Hi everyone

I'm running a el manual with a j3, crow stage 3 cam, JMM extractors and CAI returning 160RWKW.

I've just finished gasket matching the 2 halves of a BBM and fitted BA butterflies. Next I will be extending my secondary's on my extractors.

When completed and fitted does the computer compensate or do I need another dyno.

What do you think these two mods will do. The research tells me top end revs, does that mean noticeable loss down low

With the longer runners, your torque will move up the rev range.

You will loose some bottom end power.

Have you any head work done?

JMM extractors usually have pretty log runners to start with. Short runners will give you better low end torque.

Thanks for the reply

Yes the head has the short turn radius ported it's a tickford head with quality valve grind 10.4 comp. The extractors have 38mm primary's and 50mm secondary's. The secondary doesn't seem that long bolts up to standard system. I was going to place the cat 300mm forward of the rear muffler then transition from 2 1/2" to twin 2" to the headers.

The car runs a manual and 3:7 diff so it's pretty reve with heaps of low down power hoping to swap 1kw down low for 2kw up top if it works that way.

When you say it will move the power higher does that mean also more power, at the moment it kicks in at 2500rpm and stays strong till 5200rpm I want to rev it to 6000rpm. As it has a new motor fully balanced BF gas rods au forged flat tops 1mm over.

I've spent a bit on it and I want to try and get to 190rwkw. The standard original motor was good for 20 years, I'm 52 if I get 50000klms good I'll be 60 by then and over it.

Any advice getting to 190rwkw will be greatly appreciated, I'm trying to ring the most out of the crow 2222549 before stepping up.