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I've hit a wall - Cams and Turbo AR

rb20-calais

By rb20-calais,
in Engines & Forced Induction

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rb20-calais Rising Star

rb20-calais

Posted
Posted

Guys,

I made the decision that with my GT28 on my RB20 I was going to go with a 0.64AR so it wouldnt have crazy lag. With this AR on 18psi I was thinking that I may make around 220rwkw.

NB: I have the support systems to get what i am after (fuel, ecu, etc) but i have standard internals.

I was wondering about camshafts. If I was to put some HKS, TODA, etc cams in would this allow me to get a bigger AR for the turbo, say 0.8 and have similar response? If this was the case I would be making a lot more power on similar boost because of the turbo supporting more flow and also the cams?

Will cams give me much more power/response with the 0.64AR? Will they justify getting a 0.8AR?

I have no idea about what cams can do for me and I am after any advice/experience but lets suppose I got some cams and the response was the same with a 0.8AR and I got say 240rwkw on lower boost like 15psi. Is this the sort of result cams will give me?

I have been looking @ greenline for types/prices of cams and its all jibberish to me so any advice wouldbe great.

HKS

Camshafts ¥35,990

256 degrees duration, 8.8 mm lift.

TODA

Camshafts ¥21,599

256 degrees duration, 10.5 mm lift.

Would either of these cams suit my application?

Thanx

Evan

P.S. I dont want to have to do any other headwork.

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Roy Grand Master

Roy

Posted
Posted

Be carfeul with the lift of the cams. I suspect 10.5mm lift would require machining of the head due the increased lift, and im also guessing the OE valve springs wont like such high lift cam as well.

Best check with an engine builder who knows modern DOHC turbo engines as for what WILL work.

RS500 Experienced

RS500

Posted
Posted

which GT28 are you talking about, do u have the CHRA number??

fyi, a friend of mine has the 400hp GT25 (A/R .64 exhaust housing) on his RB20 and on 18-19psi it made 222rwkw with an internally standard engine, standard cams, unichip, standard injectors, bigger in-tank fuel pump, FMIC, etc.

this thing goes pretty hard and isn't all that laggy so i'd say, go for it, it should be fine.

Cubes Grand Master

Cubes

Posted
Posted

I was reading a commodores mag at work the other night and it had a RB20DET head that had been welded up so that it could be bolted on to the RB30 bottom end.

It had WADE cams in it and making around 280rwkw.

You own a VL so i'm sure you have heard of a WADE cam before. :)

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