Big Power Turbos for a 300ZX

[Carlos Ramirez]

Good day All

I am new to this forum and would request some assistance on choosing some turbos for my 300ZX build up.

I have a full worked motor already which actually uses a CIMA short block. The engine has been ported, and full worked. Cams have been upgraded, valves were oversized. And this engine has already proven to flow enough for 700 rwHP at 21 PSi on a Hybrid T72 turbo.

The orginal car with that turbo setup is no longer and all that remains is the engine itself. The custom exhaust manifold to make that single turbo 300ZX are no longer as well. And honestly they required a slotted frame of the car and lots of custom stuff.

So I want to take the engine and use it on my car and go with a twin turbo setup.

I have been looking at the pentroof kit which uses HKS 2835s but I am not sure I want to spend a premium on those turbos and that setup. The setup with manifolds, turbos, and wastegates is like $6K USD.. Here my importer for that..

http://www.zedparts.com/Turbos/turbo.htm

The guy who orginally built the engine saids he will be build me some manifolds and some T3/T04 54 trim with stage II turbine.

But I am considering having some GT25 or GT30 turbos made as well. However I am sort of pioneer in this field and I am looking for feedback.

According to search on HKS forum the 2835s do 42lbs/min but they didn't state at what boost lvl. If they used the garret STD that would be at 1barr.

My goals are simple atleast I think..

550-600RWHP on the street at low boost on pump gas (93 octane.. I can run 100 octane as well but rather keep it on pump gas).. 700-800RWHP on 103-108 octange gas at say 28PSI.. I like to have main power come on before say 4500 RPMS.

I have a few more mods to make to the car itself like replacing my Stillen Intercoolers and replace it with a FMIC, and put dual in tank Walbro fuel pumps.

I thank you guys for any advise in advance, oh just in case you guys recommend www.twinturbo.net I am moderator from there and there isn't that much info on these larger turbos on 1.5L displacement engine (3.0 total 1.5L per turbo).

[vrmmmpshhh]

550-600hp on 93 octane fuel is just NUTS... in australia the subaru sti melted engines on premium 98 octane fuel. isnt the 300zx built stock to run on 100 octane fuel.

[JiMiH]

Which GT series turbos would be equivalent to a T3/T4?

Sorry to hijack the thread, but I was about to ask about vg30 turbos and t3/t4, and sort of found it appropriate to ask in here) :)

[Carlos Ramirez]

T3 /T04E the best i can think of GT3040
Which is a T3 turbine and TS04 Compressor..

[180sx]

Ummm, I think this guy is from the US of A. I think their octane ratings are different over there, correct me if I'm wrong. I think 93 over there equates to around 97 over here. ( so a little bit better than our 'stadnar" pump premium )

[THE ASH]

Yeah, 180SX is right. In Aust. we use the RON rating, in the US they use an average of RON & MON. 93 octane equates to roughly 97-98 RON.

[Carlos Ramirez]

yeah our octane lvls is R+M/2

But back to my orginal questions or request for comments anyone have any feedback.

[180sx]

I would recommend 2 of the Garrett GT30 BallBearing turbos. Exactly what size ones though I'm not sure without getting access to flow maps for the turbos. Go to www.turbofast.com.au and go to their "high performance turbos" section. Try and find what flywheel horsepower figure you are chasing, divide it by 2 and look one the stats of the turbos to find ones that will flow the required horsepower. You can get the CHRA number from the same site, and should be able to assemble the required housings, CHRA from the same Garrett parts in the states.

This is a rough way of matching the turbos for your application, but to fine tune it any better than that, you'd need the compressor maps, and they aren't made available by Garrett unfortuneately.

Oh yeah, the HKS items are Garrett cores with different spec wheel trims and housings, so your not losing quality by choosing Garrett over HKS. But can definitely save some $$$

[Kangz]

OK,
First of all, and you probably already know this, space is at a premium in the engine bay. Hanging big turbos off the VG30 has always been the problem when chasing big hp, thats why you dont see many Z's with huge hp, the engine can do it, there is just no space.

I shudder to think what a single turbo setup would look like!

Most guys in Australia are now opting to rebuild their standard turbos and enlarge the housings. Most are using either HKS 2535 internals or 2540. Both can be used in the standard housing with a little work. Whether or not you can get that power out of them is a little beyond me.

Other than that you would be going for expensive kits and the like.

Cruise on to www.aus300zx.com they will be able to sort you out.

:)

[Carlos Ramirez]

actually my friend has T04E/t3 54 trim turbos on his 300ZX with a custom made manifold :-)

The pentroof is a very nice manifold as well. And it use HKS 2835s
so some of that is being addressed.

And I can get either one.. The real question is turbos and how big my hammer is :-)

[Carlos Ramirez]

bump still looking for replies..

[SiMMMo]

I've know the td0x (trust?) turbo's are pretty popular on the 300's..... i'd imagine twin td06's or td07's would made for some nice rwhp.......

geoff risbey from prestige motorsport (www.prestigemotorsport.com.au) is making 400+rwhp with twin td05's..... and I think there is the potential for more from that car..... so td07's would be about the size you are after i'd say...... I think they are rated at close to 700hp each......

The HKS turbo's wont flow that at 1bar..... it would be more like 2bar....... HKS make there turbo's to run high pressures...

Anyway, hope this helps...

If you can afford the kit go that way - HKS etc make fantastic quality kits... I dont know about other companies but the jap ones are all fantastic quality and usually fit perfect...... the same can't be said for a lot of other kits....

Cheers,
S.