68 to 65mm pulley is it worth it?

[Spicy G60 0]

Hello people

 

I'm currently running a 68mm pulley on my G60 but someone told me there's a big difference between the 68 and the 65. Was wandering if anyone had changed between the two and noticed a big change?

 

Thanks for any help.

[sparks 0]

most people on here think its not worth it due to the decreased refurb time 68 you need to service every 30k 65 you need to service every 20k

plus the fact you not surposed to hit max revs with a 65 due to its spinning very close to the max it can do

 

you would be better off with a nice "fmic " and a big valve head a cam and red top injectors as greens will only do 200 bhp and with that added to your car you will be pushing close to 200 bhp

 

hope this helps stu..

[flusted 0]

i ran a 65mm, nice instant power, just change at 6k

[Neil VR6 0]

I think you'd make safer power by making the engine more efficient at processing the air which you're forcing into it as sparks alludes to (although my understanding is that with a 68 the service interval is 40K)

 

Just remember that the boost you read on your boost guage is air queueing up against the inlet of the engine because the engine can't use it all. I remember Darren telling me about a G60 with a CNC'd head which would actually read 0psi because the head flowed so well.

[Spicy G60 0]

I've got a FMIC all ready. I'm saving to get head and cam's done but was thinking of changing to the smaller pulley at the same time.

[flusted 0]

you will make more boost lower down either way

[g60karmann 0]

is this your daily driver and do you do lots of miles, any motorway driving? I would normally say more power is always the way to go but I wouldn't think it would be worth the disadvantages if it is your daily driver compared to the gains from a 68mm (which aren't that large ) :shrug:

[Neil VR6 0]

If I was you, for a bit of interim performance gain whilst you

[Spicy G60 0]

cool i wanted to get the manifold changed at some point. Maybe i'll look into getting a tubular one from Dal. Think from most of the replys here its not really worth changing the pulley till i've done everything else and i'm looking for the last little things to up the power.

[junkie 0]

Just remember that the boost you read on your boost guage is air queueing up against the inlet of the engine because the engine can't use it all. I remember Darren telling me about a G60 with a CNC'd head which would actually read 0psi because the head flowed so well.

 

I agree you need to make the efficient and in an ideal world you could flow exactly the amount of air you need to make your target horsepower without undue stress on the engine, but we dont live in an ideal world as we all know, although the pressure on the gauge is the que of air caused by the restriction of the head not been efficient enough to consume the air, the air is also entering the engine at a higher pressure so instead of cramming it all in its cramming it in pressured which is like increasing the compression ratio as a way of making more power but hence been more unreliable due to more stress been on the engine internals.

 

So the CNC'd yes was been very efficient but the head/engine was also begging out for more boost to make more power.