What are the differences between a 15, 16, 17 & 19% pulley..?

Whats the most favoured pulley these days? When I left the Mini Scene last time round, the 17% was being ditched for 15%s

[Jaw_F430]

Originally Posted by George

Whats the most favoured pulley these days? When I left the Mini Scene last time round, the 17% was being ditched for 15%s

I would say it is prob 17% pulley. I stick with 15% though. Did think about switching but don't think it would benefit me much

[R53mcs]

PS the reason behind the 15-19 pulleys is that as you reduce the size in % it increases the spin of the charger, thus creating more boost and on forced induction cars boost = power

Howeveer boost also = heat, so you have to do your best to keep it cool with other mods. Difference in boost is significant 15-19 but so is the heat, so some power can be lost from a 19 if you can't keep it cool enough.

george - I still run a 15%, 1320 like the 15s but I believe they are happy to fit 17s and recomend ways to keep temps down so you can utilise the power. Dave and Adrian have proved that big power can be had if you have the right gear fitted (this backs up 1320s observations on the 15 and 17 pulleys) and they probably prefer the delivery that a 17 can give. Bhozar is 17 mad, howver I'm a weed so still like my 15, although i am looking at a crank or maybe a 17

[blaze6]

get a 20% pulley from BBR ....just kidding....17% seems to be the best of both worlds, low end grunt,and if you wanted to you could safely track it with the right mods.

So is it a good idea to get a IC at the same time as a 17%? I.e. not run a 17% without a GRS / GP

[luca]

I would recommend doing the grs with the reduced pulley at the same time. The stock intercooler is rubbish IMO

[R53mcs]

I'd do both at same time personally, however the GTT 220 runs well on Bert @ ********* (thats a 17 with no IC change)

Personally if you go 15 then stock IC will be OK for a while, just get colder plugs and run 97 super unleaded, mine never had a real problem. If you do go 17 again then I'd do the IC at same time, it just gets you more from the package. The GTT IC is fantastic on the road, it just suffers from heat soak overwealming its cooling when on the rolling road (mainly as its soo much more metal conducting heat when sat in still air) ... once up to 40-50mph it really comes alive though and IMO it is better then even the GRS. However GRS is plain bolt on the GTT is a bt more fiddle, not much but some.

[Hyper Active]

Originally Posted by R53mcs

The GTT IC is fantastic on the road, it just suffers from heat soak overwealming its cooling when on the rolling road (mainly as its soo much more metal conducting heat when sat in still air) ... once up to 40-50mph it really comes alive though and IMO it is better then even the GRS. However GRS is plain bolt on the GTT is a bt more fiddle, not much but some.

Does this mean you have done a back to back test on both GRS and GTT intercoolers . I have say IMHO that the design of the GTT one doesn't look as good as the GRS .

[Reedy]

i think Sayanthan and Paul at 1320 are planning on doing some back to back tests with a GP, GRS and GTT I/C soon

[Reedy]

Right following on from Pulleys as i now have a better understanding
Thanks everyone

What does a upgraded crank pulley do..?

I have seen 2% crank pulleys is there any other types..??

Is a crank pulley a worth while upgrade..??

If you have a 15% supercharger pulley and you add a 2% crank pulley does that mean you get the performance of a 17% supercharger pulley..??

If you do why not just fit a 17% supercharger pulley...?? or are there other benefits from fitting a 2% crank pulley..??