'best' Gt3076r For Street

[D-limo]

Hi all,

Firstly I'm new to the nitty gritty of turbos so bare with me..

So I want to fit a 'real' twin scroll GT30 to a standard fj20et exhaust manifold. Issues?

For a street/drift application whats going to be the best sized gt3076r? Think I saw discopotato03 mention a rare HKS spec trim >500hp varient is now available... If I could see full boost just after 4000rpm that would be sufficeint. Plan on bringing the old fj out to 2.2L and cams at a later date.

Edited October 25, 2009 by D-limo

[Dale FZ1]

If the turbine housing you use is the Evo spec IW, then flange pattern is the issue.

If you use the EW 0.78 split pulse, then mounting a wastegate to the stock manifold is the issue.

[discopotato03]

GT30 turbine based turbos all suffer to varying degrees the large trim size of their turbines , same as GT35 based turbos . FJ's have a very good bore/stroke and rod/stroke ratio but still they a 1990cc .

I got really good road car results from my FJ20ET and all it had was fresh std internals and a custom T28 flanged manifold with a GT2860RS on it .

Same as with RB25DET's it is a challenge to get a GT3076R/GT3037 to be responsive without fitting small turbine housings and very expensive to go the twin scroll route . The Evo 10 TS GT30 turbine housing has issues so still needs work from its suppliers . Wrong flange for anything else as well .

You could help your FJ by using a longer stroke crank and higher pin height pistons but thats very expensive to do .

I really liked FJ's but the sad truth is that they are very heavy and bulky AND very expensive and time consuming to work on . So so long with the big bores/big gaps between them/two staggered twin row timing chains/and a timing cover with a water pump on the front of it . Slack in the chains and the work involved getting at the shims under the buckets drives you crazy in the end .

So many times I have asked why people don't turbocharge the KA24DE and I'm still waiting for an answer . These are a bit long in the stroke but luckily they have long rods (I think longer than RB30's) so not all bad .

A road or drift engine doesn't desperatly need to turn huge revs particularly if it makes its torque from extra capacity and boost as well so I think the KA stacks up pretty well .

I know FJ people won't but to broaden your horizons do a bit of searching on the American 240SX sites because they get real good usable power from the larger 2.4L .

Also look in Freshalloy.com and note what people have achieved with Full Races gear on KA engines .

We actually get the KA24DE DOHC16 engine in the poverty pac Navara and it has or had 8.6 CR pistons std . From memory they had a version of the gearbox that Nissan puts in R33 GTS25T's so with that bellhousing a box with reasonable ratios and strong gears bolts up .

The best version of the GT3076R for a streetable FJ20 IMO would be the very hard to find 48 compressor trim version of the GT3037 , I have the 52 trim version of that turbo with the port shrouded comp housing and while it should be more responsive than the usual 56T version on an RB25 or FJ20 I don't know by how much .

Personally I think the RB25DET's higher CR (9.0 vs at best 8.5) helps make them a bit crisper and easier to spool the turbo so something to keep in mind . Early non intercooled FJ's had deeper dish pistons and a CR in the 7.9-8.0 range which IMO is too low for the fuels available today .

The weight and bulk really killed these engines for me and the dizzy ignition system didn't help .

Cheers A .

[SLAPS]

Same as with RB25DET's it is a challenge to get a GT3076R/GT3037 to be responsive without fitting small turbine housings and very expensive to go the twin scroll route .

Not sure.. Lithiums looks pretty damn good to myself.

The trick is to use a good actuator/ext gate and a genuine turbine housing.

A mate tried a 3076r with the .7 avo rear housing and the response was dismal compared to a 'real' .82.

But in saying that ol' Simon with his GT3071 with a .7 rear. Dismal response until cams were fitted then it was rather impressive.

Edited October 27, 2009 by SLAPS

[gotRICE?]

Not sure.. Lithiums looks pretty damn good to myself.

The trick is to use a good actuator/ext gate and a genuine turbine housing.

A mate tried a 3076r with the .7 avo rear housing and the response was dismal compared to a 'real' .82.

But in saying that ol' Simon with his GT3071 with a .7 rear. Dismal response until cams were fitted then it was rather impressive.

x2. He played around with Actuators and various things to get it like it is. Could be wise to ask him what he did.

Makes i think 1.1bar at under 3400rpm as far as im aware, cant remember exactly.

Very nice to drive to. Feels like a stock R33, but with heaps more go.. power delivery wise.

The only thing i noticed when comparing to a stock turbo is the immediate torque the stock one creates. But it doesnt take much right foot to rectify it