Gtss On Rb26, Tomei Type A Or B?

[Macross]

As per the title, I currently have a rb26 with GTSS turbos and Tomei Type B poncams. I want a bit better response (currently hitting fullboost - 20psi - at 4krpm), but I also don't wany to run out of puff in the top end. I'm on stock rev limiter at the moment, but I also don't want to change back if I move to a 10krpm redline.

So in summary, on an unbuilt engine with GTSS turbos would the Type B's I have currently be better suited than changing to the Type A's for the sake of a better power curve, or should I switch?

[GTScotT]

A: Are you sure 4krpm is too late? Despite when it hits full boost how does it actually feel? And have you considered cam gears and/or a better tune OR whatever else could be lacking (as you have not mentioned).

B: Is worrying about swapping back to type Bs really an issue if you choose to go for a 10krpm limit? GTSS and poncams... Are you sure?

Sounds like you need to do both some R and D.

[Macross]

A: Are you sure 4krpm is too late? Despite when it hits full boost how does it actually feel? And have you considered cam gears and/or a better tune OR whatever else could be lacking (as you have not mentioned).

B: Is worrying about swapping back to type Bs really an issue if you choose to go for a 10krpm limit? GTSS and poncams... Are you sure?

Sounds like you need to do both some R and D.

For me, I'm not happy with 4krpm, I would prefer boost to come on a bit earlier 3500rpm for instance would be a good goal. Boost always comes on strong and I already have cam gears, the tune could be improved as I'm not sure how good it is, but I don't want to spend money on having the tune redone only to realise that I'm still not satisfied with the delivery.

The car already has Type B poncams with the GTSS turbos, so it's not like I'm going to be shelling out for these items, except if I decide to replace the poncams with the type A's mentioned.

[R.3.2.G.T.R]

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.

[GDZ-14R]

Stick with the type B's, i have better then stock response with a similar setup that has cams dialled in for more top end power.

If you find the minimal lag you have described as inconvenient, you should be driving a V8 as opposed to any turbo car. Do some reading too, you should not be getting too close to that redline with a stock oil pump, let alone a 10k rev limiter!!