Rb25/30De To De + T

[walky01]

Hey guys, im going to turbo my na RB25/30 DE, im only going stock stuff for the moment. so std rb25 manifold turbo etc... ill get custom downpipe made because im sure it wouldnt fit. only thing im confused about is the turbo and water lines on the rb30. does anyone have pictures on where they go or any advice on where they go on the turbo? ive never done it before and id like to know before i start exactly where everything goes ! cheers guys

[Ben C34]

Isn't your engine crazy high comp?

[walky01]

yeah around 12:1...But my tuner said i could run it on low boost and still make some good power

[Ben C34]

Or not. Anyway it will be interesting.

I hope your running e85.

There's an entire section dedicated to rb2530 conversions.

Pretty much all are turbo so it's easy to see by the pics where the oil feed and drain goes. There's even a pdf on how to do the conversion.

[scotty nm35]

Or not. Anyway it will be interesting.

I hope your running e85.

^^ this.

Make sure the camera is rolling on the dyno.

[walky01]

I dont know why they would say it would be fine to run low boost if it would damage something, although i am a bit scared to do it and it all end in tears.....

[GTSBoy]

You could run low boost. Really low. Like less than 5 psi. With good intercooling and a large rear side on the turbo (to reduce exhaust backpressure) you could probably do even more than that on 98, but no-one around has much experience with running high static comp and much boost. So the limit will not be well known. On E85 you could well be able to run quite decent boost.

A large exhaust side on the turbo will dull response a little, but it's already a high comp twin cam 3L, so it shouldn't be too bad off boost. And the tradeoff when it starts making power will be well worth it.

If it were me - I wouldn't be using the standard log manifold. I'd be trying to make a decent manifold with nice anti-reversion steps at the head face and 6Boost style merge collector to try to keep the exhaust flow as clean as possible. Big fat dump pipe and cat to get the backpressure as low as possible.

[Blackkers]

definitely listen to gts boy.

big turbo, big rear housing on said turbo, low boost, aftermarket manifold, external gate 50mm minimum. 3.5" dump pipe minimum

with compression around the 12s i wouldnt go smaller than a GT35 size and on 98 fuel I'd be more inclined to use a 1.06 ar turbine housing

[Dose Pipe Sutututu]

I dont know why they would say it would be fine to run low boost if it would damage something, although i am a bit scared to do it and it all end in tears.....

it's fine.. all comes down to tuning, fuel type and cooling hardware

Honda boys have been turbo charging their motors since forever.

[matthewcucuzza]

I purchased a std rb25 turbo today and standard manifold. i wanted to get it running and upgrade it later, ill get a custom dump made up because the standard one wont fit anyway for my car im going to rebuild the turbo too since its not running at the moment. im not looking for major boost or power just something to give it an extra kick. i was intending to race the car but now have changed it. just want it a good weekend cruiser. 200rwkw is enough and its making around 160rwkw in n/a form now im sure 4-6psi on 98 will be over that mark. ill keep you guys posted how i go and what i decide to do though.

[matthewcucuzza]

A large exhaust side on the turbo will dull response a little, but it's already a high comp twin cam 3L, so it shouldn't be too bad off boost. And the tradeoff when it starts making power will be well worth it.

Thats the thing, this thing is a pig ! unless you are over 4000rpm it has nothing at all. its a weird setup it needs to be revved to keep the thing going.

[GTSBoy]

And just how are you getting 160rwkW from a 25/30? The 2JZ is an eminently better twin cam 3L than the dirty 30 ever was, and they are doing well when they are making >140rwkW NA. I'd need to see massive cams, special exhaust and inlet stuff on your engine to go close to believing it.

[Kanaric]

how much boost can you run on such a high comp engine? 4psi? I remember of 350Zs people were running like 7.

Edited August 10, 2014 by Kanaric

[scotty nm35]

It really depends on the chamber, and how many hot spots there are for detonation to occur. The VQ35 is a pretty good modern design and still had issues, mainly as the rods couldn't take it.

The 12:1 comp FT86 engine can handle plenty of boost as the direct injectors don't spray fuel until after top dead centre, No fuel, no det.

[matthewcucuzza]

And just how are you getting 160rwkW from a 25/30? The 2JZ is an eminently better twin cam 3L than the dirty 30 ever was, and they are doing well when they are making >140rwkW NA. I'd need to see massive cams, special exhaust and inlet stuff on your engine to go close to believing it.

Its got custom cams , oversize valves custom extractors and 3" exhaust.... last made 153kw atw i just found the dyno sheet....

[matthewcucuzza]

[Dose Pipe Sutututu]

^ jesus, that motor is itching for a turbo, E85 and 400kW

They're rubbish in NA form, even a mild modded on E85 B18C HonGayDA 1.8L motor makes more power LOL.

[GTSBoy]

Its got custom cams , oversize valves custom extractors and 3" exhaust.... last made 153kw atw i just found the dyno sheet....

OK. Makes sense now. Some cams + compression + decent exhaust makes sense in the 150+rwkW region.

[Blackkers]

sounds like a good engine set up but please don't use the factory 25 turbo... you won't make much power anyway

[Dose Pipe Sutututu]

lower the compression, run E85 + a Hypergear SS3... that thing will bake tyres all day