1JZ T3 manifold options

I have a 1JZ toyota with an HKS3037S turbo kit. The original exhaust manifold from the HKS kit had a T25 inlet - which meant great spool, but did choke a bit at high revs. When the manifold fell apart sending shards into my turbo, I had Owens rebuild it with a GT3076R core. However, that now leaves me with a problem: Garrett recommend a T3 inlet with the GT30 range, but trying to find a decent 1JZ manifold with a T3 flange on it is not easy. The only options available are all pretty crappy. I tried a Japspeed RS tubular, and it was basically a bunch of pipework (admittedly well made) for a T4, but with a T3 welded on instead - which resulted in a serious step cutting into the gas flow where the pipes meet the flange. That probably would not matter for peak hp, but for spool, its a major no-no. Every other manifold (XSPower, ebay china manifolds etc.) I have seen have the same problem, they all have large pipework for a T4, but with T3 flanges bodged on top. The single exception to this seems to be the 6Boost from Australia - but at over a grand, they are a little out of range for me. The only option appears to be to go for a T4 flange, but that has problems of its own. I have a T4 manifold which will fit, but the only turbine housings available for the Gt30 are all pretty large (1.06 a/r divided from ATP) which would cut into the main reason I want a GT30 - fast spooling. I very much doubt that a T4 hot side with a 1.06 will ever spool at less than 3500.

I am not interested in big power: what I want is decent mid range (spooling at 3K please), with top end of around 425 - 450bhp. Does anyone know where I can buy a decent 1JZ manifold that was actually designed for a T3 (i.e not a T4 bodge job)? Or do I have to get a custom manifold made up?

 

I don't think its a turbo issue -I already have a dual ball bearing turbo (and its really a Garrett now, with the GT3076R core), and I know it will spool OK with a T3 housing - but there just aren't any good T3 manifolds out there (other than the 6boost for £1200!). The problem is that I don't want a T4 and I want to stay with the 1JZ. A T4 really needs at least 3 litres of swept volume to flow enough at lower engine speeds to give good spool-up, so I don't want to go there.

 

Thanks Phil, I'll check them out - one further thought though: does anyone have a 1JZ on a T4 manifold that spools at 3500 (or less)? if so please let me know your spec.

 

like I said, I am not interested in big power.

 

After reading a bit more, you may be right - I already have a T4 divided manifold for a 1JZ, so a 1.06 A/R divided housing might work. So why do Garrett recommend a T3 for the GT3076?