Toms-SC said:
No exhaust mods done yet Dave. All these parts are, or will be sitting in my basement until the next summer season. Being in Canada, that is atleast 8 months away.
So you confused me, MP Inlet does not yeild that much of a gain without a ported blower? Being at a high elevation I will not over drive my blower over 5% if that.
The only benefit of the MP inlet is that it flows more air. It is not a magic HP piece. If you do not have the need for more air, it won't help you much if any. Once you start to exceed the flow capacity of the stock plenum then larger gains are to be seen (in certain circumstances, NOT ALL!). The reason people get more boost from a MP plenum is that when the SC starts to move more air than the inlet can provide, a vacuum is created at the inlet of the blower and boost(airflow) per revolution starts to drop. On a stockish motor overdriving the blower will achieve the same basic result as adding an MP inlet. Once you have achieved about 15-16 psi, there really isn't any more to be had (at least reliably) from a stock motor because of the heat generated in doing so. Heat is always your enemy and there is no way around it. You have to eliminate it.
So what you do is a juggling act. What does it take, on your car, to achieve 16psi? If you are doing it already with your stock blower, then you need to look at ways to drop boost and/or reduce outlet temps or any more boost/ariflow is going to be a waste of time and money.
You could have the blower ported now, because doing so will reduce outlet temps, but you have to be careful not to exceed 16psi. So you may have to reduce the drive ratio on the new blower. There are some reductions in parasitic loss to be had from spinning the blower slower, but they are minimal. Certainly not worth the cost of a ported blower at this point. If you are just planning for the future, then that is fine, but don't expect a ported blower and 18psi to be a good thing at this point.
I would install the exhaust and upgrade the IC first. Then see where your boost falls to. It may drop to 13psi. Then you can look logically at what to do next. I would get the MP inlet because that will bring your boost back up to 15 and you will be in good shape until you port the heads and add a cam. Then the boost will drop down to 13psi again and you can then add the ported blower and pick up the OD ratio to get you back to 16psi again.
This is the safe and logical way to do it.
Being at high elevation allows you to run more OD to achieve the same boost as us guys at lower elevations. In Alberta I lose at least 1-2psi boost on my car. Keep in mind though that your IC is less effective so that becomes an even more critical area to upgrade.
David