Wish I could be 21 again
Congratulations young man
i really think you should consider these.
http://www.turbobygarrett.com/turbob...R_707160_9.htm
when looking at turbo sizing refrain from gauging by the single CFM number or horsepower range that they are marketed by.
they are not ball park figures, they are more like national park figures - just too variable.
look at map width, height, efficiency islands and as nutter is counseling you to do - engine demand.
if your engine is not capable of consuming the flow your gonna need more boost (taller map, higher temps) or some really nice port and valve work.
the cfm number advertising turbos is often plucked from the right hand edge of the map - but you have to get there first. if not enough engine demand, you are stuck on the left side of the map surging or not even making enough to surge.
i looked at 466541 - 1(gt2560r). only because they are easy to get from nissans. map is too wide and not tall enough. also the turbine wheel may be restrictive being the gt25 not gt28 series.
739548 - 5 (gt2860rs) imo are worse in the compressor. better in the turbine. great for 2L 4 bangers tho -more engine demand, low temp rise in the compressor.
and 707160 - 9 (gt2860r -9)'s offer everything 707160 - 7 (gt2860r -7)'s have but more.
I think if you expect to flow 60lbs/min with that low a boost level (gt2860rs) you are looking at head work witchcraft.
dont forget the pressure ratio the turbo has to run is greater than your '(boost+ atmo) / atmo' number due to pressure loss in everything else and then some for altitude.
plenty of cars out with plain wrong turbos on them. would be very satisfying to get it right.
"You can tow a trailer with your moped, but you can't tow any other sort of vehicle. Your moped can't be towed by another vehicle." Land Transport Safety Authority Fact sheet 43 -Mopeds
yeah i get that. i will tackle that when i get there, the first and foremost issue is getting the bottom end built and then head work to support the rev range i wish to have. thankyou for your input though
recently i have been talking to some head work and cam specialists, kennelly cams here in christchurch (run by the man who used to desgin cam profiles for kelfords) says he can regrind factory cams to an advertised duration @ 0.1mm lift of around 264 degrees with in the relm of 10.5m of lift for around the $600 mark.
this seems fantastic to me and alot cheaper then buying billet "HKS" grinds which are as far as i have seen 272 duration but measured at 0 lift, and the most lift I have seen on aftermarket cams if .343" or aproxx 8.5mm
along with this I Have compared 4g63t valve springs to 6A13TT ones..... They FIT !! the only issue i can see so far is i think the valve stem diameter in the 6A13 is narower then the 4G63T, however it is the same as 4G93T
when i can get my hands on a valve spring compressor i will test if 4g63T retainers and collets fit if not i will test the 4G93T ones. this could open a door to cheaper cam and valve train modifications.
You should do all your testing on my spare set of heads. I will let you use them for free if I get to keep the resultant awesome heads. Deal?
I have my own spares thankyou very much, i just started another thread with the exact same stuff in it with an EOI for a group buy on cams and springs if your intresed
Awww
Very interesting news and great info! Are there any advantages of using aftermarket cams rather than regrinding the stock ones then?Originally Posted by Adam.Findlay
Daily driver / circuit car / drag car / show car / weekend cruiser / project car
umm not that I know of, i will be going and having a more in depth conversation with the cam guy tomorow, hopefully to get a reccomended valve spring and retainer and the benifits of ground vs billet, if your are intrested i have another thread "cams, springs, revs and power" somewhere which is a EOI for a sort of group buy on cams and springs
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