interesting post, I have same turbo on unbuilt 26, and have looked at the tomei option on previous threads, no definate concensus was reached.. some prefer stock cams, majority use type b for some reason although i would have thought it was more suited to -5 turbo
anyways some figures:
STOCK INTAKE 240 WITH 8.58 LIFT - EXHAUST 236 WITH 8.28 LIFT
TYPE-R INTAKE 250 WITH 9.15MM LIFT - EXHAUST 250 WITH 9.15mm LIFT
TYPE-A INTAKE 260 WITH 9.15MM LIFT - EXHAUST 252 WITH 9.15mm LIFT
TYPE-B INTAKE 260 WITH 9.15MM LIFT - EXHAUST 260 WITH 9.15mm LIFT
* Type A
Designed to best suit the stock & N1 turbos for optimum performance balance of low to mid range torque.
The Exhaust cams duration was reduced to maintain best idling.
* Type B
By extending the duration timing compared to the Type A Poncams, both response and peak power was raised and these camshafts best compliment the mid to large size turbo charged applications.
* TYPE R(for Stock Cat. Equiped Cars))
The Type R camshafts were designed due to popular demand from end users who are looking at upgrading the performance potential of their GTR while staying within the limits of recent street legal requirements. Recent laws on emissions and exhaust noise was made stricter in Japan so to have a quieter car by running smaller exhaust systems raises the exhaust back pressure which greatly reduces the response and hinder performance. Our engineers then designed these Type R camshafts to suit the needs of those who need to keep such setup and benefit with performance gains.