JUSTINTHECOASTIE

Formula/ table was created for me by 99SH aka Arax another member on here currently running the 6.75" crank pulley by ASP

rmerchant3

I am waiting on my pulley to get back from ASP as well. My original one was damaged in shipping, so I had to get another sent out. As for the belt, I am going to just measure once I get everything bolted up to find out what length I need.

The formula for calculating blower speed is (crank pulley size / blower pulley size) * 3.61 * engine RPM = Blower RPM The 3.61 is the blower step-up ratio. For example on your setup. (6.5 / 3.4) * 3.61 * 8000 = 55,212rpm

I was running two Bosch valves on my 1220 setup with a 3.4" pulley and was getting surge at high rpm throttle lifts. The 1200 flows more CFM and for what you are doing you will need to upgrade. I personally went with a Tial QRJ with the -1.5psi spring. I tested it on my 1220 before I sent it off and it evacuated a TON more air. I may need to still add a Bosch to the air pomp nipple, but I am hoping that I wont.

amdaman

Thanks - can you give me some idea of the belt size once you get yours? SOS have said they are waiting for more 1200's which will be 2 weeks. I also ordered it with th 3.4" so I'll have to deal with it.

I've ordered the Bosch 710P as a replacement valve which are rated to 2BAR. What is boost surge? Where the air can't evacuate quick enough? I might order a second 710P and add it to the air pump inlet. I believe the 710P was standard on the RS6 and other high flow applications??

JUSTINTHECOASTIE

When looking for a diverted valve it isn't about how much pressure it can hold but more so about the amount it can vent

JUSTINTHECOASTIE

Also for my set up the 4060400 or 4060405 belt range should fit (give or take).

amdaman

I've ordered two 710Ps and a 1" to 3/4" reducer. Total cost was 30USD. Hopefully it can vent enough. Also got the 4060400...ill let you know how it goes. Thanks for the help!

amdaman

Guys - another thread has prompted me to double check my setup.. I'm just wondering if I have everything I need to support 16-18PSI with this setup.. I realise 500whp won't de doable with the fuel I'll be using but will my fuelling and other mods be sufficient? My spec:

AP1 1999
N1200 (6.5" crank / 3.6" pulley)
Fuel - 98RON (New Zealand) I think this is equivalent to your 93 pump but I'm not sure.
ID1000
Walbro 255 in tank pump + OEM FRR
High compression JDM spec motor - stock (230~235psi comp test)
New coils and plugs (as recommended on here)

Currently running ~14PSI on my N1000 and have been for a year with 420whp.

Are the above mods capable of supporting that boost? Not so much in terms of reliability but in terms of detonation etc.. Will the tuner be able to pull the timing so he can still produce a safe tune or do I need less boost? Will fuelling be ok? (will I need an FPR?) I'd prefer not to change the pump again if I don't have to.

Please let me know - thanks all.

honda85

if I'm running a Paxton 1200 with a 3.8 pulley and a 6.5 crankpulley what belt should I use and what PSI will be getting?

amdaman

Hi, you should be seeing 16-18 depending on your setup.

Go here:

http://www.calculatoredge.com/mech/vbelt%20length.htm

use 13.26 as the centre distance to calculate your belt length.

K20iVTEC

Any updates? Would like to know how you made out with the 6.5 crank and 3.6 pulley. Psi? Power? Injector duty cycle? Any other issues pop up?