16v Pugsport cams with a turbo

[e8_pqck]

i bought my car with a TD04 and pugsport cams fitted, they did go pretty well with pretty much zero lag and good power, there has also been some headwork with cutback valve guides etc, running on a KMS.

I have now fitted an IHI VF35 turbo and we should be getting it mapped next week. Do you think i will get blow through with these cams or notice more lag, the VF35 spools around 800rpm later by all accounts but should see me over 300bhp.

Engine is a VTS 16v.

Does anyone have the full cam specs for the pugsport cams?

[sexy_gt]

i dont know the specs but i can imagine the inlet cam may need to be swapped back for a standard one.

[yr51ocw]

I have suggested to ian to keep the pugsport inlet and use the j4 exhaust, with the inlet retarded to achieve the same overlap as a standard j4. The reason being with a boosted engine you can keep the inlet valve open for longer without the piston pushing fresh charge out of the inlet valve (miller cycle style) as the pressure differential across the valve is higher. Also the exhaust cam is kept short as you dont want to open the exhaust valve too early and loose some of the combustion pressure and raise exhaust gas temps too much while retaining a sensible amount of overlap. The standard j4 cam profiles are actually quite long in duration compared to modern downsized highly boosted engines.

Ideally you would want a little more lift than the pugsport and j4 profiles while keeping the duration the same, but this will mean a very aggressive lift rate which will increase valve train wear.

[KamRacing]

Some race cams are group N and basically machined within the maximum tolerances allowed for a standard camshaft. It would not surprise if this was the case.

[yr51ocw]

^ we certainly used to do this in with the bike engines. The series stated that the maximum allowed valve lift was to remain at OEM, the camshaft drawing was something like 10.0mm+/-0.1mm so we used to have cams made to 10.1mm!