Hey guys,

Looking into my 2.5ltr rebuild and hoping that u guys could offer some assistance in my build process. The aim of the question is to find out which one of these mods i.e

1) Boring out the 2.5ltr block to 2.65ltr.
2) or fitting bigger cams to ported heads.

would reduce the spool up of a GT35R (A/R 0.82) and thus give better off boost response and power..

I only want to be able to rev each engine to a max of 8000rpm

advantages and disadvantages of either option

as the saying goes... there is no replacement for displacement (unless ur name is stacey)

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deaded

Option one would be a hell of a lot cheaper if thats a factor.

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Ho's gotta eat too

Go For Cams and heads You already have decent capacity

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11.1@125mph

downside to going massive cams is that you tent to move the point where power actually kicks in up int he RPM range, trick is not to go too large on the cam profile otherwise they become ineffective before rpm point X..

eg in the rb26, i was considering 272 cams, but they only really egtw orking at about 5k rpm, so really you limiting your power band down a bit, where as 264's, bring in turb nice and early, and i have a really wide useable power band..

food for thought, bigger isn't always better...

as for going bigger displacement, porivded they can show the block will hold together <doubtful> you'e be better of going a rebuilt with forged slugs, good rods, balance and blueprint the crank, and looking at a cam profile that suits your turbo choice...

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Jesus Built my car, Its a love affair, Mainly Jesus and my hotrod

i was advised to dump my version 3 cams on my 2.35 as they would no be as efficient on a larger motor, hence i source some cams from Ivan Tighe that will bring a larger turbo on quicker with more mid range, plus a head job to further assist air flow, anyway thats the theory...........time will tell.....

thanks for the responses guys.. i am total aggreement with u denver that the cam profile needs to suit the turbo..

And in reality the extra displacement over the 2.5 would prolly only bring the rpm down maybe 1-200rpm. Thus cams would be a better option..

Mild cams, head job, 2.5L and she'll be sweet mate.

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www.racewars.com.au

What about extending the stroke? is that an option?