Exhaust manifold porting.

Allright guys, had a spare manifold knocking round on the garage floor and heard that it was possible to port it for better flow and faster spooling turbo. below are some pics of my efforts on the manifold. Just wondering what you lot think? it's matched to the exhaust gasket now, do you think I have taken enough out or should I go bigger or deeper into manifold.
anyway constructive criticism is more than welcome!

cant see any of the pics

I can get pictures of mine up mate was done by a professional who ports heads and has a flow bench etc very well known with cars also in the kit car buisness. How long did it take ?

Took about an hour for each one, did it over a couple of weekends. Just thought what the hell, not got anything better to do, best way to learn is have a go and see what happens, nothing to lose as it was a spare and have all the grinding bits in my toolbox. some pics of a professional job would be good to look at and compare

Does any body know what a standard ported manifold will flow bhp wise? Will it allow 450?

Yes and if heavily ported even better i would say. But that said i would be lookin at a quality stainless for maximum flow at that sort of power

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PartyPete wrote:Does any body know what a standard ported manifold will flow bhp wise? Will it allow 450?

Would you worth you speaking to Bogdan about a decent manifold, would be a shame to have a cast manifold at 450!

You ran many stainless Tom ?

Had a DP motorsport manifold on with the 2876 for a while but never ran the car up or had chance to use it properly. Then thats when I stripped the car back and put it back to stockish configuration. Also had a re welded japspeed one on when I had the 3071r and that helped with fitting the big turbo although I did have to take a bit of the block/engine mount to get it on right.

Also Had it mapped by Greg protuner but it only lasted 30 minutes and it went pop lol. Thats when I took it down to Leon and then had a load of trouble and a few years wasted :-(. I know Bob has run a few decent ones on his track car and I would definately want to get as much of the cast iron crap out the way if I am running big power, would make the car flow a lot better and ultimately run safer.

But there is the problem of quality and cracking. The DP one I had was quite thin but I know others run them ok.

I would have to be well proved otherwise to run one I have braced them re welded them the lot they all crack in very little time I have had 3 now and seen plenty others from cheap to dp to a custom one. I would like to hear from people on here running them with no issues ?

Daniel on here has one fitted in his car 'japspeed' that's been fitted for years with a 2871 and no cracks so depends whether your lucky or not I guess.

Personally I think a ported stock manifold takes some beating and I've ran 468hp on one in the past and no problems but how much more it would flow over that remains to be seen.

Was talking to our new guy the other day about them and he believes that it would not flow much more than that and a good stainless free flowing mani would be much more beneficial so il accept his advice after being brain fried by his mathematical calculations lol

Yeah...I had a look back at my receipts and the japspeed manifold has been on the car since early 2013...so just been lucky as Bob said(touch wood)

What turbo and power do you run ?

I had a japspeed mani on for around 5 years - it lasted well (running 1.2bar ~310bhp) but i only cover around 1500miles a year

Eventually it cracked - pretty bad - so i lumped the original mani back on as a quick fix

Not sure if it was just me but it seemed a little slugglish in comparison with the original unit back on

I'd just had a bogdan elbow fitted so probably not seeing the full benifit of that either.

I'll either get the original ported (im sure someone posted a link for someone doing them for like £80) or go for another japspeed type and hope it lasts a few years like the last one did.

Proper manifolds are just to expensive for me.... £200 ok..... £400-500 just to steep !

No offence but see 310 is no power and not a heavy turbo. It's all about the bracing I suppose but

No offence taken Johnny !
Was just giving figures that particluar manifold ran on for so many years
Probably why it lasted a bit longer than the average on a higher power/spec car !
Did the job for me which is why id possibly consider something similar again

Glad it worked that's why I put the question up as I just can never get them to last. Last chance is my big hks top mount manifold see how long it lasts cause it was far from cheap. I just seem to make them glow red soon as there getting that hot then cool a few times and slight movement when hot just cracks them.

I know a lot of people take the brace off the downpipe etc. Would this help support the weight a bit? I have just taken a japspeed manifold off my other R as the tubby has gone but I definately wont be putting it back on lol

Stainless is just a poor material for turbo manifold use unless absolute top quality material & welding plus effort in bracing to reduce stress.
For road use some of the better china manifolds could last a while & if bracing added they would do far better.
I use steam pipe bends & it easy to weld, very durable & takes ceramic coatings well.
Stainless ok for someone like Bogdan as he particularly good welder/fabricator & seems have easy access to good thickness & quality stainless bends.

I wish I knew somewhere that would make me a similar to standard better flowing cast one

There was a company doing the cast manifold for the gtir .... i think it may well of been japspeed johnny will try find some info on it for you ....

I know someome did the log manifold top mounts as Dobby had one on his red R was good up until 450 but thats a lot of power!

Leighton I think bob pointed out they listed gtir but we're 200sx mate. But try no external waste gate like some had please