3 times to cover anything that even resembled a pinhole. Don't want any exhaust leaks if I can help it!

They're not equal length either, but according to David Vizard's exhaust article, it's flow that's more important. He writes that scavenging effect tends to have a 3-4000 range, and a 12" difference in runner length will only move this band of effect by 1000rpm or so, so the powerbands still overlap. The longest runner compared to the shortest runner is only roughly 8" different, so will only shift scavenging effect for that cylinder by about 600rpm.

The beauty of these headers is that they can be removed out from under the car without unmounting the motor, all you have to do is temporarily disconnect the steering column bush on the driver's side to get that one out.

Mark

How hard would it be to remake those things with VH45 flanges???

Quote, originally posted by elwesso »

wow those are beautiful, a litlte owrk with the grinder and you could be a millionare... How hard would it be to remake those things with VH45 flanges???

Hehehe, well it took me quite a long time since I work full time, but there wasn't anything overly hard about it. I'd avoid the stock header flanges like the plague, and get some new ones laser cut like mine. The factory plates are uuuuugly , bigger than the ports, rough edges, etc.

Rookie question: I know the KA-T guys usually cut slots in the flange between each runner. Is this only necessary with the added heat of a turbocharged motor? Seems like slotting the flange of long tube headers like this would just weaken it.

My estimation is that this gasket failure was due to the fact that some of the manifold->head and manifold->turbine housing bolts did not have locktite on them so they eventually backed off and allowed a bigger gap that just blows the hell out of the exhuast gaskets. One MAY make a case that this is due to warping as well, since it was daily driven and often went from the cold of sitting in the winter to the hot of a heated turbo. Or even if it was not permanently warped, one may make a case that there was rapid metal expansion at different rates (head is aluminum, manifold is cast iron, turbo is steel I think) that caused a temporary gap between mating surfaces allowing the gasket to be destroyed sooner.

I chalk it up to some bolts missing locktite and a cheap replacement gasket that came with the turbo manifold, instead of a nissan or nice aftermarket one (like a copper one for example).

Most of the time when I hear about cracks its on thing gage tubular steel manifolds. YMMV

and mr mod-h if the age of the thread is a problem why not delete the thread? if the age is not a problem why bring it up?

i found it through google...

mazworx may be cheap to you but we dont all have the same income...and with bills thats a couple months extra saving im trying to avoid...thanks for the advice ill keep it in mind though

never said mazworx was cheap, in fact i think quite the opposite.
with my vh swap i built and fabricated every part of the swap including headers.
if you can fab then the swap is relatively cheap and easy, else mazworx is the only option.

I'm from NEW ZEALAND!!! Not Australia!!! lol...

Also, I long since ditched those s***ty custom headers, and built a much sexier equal length set to suit the new engine position! 787mm runners ftw!

But no, building custom headers is a nightmare... especially when you only have a handheld 4" disc grinder, no bandsaw or dropsaw to make cutting pieces easy. So I'm reluctant to ever make another set of headers after these. Just get your hands on a welder and make your own!

A new West Tesxas and Eastern NewMexico Import Forum
http://www.WeastTexasImpots.net

they look really good