I thought I'd add this after Garth's mention of '6Boost' manifolds.
I'm not intending for it to sound like an advert, but this bloke, Kyle/6boost, contributes to the Australian Toyota forum I'm a member of and I thought it'd be a worth while addition to the discusion of turbo manifold design:
"Just a quick post to tell the results of my exhaust manfiold change/conversion.
after running the 9.9 at wsid (Western Sydney International Dragracing) months back Kyle from 6boost manifolds contacted me askign would i be interested in testing one of his manifolds. i thought why not. Kyle backed his product well stating he would build me a manifold with the same flange position so i wouldnt have to change my dump pipe or wastegate so that if i didnt find good results i could put my old one back on and nothing would cost me money.
so i took off my manifold sent it up to him, he built his design manifold with the merge collector to suit a split pulse turbo and sent it back. all i had to do was finish off the wastegate plumbing to suit the car as it would have been difficult for him to do it without the car. at this point i had decided to go to twin tial wastegates as they are a contigency sponsor for sport compact and sean (super crown) had found good results running twin gates.
so with no other changes than kyles manifold and the wastegates (which aren't going to change power outputs)and also a minor convertor adjustment we put it on the rollers with the same tune, at 16 psi we picked up 64 rwhp, with a change of 440rwhp to 504 rwhp. we also picked up early spool of about 600 rpm.
i was really happy with this. the car at boost of 28 psi use to make 635rwhp with the rear tires peeling off rubber. the car now makes 721rwhp and it either climbs out of the dyno or smokes the tires like your doing a static burnout (even with 3 110 kilogram guys sitting in the back of it) so i cant say exactly what power it is making due to the wheel spin, i know we have run out of injector (they are 1000CC) at 55 psi of fuel pressure and will need to up them to put any more boost into it.
now the most impressive part in my opinion, since going to the 1.5jz (A 1.5jz is considered a 1jzgte 2.5ltr cylinder head, which has different head flanges, bolted to a 3 ltr 2jzgte bottom end) and the GT42R turbo i have struggled to get the car to sixty foot better than a 1.77, when it used to consistantly low 1.6 and a couple of times 1.5'd with the 1j package. the car set a pb sixty foot of 1.51 at jamboree. and thats with a tighter converter which should make sixty footing even slower and harder to do.
now put that 1.51 sixty foot with the rest of my increments from the 9.952 pass at 149.58 mph at wsid and that would equate to a 9.4 et without the increase in power. now thats what gives me a chubby, as racing is what i built this car to do, not win dyno comps.
its safe to say my old exhaust manifold has been sold to a very happy buyer and i will be sticking with the 6boost manifold.
i was skeptical at the results i was being told about kyles manifolds, but i can now first hand recommend to any one serious about going to a single turbo, if you want early response and power, i dont think you can go past the 6boost manifold. sure its more expensive than a china manifold, but you get what you pay for, i believe the 6 boost manifold comes with a life time warranty from cracking, which i have seen plenty of brand name japanese and these chinese manifolds do, even with a lot of bracing."
*This guys car is FAST!!! I've done some minor editing of his
http://www.toymods.net/forums/showthrea ... t+manifold post, but the mass and important stuff is all original!
Also, while I haven't personally used the Adaptonic, it's configurabillity, number of inputs and outputs, tuning density and support says volumes!
Certainly much better than some of the established 'cheeper' brands here in Australia!!!