weir does make a bunch of good products. he is an awesome fabricator...although i am pretty sure i read a post of his that stated that he does not backpurge the manifolds. He said he would stand behind anything that fails that he made, but i would just prefer my manifold to be backpurged. i could be wrong thinking that it was him that said it, so don't hold me to it.
but as you can see by the above pics, the quality of his stuff is great.


again, like i said in the first post, i would just use an inline pro cast manifold for 400hp and be done with it. it is very durable, will make the power you want, and it won't cost an arm and a leg.

A cast manifold is better than a stainless pipe log manifold for many reasons. this thread is not really geared towards that however.

 

Here are some pics of a manifold that is being produced by some of the local guys. Sorry about the crappy pics.

 

Looks good but I´m going for a "stealth" look, IP cast or LoveFab Mini Me is first on the list right now.

Got another question, turbine A/R. A Honda tuner told me to use big turbines to handle the high rpm´s.
Any truth here? Do you use bigger A/R turbines than other 2 litre tuners?

 

I wouldnt go crazy with A/R. I wouldnt run anything larger than like a .8X a/r for your power goals. the standard .63a/r seems to work fine on our engines. if the turbo is large enough it wont run out of breath in the higher rpms.

 

Sorry.


Also What are the cons of having a log manifold like Pfabs?

I was looking for about 400whp out of that manifold but after reading this thread it has gotten to second thinking this idea and going out and looking for an Inline pro mani instead now.

What about something like this? It's in the fs forum right now.

better or worst than something like IP log?

THanks

 

i wouldn't buy that...looks like the welds are underfilled on that runner, both those will most likely crack after some serious heat cycling.

 

no, i don't backpurge unless it is required. i will backpurge downpipes, or areas of a runner that have even a slight gap. of all the manifolds i've built, i've had 3 come back for repair due to failure and not one of them was as a result of not back purging. they were all related to wastegate branches being too long or unsupported. corrective action was taken and now wastegates flanges are welded directly to the collector in most setups. at any rate, i do warranty my work for life and do 99% of my fabrication for local customers, so servicing that warranty isn't a concern for my customers, it is peace of mind knowing if they have an issue, they can just come back to me and discuss it.

i don't feel backpurging is necessary if the welds are consistent and done cleanly. although turbo manifolds do see some degree of pressure, they are not nearly as critical as something like a pressure vessel. i have also done repairs on other company's manifolds that were back purged as well... so just because it is claimed to be backpurged, doesn't mean it is done properly.

 

You can make good power with logs, you will make more power with tubular. I think the inline log is probably the most stout manifold you can get for our car. Tubualrs do create more heat and may require you move more stuff around and are more prone to crack. So you need to figure your power goals and how your gona use the car. If your going for big power then tubular. If just adding more power street drivable then you could run a log with a gt30 gt35.

 

okay aaron so it was you that stated that. i wasn't bashing your work at all, like i said all the stuff i have seen you produce looks to be very high quality.
As long as you stand behind your work, then you get my vote!

 

Yeah, I get that. Will go tubular if I decide to go further, 400whp is good for now.

Any internal pics of the IP cast?